+publisher:"University of Texas – Austin" +contributor:("Daigle, Hugh")

University of Texas – Austin

1. -7707-8397. Dependence of transport properties on grain size distribution.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

► The topic of this thesis is investigating the relationship between grain size distribution and absolute permeability for medium silt to very fine-grained sandstones that are… (more)

Subjects/Keywords: Grain size distribution; Permeability; Porosity

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APA (6^th Edition):

-7707-8397. (2016). Dependence of transport properties on grain size distribution. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/45845

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-7707-8397. “Dependence of transport properties on grain size distribution.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/45845.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-7707-8397. “Dependence of transport properties on grain size distribution.” 2016. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-7707-8397. Dependence of transport properties on grain size distribution. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/45845.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-7707-8397. Dependence of transport properties on grain size distribution. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/45845

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

2. -4888-7993. Effect of a discrete three-phase methane equilibrium zone on the bottom-simulating reflection.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/46022

► Marine gas hydrates are stable under conditions of low temperature and high pressure in the upper few hundreds of meters below the seafloor in a… (more)

▼ Marine gas hydrates are stable under conditions of low temperature and high pressure in the upper few hundreds of meters below the seafloor in a variety of geological setting. At a discrete horizon where thermodynamically favored phase switches from hydrate to gas, a characteristic seismic reflection referred as the bottom-simulating reflection (BSR) is produced. Furthermore, in sediments with a distribution of pore sizes, the gas and hydrate phases can coexist in pores of different sizes, giving a rise to three-phase equilibrium zone. This three-phase zone causes the BSR to have distinct characteristics that differ from those observed with a discrete phase boundary. The main objective of this thesis is to model the seismic response of a potential three-phase zone at the Walker Ridge Block 313H in the northern Gulf of Mexico. I modeled the BSR arising from this three-phase zone and analyzed the characteristics of the BSR and their relationships to the thickness and phase saturation within the three-phase zone. This was done by determining the elastic properties of the formation via rock physics models and their mathematical convolution with a seismic wavelet to create synthetic seismograms. Results show that the main factor for the intensity of the BSR is the abundance of the free gas in the three-phase zone. Free gas saturation as low as 5% in the three-phase zone is enough to make the BSR visible in synthetic seismograms regardless of the hydrate saturation. Results of this thesis are significant for resource prospecting based on seismic data, drilling hazard identification, as well as the importance of hydrate as a potential source of energy and its influence on the global climate. For seismic prospecting, the presence of a three-phase zone inferred from BSR characteristic indicates the minimum methane flux into the base of the hydrate stability zone, and can be used to infer whether sufficient methane is available to form hydrate. For drilling hazard identification, the BSR characteristic indicates a possible shallower occurrence of gas than would be estimated under the assumption of a discrete phase boundary. Advisors/Committee Members: Daigle, Hugh (advisor).

Subjects/Keywords: Methane hydrate; Methane; Hydrate; Gas hydrate; Bottom-simulating reflection; BSR, Synthetic seismograms; Seismic; Walker Ridge; Three-phase zone; Rock physics; Amplitude versus offset; AVO

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-4888-7993. (2016). Effect of a discrete three-phase methane equilibrium zone on the bottom-simulating reflection. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/46022

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-4888-7993. “Effect of a discrete three-phase methane equilibrium zone on the bottom-simulating reflection.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/46022.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-4888-7993. “Effect of a discrete three-phase methane equilibrium zone on the bottom-simulating reflection.” 2016. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-4888-7993. Effect of a discrete three-phase methane equilibrium zone on the bottom-simulating reflection. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/46022.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-4888-7993. Effect of a discrete three-phase methane equilibrium zone on the bottom-simulating reflection. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/46022

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

3. Rasromani, Ebrahim Khalil. Exploring anisotropy in rock fluid flow and elastic behavior.

Degree: Petroleum and Geosystems Engineering, 2019, University of Texas – Austin

URL: http://hdl.handle.net/2152/72721

► The difficulty in modeling hydrocarbon reservoirs stems from their inherent anisotropic and heterogeneous nature. Due to their simplicity, isotropic fluid flow and geomechanical models are… (more)

▼ The difficulty in modeling hydrocarbon reservoirs stems from their inherent anisotropic and heterogeneous nature. Due to their simplicity, isotropic fluid flow and geomechanical models are often used in industry. In comparison to the isotropic models, anisotropic models require more data to be collected for initialization and higher computational power for processing. The increasing complexity of reservoirs today and demand for higher accuracy production forecasting and better optimization of production and drilling development programs makes the case for the use of these more complex models. This thesis first presents a scheme for efficiently calculating the anisotropic permeability tensor to better represent the initial reservoir flow behavior. Various methods for modeling the change in permeability throughout the reservoir development are then explored. As hydrocarbons are produced and reservoir pressure depletes, the change in stress state induces a change in the reservoir permeability. The error associated with the assumption that permeability change is the same in all directions, often used in industry, is assessed by comparing an isotropic permeability change model to the strain-induced anisotropic permeability change model developed by Wong (2003) through a case study of a production well in Tor formation of Valhall field. The final part of the thesis assesses the difference between the resulting fracture pressure predicted by the Kirsch equations and the Amadei solution to stress around a wellbore to demonstrate the importance of the incorporation of anisotropic elastic rock properties in geomechanical modeling of shale formations (Kirsch, 1898; Amadei, 1983). This is done through a case study of a horizontal well in the Lower Barnett Shale in Fort Worth Basin. Our results suggest that anisotropic reservoir behavior can be incorporated into reservoir models without a significant increase in computational power required and in some cases can significantly improve the prediction of the current and future reservoir state. Advisors/Committee Members: Daigle, Hugh (advisor), Gray, Kenneth E., Ph. D. (advisor).

Subjects/Keywords: Lattice-Boltzmann; Permeability tensor; Fast-marching method; Anisotropy; Tortuosity tensor; Near-wellbore permeability; Far-field permeability; Pressure depletion; Valhall field; Strain-induced permeability; Geomechanics; Wellbore stability; Anisotropic shale

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APA (6^th Edition):

Rasromani, E. K. (2019). Exploring anisotropy in rock fluid flow and elastic behavior. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/72721

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Rasromani, Ebrahim Khalil. “Exploring anisotropy in rock fluid flow and elastic behavior.” 2019. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/72721.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Rasromani, Ebrahim Khalil. “Exploring anisotropy in rock fluid flow and elastic behavior.” 2019. Web. 19 Feb 2019.

Vancouver:

Rasromani EK. Exploring anisotropy in rock fluid flow and elastic behavior. [Internet] [Thesis]. University of Texas – Austin; 2019. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/72721.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Rasromani EK. Exploring anisotropy in rock fluid flow and elastic behavior. [Thesis]. University of Texas – Austin; 2019. Available from: http://hdl.handle.net/2152/72721

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

4. Ghimire, Bishwas. Modeling formation resistivity changes during Leak-Off Tests (LOT’s).

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/63890

► Leak-Off-Tests (LOT’s) are performed shortly after drilling into the new formation below a cased interval in order to determine the strength of the formation below… (more)

▼ Leak-Off-Tests (LOT’s) are performed shortly after drilling into the new formation below a cased interval in order to determine the strength of the formation below the cased interval. This helps determine the upper limit of mud weight that can be used safely while drilling the next section, without risking formation breakdown and lost circulation. During LOT, well is shut in, and drilling fluid is pumped into the wellbore by a surface pump. As wellbore pressure increases due to pumping, the entire wellbore system including the formation first responds by expanding. When the wellbore pressure goes beyond a critical value called Leak-Off Pressure (LOP), drilling fluid starts to leak into the formation in the open hole section, first through porous flow and then, through fractures that are induced at the wellbore due to high pressure. This leakage of drilling fluid from the wellbore into the formation along with formation deformation can cause many changes in formation resistivity. Typically, formation resistivity depends on formation water saturation and salinity, and porosity through Archie’s equation. Hence, any change in resistivity can be modeled by modeling deformation and invasion during LOT. In this study, a poro-elastic model has been developed to investigate the resistivity change around wellbore during LOT by coupling the effects of deformation and invasion that occur as pressure builds up in the wellbore. Having a model to obtain resistivity around the wellbore during LOT is a prerequisite to predicting the resistivity tool response of a given tool during LOT. By predicting resistivity response during LOT and matching with measured field data, important properties of the formation like permeability and compressibility can be determined. The model developed assumes porous flow around the wellbore to determine the true formation resistivity during initial LOT pressure buildup by coupling the effects of deformation and invasion manifested in the formation in terms of change in formation porosity, water salinity, and water saturation. The results show that the effects of deformation on formation resistivity are relatively small, and while salinity mostly controls formation resistivity in a completely water-saturated zone, water saturation becomes a more important variable in an arbitrarily saturated zone with changing water saturation. Advisors/Committee Members: Daigle, Hugh (advisor), Gray, Kenneth E., Ph. D. (advisor).

Subjects/Keywords: Leak-Off Test; Formation resistivity

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APA (6^th Edition):

Ghimire, B. (2015). Modeling formation resistivity changes during Leak-Off Tests (LOT’s). (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/63890

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ghimire, Bishwas. “Modeling formation resistivity changes during Leak-Off Tests (LOT’s).” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/63890.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ghimire, Bishwas. “Modeling formation resistivity changes during Leak-Off Tests (LOT’s).” 2015. Web. 19 Feb 2019.

Vancouver:

Ghimire B. Modeling formation resistivity changes during Leak-Off Tests (LOT’s). [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/63890.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ghimire B. Modeling formation resistivity changes during Leak-Off Tests (LOT’s). [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/63890

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

5. Senthilnathan, Siddharth. Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO₂ flow: Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO2 flow.

Degree: Petroleum and Geosystems Engineering, 2017, University of Texas – Austin

URL: http://hdl.handle.net/2152/64206

► In light of growing concerns over rising atmospheric concentrations of greenhouse gases like carbon dioxide (CO₂), carbon capture and storage (CCS) has been suggested as… (more)

▼ In light of growing concerns over rising atmospheric concentrations of greenhouse gases like carbon dioxide (CO₂), carbon capture and storage (CCS) has been suggested as a means to reduce the rate of net addition of CO₂ to the atmosphere. One potential CCS method involves injecting CO₂ into deep saline aquifers, where they are designed to reside for long periods of time. High-pressure and high-temperature CO₂/brine flow through porous media is the subject of active research, but faithfully recreating the conditions and forces found deep in the subsurface remains a challenge. In particular, the role of buoyant forces in transporting CO₂ must be studied further, since the long-term migration of CO₂ is dominated by buoyancy. This study consists of two parts. Chapter 1 discusses buoyancy as relevant to the context of CO₂ sequestration and prior methods used to study buoyancy-dominated flow. Four methods to experimentally recreate buoyancy-driven flow in high-pressure corefloods are presented: “inject low and let rise,” progressive pressure increase, simplified Darcy’s Law, and the Buckley-Leverett approach. Chapter 2 investigates the potential of using surface-coated silica nanoparticles to improve the conformance of CO₂ during flow through aquifers. The Buckley-Leverett approach is used to determine a single buoyancy-driven flow rate, and a vertical coreflood is conducted using this flow rate. Core-average saturation and pressure drop measurements across the core are measured, and the in-situ CO₂ distribution is visualized by taking axial X-ray CT scans of the core during the experiment. The effect of the nanoparticles is studied by conducting the experiment with three different nanoparticle concentrations: 0 wt% (as a control), 0.5 wt%, and 5 wt%. The addition of 0.5 wt% of nanoparticles (NP) does not markedly improve the conformance of CO₂ when compared to the control. However, at concentrations of 5 wt% NP, steady-state and residual CO₂ saturation increases, sweep efficiency increases, and CO₂ mobility decreases significantly when compared to the control. The lack of effectiveness of the 0.5 wt% formulation may be due to the influence of perpendicular-to-flow bedding layers that are present in the cross-bedded sandstone core used in the experiments. There are mixed indications regarding the suitability of the Buckley-Leverett approach to predicting the buoyancy-driven flow regime. Advisors/Committee Members: DiCarlo, David Anthony, 1969- (advisor), Daigle, Hugh (committee member).

Subjects/Keywords: Buoyancy; CO2; Carbon dioxide; Sequestration; Climate change; Nanoparticles; Coreflood; Conformance control; Sweep efficiency; Reservoir engineering; CO₂

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APA (6^th Edition):

Senthilnathan, S. (2017). Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO₂ flow: Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO2 flow. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/64206

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Senthilnathan, Siddharth. “Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO₂ flow: Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO2 flow.” 2017. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/64206.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Senthilnathan, Siddharth. “Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO₂ flow: Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO2 flow.” 2017. Web. 19 Feb 2019.

Vancouver:

Senthilnathan S. Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO₂ flow: Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO2 flow. [Internet] [Thesis]. University of Texas – Austin; 2017. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/64206.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Senthilnathan S. Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO₂ flow: Surface-coated silica nanoparticles for conformance control of buoyancy-driven CO2 flow. [Thesis]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/64206

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

6. -9608-5886. Nanoparticle stabilized oil-in-water emulsions for residual oil recovery.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/32048

► Transport of emulsions through porous media has the ability to play a significant role in many EOR processes. Nanoparticles can act as efficient emulsifying agents,… (more)

▼ Transport of emulsions through porous media has the ability to play a significant role in many EOR processes. Nanoparticles can act as efficient emulsifying agents, producing emulsions that can improve sweep efficiencies leading to improved oil recoveries. This thesis has explored emulsion stability and flow through porous media whilst also assessing emulsion capabilities in residual oil recovery. Hydrophilic nanoparticle-stabilized oil-in-water emulsions of two different average droplet sizes were injected into hydrophobic beadpacks of varying bead size diameters. The smaller sized emulsion appeared to be more stable in its properties, more frequently being regenerated in the effluent in comparison to the larger droplet sized emulsion. With a decrease in bead diameter, the smaller droplet sized emulsion could not survive passage with regeneration. Smaller bead pack sizes also did not allow passage of the less stable emulsions with larger droplet sizes. The fastest emulsion regeneration was seen for emulsions with small droplet sizes through a beadpack of larger sized beads. Through the largest bead sized beadpack, small amounts of the less stable emulsion were seen to be regenerated but much later in the life of the experiment. Higher flow rates were able to regenerate emulsion for smaller droplet sizes but were unable to do so for the less stable larger sized emulsion. Pressure profiles appeared to similar for most runs where approximately the first 0-10 pore volumes show the greatest pressure buildup followed by what appears to be a more stable and slower increase in pressure. Coreflood experiments were performed to assess residual oil recovery for various oil-in-water emulsions. Higher percentage recoveries were seen to be dependent on a few leading factors. For more viscous, stable emulsions, it appeared that lower flow rates lead to higher percentage recoveries. At lower flow rates, no emulsion would also be produced in the effluent for the duration of the experiment. As pressure profiles were seen to increase throughout the experiment, attempted coalescence and regeneration were likely taking place. However, as regeneration was less successful, complete coalescence might be the reason for increased miscibility in the core, leading to higher recovery potentials. Encouraging recoveries were seen when a more viscous stable emulsion was used to recover residual oil less viscous than that of the continuous oil in the emulsion. Increasing the slug size of the emulsion injected helped recover more residual oil. Increasing the slug size however is only advantageous up till a limiting value where the injected emulsion slug would produce the same result as injected emulsion continuously through the sandstone core. Where enough emulsion was injected and therefore available inside the core, emulsion regeneration was seen. Lighter organic phases in emulsion form were used for oil recovery coreflood experiments. Similar to experiments performed with heavier organic phases in emulsion form i.e. mineral oil-in-water emulsion,… Advisors/Committee Members: Daigle, Hugh (advisor), Huh, Chun (committee member).

Subjects/Keywords: Nanoparticle; Residual oil recovery; Emulsion

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-9608-5886. (2015). Nanoparticle stabilized oil-in-water emulsions for residual oil recovery. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/32048

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-9608-5886. “Nanoparticle stabilized oil-in-water emulsions for residual oil recovery.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/32048.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-9608-5886. “Nanoparticle stabilized oil-in-water emulsions for residual oil recovery.” 2015. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-9608-5886. Nanoparticle stabilized oil-in-water emulsions for residual oil recovery. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/32048.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-9608-5886. Nanoparticle stabilized oil-in-water emulsions for residual oil recovery. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/32048

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

7. -7168-0275. Investigations of porous media using nuclear magnetic resonance secular relaxation measurements and micro-CT image analysis.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/32138

► Nuclear magnetic resonance (NMR) has been used as a common and powerful tool for petrophysical investigation of fluid-bearing porous media. A common application in this… (more)

▼ Nuclear magnetic resonance (NMR) has been used as a common and powerful tool for petrophysical investigation of fluid-bearing porous media. A common application in this field is the extraction of pore size distributions, which are important descriptors of pore system morphologies. The common technique is to correlate mercury-injection porosimetry (MICP) measurements with NMR T₁ or T₂ distributions to obtain NMR-derived pore sizes. The limitations of MICP include pore-throat sensitivity and percolation effects, which compromise interpretation of results. Micro-CT image analysis has no such limitations, and measurements of pore size are characterized by pore body voxel counts. Presented are image analysis and NMR-correlated results for samples of Berea sandstone and Silurian dolomite. These results are compared to MICP-correlated results and the discrepancies interpreted as pore throat-to-body aspect ratios. Nuclear magnetic resonance pore size distributions are valid for single-phase fluids in the fast-diffusion NMR relaxation regime. When the effects of proton diffusion through internal magnetic field gradients become prominent, however, this relationship becomes entangled. Simultaneous measurement of longitudinal (T₁) and transverse (T₂) relaxation times using combined inversion recovery-CPMG pulse sequences allows for interpretation of a computed NMR attribute called secular relaxation (T₂sec). This quantity is defined as the difference in transverse and longitudinal relaxation rates (1/T₂-1/T₁) and can reveal important pore system properties. Presented are results that extract internal magnetic field gradient strengths based on changes in T₂sec as a function of the NMR experimental parameter τ. Further results consider a two-dimensional χ² analysis to attempt to invert for mean pore size and the difference in transverse and longitudinal surface relaxivities. The benefit of these types of analyses is to provide a simple methodology for inferring the average strengths of internal magnetic field gradients and pore sizes from NMR measurements without the need for independent measurements of pore size distributions, such as from mercury injection porosimetry. In addition, secular relaxation analysis removes the effects of bulk fluid relaxation. Advisors/Committee Members: Daigle, Hugh (advisor), Torres-Verdin, Carlos (committee member).

Subjects/Keywords: NMR; Image analysis

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-7168-0275. (2015). Investigations of porous media using nuclear magnetic resonance secular relaxation measurements and micro-CT image analysis. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/32138

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-7168-0275. “Investigations of porous media using nuclear magnetic resonance secular relaxation measurements and micro-CT image analysis.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/32138.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-7168-0275. “Investigations of porous media using nuclear magnetic resonance secular relaxation measurements and micro-CT image analysis.” 2015. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-7168-0275. Investigations of porous media using nuclear magnetic resonance secular relaxation measurements and micro-CT image analysis. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/32138.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-7168-0275. Investigations of porous media using nuclear magnetic resonance secular relaxation measurements and micro-CT image analysis. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/32138

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

8. -1522-4192. Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/38192

► In-situ pressure, temperature, salinity and pore size may allow coexistence of three methane phases: liquid (L), gas (G), hydrate (H) in marine gas hydrate systems.… (more)

▼ In-situ pressure, temperature, salinity and pore size may allow coexistence of three methane phases: liquid (L), gas (G), hydrate (H) in marine gas hydrate systems. A discrete zone of three-phase equilibrium may occur near the base of the gas hydrate stability zone (GHSZ) in sediments with salinity close to seawater due to capillary effects. The existence of a three-phase zone affects the location of the bottom-simulating reflection (BSR) and also has repercussions for methane fluxes at the base of the GHSZ. This project studied the hydrate stability conditions in two wells, WR313-G and WR313-H, at Walker Ridge Block 313 in the northern Gulf of Mexico. The pore size distributions were determined by constructing a synthetic nuclear magnetic resonance (NMR) relaxation time distribution. Correlations were obtained by non-linear regression on NMR, gamma ray, and bulk density logs from well KC-151 at Keathley Canyon. The correlations enabled construction of relaxation time distributions for WR313-G and WR313-H, which were used to predict pore size distribution through comparison with mercury injection capillary pressure measurements. With the computed pore size distribution, L+H and L+G methane solubility was determined from in-situ pressure and temperature. The intersection of the L+G and L+H curves for various pore sizes allowed calculation of the depth range of the three-phase equilibrium zone. In previous studies at Blake Ridge and Hydrate Ridge, the top of the three-phase zone moves upwards with increasing water depth and overlies the bulk three-phase equilibrium depth but this was not observed at Walker Ridge. In clays at Walker Ridge, the predicted thickness of the three-phase zone is approximately 5 m, but in coarse sands it is only a few centimeters due to the difference in absolute pore sizes and the width of the pore size distribution. The thick three-phase zone in the clays may explain in part why the BSR is only observed in the sand layers at Walker Ridge, although other factors may influence the presence or absence of a BSR. Advisors/Committee Members: Daigle, Hugh (advisor), Okuno, Ryosuke (committee member).

Subjects/Keywords: Gas hydrates; Methane hydrates

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APA (6^th Edition):

-1522-4192. (2016). Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/38192

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-1522-4192. “Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/38192.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-1522-4192. “Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico.” 2016. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-1522-4192. Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/38192.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-1522-4192. Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/38192

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

9. -2987-0731. Experimental study of the effect of stress and fluid sensitivity on propped and un-propped fracture conductivity in preserved reservoir shale.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/39117

► A good amount of work has been done on analyzing the effect of stress and fluid sensitivity on fracture conductivity in sandstones. This thesis tries… (more)

Subjects/Keywords: Fracture conductivity

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APA (6^th Edition):

-2987-0731. (2016). Experimental study of the effect of stress and fluid sensitivity on propped and un-propped fracture conductivity in preserved reservoir shale. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/39117

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-2987-0731. “Experimental study of the effect of stress and fluid sensitivity on propped and un-propped fracture conductivity in preserved reservoir shale.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/39117.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-2987-0731. “Experimental study of the effect of stress and fluid sensitivity on propped and un-propped fracture conductivity in preserved reservoir shale.” 2016. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-2987-0731. Experimental study of the effect of stress and fluid sensitivity on propped and un-propped fracture conductivity in preserved reservoir shale. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/39117.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-2987-0731. Experimental study of the effect of stress and fluid sensitivity on propped and un-propped fracture conductivity in preserved reservoir shale. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/39117

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

10. Cousins, Timothy Alexander. Effect of rough fractal pore-solid interface on single-phase permeability in random fractal porous media.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/42000

► Single-phase permeability k has intensively been investigated over the past several decades by means of experiments, theories and simulations. Although the effect of surface roughness… (more)

▼ Single-phase permeability k has intensively been investigated over the past several decades by means of experiments, theories and simulations. Although the effect of surface roughness on fluid flow and permeability in single pores and fractures as well as in a network of fractures was studied previously, its influence on permeability in a random mass fractal porous medium constructed of pores of different sizes remained as an open question. A fractal medium is one whose pore space and solid matrix can be characterized by statistical self-similarity and described by a fractal dimension Dm. Specifically, in a random mass fractal, each iteration of construction of the medium is composed of identical-size particles and pores of different sizes that are distributed randomly within (Hunt et al. 2014). This thesis contains the research into the effect of rough pore-solid interface on single-phase flow and permeability in fractal porous media. Using fractal geometry, randomly generated three-dimensional Menger sponges were created to model porous media with a range of mass fractal dimensionalities Dm between 2.579 and 2.893. This dimensionality characterizes both the solid matrix and the pore space of the media. The pore-solid interface of the media is subsequently roughened using the Weierstrass-Mandelbrot approach and controlled primarily by the surface fractal dimension Ds and root-mean-square of roughness height σ. The permeability was calculated for all the roughened media using the lattice-Boltzmann method using D3Q19 geometry and Bhatnagar-Gross-Krook (BGK) collision model. The LBM simulations calculated the single-phase permeability based on Darcy’s Law. Results indicate that permeability decreases sharply with increasing Ds from 1 to 1.1 regardless of Dm value, and remains relatively constant as Ds increases from 1.1 to 1.6. Furthermore, while creating the media, a lower bound for the percolation threshold appeared to be around 29.8% for randomized Menger sponges. When fitted to the percolation model presented in Larson et al. (1981) with an upper limit of 0.36 from Kim et al. (2011), the parameters from a least squares fit point to a critical porosity ϕc of 30% and a percolation exponent t between 3.1 and 3.3. Future research should investigate the effect of the percolation threshold for these simulated porous media and the effect surface roughness would have on this threshold. Finally, future research should expand into two-phase flow and investigate the effects of surface roughness on relative permeability and capillary pressure in simulated fractal porous media. Advisors/Committee Members: Daigle, Hugh (advisor), Prodanović, Maša (committee member).

Subjects/Keywords: Mass fractal dimension; Lacunarity; Permeability; Pore-solid interface; Porosity; Surface fractal dimension

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Cousins, T. A. (2016). Effect of rough fractal pore-solid interface on single-phase permeability in random fractal porous media. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/42000

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Cousins, Timothy Alexander. “Effect of rough fractal pore-solid interface on single-phase permeability in random fractal porous media.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/42000.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Cousins, Timothy Alexander. “Effect of rough fractal pore-solid interface on single-phase permeability in random fractal porous media.” 2016. Web. 19 Feb 2019.

Vancouver:

Cousins TA. Effect of rough fractal pore-solid interface on single-phase permeability in random fractal porous media. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/42000.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Cousins TA. Effect of rough fractal pore-solid interface on single-phase permeability in random fractal porous media. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/42000

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

11. Maalouf, Elsa. Numerical simulation and interpretation of sonic measurements in vertical and highly deviated wells.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/43705

► Borehole sonic measurements are widely used to estimate formation elastic properties and to construct synthetic seismograms. However, presence of noise compromises the accuracy of sonic… (more)

Subjects/Keywords: Sonic; Interpretation; Vertical wells; HA/HZ wells; Shear slowness; Compressional slowness

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APA (6^th Edition):

Maalouf, E. (2016). Numerical simulation and interpretation of sonic measurements in vertical and highly deviated wells. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/43705

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Maalouf, Elsa. “Numerical simulation and interpretation of sonic measurements in vertical and highly deviated wells.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/43705.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Maalouf, Elsa. “Numerical simulation and interpretation of sonic measurements in vertical and highly deviated wells.” 2016. Web. 19 Feb 2019.

Vancouver:

Maalouf E. Numerical simulation and interpretation of sonic measurements in vertical and highly deviated wells. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/43705.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Maalouf E. Numerical simulation and interpretation of sonic measurements in vertical and highly deviated wells. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/43705

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

12. -1393-2643. Application of superparamagnetic nanoparticle-based heating for non-abrasive removal of wax deposits from subsea oil pipelines.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/46771

► Flow assurance is a critical problem in the oil and gas industry, as an increasing number of wells are drilled in deep water and ultra-deep… (more)

▼ Flow assurance is a critical problem in the oil and gas industry, as an increasing number of wells are drilled in deep water and ultra-deep water environments. High pressures and temperatures as low as 5°C in these environments hinder flow of hydrocarbon-based fluids by formation of methane hydrate and wax deposits on the inner surface of pipelines. Commonly used methods for removal of deposits from pipelines are chemical injection and foam or gel pigs, which face several limitations. In our work, an application to use superparamagnetic nanoparticle-based heating for flow assurance, in the form of a magnetic nanopaint is presented. Superparamagnetic nanoparticle-based heating has been extensively researched in the biomedical industry for cancer treatment by hyperthermia. Superparamagnetic nanoparticles in dispersions generate heat by application of an oscillating magnetic field as explained by Neel’s relaxation theory. In our application, superparamagnetic Fe₃O₄ nanoparticles are embedded in a thin layer of cured epoxy termed ‘nanopaint’. This nanopaint coating on the internal surface of subsea pipelines could generate heat and thus remove formation of methane hydrates and wax. In our work, the role of key parameters affecting heating performance of superparamagnetic nanoparticles such as particle size, and magnetic field is quantified. Rigorous characterization of physical and magnetic properties of nanoparticles and nanopaint is performed. This is correlated to and used to optimize the heating performance. Heating performance of several samples of Fe₃O₄ nanoparticles varying in size distribution is evaluated in static experiments. Two samples having similar physical and magnetic properties are compared in terms of the correlation between their size distribution and their heating performance. Performance of nanopaint to heat static fluids, flowing fluids and wax deposit is evaluated. Heating performance of superparamagnetic nanoparticles in dispersions and in nanopaint is found to be similar and so it is concluded that Neel’s relaxation theory is applicable to nanopaint. Heating performance of nanopaint in flow experiment is found to be better than in static experiments by a factor greater than 5. A correlation of heating performance of nanopaint at magnetic fields of 100 to 1000 A/m is developed. Finally, implementation issues of nanopaint are addressed. The effect of low ambient temperatures on nanopaint heating performance is evaluated. The theoretical feasibility of generating a magnetic field inside a pipeline is studied. A COMSOL model is used to verify the feasibility of magnetic field propagation inside a steel pipeline and is subsequently used to evaluate nanopaint heating of wax deposits in pipeline. Material and power requirements are analyzed and optimized using the COMSOL model. Advisors/Committee Members: Daigle, Hugh (advisor), Huh, Chun (advisor).

Subjects/Keywords: Nanotechnology; Flow assurance; Subsea; Pipelines; Petroleum; Pipeline deposits; Wax deposits; Methane hydrate deposits; Superparamagnetic nanoparticles; Superparamagnetic nanoparticle-based heating; Magnetic nanopaint; Nanopaint; Nanoparticles

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-1393-2643. (2015). Application of superparamagnetic nanoparticle-based heating for non-abrasive removal of wax deposits from subsea oil pipelines. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/46771

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-1393-2643. “Application of superparamagnetic nanoparticle-based heating for non-abrasive removal of wax deposits from subsea oil pipelines.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/46771.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-1393-2643. “Application of superparamagnetic nanoparticle-based heating for non-abrasive removal of wax deposits from subsea oil pipelines.” 2015. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-1393-2643. Application of superparamagnetic nanoparticle-based heating for non-abrasive removal of wax deposits from subsea oil pipelines. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/46771.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-1393-2643. Application of superparamagnetic nanoparticle-based heating for non-abrasive removal of wax deposits from subsea oil pipelines. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/46771

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

13. -6232-4073. Pore-scale permeability prediction using critical path analysis.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/44020

► Using the principles set forth in percolation theory and critical path analysis (CPA), this thesis presents a method for constraining parameterized values of critical pore… (more)

Subjects/Keywords: Critical path analysis; Percolation theory; Mercury intrusion capillary pressure; Permeability; Finite scaling

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-6232-4073. (2016). Pore-scale permeability prediction using critical path analysis. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/44020

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-6232-4073. “Pore-scale permeability prediction using critical path analysis.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/44020.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-6232-4073. “Pore-scale permeability prediction using critical path analysis.” 2016. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-6232-4073. Pore-scale permeability prediction using critical path analysis. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/44020.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-6232-4073. Pore-scale permeability prediction using critical path analysis. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/44020

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

14. -4696-5791. Characterizing the petrophysical properties of shallow marine environments and their potential as methane hydrate reservoirs.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/46560

► In shallow marine sedimentary environments, characterization of sediment petrophysical and thermodynamic properties is imperative for understanding the subsurface transport of fluids and their chemical constituents.… (more)

▼ In shallow marine sedimentary environments, characterization of sediment petrophysical and thermodynamic properties is imperative for understanding the subsurface transport of fluids and their chemical constituents. This work first presents an objective method of scanning electron microscope image analysis that directly quantifies microporosity in clay-rich, fine-grained sediments typical of the shallow marine subsurface. The method is powerful because it is fast, easy, and provides a direct microporosity estimation technique to augment or replace experimental data. When used appropriately, the method can be implemented on microporous sediments and sedimentary rock in general. With an understanding of how microporosity manifests in shallow marine sediments, the impact of small pore sizes on methane hydrate solubility is then examined for core samples taken from 3 sites in the Nankai Trough offshore Japan, an area that has been heavily surveyed in recent years for its potential to host economically recoverable deposits of methane hydrate for use as a natural gas resource. Small pores in fine-grained shaley intervals are shown to significantly increase the aqueous solubility of methane in pore water relative to surrounding coarser-grained sediment strata, which can have broad implications for methane hydrate formation, including lack of formation in the clayey intervals and strong diffusive fluxes of methane into coarser sediment layers. Finally, an existing methane hydrate reservoir simulator is modified to model methane hydrate accumulations in marine environments with heterogeneous layered sediments. The impact of pore size on solubility is included in the model along with steady state microbial methanogenesis and diffusion of salt in the pore water. The simulator is then used to successfully model methane hydrate accumulations in 1D and 2D at Walker Ridge Site 313 in the Gulf of Mexico, where well logs and seismic surveys throughout the region abound. This work is an important step in building a general 3D methane hydrate reservoir simulator for shallow marine environments around the globe. Advisors/Committee Members: Daigle, Hugh (advisor), Mohanty, Kishore (committee member).

Subjects/Keywords: Methane hydrate; Reservoir modeling; Microporosity; SEM; Nankai Trough; Gulf of Mexico

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-4696-5791. (2015). Characterizing the petrophysical properties of shallow marine environments and their potential as methane hydrate reservoirs. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/46560

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-4696-5791. “Characterizing the petrophysical properties of shallow marine environments and their potential as methane hydrate reservoirs.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/46560.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-4696-5791. “Characterizing the petrophysical properties of shallow marine environments and their potential as methane hydrate reservoirs.” 2015. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-4696-5791. Characterizing the petrophysical properties of shallow marine environments and their potential as methane hydrate reservoirs. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/46560.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-4696-5791. Characterizing the petrophysical properties of shallow marine environments and their potential as methane hydrate reservoirs. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/46560

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

15. Murphy, Zachary Walter. Three-phase relative permeability of hydrate-bearing sediments.

Degree: Petroleum and Geosystems Engineering, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/69261

► During production of methane gas from hydrate-bearing sediments, gas, brine, and hydrate may all be present in the sediment. In such a situation, the relative… (more)

▼ During production of methane gas from hydrate-bearing sediments, gas, brine, and hydrate may all be present in the sediment. In such a situation, the relative permeability of each phase is the key parameter affecting flow. Thus far, the majority of relative permeability measurements made for hydrate bearing sediment are for gas in the presence of hydrate (no water) or water in the presence of hydrate (no gas). This thesis presents methodology and preliminary results from conducting three-phase relative permeability measurements on hydrate bearing sediment. The experiments took place in a cold lab kept at a hydrate-forming temperature (6°C). A sandstone core that was representative of Gulf of Mexico sediment and was 22” in length and 1.5” in diameter was used. The core holder had pressure taps along its length that are connected to differential pressure transducers to measure pressure drops and minimize sensitivity to capillary end effects. The core or sandpack was partially saturated with DI water to a water saturation of approximately 40% by injecting a specified volume of water into the core or mixing the sand with DI water before packing. The sample was then brought to hydrate forming pressure (1250 psi) by injecting methane. To determine the hydrate saturation, a pump monitored the volume of methane injected into the core in order to maintain 1250 psi. Once hydrate formed, hydrate stability was controlled by pressure, temperature, and salinity. At constant pressure and constant temperature, changes in salinity moved the stability conditions and at certain salinity, the system reached three-phase equilibrium. Three-phase brine was injected to allow flow through the core without destroying or forming any additional hydrate while continuously monitoring the pressure drops. After steady state was reached, as indicated by the pressure drop and saturation remaining constant with time, varying rates of gas were injected to change the gas saturation, and again obtain steady-state pressure drops. This process was completed for representative saturations of gas and water to create a full relative permeability curve. A procedure has been developed for forming hydrates in a pressure vessel and relative permeability values have been measured for samples with hydrate saturations of 24% and 35%. The methodology developed in this thesis will be used to conduct numerous three-phase relative permeability measurements on hydrate bearing sediment. Advisors/Committee Members: Daigle, Hugh (advisor), DiCarlo, David A (committee member).

Subjects/Keywords: Hydrate; Methane hydrate; Relative permeability

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Murphy, Z. W. (2018). Three-phase relative permeability of hydrate-bearing sediments. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/69261

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Murphy, Zachary Walter. “Three-phase relative permeability of hydrate-bearing sediments.” 2018. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/69261.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Murphy, Zachary Walter. “Three-phase relative permeability of hydrate-bearing sediments.” 2018. Web. 19 Feb 2019.

Vancouver:

Murphy ZW. Three-phase relative permeability of hydrate-bearing sediments. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/69261.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Murphy ZW. Three-phase relative permeability of hydrate-bearing sediments. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/69261

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

16. -9319-1306. ROP modeling chronology, sensitivity analyses, and field data comparisons.

Degree: Petroleum and Geosystems Engineering, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/63891

► Rate of penetration (ROP), the rate at which a drill bit breaks the rock underneath to deepen the borehole, modeling and measuring is widely used… (more)

Subjects/Keywords: ROP; Modeling; Sensitivity analyses; Field data comparisons; Model comparison; Drag bit models; Non-drag bit models; Roller bit models

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

-9319-1306. (2018). ROP modeling chronology, sensitivity analyses, and field data comparisons. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/63891

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-9319-1306. “ROP modeling chronology, sensitivity analyses, and field data comparisons.” 2018. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/63891.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-9319-1306. “ROP modeling chronology, sensitivity analyses, and field data comparisons.” 2018. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-9319-1306. ROP modeling chronology, sensitivity analyses, and field data comparisons. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/63891.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-9319-1306. ROP modeling chronology, sensitivity analyses, and field data comparisons. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/63891

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

17. Ho, Anthony, M.S. in Engineering. Testing geologic and geometric effects on drilling operations using torque and drag models.

Degree: Petroleum and Geosystems Engineering, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/63921

► Intuitively, geologic and geometric effects on torque and drag should be significant. But literature suggests otherwise. Lesage et al. (1988) wrote that friction coefficients are… (more)

▼ Intuitively, geologic and geometric effects on torque and drag should be significant. But literature suggests otherwise. Lesage et al. (1988) wrote that friction coefficients are not affected by lithology and hole angle, among other things. And if friction coefficients are similar for all of these factors, then only inclination, azimuth, and pipe specifications affect torque and drag. My thesis looks to test this statement using Johancsik’s torque and drag model and data provided by our sponsors. Johancsik’s model was chosen to test these effects because it is the most widely used torque and drag model in industry. Johancsik’s model also only relies on surface data in order to conduct an analysis. This contributes to the widespread use of Johancsik’s model and therefore increases the applicability of this paper. Once Johancsik’s model was chosen, it became natural to choose the minimum curvature method to interpolate the wellbore trajectory because Johancsik’s model was designed using the minimum-curvature method. Also, the minimum curvature method is the most widely used wellbore-interpolation method in industry. By using the minimum curvature method, this paper increases its applicability to industry. The analyses were conducted by examining the friction coefficients of each individual formation and lithology and geometric section. Friction factors encompass all factors that are not explicitly captured by the model and any factors affecting torque and drag that are not in the model will be captured by the friction factors. This study found lithology effects to affect drag consistently, though more data is needed. Drag friction factors were consistent by lithology, though they did appeared less predictable in Dataset 1 than the Datasets 2 and 3. Lithology affected torque less consistently than it did drag, though again more data is needed. Again, the results from Dataset 1 appeared to differ from Datasets 2 and 3. Further analyses are needed to conclude if this is caused by factors unrelated to lithology or individual geologies. The geometric effects of curved versus straight sections appear to not affect torque and drag. The results from the curved sections from the analyses have little relation to each other. As for more specific geometries, more analyses are needed before conclusions can be reached. Advisors/Committee Members: Gray, Kenneth E., Ph. D. (advisor), Daigle, Hugh (committee member).

Subjects/Keywords: Torque; Drag; Modeling; Model; Mechanic; Specific; Energy; Drilling; Drill; Geology; Geometry; MSE; Soft-string

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Ho, Anthony, M. S. i. E. (2018). Testing geologic and geometric effects on drilling operations using torque and drag models. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/63921

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ho, Anthony, M S in Engineering. “Testing geologic and geometric effects on drilling operations using torque and drag models.” 2018. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/63921.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ho, Anthony, M S in Engineering. “Testing geologic and geometric effects on drilling operations using torque and drag models.” 2018. Web. 19 Feb 2019.

Vancouver:

Ho, Anthony MSiE. Testing geologic and geometric effects on drilling operations using torque and drag models. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/63921.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ho, Anthony MSiE. Testing geologic and geometric effects on drilling operations using torque and drag models. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/63921

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

18. Mattos de Salles Soares, Cesar. Development and applications of a new system to analyze field data and compare rate of penetration (ROP) models.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/41200

► Improvements in data acquisition technology have enhanced rate of penetration (ROP) modeling capabilities. Modern logging tools are able to record more complete drilling datasets at… (more)

▼ Improvements in data acquisition technology have enhanced rate of penetration (ROP) modeling capabilities. Modern logging tools are able to record more complete drilling datasets at a higher frequency, allowing for better understanding of the many variables that affect the drilling process. ROP models published in literature simplify drilling rate formulations by combining complex drilling factors into model coefficients. The lithology dependence of ROP model coefficients, as well as the model's performance evaluated based on different types of rocks, is a topic explored throughout this project. A data analysis software developed in Microsoft Excel VBA, named ROPPlotter, provides ROP field data visualization and comparison of different ROP models. Userforms offer great flexibility in selecting different sections of the well and in highlighting lithology changes. The program accomplishes data filtering by detecting data outliers in the original dataset and excluding them for a more meaningful analysis. Then, VBA coding is applied in order to produce neat-looking plots automatically, overcoming Excel’s poor standard plot formatting. Excel Solver is employed in determining coefficients of six ROP models: Bingham (1964), Bourgoyne & Young (1974), Winters-Warren-Onyia Roller Bit (1987), Hareland Drag Bit (1994), Hareland Roller Bit (2010) and Motahhari PDC Bit (2010). By studying how these coefficients change with varying rock formations, valuable information about each model's behavior is obtained. Plots containing field data and ROP models, in addition to parsed data utilized in model calculations, can be saved for future analysis with the click of a button. ROPPlotter is useful in conducting case studies for industry, such as slow ROP in a section of the well or slide drilling. Furthermore, it provides a systematic way to assess ROP model performance and aims to quantify the lithology dependence of ROP models and their coefficients. This exercise provides a means of determining which ROP model works best for a specific field application. Later, by using an average value of model coefficients calculated for a certain field, optimal values of parameters controlled at the rig floor (weight-on-bit, rotary speed, flow rate) are determined for a future well to be drilled on the same pad. Advisors/Committee Members: Gray, Kenneth E., Ph. D. (advisor), Daigle, Hugh C (committee member).

Subjects/Keywords: ROP; Rate of penetration; Modeling; Drilling; Optimization

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mattos de Salles Soares, C. (2015). Development and applications of a new system to analyze field data and compare rate of penetration (ROP) models. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/41200

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Mattos de Salles Soares, Cesar. “Development and applications of a new system to analyze field data and compare rate of penetration (ROP) models.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/41200.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Mattos de Salles Soares, Cesar. “Development and applications of a new system to analyze field data and compare rate of penetration (ROP) models.” 2015. Web. 19 Feb 2019.

Vancouver:

Mattos de Salles Soares C. Development and applications of a new system to analyze field data and compare rate of penetration (ROP) models. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/41200.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Mattos de Salles Soares C. Development and applications of a new system to analyze field data and compare rate of penetration (ROP) models. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/41200

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

19. Gandomkar, Arjang. Leak-off test (LOT) models combining wellbore and near-wellbore mechanical and thermal behaviors.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/41736

► Considerable efforts to model leak-off test (LOT) and leak-off behaviors have been carried out in the past. Altun presented a model to estimate leak-off volume… (more)

▼ Considerable efforts to model leak-off test (LOT) and leak-off behaviors have been carried out in the past. Altun presented a model to estimate leak-off volume by dividing the wellbore system into four sub-systems: mud compression, casing expansion, fluid leakage, and borehole expansion (Altun 2001). The volume response from each sub-system is then combined to represent the total volume pumped during a LOT. Most existing leak-off models do not account for mechanical behavior of cement and rock formations around the wellbore. While their compressibilities are small, the cement and rock formation volume changes can be significant. In this research, a mechanical expansion model has been developed, based on a linearly elastic, concentric cylinder theory developed by Norris (Norris 2003). The model is an extension of Lamé equations for multi concentric cylinders and assumes the horizontal stresses on the system’s boundary are applied equally in all directions, i.e., the horizontal, far-field stresses around the system are isotropic. The resulting model simulates the compound radial displacements of casing, cement, and formation along the cased hole, based on pressures inside the wellbore and in the far-field stress region. The volume generated from concentric cylinder expansion is then combined with Altun’s model to simulate the total volume pumped during a LOT. One use of the model is the estimation of minimum horizontal far field stress. Since the model consists of concentric cylinders, the pressure on the outside boundary can approximate the minimum horizontal far field stress, which in turn is related to overburden pressure. The pressure inside the most inner cylinder is calculated from known mud weight. With an initial estimation for the far field stress and iterative methods, the minimum horizontal stress can be estimated. The developed models were then applied to field LOT data from Gulf of Mexico. The results show that leak-off volume along the cased hole should be analyzed as a compound expansion of casing, cement, and formation. Advisors/Committee Members: Gray, Kenneth E., Ph. D. (advisor), Daigle, Hugh C (advisor).

Subjects/Keywords: Leak-off test; LOT; Thermal; LOT behavior; Lost circulation; Fracture gradient; History matching; Mechanical behavior; Compressibility; Drilling; Leak-off pressure

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gandomkar, A. (2015). Leak-off test (LOT) models combining wellbore and near-wellbore mechanical and thermal behaviors. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/41736

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Gandomkar, Arjang. “Leak-off test (LOT) models combining wellbore and near-wellbore mechanical and thermal behaviors.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/41736.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Gandomkar, Arjang. “Leak-off test (LOT) models combining wellbore and near-wellbore mechanical and thermal behaviors.” 2015. Web. 19 Feb 2019.

Vancouver:

Gandomkar A. Leak-off test (LOT) models combining wellbore and near-wellbore mechanical and thermal behaviors. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/41736.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gandomkar A. Leak-off test (LOT) models combining wellbore and near-wellbore mechanical and thermal behaviors. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/41736

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

20. Jaffal, Hamza Ali. Evaluation of mudcake buildup and its mechanical properties.

Degree: Civil, Architectural, and Environmental Engineering, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/68039

► The use of drilling fluids while drilling for oil and gas is critical for successful drilling. The mud pressure is usually maintained higher than the… (more)

Subjects/Keywords: Static filtration; Mudcake buildup; Mudcake mechanical properties

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APA (6^th Edition):

Jaffal, H. A. (2018). Evaluation of mudcake buildup and its mechanical properties. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/68039

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Jaffal, Hamza Ali. “Evaluation of mudcake buildup and its mechanical properties.” 2018. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/68039.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Jaffal, Hamza Ali. “Evaluation of mudcake buildup and its mechanical properties.” 2018. Web. 19 Feb 2019.

Vancouver:

Jaffal HA. Evaluation of mudcake buildup and its mechanical properties. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/68039.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Jaffal HA. Evaluation of mudcake buildup and its mechanical properties. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/68039

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

21. Maalouf, Elsa. Rapid modeling and inversion-based interpretation of borehole acoustic measurements acquired in isotropic and vertical transversely isotropic formations.

Degree: Petroleum and Geosystems Engineering, 2017, University of Texas – Austin

URL: http://hdl.handle.net/2152/72438

► Borehole acoustic measurements are often affected by instrument noise, motion and eccentricity, environmental conditions, and spatial averaging that can compromise the accuracy of elastic properties… (more)

▼ Borehole acoustic measurements are often affected by instrument noise, motion and eccentricity, environmental conditions, and spatial averaging that can compromise the accuracy of elastic properties of rock formations calculated with conventional interpretation methods. Forward and inverse modeling can be used to improve the interpretation of acoustic logs acquired in the presence of spatially complex rock formations and adverse borehole conditions. However, forward modeling of acoustic modes often requires time-consuming numerical algorithms. The main objective of this dissertation is to develop fast-forward modeling and inversion-based interpretation procedures of borehole acoustic logs for isotropic and vertical transversely isotropic (VTI) formations. Fast-forward modeling is achieved with spatial sensitivity functions which are calculated from frequency-domain linear perturbation theory of borehole acoustic modes. Spatial sensitivity functions quantify both the dependence of measured slowness on elastic properties and the spatial averaging introduced by acoustic tools. Fast-forward modeling using spatial sensitivity functions is applied to synthetic examples that include thin layers, anisotropy, and dipping layers, and is successfully validated with numerical simulations performed with finite-difference and finite-element methods. Two inversion-based interpretation methods are then developed: (1) a physics-based inversion method to reduce noise and spatial averaging effects on acoustic logs acquired in horizontally layered formations penetrated by vertical wells, and (2) a sequential inversion method to estimate stiffness coefficients of VTI formations from multi-frequency flexural/quadrupole, Stoneley, and compressional logs. The physics-based inversion method is applied to mitigate measurement noise and spatial averaging effects of acoustic logs acquired in two hydrocarbon reservoirs. Results confirm the accuracy and reliability of the estimated layer-by-layer elastic properties compared to conventional numerical filters and are obtained in less than 14 CPU seconds for a 100 ft-depth log. In VTI formations penetrated by vertical wells, sequential inversion is applied to estimate layer-by-layer stiffness coefficients of synthetic formations from borehole acoustic logs. Results indicate that mitigating spatial averaging of frequency-dependent slowness logs prior to inversion improves the layer-by-layer estimation of slownesses by a factor of 2, and that sequential inversion yields accurate and reliable estimates of rock stiffness coefficients. Finally, in high-angle wells fast-forward modeling yields flexural slownesses measured with orthogonal dipoles with 2% relative errors and in 3 CPU minutes for a log consisting of 50 measured-depth samples, compared to 15 CPU hours when using finite-difference simulation methods. Analysis of field and synthetic examples confirms that inversion-based interpretation methods yield more accurate estimations of elastic properties than conventional sonic-log interpretation… Advisors/Committee Members: Torres-Verdín, Carlos (advisor), Daigle, Hugh (committee member), Heidari, Zoya (committee member), Sepehrnoori, Kamy (committee member), Spikes, Kyle (committee member).

Subjects/Keywords: Rapid-modeling; Inversion; Acoustic; Vertical wells; High-angle wells; Borehole; Well-logging; Vertical transversely isotropic

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Maalouf, E. (2017). Rapid modeling and inversion-based interpretation of borehole acoustic measurements acquired in isotropic and vertical transversely isotropic formations. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/72438

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Maalouf, Elsa. “Rapid modeling and inversion-based interpretation of borehole acoustic measurements acquired in isotropic and vertical transversely isotropic formations.” 2017. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/72438.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Maalouf, Elsa. “Rapid modeling and inversion-based interpretation of borehole acoustic measurements acquired in isotropic and vertical transversely isotropic formations.” 2017. Web. 19 Feb 2019.

Vancouver:

Maalouf E. Rapid modeling and inversion-based interpretation of borehole acoustic measurements acquired in isotropic and vertical transversely isotropic formations. [Internet] [Thesis]. University of Texas – Austin; 2017. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/72438.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Maalouf E. Rapid modeling and inversion-based interpretation of borehole acoustic measurements acquired in isotropic and vertical transversely isotropic formations. [Thesis]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/72438

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

22. Dahl, Elliot Jeremy Hans. Viscoelastic wave propagation along a borehole using squirt flow and Biot poroelastic theory.

Degree: Geological Sciences, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/63849

► Observations of seismic waves provide valuable understanding of Earth subsurface properties. These measurements are used to study large-scale subsurface features, kilometers in width, borehole-scale situations,… (more)

▼ Observations of seismic waves provide valuable understanding of Earth subsurface properties. These measurements are used to study large-scale subsurface features, kilometers in width, borehole-scale situations, meters of interest, and with core samples, a few centimeters in length. A common practice is to assume that the elastic rock-properties (P- and S-wave velocities) are the same for all frequencies. This is why sonic logs without corrections, for example, are used to constrain velocity models that transform seismic data from time to depth and to calibrate rock physics models used in seismic inversion to link elastic properties to reservoir properties. However, when seismic waves propagate in Earth materials, they are subject to different dispersion mechanisms, which makes the velocities frequency dependent. Understanding these effects on acoustic wave propagation can improve our models that constrain the subsurface and ultimately give us better hydrocarbon predictability. The main objective of this dissertation is to contribute to the understanding of how fluid in the pore space affects acoustic wave propagation. To achieve this goal, I first developed a frequency-dependent wave equation that accounts for local (squirt) and global (Biot) flow. The new model is tested against other squirt-Biot flow theories for both synthetic cases and utrasonic velocity data. I find the developed model to be consistent with the compared models in the synthetic cases. For the utrasonic velocity data, I find predictions from the new model to be closest to the measured data. In the second part of the dissertation, I use the developed squirt-Biot flow wave equation to simulate wave propagation in fluid-filled boreholes containing formations with different quantities of compliant pores. These are compared with formations where no compliant pores are present. I use the discrete wavenumber summation method with both a monopole and a dipole source to generate the wave fields. I find that fluid-saturated compliant pores can significantly affect the effective formation P- and S-wave velocities. This in turn affects the various acoustic wave modes causing increasing dispersion and attenuation. Thus, knowledge of the micro-scale structure of the fluid-saturated rock is of importance for understanding the acoustic waveforms and the dispersive behavior of the various modes. Depending on the locations where the critical frequencies for the different dispersion mechanisms occurs, acoustic velocity estimates can differ from the seismic-frequency velocities. Having a frequency dependent model accounting for the various dispersion mechanisms can help better connect the various velocity measurements and ultimately serve to give us an even more realistic picture of the subsurface. Advisors/Committee Members: Spikes, Kyle (advisor), Torres-Verdin, Carlos (committee member), Sen, Mrinal (committee member), Mohrig, David (committee member), Daigle, Hugh (committee member).

Subjects/Keywords: Global and local flow model; Wave propagation; Dispersion; Attenuation; Borehole acoustic measurements

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Dahl, E. J. H. (2018). Viscoelastic wave propagation along a borehole using squirt flow and Biot poroelastic theory. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/63849

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Dahl, Elliot Jeremy Hans. “Viscoelastic wave propagation along a borehole using squirt flow and Biot poroelastic theory.” 2018. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/63849.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Dahl, Elliot Jeremy Hans. “Viscoelastic wave propagation along a borehole using squirt flow and Biot poroelastic theory.” 2018. Web. 19 Feb 2019.

Vancouver:

Dahl EJH. Viscoelastic wave propagation along a borehole using squirt flow and Biot poroelastic theory. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/63849.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Dahl EJH. Viscoelastic wave propagation along a borehole using squirt flow and Biot poroelastic theory. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/63849

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

23. Darnell, Kristopher Nickolas. Phase behavior and the interaction of multiple gas molecules in hydrate-dominated geological flow processes.

Degree: Geological Sciences, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/65473

► Hydrate is a non-stoichiometric, ice-like solid compound of water and gas molecules that forms at low temperatures and high pressures. The stability of a particular… (more)

▼ Hydrate is a non-stoichiometric, ice-like solid compound of water and gas molecules that forms at low temperatures and high pressures. The stability of a particular hydrate is affected by the molecular composition of the environment in which it forms. For example, salt causes freezing point depression of hydrate much like it does for ice. In addition, a gas molecule, such as methane, that ordinarily forms hydrate at one pressure-temperature condition, may not form hydrate if the gas is mixed with another molecule, such as nitrogen, that requires increased pressure or decreased temperature to form hydrate. Here, I develop a modeling framework that incorporates the phase stability of gas mixtures to understand the coupling of equilibrium thermodynamics and fluid flow that governs hydrate-dominated geological flow processes. I first present a benchmark study that utilizes standard hydrate models to demonstrate the complex phase stability that occurs when salt and only methane are considered. The results show the impact that three-phase equilibrium, or the co-existence of a gas phase, a liquid water phase, and a hydrate phase, has on the evolution of hydrate systems. I then develop compositional phase diagrams for systems composed of water, methane, carbon dioxide, and nitrogen that elucidate how multiple hydrate-forming components interact to alter the composition of hydrate, completely de-stabilize hydrate, or create three-phase equilibrium conditions. I finally incorporate these compositional phase diagrams into a mathematical framework that describes multi-phase fluid flow that I use to simulate a subsurface injection strategy designed to simultaneously sequester carbon dioxide as hydrate and produce methane gas. The modeling framework illuminates the processes that govern the dynamic behavior of multiple hydrate-forming components. Simulations of subsurface injection demonstrate behaviors that support field and laboratory observations and clarify how composition impacts internal reservoir dynamics. The modeling framework developed here is general and flexible, so it can be modified to model additional components or to include additional physics. In particular, the modeling framework presented here is well-suited to simulate the buoyant ascent of thermogenic gas mixtures through marine sediments or the out-gassing of hydrate layers within the interior of icy planetary bodies like Enceladus. Advisors/Committee Members: Flemings, Peter Barry, 1960- (advisor), DiCarlo, David (committee member), Hesse, Marc (committee member), Mohrig, David (committee member), Daigle, Hugh (committee member).

Subjects/Keywords: Hydrate; Multiphase flow; Thermodynamics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Darnell, K. N. (2018). Phase behavior and the interaction of multiple gas molecules in hydrate-dominated geological flow processes. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/65473

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Darnell, Kristopher Nickolas. “Phase behavior and the interaction of multiple gas molecules in hydrate-dominated geological flow processes.” 2018. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/65473.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Darnell, Kristopher Nickolas. “Phase behavior and the interaction of multiple gas molecules in hydrate-dominated geological flow processes.” 2018. Web. 19 Feb 2019.

Vancouver:

Darnell KN. Phase behavior and the interaction of multiple gas molecules in hydrate-dominated geological flow processes. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/65473.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Darnell KN. Phase behavior and the interaction of multiple gas molecules in hydrate-dominated geological flow processes. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/65473

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

24. Sayar, Paul Mikhaël. Development of effective medium models for quantification of elastic properties and modeling of velocity dispersion of saturated rocks.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/33511

► Elastic effective medium theory (EMT) relates to quantitative rock physics modeling that calculates macroscopic properties of a mixture by incorporating the individual elastic properties, the… (more)

▼ Elastic effective medium theory (EMT) relates to quantitative rock physics modeling that calculates macroscopic properties of a mixture by incorporating the individual elastic properties, the volume fractions, and the spatial arrangement of the constituents that make up the rock. Despite the valuable merits of effective medium models, these theories exhibit limitations that require further investigation. Common instances are the non-unique configurations of the rock’s elements that give rise to identical wave velocities and the limiting assumption that rocks are purely elastic materials. Consequently, direct applications of classical EMTs can yield inaccurate and non-unique estimates of rock fabric properties that directly affect the assessment of elastic properties. The primary purpose of this dissertation is to improve the reliability of rock physics models based on the use of effective medium theories. In the first part, a rock physics model is developed for reliable estimation of velocities and elastic properties for sandstone-shale laminated rocks that are assumed to be vertical transverse isotropic (VTI). The new model is concerned with the reproduction of typical geological features and petrophysical properties of such formations that exhibit complex rock fabric. Isotropic and anisotropic versions of the self-consistent approximation and the differential effective medium theory, and Backus average are invoked to compute the effective medium’s stiffness tensor. The rock is separated into volumes of sandstone (regarded as isotropic) and shale (regarded as VTI), which are treated separately to reliably reproduce the spatial arrangement of the individual components included in the rock. Shale volumes enclose penny-shaped cracks and clay platelets aligned in the horizontal direction. Total porosity is divided into percolating porosity, isolated pores, and aligned fractures. The new simulation method is implement in three wells in the Haynesville shale and the Barnett shale. Estimates of elastic properties are verified when calculated velocities and sonic logs are in agreement. All relative differences between simulated and measured velocities are below 5.4%. To reduce non-uniqueness, electrical resistivity is calculated with modified effective medium theories and a procedure to compute Stoneley velocity is combined with the rock physics model. A method is advanced to calculate stress distribution and fracture initiation pressure around potential wellbores drilled horizontally in VTI rocks from the stiffness tensor obtained with the improved rock physics model. Effects of degree of anisotropy and elastic properties on fracture initiation pressure are investigated to determine a criterion to locate optimal depths along a vertical well to place a horizontal well. In the second part of the dissertation, an effective medium model is developed for reproduction of four of the main mechanisms of dispersion and attenuation of acoustic waves in saturated rocks. Simple and practical alternatives are introduced for effective… Advisors/Committee Members: Torres-Verdín, Carlos (advisor), Daigle, Hugh (committee member), Spikes, Kyle T (committee member), Olson, Jon (committee member), Sepehrnoori, Kamy (committee member).

Subjects/Keywords: Effective-medium modeling; Rock physics; VTI modeling; Unconventional reservoirs; Dynamic modeling; Saturated rocks

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APA (6^th Edition):

Sayar, P. M. (2015). Development of effective medium models for quantification of elastic properties and modeling of velocity dispersion of saturated rocks. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/33511

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Sayar, Paul Mikhaël. “Development of effective medium models for quantification of elastic properties and modeling of velocity dispersion of saturated rocks.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/33511.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Sayar, Paul Mikhaël. “Development of effective medium models for quantification of elastic properties and modeling of velocity dispersion of saturated rocks.” 2015. Web. 19 Feb 2019.

Vancouver:

Sayar PM. Development of effective medium models for quantification of elastic properties and modeling of velocity dispersion of saturated rocks. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/33511.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Sayar PM. Development of effective medium models for quantification of elastic properties and modeling of velocity dispersion of saturated rocks. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/33511

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

25. Ren, Bo. Local capillary trapping and permeability-retarded accumulation during geologic carbon sequestration.

Degree: Petroleum and Geosystems Engineering, 2017, University of Texas – Austin

URL: http://hdl.handle.net/2152/62236

► Safe storage of CO2 in saline aquifers depends on CO2 migration rate, accumulation, and trapping inside saline aquifers that have intrinsic heterogeneity. This heterogeneity can… (more)

▼ Safe storage of CO2 in saline aquifers depends on CO2 migration rate, accumulation, and trapping inside saline aquifers that have intrinsic heterogeneity. This heterogeneity can be in both capillary entry pressure and permeability. The former heterogeneity causes local capillary trapping while the latter results in permeability-retarded accumulation. A main objective of this dissertation is to understand how both local capillary trapping and permeability-retarded accumulation secure CO2 storage. We establish a fast simulation technique to model local capillary trapping during CO2 injection into saline aquifers. In this technique, modeling efforts are decoupled into two parts: identifying trapping in a capillary entry pressure field and simulating CO2 flow in a permeability field. The former fields are correlated with the latter using the Leverett j-function. The first part describes an extended use of a geologic criterion originally proposed by Saadatpoor (2012). This criterion refers to a single value of ‘critical capillary entry pressure’ that is used to indicate barrier or local traps cells during buoyant flow. Three issues with the criterion are the unknown physical critical value, the massive overestimation of trapping, and boundary barriers. The first two issues are resolved through incorporating viscous flow of CO2. The last issue is resolved through creating periodic boundaries. This creation enables us to study both the amount and clusters of local capillary traps in infinite systems, and meanwhile the effects of reservoir heterogeneity, system size, aspect ratio, and boundary types are examined. In the second part, we adapt a connectivity analysis to assess CO2 plume dynamics. This analysis is then integrated into the geologic criterion to evaluate how injection strategies affect local capillary trapping in reservoirs. We demonstrate that reservoir heterogeneity affects the optimal injection strategies in terms of maximizing this trapping. We conduct analytical and numerical modeling of CO2 accumulations caused by both permeability hindrances and capillary barriers. The analytical model describes CO2 buoyant migration and accumulation at a low permeability region above a high-permeability region. In the limiting case of zero capillary pressure, the model equation is solved using the method of characteristics. The permeability-retarded accumulation is illustrated through CO2 saturation profiles and time-distance diagrams. Capillary trapping is subsequently accounted for by graphically incorporating the capillary pressure curve and capillary threshold effect. The relative importance of these two types of accumulations is examined under various buoyant source fluxes and porous media properties. Results demonstrate that accumulation estimate that account for only capillary trapping understates the amount of CO2 accumulated beneath low permeability structures during significant periods of a sequestration operation. Advisors/Committee Members: Lake, Larry W. (advisor), Bryant, Steven L. (advisor), DiCarlo, David A (committee member), Daigle, Hugh C (committee member), Meckel, Timothy A (committee member).

Subjects/Keywords: Local capillary trapping; Permeability-retarded accumulation; Geologic carbon sequestration; Buoyant flow

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APA (6^th Edition):

Ren, B. (2017). Local capillary trapping and permeability-retarded accumulation during geologic carbon sequestration. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/62236

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ren, Bo. “Local capillary trapping and permeability-retarded accumulation during geologic carbon sequestration.” 2017. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/62236.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ren, Bo. “Local capillary trapping and permeability-retarded accumulation during geologic carbon sequestration.” 2017. Web. 19 Feb 2019.

Vancouver:

Ren B. Local capillary trapping and permeability-retarded accumulation during geologic carbon sequestration. [Internet] [Thesis]. University of Texas – Austin; 2017. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/62236.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ren B. Local capillary trapping and permeability-retarded accumulation during geologic carbon sequestration. [Thesis]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/62236

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

26. Zhang, Peng, Ph. D. Low frequency downhole electrical measurements for mapping proppant distribution in hydraulic fractures in cased-hole wells.

Degree: Petroleum and Geosystems Engineering, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/69264

► A tool using downhole electrical measurements for mapping electrically conductive proppant in hydraulic fractures is presented. The method relies on direct excitation of the casing,… (more)

▼ A tool using downhole electrical measurements for mapping electrically conductive proppant in hydraulic fractures is presented. The method relies on direct excitation of the casing, which is expected to overcome the severe limitations of induction tools in cased-hole wells. An array of insulating gaps is installed and cemented in place as a permanent part of the casing string. The electrical measurements are done by imposing a voltage across each insulating gap, one at a time, before and after hydraulic fracture operations. The voltages across other insulating gaps near the transmitter gap are recorded. A conductive proppant, petroleum coke (PC) was tested using a resistivity core holder. Experimental results show that the electrical resistivity of PC stays low [...] under confining stress of 4000 psi when up to 50% sand is added, which makes it a good candidate proppant for the tool’s application. The tool’s response to the presence of fractures was modeled by solving for the electrical potential using a finite volume method. Simulation results show that the electrically conductive proppant alters the path of the electrical current in the formation and this is recorded as differential signals by the string of insulating gaps surrounding the source gap. The simulated differential signals are highly sensitive to a fracture’s conductivity, location and length, and less sensitive to a fracture’s orientation and asymmetry with the wellbore axis. Parametric inversion of multiple fractures from synthetic data, generated by exciting various gaps in a casing string, was solved with a divide-and-conquer approach. The original problem was divided into sub-problems and each sub-problem was solved separately using a global optimization algorithm Very Fast Simulated Annealing (VFSA). The results show that VFSA can invert the data and output widths and radii of multiple fractures without requiring a large number of forward simulations. The robustness of VFSA was also tested by adding Gaussian noise to the synthetic data. Example cases show that when 5% noise is introduced, VFSA still provides very accurate inversion results with moderate uncertainties. Advisors/Committee Members: Sharma, Mukul M. (advisor), Daigle, Hugh (committee member), DiCarlo, David (committee member), Mohanty, Kishore (committee member), Sen, Mrinal (committee member).

Subjects/Keywords: Proppant mapping; Cased-hole wells; Insulating gaps; Petroleum coke; Forward model; Parametric inversion

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APA (6^th Edition):

Zhang, Peng, P. D. (2018). Low frequency downhole electrical measurements for mapping proppant distribution in hydraulic fractures in cased-hole wells. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/69264

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Zhang, Peng, Ph D. “Low frequency downhole electrical measurements for mapping proppant distribution in hydraulic fractures in cased-hole wells.” 2018. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/69264.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Zhang, Peng, Ph D. “Low frequency downhole electrical measurements for mapping proppant distribution in hydraulic fractures in cased-hole wells.” 2018. Web. 19 Feb 2019.

Vancouver:

Zhang, Peng PD. Low frequency downhole electrical measurements for mapping proppant distribution in hydraulic fractures in cased-hole wells. [Internet] [Thesis]. University of Texas – Austin; 2018. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/69264.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Zhang, Peng PD. Low frequency downhole electrical measurements for mapping proppant distribution in hydraulic fractures in cased-hole wells. [Thesis]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/69264

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

27. -4441-2942. Fracture analysis for lost circulation and wellbore strengthening.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/72436

► Lost circulation is the partial or complete loss of drilling fluid into a formation. It is among the major non-productive time events in drilling operations.… (more)

▼ Lost circulation is the partial or complete loss of drilling fluid into a formation. It is among the major non-productive time events in drilling operations. Most of the lost circulation events are fracture initiation and propagation problems, occurring when fluid pressure in a wellbore is high enough to create fractures in a formation. Wellbore strengthening is a common method to prevent or remedy lost circulation problems. Although a number of successful field applications have been reported, the fundamental mechanisms of wellbore strengthening are still not fully understood. There is still a lack of functional models in the drilling industry that can sufficiently describe fracture behavior in lost circulation events and wellbore strengthening. A finite-element framework was first developed to simulate lost circulation while drilling. Fluid circulation in the well and fracture propagation in the formation were coupled to predict dynamic fluid loss and fracture geometry evolution in lost circulation events. The model provides a novel way to simulate fluid loss during drilling when the boundary condition at the fracture mouth is neither a constant flowrate nor a constant pressure, but rather a dynamic wellbore pressure. There are two common wellbore strengthening treatments, namely, preventive treatments based on plastering wellbore wall with mudcake before fractures occur and remedial treatments based on bridging/plugging lost circulation fractures. For preventive treatments, an analytical solution and a numerical finite-element model were developed to investigate the role of mudcake. Transient effects of mudcake buildup and permeability change on wellbore stress were analyzed. For remedial treatments, an analytical solution and a finite-element model were also proposed to model fracture bridging. The analytical solution directly predicts fracture pressure change before and after fracture bridging; while the finite-element model provides detailed local stress and displacement information in remedial wellbore strengthening treatments. In this dissertation, a systematic study on lost circulation and wellbore strengthening was performed. The models developed and analyses conducted in this dissertation present a useful step towards understanding of the fundamentals of lost circulation and wellbore strengthening, and provide improved guidance for lost circulation prevention and remediation. Advisors/Committee Members: Gray, Kenneth E., Ph. D. (advisor), Daigle, Hugh C (committee member), Foster, John T (committee member), Jones, John F (committee member), McClure, Mark W (committee member).

Subjects/Keywords: Lost circulation; Wellbore strengthening; Fracture analysis

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APA (6^th Edition):

-4441-2942. (2016). Fracture analysis for lost circulation and wellbore strengthening. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/72436

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-4441-2942. “Fracture analysis for lost circulation and wellbore strengthening.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/72436.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-4441-2942. “Fracture analysis for lost circulation and wellbore strengthening.” 2016. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-4441-2942. Fracture analysis for lost circulation and wellbore strengthening. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/72436.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-4441-2942. Fracture analysis for lost circulation and wellbore strengthening. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/72436

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

University of Texas – Austin

28. Liu, Xiangyu, Ph. D. Mud-to-cement conversion of synthetic-based drilling muds using geopolymers.

Degree: Petroleum and Geosystems Engineering, 2017, University of Texas – Austin

URL: http://hdl.handle.net/2152/63651

► When constructing wells ranging from simple land wells to complex deepwater wells, incompatibility between oil-based and synthetic-based muds (OBM / SBM) and Portland cements can… (more)

▼ When constructing wells ranging from simple land wells to complex deepwater wells, incompatibility between oil-based and synthetic-based muds (OBM / SBM) and Portland cements can lead to poor cementation and loss of cement integrity, which in turn may compromise zonal isolation. An alternative cementitious material based on geopolymers has been developed with improved OBM / SBM compatibility for primary cementing and lost circulation control as well as well abandonment. Benefits of using geopolymers go beyond mere OBM / SBM compatibility: it is in fact possible to solidify non-aqueous drilling fluids (NAF) such as SBM and OBM using geopolymer formulations. This also means that such NAFs can be disposed of in a more cost-effective way, which presents a viable option for environmentally acceptable on-site or off-site disposal of drilling muds and cuttings. In the following, focus will be primarily on the compatibility between SBM and geopolymers, with the understanding that the results obtained for SBM can generally be extrapolated to OBM as well. Geopolymer is a type of alkali-activated material that forms when an aluminosilicate precursor powder (such as fly ash) is mixed with an alkaline-activating solution (such as sodium hydroxide). A novel SBM solidification method was developed by blending varied amounts of geopolymer and SBM. The consolidated mud was named a “geopolymer hybrid cement”. In an effort to develop the geopolymer hybrid system as a novel well cementing material, the solidification method was comprehensively studied with various sources of precursor powders, activators, as well as SBM and OBM formulations. Fresh state properties, such as slurry rheology and thickening time, and hardened state mechanical properties, such as compressive strength (under both uniaxial and triaxial confinement conditions), as well as the self-healing capabilities of the geopolymer hybrid cement were evaluated. Strength testing results showed that geopolymer cement can solidify up to a 60/40 geopolymer/SBM ratio by volume. The incorporation of SBM greatly improved the rheological properties of the geopolymer hybrid, allowing for the otherwise non-pumpable slurry to become pumpable for well cementation and lost circulation control purposes. The laboratory evaluations showed that the geopolymer hybrid cement could meet typical requirements as a well cementing slurry. By changing the amount of geopolymer and SBM in the slurry, the geopolymer hybrid can be deliberately designed with high compressive strength for primary cementation, or with lower compressive strength for lost circulation control. Moreover, geopolymer and geopolymer hybrid cements reveal true self-healing capability, which means that they can recover and even increase their strength after prior yielding. This ability would possibly allow such cements to better adapt to subsurface stress changes acting on abandoned wells, making them better suited for use in permanent barriers in plug and abandonment operations. Advisors/Committee Members: Van Oort, Eric (advisor), Bommer, Paul M. (committee member), Daigle, Hugh C. (committee member), Espinoza, David N. (committee member), Juenger, Maria G. (committee member), Nair, Sriramya D. (committee member).

Subjects/Keywords: Zonal isolation; Geopolymer; Mud-to-cement conversion; Cementing

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APA (6^th Edition):

Liu, Xiangyu, P. D. (2017). Mud-to-cement conversion of synthetic-based drilling muds using geopolymers. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/63651

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Liu, Xiangyu, Ph D. “Mud-to-cement conversion of synthetic-based drilling muds using geopolymers.” 2017. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/63651.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Liu, Xiangyu, Ph D. “Mud-to-cement conversion of synthetic-based drilling muds using geopolymers.” 2017. Web. 19 Feb 2019.

Vancouver:

Liu, Xiangyu PD. Mud-to-cement conversion of synthetic-based drilling muds using geopolymers. [Internet] [Thesis]. University of Texas – Austin; 2017. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/63651.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Liu, Xiangyu PD. Mud-to-cement conversion of synthetic-based drilling muds using geopolymers. [Thesis]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/63651

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

29. Ezidiegwu, Sandra Nkechinyere. Investigation of the pore size and structure in organic-rich shales.

Degree: Petroleum and Geosystems Engineering, 2015, University of Texas – Austin

URL: http://hdl.handle.net/2152/32040

► Permeability in source rocks allows the flow of reservoir fluids during production and is dependent on the pore size distribution. In organic shales, the level… (more)

▼ Permeability in source rocks allows the flow of reservoir fluids during production and is dependent on the pore size distribution. In organic shales, the level of porosity of organic material (OM) is based on its range of pore sizes. Scanning electron microscope (SEM) images are commonly used to examine OM-hosted pores, but this technique is limited by resolution, which is in the order of ~5 nm. This study seeks to increase this range of pore size distribution (PSD) to ~ 0.38 nm, in organic-rich shales by using low-pressure carbon dioxide (CO₂) adsorption coupled with density functional theory (DFT). In addition, we coupled low-pressure nitrogen (N₂) adsorption with the Barrett-Joyner-Halenda (BJH) and DFT models to quantify pore sizes between ~2 to 170 nm. To characterize the entire range of pore sizes, we used high-pressure mercury intrusion because it is commonly used to quantify larger pores. The samples used in this study include a bulk sample and isolated kerogen of Green River shale (Eocene, Utah), Woodford shale (Upper Devonian, Oklahoma), and Cameo Coal (Cretaceous, Colorado). These samples represent type I, II and III, kerogen, respectively, at similar maturity levels and thus provide a good experimental basis for evaluating the PSD. The methodology consisted of four steps: i) Kerogens were isolated from the bulk samples by demineralization, ii) Samples were divided into sizes of ~ 0.5 grams into test tubes and degassed, iii) Samples were analyzed in the Porosimeter using low-pressure N₂ and CO₂ adsorption techniques, iv) Isotherm data from the adsorption measurement were extracted to create the PSD. Our results showed the presence of pore sizes as small as ~ 0.38 nm, based on combining techniques of N₂ adsorption at 77 K and CO₂ adsorption at 273 K in all three samples. Hence, we have expanded our understanding of the range of pore sizes contained in organic-rich material. In addition, the majority of pores in Green River shale and cameo coal fell below the SEM resolution limit of ~5 nm. Lastly, the kerogen and bulk samples of the Green River and Woodford shales showed a variation in the PSD, with the larger pores in the kerogen, which indicates that kerogen constitutes the majority of the pores in the samples. In conclusion, we developed a novel approach to investigate OM-hosted pore sizes. This approach increased the range of pore sizes from ~ 5 nm to ~ 0.38 nm, thus improving the estimation of flow rates during production in shale and in applicable reservoirs. Advisors/Committee Members: Daigle, Hugh (advisor).

Subjects/Keywords: Organic-rich shales; Porosity

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APA (6^th Edition):

Ezidiegwu, S. N. (2015). Investigation of the pore size and structure in organic-rich shales. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/32040

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ezidiegwu, Sandra Nkechinyere. “Investigation of the pore size and structure in organic-rich shales.” 2015. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/32040.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ezidiegwu, Sandra Nkechinyere. “Investigation of the pore size and structure in organic-rich shales.” 2015. Web. 19 Feb 2019.

Vancouver:

Ezidiegwu SN. Investigation of the pore size and structure in organic-rich shales. [Internet] [Thesis]. University of Texas – Austin; 2015. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/32040.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ezidiegwu SN. Investigation of the pore size and structure in organic-rich shales. [Thesis]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/32040

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

30. -0972-2929. The effect of restrictive diffusion on hydrate growth.

Degree: Petroleum and Geosystems Engineering, 2016, University of Texas – Austin

URL: http://hdl.handle.net/2152/39166

► Methane hydrate is formed naturally in a number of geologic settings around the world. The most predominant methane hydrate reservoirs are found in shallow oceanic… (more)

Subjects/Keywords: Methane; Hydrate; Diffusion; Model

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APA (6^th Edition):

-0972-2929. (2016). The effect of restrictive diffusion on hydrate growth. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/39166

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

-0972-2929. “The effect of restrictive diffusion on hydrate growth.” 2016. Thesis, University of Texas – Austin. Accessed February 19, 2019. http://hdl.handle.net/2152/39166.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

-0972-2929. “The effect of restrictive diffusion on hydrate growth.” 2016. Web. 19 Feb 2019.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-0972-2929. The effect of restrictive diffusion on hydrate growth. [Internet] [Thesis]. University of Texas – Austin; 2016. [cited 2019 Feb 19]. Available from: http://hdl.handle.net/2152/39166.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

-0972-2929. The effect of restrictive diffusion on hydrate growth. [Thesis]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/39166

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations