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Full-Text Articles in Engineering

Application Of Artificial Neural Networks In The Drilling Processes: Can Equivalent Circulation Density Be Estimated Prior To Drilling?, Husam Hasan Alkinani, Abo Taleb Al-Hameedi, Shari Dunn-Norman, David Lian Dec 2019

Application Of Artificial Neural Networks In The Drilling Processes: Can Equivalent Circulation Density Be Estimated Prior To Drilling?, Husam Hasan Alkinani, Abo Taleb Al-Hameedi, Shari Dunn-Norman, David Lian

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

As the drilling environment became more challenging nowadays, managing equivalent circulating density (ECD) is a key factor to minimize non-productive time (NPT) due to many drilling obstacles such as stuck pipe, formation fracturing, and lost circulation. The goal of this work was to predict ECD prior to drilling by using artificial neural network (ANN). Once ECD is recognized, the crucial drilling variables impact ECD can be modified to control ECD within the acceptable ranges. Data from over 2000 wells collected worldwide were used in this study to create an ANN to predict ECD prior to drilling. Into training, validation, and ...


Critical Review Of Asphaltene Properties And Factors Impacting Its Stability In Crude Oil, Sherif Fakher, Mohamed Ahdaya, Mukhtar Elturki, Abdulmohsin Imqam Dec 2019

Critical Review Of Asphaltene Properties And Factors Impacting Its Stability In Crude Oil, Sherif Fakher, Mohamed Ahdaya, Mukhtar Elturki, Abdulmohsin Imqam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Asphaltene is a component of crude oil that has been reported to cause severe problems during production and transportation of the oil from the reservoir. It is a solid component of the oil that has different structures and molecular makeup which makes it one of the most complex components of the oil. This research provides a detailed review of asphaltene properties, characteristics, and previous studies to construct a guideline to asphaltene and its impact on oil recovery. The research begins with an explanation of the main components of crude oil and their relation to asphaltene. The method by which asphaltene ...


Extraction And Visualization Of Orientation Data From Virtual Geologic Surfaces With Matlab®, Avery J. Welker, John Patrick Hogan, Andreas Eckert Nov 2019

Extraction And Visualization Of Orientation Data From Virtual Geologic Surfaces With Matlab®, Avery J. Welker, John Patrick Hogan, Andreas Eckert

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

High-resolution visualization of surfaces of geologic interest, at a multitude of scales, using 3D point cloud technologies provides an opportunity to analyze spatial relationships of surfaces using orientation data. We present a MATLAB® script that produces planar geologic attitude data (e.g., strike, dip, and dip-direction data) from 3D datasets (e.g., point clouds, 3D scanning). The method utilizes Cartesian coordinates of triangular planar surfaces and converts them into matrices of conventional geologic attitude data. Spatial relationships among data points can be investigated, using polar tangent diagrams, stereographic analysis, or geologic curvature analysis. We utilize this script to create "synthetic ...


An Experimental Investigation Of Asphaltene Stability In Heavy Crude Oil During Carbon Dioxide Injection, Sherif Fakher, Mohamed Ahdaya, Mukhtar Elturki, Abdulmohsin Imqam Sep 2019

An Experimental Investigation Of Asphaltene Stability In Heavy Crude Oil During Carbon Dioxide Injection, Sherif Fakher, Mohamed Ahdaya, Mukhtar Elturki, Abdulmohsin Imqam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Carbon dioxide (CO2) injection is one of the most applied enhanced oil recovery methods in the hydrocarbon industry, since it has the potential to increase oil recovery significantly and can help reduce greenhouse gases through carbon storage in hydrocarbon reservoirs. Carbon dioxide injection has a severe drawback, however, since it induces asphaltene precipitation by disrupting the asphaltene stability in crude oil that bears even the slightest asphaltene concentration. This can result in severe operational problems, such as reservoir pore plugging and wellbore plugging. This research investigates some of the main factors that impact asphaltene stability in crude oil during ...


The Potential Of Using Micro-Sized Crosslinked Polymer Gel To Remediate Water Leakage In Cement Sheaths, Murad Abdulfarraj, Abdulmohsin Imqam Sep 2019

The Potential Of Using Micro-Sized Crosslinked Polymer Gel To Remediate Water Leakage In Cement Sheaths, Murad Abdulfarraj, Abdulmohsin Imqam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Cementing is a major step in the construction and sealing of hydrocarbon wells. During the life cycle of the well, cement is prone to cracking due to a change in downhole conditions. This research investigates the use of micro-sized crosslinked polymer gel as a sealant material to mitigate cracked cement sheaths. Two experimental setups were designed to investigate water leakage through cement. The impact of polymer gel strength on the gel's ability to seal cement cracks was investigated using four gel strengths, including 500 pa, 1200 pa, 1450 pa, and 2440 pa. The impact of the width of the ...


Novel Coupling Smart Water-Co₂ Flooding For Sandstone Reservoirs, Hasan N. Al-Saedi, Ralph E. Flori Aug 2019

Novel Coupling Smart Water-Co₂ Flooding For Sandstone Reservoirs, Hasan N. Al-Saedi, Ralph E. Flori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

CO2 flooding is an environmentally friendly and cost-effective EOR technique that can be used to unlock residual oil from oil reservoirs. Smart water is any water that is engineered by manipulating the ionic composition, regardless of the resulting salinity of the water. One CO2 flooding mechanism is wettability alteration, which meets with the main smart water flooding function. Injecting CO2 alone increases the likelihood of an early breakthrough and gravity override problems, which have already been solved using water-alternating-gas (WAG) using regular water. WAG is an emerging enhanced oil recovery process designed to enhance sweep efficiency during gas ...


Experimental Investigation Of Environmentally Friendly Drilling Fluid Additives (Mandarin Peels Powder) To Substitute The Conventional Chemicals Used In Water-Based Drilling Fluid, Abo Taleb T. Al-Hameedi, Husam H. Alkinani, Shari Dunn-Norman, Mustafa A. Al-Alwani, Abdullah F. Alshammari, Mohammed M. Alkhamis, Rusul A. Mutar, Waleed H. Al-Bazzaz Jul 2019

Experimental Investigation Of Environmentally Friendly Drilling Fluid Additives (Mandarin Peels Powder) To Substitute The Conventional Chemicals Used In Water-Based Drilling Fluid, Abo Taleb T. Al-Hameedi, Husam H. Alkinani, Shari Dunn-Norman, Mustafa A. Al-Alwani, Abdullah F. Alshammari, Mohammed M. Alkhamis, Rusul A. Mutar, Waleed H. Al-Bazzaz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The non-biodegradable additives used in controlling drilling fluid properties cause harm to the environment and personal safety. Thus, there is a need for alternative drilling fluid additives to reduce the amount of non-biodegradable waste disposed to the environment. This work investigates the potential of using mandarin peels powder (MPP), a food waste product, as a new environmentally friendly drilling fluid additive. A complete set of tests were conducted to recognize the impact of MPP on the drilling fluid properties. The results of MPP were compared to low viscosity polyanionic cellulose (PAC-LV), commonly used chemical additive for the drilling fluid. The ...


Novel Coupling Smart Water-Co₂ Flooding For Sandstone Reservoirs; Smart Seawater-Alternating-Co₂ Flooding (Smsw-Agf), Hasan N. Al-Saedi, Ralph E. Flori Jun 2019

Novel Coupling Smart Water-Co₂ Flooding For Sandstone Reservoirs; Smart Seawater-Alternating-Co₂ Flooding (Smsw-Agf), Hasan N. Al-Saedi, Ralph E. Flori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

CO2 flooding is an environmentally friendly and cost-effective EOR technique that can be used to unlock residual oil from oil reservoirs. Smart water is any water that is engineered by manipulating the ionic composition, regardless of the resulting salinity of the water. One CO2 flooding mechanism is wettability alteration, which meets with the main smart water flooding function. Injecting CO2 alone raise an early breakthrough and gravity override problems, which have already been solved using water alternating gas (WAG) using regular water. WAG is an emerging enhanced oil recovery process designed to enhance sweep efficiency during gas ...


Mud Loss Estimation Using Machine Learning Approach, Abo Taleb T. Al-Hameedi, Husam H. Alkinani, Shari Dunn-Norman, Ralph E. Flori, Steven Austin Hilgedick, Ahmed S. Amer, Mortadha Alsaba Jun 2019

Mud Loss Estimation Using Machine Learning Approach, Abo Taleb T. Al-Hameedi, Husam H. Alkinani, Shari Dunn-Norman, Ralph E. Flori, Steven Austin Hilgedick, Ahmed S. Amer, Mortadha Alsaba

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Lost circulation costs are a significant expense in drilling oil and gas wells. Drilling anywhere in the Rumaila field, one the world's largest oilfields, requires penetrating the Dammam formation, which is notorious for lost circulation issues and thus a great source of information on lost circulation events. This paper presents a new, more precise model to predict lost circulation volumes, equivalent circulation density (ECD), and rate of penetration (ROP) in the Dammam formation. A larger data set, more systematic statistical approach, and a machine-learning algorithm have produced statistical models that give a better prediction of the lost circulation volumes ...


Influence Of Frictional Or Rotational Kinetic Energy On Wellbore-Fluid/Temperature Profiles During Drilling Operations, Ahmed Q. Al Saedi, Ralph E. Flori, C. Shah Kabir Jun 2019

Influence Of Frictional Or Rotational Kinetic Energy On Wellbore-Fluid/Temperature Profiles During Drilling Operations, Ahmed Q. Al Saedi, Ralph E. Flori, C. Shah Kabir

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Temperature-profile distributions in a wellbore during drilling operations might take different forms when applying the energy balance in the overall system. For steady-state conditions, wherein the wellbore is considered a closed system, adding any source of additional energy to this system can influence the predicted temperature profiles. This study presents a new analytical model to investigate the influence of rotational energy arising from the drillstring operation on the wellbore-temperature behavior.

A significant part of the drilling operation is rotation of the drillstring. Depending on the drilling rig, various equipment provides this kind of energy, such as the rotary table or ...


A Review Of Field Oil-Production Response Of Injection-Well Gel Treatments, Munqith Aldhaheri, Mingzhen Wei, Na Zhang, Baojun Bai May 2019

A Review Of Field Oil-Production Response Of Injection-Well Gel Treatments, Munqith Aldhaheri, Mingzhen Wei, Na Zhang, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

As life-span extenders, bulk gels have been widely applied to rejuvenate oil production from uneconomic producers in mature oil fields by improving the sweep efficiency of improved-oil-recovery (IOR)/enhanced-oil-recovery (EOR) floods. This paper presents a comprehensive review of the responses of injection-well gel treatments implemented between 1985 and 2014. The survey includes 61 field projects compiled from SPE papers and US Department of Energy reports. Seven parameters related to the oil-production response were evaluated according to the reservoir lithology, formation type, and recovery process, using univariate analysis and stacked histograms. The interquartile-range (IQR) method was used to detect the underperforming ...


Revisiting The Butler-Mokrys Model For The Vapor-Extraction Process, Vijitha Mohan, Partho Neogi, Baojun Bai Apr 2019

Revisiting The Butler-Mokrys Model For The Vapor-Extraction Process, Vijitha Mohan, Partho Neogi, Baojun Bai

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamics of a process in which a solvent in the form of a vapor or gas is introduced in a heavy-oil reservoir is considered. The process is called the solvent vapor-extraction process (VAPEX). When the vapor dissolves in the oil, it reduces its viscosity, allowing oil to flow under gravity and be collected at the bottom producer well. The conservation-of-species equation is analyzed to obtain a more-appropriate equation that differentiates between the velocity within the oil and the velocity at the interface, which can be solved to obtain a concentration profile of the solvent in oil. We diverge from ...


Preformed Partial Gel Injection Chased By Low-Salinity Waterflooding In Fractured Carbonate Cores, Ali K. Alhuraishawy, Baojun Bai, Mingzhen Wei, Abdullah Almansour Feb 2019

Preformed Partial Gel Injection Chased By Low-Salinity Waterflooding In Fractured Carbonate Cores, Ali K. Alhuraishawy, Baojun Bai, Mingzhen Wei, Abdullah Almansour

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Fractures and oil-wet conditions significantly limit oil recovery in carbonate reservoirs. Gel treatment has been applied in injector wells to modify the prevailing reservoir streamlines and significantly reduce fracture permeability, whereas low-salinity waterflooding has been applied experimentally to modify rock wettability toward water-wet for improved oil recovery. However, both processes have limitations that cannot be resolved using a single method. The objective of this study was to test whether low-salinity water could enable gel particles to move deeply into fractures to efficiently increase oil recovery and control water production. A semitransparent fracture model of carbonate cores and acrylic plates was ...


Plugging Performance Of Preformed Particle Gels In Fractures And Its Influencing Factors, Ze Wang Jan 2019

Plugging Performance Of Preformed Particle Gels In Fractures And Its Influencing Factors, Ze Wang

Doctoral Dissertations

"Preformed particle gels (PPG) has been successfully applied to combat the water channeling caused by fractures or fracture-like channels. Understanding the placement and plugging of PPG in fractures is crucial for gel treatment design. The objective of the dissertation is to explore the plugging performance of three PPG products in two types of fracture models, the partially and fully open fractures. The following studies has been conducted and conclusions have been drawn based on the results and analysis. First, the placement and plugging performance of conventional PPG was investigated using core flooding experiments conducted partially open fractures. The plugging efficiency ...


Investigating The Use Of Different Types Of Sealant Materials For Cement Remedial Applications, Murad Mohammedahmed Abdulfarraj Jan 2019

Investigating The Use Of Different Types Of Sealant Materials For Cement Remedial Applications, Murad Mohammedahmed Abdulfarraj

Doctoral Dissertations

"The overall objective is to investigate the ability of several material to mitigate cement failures such as channels, fractures, and micro-annuli in oil and gas wells. The sealant material that can also be used in the wells that are used for geologic storage of carbon dioxide CO2. Evaluating the sealant material is critical to improve the zonal isolation of the wells, which would lead to safer operations. The approach of this dissertation is to utilize particles gel that has been used successfully in conformance control application, and epoxy resin systems, that have superior seal characteristics compared to conventional Portland ...


Asphaltene Stability In Crude Oil During Carbon Dioxide Injection And Its Impact On Oil Recovery: A Review, Data Analysis, And Experimental Study, Sherif M. Fakher Jan 2019

Asphaltene Stability In Crude Oil During Carbon Dioxide Injection And Its Impact On Oil Recovery: A Review, Data Analysis, And Experimental Study, Sherif M. Fakher

Masters Theses

"Crude oils are usually associated with many compounds, some of which are favorable and others, which are not. One of the most unfavorable components of crude oil that pose severe operational problems and decreases oil production significantly are asphaltenes. These compounds are solids that are homogenized in the crude oil at room temperature but tend to separate from solution when agitated. They can deposit in the reservoir pores, wellbore, and transportation pipelines thus causing severe operational problems and oil recovery reduction.

Even though researchers have been studying asphaltenes for more than 100 years, there is still an ambiguity concerning asphaltene ...


Investigating The Use Of Class C Flyash-Based Geopolymer Cement As A Potential Alternative To Portland Cement To Seal Co₂ Storage Wells, Priyesh Parimal Jani Jan 2019

Investigating The Use Of Class C Flyash-Based Geopolymer Cement As A Potential Alternative To Portland Cement To Seal Co₂ Storage Wells, Priyesh Parimal Jani

Masters Theses

"Capturing emitted carbon dioxide from the source of emission and storing it underground is one effective way to reduce the amount of CO2 in the atmosphere and is called carbon capture and storage (CCS). For the successful CCS project, it is necessary to ensure long term storage of injected CO2 inside these selected reservoirs. Portland cement used to cast wells in these reservoirs degrade in CO2 environment and can create migration path for leakage of CO2. The aim of this study was to provide a comprehensive review about the problem, to propose a new geopolymer cement ...


Computational Fluid Dynamics Modeling Of Proppant Static Settling Velocity In High Viscosity Friction Reducers, Chen Yuan Jan 2019

Computational Fluid Dynamics Modeling Of Proppant Static Settling Velocity In High Viscosity Friction Reducers, Chen Yuan

Masters Theses

"In the current petroleum fracturing industry, it is necessary to understand the downhole migration and settling velocity of the proppant. If we can master this information well, it will be a great help to obtain effective propped fracture conductivity. In order to study the transport of proppants in the well, we used laboratory experiments and computer numerical simulations to compare the results to get a meaningful conclusion. We spent a lot of time building models on a powerful computer and comparing the experimental conclusions. We finally decided to use computational fluid dynamics (CFD) as the simulation platform, discrete phase method ...


Modeling Overpressure Development During Shale Rock Compaction Coupling Poroelasticity And Permeability Evolution Above 3km Depth, Wenyu Zhao Jan 2019

Modeling Overpressure Development During Shale Rock Compaction Coupling Poroelasticity And Permeability Evolution Above 3km Depth, Wenyu Zhao

Masters Theses

"The evolution of pore pressure including overpressure during sedimentation is an important process to consider when analyzing whether high pore pressure causes rock failure. High pore pressure is caused by under-compaction due to the rapid burial of low-permeability sediments, and as a result, porosity decreases less rapidly with depth than in normally compacted sediments where porosity decreases exponentially with depth. While under-compaction related pore pressure magnitudes have been determined empirically, in most numerical modeling approaches, the pore pressure is either applied as a static magnitude or coupled to a fluid flow simulator. This study simulates the pore pressure evolution during ...


Gel Composition And Brine Concentration Effect On Hydrogel Dehydration Subjected To Uniaxial Compression, Xinrui Zhao Jan 2019

Gel Composition And Brine Concentration Effect On Hydrogel Dehydration Subjected To Uniaxial Compression, Xinrui Zhao

Masters Theses

"Gel treatment is a process that injects the gel into a reservoir to control the conformance and improve the sweep efficiency of injection fluids. At a certain pressure gradient, the gel dehydrates in a reservoir due to mechanical forces. This work evaluates the effects of the gel composition and brine concentration on gel dehydration under uniaxial compression. A sodium acrylate-co-acrylamide based gel cross-linked with N, N'-Methylenebisacrylamide (MBAA) was used for the study. The compression test is performed with a rheometer with a plate-plate geometry. The gel dehydration under pressure was measured to see how gel dehydration would be impacted ...


Breaker Evaluation And Formation Damage Remediation Of Re-Crosslinkable Preformed Particle Gel (Rppg), Enze Zhou Jan 2019

Breaker Evaluation And Formation Damage Remediation Of Re-Crosslinkable Preformed Particle Gel (Rppg), Enze Zhou

Masters Theses

"Re-crosslinkable preformed particle gel (RPPG) is a newly developed preformed particle gel for improving sweep efficiency and oil recovery by blocking or reducing the conductivity of fractures and fracture-like channels or conduits. However, RPPG has the potential to plug the facilities or damage the formation if a treatment is not properly conducted.

This work presents the performance of selected oxidizing breakers on the degradation of RPPG. The influence of a few factors on the degradation process was investigated, including breaker type, breaker concentration, temperature, gel concentration, gel aging time, and gel size. Results indicate that breaker type, concentration, and temperature ...


Review And Data Analysis Of Low Salinity Water Effect Through Induced Fine Migration, Dawei Xu Jan 2019

Review And Data Analysis Of Low Salinity Water Effect Through Induced Fine Migration, Dawei Xu

Masters Theses

"Low salinity water flooding (LSWF) is well proved to be an effective EOR technology both in laboratory and field tests, however, the conditions for LSWF to work and EOR mechanism is still debatable. Up till now, many mechanisms have been proposed to explain the incremental oil recovery in sandstone by LSWF, for instance, fine migration, ionic exchange, wettability alteration and pH increase.

In this study, we only focus on low salinity water flooding effect through induced fine migration mechanism. The objective of this study is to conduct a comprehensive analysis using statistical analysis methods and explaining the mechanism of fine ...


Transient Multiphase Flow Simulation For Unloading Of Frac Hit Gas Wells, Miguel Angel Cedeno Moreno Jan 2019

Transient Multiphase Flow Simulation For Unloading Of Frac Hit Gas Wells, Miguel Angel Cedeno Moreno

Doctoral Dissertations

"This work seeks to develop a fully step-by-step transient multiphase flow simulation valid for unloading gas wells using nitrogen. It studies the behavior of nitrogen for unloading horizontal gas wells with gas injection in the annulus. The work investigates unloading non-Newtonian fluids such as those which invade offset wells when a frac hit occurs during hydraulic fracturing operations in unconventional wells. The effect of varying tubing depth and injection pressure are included in the study.

Results show that as the plastic viscosity increases, the nitrogen volume and time to unload will be increased. As tubing depth increases, the nitrogen volume ...


Building Shared Knowledge For Eor Technologies: Screening Guideline Constructions, Dashboards, And Advanced Data Analysis, Na Zhang Jan 2019

Building Shared Knowledge For Eor Technologies: Screening Guideline Constructions, Dashboards, And Advanced Data Analysis, Na Zhang

Doctoral Dissertations

"Successful implementation of enhanced oil recovery (EOR) technology requires comprehensive knowledge and experiences based on existing EOR projects. EOR screening guidelines and EOR reservoir analog are served as such knowledge which are considered as the first step for a reservoir engineer to determine the next step techniques to improve the ultimate oil recovery from their assets. The objective of this research work is to provide better assistance for EOR selection by using fundamental statistics methods and machine learning techniques.

In this dissertation, a total of 977 worldwide EOR projects with the most uniformed, high-quality, and comprehensive information were collected from ...


Novel Insights Into Low Salinity Water Flooding Enhanced Oil Recovery In Sandstone Reservoirs, Hasan N. Al-Saedi Jan 2019

Novel Insights Into Low Salinity Water Flooding Enhanced Oil Recovery In Sandstone Reservoirs, Hasan N. Al-Saedi

Doctoral Dissertations

"Ever growing global energy demand and the natural decline in oil production from mature oil fields have been the main incentives to search for methods to increase recovery efficiency for several decades. Water flooding is extensively applied worldwide to improve oil recovery. The recent drop in oil prices has turned the oil industry to the cheapest improved oil recovery (IOR) techniques, such as low salinity (LS) waterflooding. Also, the reduction in reservoir energy and the friendly environmental aspects of low salinity water flooding (LSWF) provide additional incentives for its use. That LS water requires decreasing only the active divalent cations ...


Investigating The Performance Of High Viscosity Friction Reducers Used For Proppant Transport During Hydraulic Fracturing, Mohammed Salem Ba Geri Jan 2019

Investigating The Performance Of High Viscosity Friction Reducers Used For Proppant Transport During Hydraulic Fracturing, Mohammed Salem Ba Geri

Doctoral Dissertations

"Over the last few recent years, high viscosity friction reducers (HVFRs) have been successfully used in the oil and gas industry across all premier shale plays in North America including Permian, Bakken, and Eagle Ford. However, selecting the most suitable fracture fluid system plays an essential role in proppant transport and minimizing or eliminating formation damage.

This study investigates the influence of the use of produced water on the rheological behavior of HVFRs compared to a traditional linear guar gel. Experimental rheological characterization was studied to investigate the viscoelastic property of HVFRs on proppant transport. In addition, the successful implication ...


Experimental Study On Enhanced Oil Recovery (Eor) Mechanisms Of Nanogel Combining With Low Salinity Water For Carbonate Reservoirs, Pu Han Jan 2019

Experimental Study On Enhanced Oil Recovery (Eor) Mechanisms Of Nanogel Combining With Low Salinity Water For Carbonate Reservoirs, Pu Han

Doctoral Dissertations

"Nanomaterials have been widely studied and applied in the oil and gas industry. Among the developed nanomaterials, nano-sized crosslinked polymeric gel particle (nanogel) has shown great potential in recovering residual oil and improving oil recovery. This dissertation carried out their potential EOR mechanisms and the synergetic effect between nanogel and low salinity water. Nanogel used in this study was synthesized through the suspension polymerization process in our lab. The morphology, size distribution, and zeta potential were studied for nanogel dispersed in brine with variable ionic strength. The injectivity of nanogel was elucidated at first to ensure their in-depth penetration ability ...


Thermomechanical Analysis Of Rock Asperity In Fractures Of Enhanced Geothermal Systems, Chao Zeng Jan 2019

Thermomechanical Analysis Of Rock Asperity In Fractures Of Enhanced Geothermal Systems, Chao Zeng

Doctoral Dissertations

"Enhanced Geothermal Systems (EGS) offer great potential for dramatically expanding the use of geothermal energy and become a promising supplement for fossil energy. The EGS is to extract heat by creating a subsurface system to which cold water can be added through injection wells. Injected water is heated by contact with rock and returns to the surface through production well. Fracture provides the primary conduit for fluid flow and heat transfer in natural rock. Fracture is propped by fracture roughness with varying heights which is called asperity. The stability of asperity determines fracture aperture and hence imposes substantial effect on ...