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Full-Text Articles in Engineering

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 ...


The Effects Of Low Aspect Ratio And Heat Exchanging Internals On The Bubble Properties And Flow Regime In A Pilot-Plant Bubble/Slurry Bubble Column For Fischer-Tropsch Synthesis, Hayder Al-Naseri Jan 2019

The Effects Of Low Aspect Ratio And Heat Exchanging Internals On The Bubble Properties And Flow Regime In A Pilot-Plant Bubble/Slurry Bubble Column For Fischer-Tropsch Synthesis, Hayder Al-Naseri

Doctoral Dissertations

"Fischer-Tropsch synthesis (F-T) is a process utilized to convert the syngas mixture of CO and H2 to synthetic fuel and chemicals that executed commercially by using the bubble/slurry bubble column reactor. The experimental results reveal that the investigated parameters, in terms the presence of internals, and reducing the aspect ratio and the solids loading, increase the local gas holdup, interfacial area, bubble passage frequency, and decrease the bubble rise velocity, bubble chord length. Meanwhile, the aspect ratio H/D = 4, and 5 provide enough height to established the fully developed flow regime. As a result of the variation ...


Hydrodynamics Of Trickle Bed Reactors (Tbrs) Packed With Industrial Catalyst Using Advanced Measurement Techniques, Mohammed Jaber Al-Ani Jan 2019

Hydrodynamics Of Trickle Bed Reactors (Tbrs) Packed With Industrial Catalyst Using Advanced Measurement Techniques, Mohammed Jaber Al-Ani

Doctoral Dissertations

"The impacts of the packing characteristics on the hydrodynamics od a trickle bed reactor (TBR) have been investigated using advanced measurements techniques of Gamma-ray densitometry (GRD) and Optical fiber probe and conventional measurement techniques of high-frequency differential pressure transducer and load cell. Two different reactor sizes of bench and pilot plant scale were used. Bench-scale TBR carried out the experiments to assess phase distribution and catalyst utilization with 1.18 cm inside diameter and 72 cm length at ambient pressure and temperature. The mixture of catalyst and fine particles displayed considerable improvements in the phase distribution, liquid holdup profile, and ...


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 ...


Characterization Of A Green Electric Solid Propellant For Electric Propulsion, Matthew Scott Glascock Jan 2019

Characterization Of A Green Electric Solid Propellant For Electric Propulsion, Matthew Scott Glascock

Doctoral Dissertations

"Electric solid propellants are advanced solid chemical rocket propellants that can be controlled (ignited, throttled and extinguished) through the application and removal of an electric current. These propellants are also being considered for use in ablative pulsed plasma thruster and multimode systems. In this work, the behavior and performance of a novel green electric solid propellant operating in an electrothermal ablation-fed pulsed plasma thruster was investigated. Using an inverted pendulum micro-Newton thrust stand, the impulse bit and specific impulse of the device using the electric solid propellant were measured for short-duration and long-duration runs to end-of-life, at energy levels of ...


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 ...


Developing And Evaluating A Partition-Cavity Solar Thermochemical Reactor For Syngas Production Via Computational Fluid Dynamics, Han Zhang Jan 2019

Developing And Evaluating A Partition-Cavity Solar Thermochemical Reactor For Syngas Production Via Computational Fluid Dynamics, Han Zhang

Doctoral Dissertations

"Solar thermochemical processes are attractive since they have the advantages of storing solar energy as chemical fuels. In this dissertation, a partition-cavity solar thermochemical reactor was developed, and the heat and mass transfer of the solar thermochemical processes were numerically analyzed in this directly-irradiated reactor.

The reduction reaction of two-step CeO2/CeO2-δ solar redox process was investigated using the coupling of computational fluid dynamics (CFD) and discrete element method (DEM). The reduction rate was studied based on the catalyst textual properties and the reaction condition. The results revealed that the increase of catalyst specific surface area and the ...


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 Investigation Of Liquid Contact In The Developing Post-Dryout Chf Flow Boiling Regime Using Surface Mounted Thermistors, Hiralkumar Harshadbhai Patel Jan 2019

Experimental Investigation Of Liquid Contact In The Developing Post-Dryout Chf Flow Boiling Regime Using Surface Mounted Thermistors, Hiralkumar Harshadbhai Patel

Doctoral Dissertations

"Understanding heat transfer in the post-critical heat flux (CHF) flow boiling regime is important for determining the performance of the heat transfer equipment for various industrial applications requiring high heat transfer rates, e.g., heat exchangers, boilers, chemical and nuclear reactors. Liquid can be present in the core of the flow channel in the form of entrained liquid droplets, especially immediately downstream of film dryout. These droplets are suspected to provide an important heat transfer mechanism as they impinge on the heated wall. The objective of the current study is to investigate liquid contact with the heated wall in this ...


Spatiotemporal Modeling And Model Restructuration Approaches In Studies Of Intracellular Signalling Pathways, Md Shahinuzzaman Jan 2019

Spatiotemporal Modeling And Model Restructuration Approaches In Studies Of Intracellular Signalling Pathways, Md Shahinuzzaman

Doctoral Dissertations

"The main focus of the research is to understand the complex phenomena of cell transduction pathways and cell biology in a single cell. Mathematical modeling and experimental evaluation are widely used approaches for this kind of research. Firstly, A multiscale framework for protein-protein interaction has been established using Brownian dynamics algorithm. Sit specific feature, steric collision, diffusion, co-localization and complex formation with time and space has been included in this spatial modeling framework. By implementation of the time adaptive feature in this framework, the computation time reduces in an order of magnitude compared with traditional modeling framework. This multiscale Brownian ...


Multiscale Spatio-Temporal Modeling Of Cell Population In Tissue Architecture And Drug Delivery Nanoparticles, Mohammad Aminul Islam Jan 2019

Multiscale Spatio-Temporal Modeling Of Cell Population In Tissue Architecture And Drug Delivery Nanoparticles, Mohammad Aminul Islam

Doctoral Dissertations

"Multiscale nature of a biological system span at many order of magnitudes in time and space. Molecular interaction at lower scale is connected with the higher scale behavior of tissue or organism. Integrating the dynamics and information at different time and space can give a fundamental physiological understanding of the higher level phenomena. But complex features, functions, interconnectivity between different scales and lack of information on the fundamental physiological property make the model difficult and computationally challenging. The multiscale modeling approach can bridge the gap between different scale by a systemic integration of the complex dynamic behavior.

Here, the focus ...


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 ...


Modeling And Simulation Of Micro/Nano-Rod Distribution In Micro Channel Flows, Saman Monjezi Jan 2019

Modeling And Simulation Of Micro/Nano-Rod Distribution In Micro Channel Flows, Saman Monjezi

Doctoral Dissertations

"The behavior of a typical nanorod particle in microscale flows was theoretically investigated, considering the effect of the wall on the rotational and translation motions of the non-spherical particle. Initially, a systematic method using Brownian dynamics simulation of the rotational motion of nanorod was performed to obtain the average orientation distribution of a nanorod in various range of Peclet number and position from the confining wall. Subsequently, the results of the angle distributions simulation were employed to generate a universal mathematical model for the particle orientation distribution, which our model of concentration distribution of high aspect ratio nanorods in the ...


Techno-Economic Optimization And Environmental Life Cycle Assessment Of Microgrids Using Genetic Algorithm And Artificial Neural Networks, Prashant Nagapurkar Jan 2019

Techno-Economic Optimization And Environmental Life Cycle Assessment Of Microgrids Using Genetic Algorithm And Artificial Neural Networks, Prashant Nagapurkar

Doctoral Dissertations

"This dissertation focuses primarily on techno-economic optimization and environmental life cycle assessment (LCA) of sustainable energy generation technologies. This work is divided into five papers. The first paper discusses the techno-economic optimization and environmental life cycle assessment of microgrids located in the USA using genetic algorithm. In this paper, a methodology was developed that assessed the techno-economic and environmental performance of a small scale microgrid located in US cities of Tucson, Lubbock and Dickinson. Providing uninterrupted power the microgrid was composed of seven components -- solar photovoltaics, wind-turbines, lead acid batteries, biodiesel generators, fuel cells, electrolyzers and H2 tanks. The ...