Petroleum Engineering Commons^™

Numerical Simulations Of Fracture Propagation And Sealing: Implications For Wellbore Strengthening, Saeed Salehi

Doctoral Dissertations

"To mitigate the small tolerance between pore pressure and fracture gradients an engineering practice referred to as "wellbore strengthening" is conducted to increase the fracture gradient. The method relies on propping and/or sealing the fractures with specially designed materials. Different competing theories exist for physical wellbore strengthening mechanisms which can be categorized into two groups. The first group explains that strengthening happens as a result of increasing wellbore hoop stress when fractures are sealed while the second group emphasis is on fracture tip isolation with suitable materials and enhancing fracture propagation pressure. The numerical models and lab experiments …

Numerical Study Of Downhole Heat Exchanger Concept In Geothermal Energy Extraction From Saturated And Fractured Reservoirs, Yin Feng

LSU Doctoral Dissertations

Geothermal energy has gained a lot of attention recently due to several favorable aspects such as ubiquitously distributed, renewable, low emission resources while leveraging the advances in the associated technologies such as directional drilling and low enthalpy power generation plant. However, there are still many challenges such as the high initial capital cost of drilling and surface facilities, environmental risk of seismicity due to the induced disequilibrium in the formation, and sustainability of project over designed operational life. Traditional downhole heat exchangers (DHE) could potentially reduce the capital cost and the risk of seismicity, but they are unable to maintain …

Strategies For Real Time Reservoir Management, Yuanyuan Shuai

LSU Doctoral Dissertations

Real–time reservoir management is developed to manage a shrinking labor force and rising demand on energy supply. This dissertation seeks good strategies for real–time reservoir management. First, two simulator–independent optimization algorithms are investigated: ensemble–based optimization (EnOpt) and bound optimization by quadratic approximation (BOBYQA). Multiscale regularization is applied to both to find appropriate frequencies for well control adjustment. Second, two gathered EnKF methods are proposed to save computational cost and reduce sampling error: gathered EnKF with a fixed gather size and adaptively gathered EnKF. Finally, oil price uncertainty is forecasted and quantified with three price forecasting models: conventional forecasting, bootstrap forecasting …

Direct Shear Testing Of Fractured Rocks From Missouri Used To Evaluate Potential Fault Reactivation Induced By Carbon Dioxide Sequestration, Ishan Kumar

Masters Theses

"Geological storage projects of CO₂ are designed to maintain secure storage for thousands of years. Carbon Capture and Storage has been identified as one of the methods which is used to reduce global emission of CO₂ and achieve lower concentration of CO₂ in the atmosphere by capturing the CO₂ from the flue gases and storing it in underground formations. Potential leakage of injected CO₂ from the reservoir to the surface is caused by the reactivation of pre-existing faults and fractures which is caused by the change in the state of stresses and the pore pressure. To avoid damage to the …

Hydraulic Fracturing Experiments To Investigate Circulation Losses, Maximiliano Liberman

Masters Theses

"In recent years the oil and gas industry has been drilling more challenging wells due to long deviated wells, drilling through already depleted reservoirs, sub salt wells and increasing water depth. A major challenge these wells create is to prevent fluid loss into the formation and wellbore breakouts by having accurately determined the mud weight operational window. In addition to accurately determine the fracture gradient, additives in the drilling fluid have been used to enhance the fracture gradient in an industry process named wellbore strengthening. In order to study the phenomenon of fracture gradient alteration, a hydraulic fracturing apparatus was …

Surfactant Enhanced Oil Recovery By Wettability Alteration In Sandstone Reservoirs, Omar Elmofty

Masters Theses

"Recovering more oil from existing oil reservoirs using enhanced oil recovery methods holds the key for meeting future energy demands. Even though wettability is a cornerstone in oil recovery, few studies have focused on increasing oil recovery in sandstone reservoirs through wettability alteration. The objective of this thesis is to prove that altering the wettability of a sandstone rock to preferentially water-wet condition will reduce the remaining oil saturation and thus increase the percentage of recovered oil.

Two commercial surfactants were selected after studying both the phase behavior and the interfacial properties of 30 surfactants with oil and 1.00% sodium …

Effect Of Surfactants And Brine Salinity And Composition On Spreading, Wettability And Flow Behavior In Gas-Condensate Reservoirs, Yu Zheng

LSU Doctoral Dissertations

The well-known condensate blockage problem causes severe impairment of gas productivity as the flowing bottom-hole pressure falls below the dew point in gas-condensate reservoirs. Hence, this study attempts to investigate the concept of modifying the spreading coefficient and wettability using low-cost surfactants in the near wellbore region, to prevent the gas flow problems associated with condensate buildup. This study also examines the effect of brine salinity and composition on wettability, spreading and adhesion in condensate buildup regions, to evaluate the ability of brine salinity/composition for enhanced gas productivity in gas-condensate reservoirs. In this study, experiments were performed at both ambient …

A Methodology For Statistical Propped Fracture Treatment Design In Fluvial Environments, Prue Elizabeth Smith

Doctoral Dissertations

"Treatment design for hydraulic fracturing historically has been deterministic in nature. In a deterministic design, required variables can be determined and are assumed to be laterally continuous. This is difficult for geologic settings in general, but nearly impossible in fluvial geologic environments where the second assumption is violated.

Recent work has employed statistical methods to account for the complexity and heterogeneity in fluvial environments. Statistical design tools have been used to assist with improving the design process in complex fluvial geologic systems. Currently, the statistical design tools must be created using a "trial and error" process, which requires first completing/fracturing …

Updated Eor Screening Criteria And Modeling The Impacts Of Water Salinity Changes On Oil Recovery, Ahmad Aladasani

Doctoral Dissertations

"Developing technologies for enhanced oil recovery (EOR) from existing oil fields would supply the world's energy needs for several decades. The application of EOR in many major oil-producing countries remains in its conceptual stage. Thermal and gas EOR methods achieve high incremental rates; however, their application range has not broadened significantly as they have matured, while the rate at which new, promising EOR methods such as Low-salinity water flooding (LSWF) are being implemented is alarming. Despite, the potential of LSWF its development and application has been hindered by the lack of consensus concerning its recovery mechanism(s). Every oil reservoir has …

Development Of A Shared Earth Model To Investigate Potential For Carbon Dioxide Sequestration In The Springfield Area, Mo, Imowo Celestine Akpan

Masters Theses

"Carbon dioxide (C0₂) sequestration has been extensively implemented and explored predominantly in depleted oil reservoirs and deep saline aquifers where the C0₂ is stored under supercritical conditions. A lesser explored option with great potential is based on injection into shallow reservoirs where the C0₂ may not always be in its denser supercritical state. The research evaluates the potential for injecting C0₂ into saline aquifers at depths of ~550-650 meters and formation temperatures of -22⁰C.

To evaluate injectivity and cap rock integrity, reservoir and geomechanical simulations need to be conducted separately and subsequently coupled. A Shared Earth Model is developed utilizing …

Investigation Of Drillstring Vibration Reduction Tools, Mohammed Fayez Al Dushaishi

Masters Theses

"Drilling related problems such as drillstring vibration is an important cause of premature failure of drillstring components and drilling inefficiency. The vibration of drillstring interferes with measurement collected while drilling. In severe cases, drillstring vibration will lead to wellbore instability that will result in an increase in the operation cost. In the late 1980's, a lot of studies and techniques were developed to mitigate drillstring vibration and downhole vibration measurements were introduced to the industry in two forms; real time measurements and memory devices measurements

A study of drillstring vibration of three different wells located in the Norwegian North Sea …

Modeling Carbon Sequestration In Transition Zone To Optimize Storage Potential, Fang Yang

Doctoral Dissertations

"Shallow aquifers are potential candidates for carbon sequestration because of their wide distribution and low injection cost. Injected CO₂ in a shallow region segregates into two zones according to CO₂ phases within the initial reservoir pressure and the maximum bottom hole pressure: gas zone and transition zone. Transition zone is a better option because of favorable CO₂ properties. This work investigated the CO₂ storage potential in transition zone using the compositional simulator CMG-GEM and a design of experiment software iSIGHT. First, it addressed the basic characteristics of CO₂ sequestration in transition zone, and then modeled CO₂ injection with simultaneous water …

Evaluation Of The Reagan And Lamotte Sandstones In Southwestern Missouri For Carbon Dioxide Sequestration, Todd Jeffrey Miller

Masters Theses

"Carbon dioxide sequestration has been proposed as a way to reduce anthropogenic carbon dioxide emissions. Several characteristics are required in order for a geologic formation to be suitable for sequestration. There must be an impermeable confining layer to restrain CO₂ migration toward the surface, the porosity and permeability must be high enough to allow for long term injection and substantial storage capacity, and the formation must be strong enough for long term injection to occur without inducing fractures. In this work, The Reagan and Lamotte Sandstones near Springfield, Missouri were evaluated for the potential for carbon dioxide sequestration. The Derby-Doe …

Geomechanical Characterization Of Reservoir & Cap Rocks For Co₂ Sequestration, Sudarshan Govindarajan

Masters Theses

"Geological sequestration of CO₂ has been identified as one method to reduce global emissions of CO₂ and achieve lower levels of CO₂ concentrations in the atmosphere. Geological formations have to be assessed in terms of their capacity, sealing capabilities and economic feasibility before CO₂ sequestration can commence. Potential leakage of injected CO₂ from the reservoir formation could occur due to natural or injection induced faults or fractures in the reservoir or sealing formations. As part of a potential leakage investigation a geomechanical characterization which refers to the assessment of the in-situ stress conditions, rock strength and stiffness properties of the …

Investigation Of Geosteering In Non-Trivial Geological Settings, Anuroop Pandey

Masters Theses

"The well placement technology has advanced to a stage where we can explore small tolerance targets such as thin reservoirs. Well placement with geosteering, which is the real time adjustment of the well path based on the geological responses to place and maintain the well within the best part of the reservoir, is the technology that has made this progress possible. Geosteering however can get very complex with the increasing heterogeneities of the formations and there is no fixed methodology to devise a steering strategy in such complex geological settings. To accommodate this challenge, we investigated three methods to verify …

Enhanced Heavy Oil Recovery By Alkali-Surfactant In The Pennsylvania Warner Sandstone, Rabia Mohamed Hunky

Doctoral Dissertations

"In this research, a study of the non-thermal method of alkaline-surfactant (AS) flooding to enhance heavy oil recovery from the Pennsylvanian Warner sandstone reservoir in Western Missouri was conducted. This work includ [sic] testing approximately 30 commercial surfactants and using a heavy oil sample with an API of 17. It was found that a number of surfactants could create stable emulsions. The viscosity of heavy oil could be reduced from 18,518 cp to 2.5 cp at 25⁰C through emulsification of certain surfactants. One of the major findings was that the emulsion created by the commercial surfactant, Igepalʼ CO-530 was stable …

A Novel Biodiesel And Glycerol Carbonate Production Plant, Nghi T. Nguyen, Yaşar Demirel

Yaşar Demirel Publications

Crude glycerol is the byproduct of biodiesel production plant and the economic value of glycerol may affect the profitability of the biodiesel production plant. As the production rate of bioglycerol increases, its market values drop considerably. Therefore, conversion of bioglycerol into value-added products can reduce the overall cost, hence, leading to a more economical biodiesel production plant. In a direct carboxylation reaction, CO₂ reacts with glycerol to produce glycerol carbonate and water. This study presents a direct comparison of the economic analysis of the conventional biodiesel production plant and the possible next generation biodiesel-glycerol carbonate production plant. At the …

Physical Impact Of Waterjet-Based Sediment Remediation On Benthic Organisms, Grace Harper, Andrew Curtis Elmore, Christopher Redell, Gavin Risley, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Adding Activated Carbon to Sediments Has Been Shown to Be an Effective Means of Reducing the Bioavailability of Certain Contaminants. the Current State of the Practice is to Mechanically Mix Activated Carbon to a Target Concentration of 3 Percent at Depths of Approximately 30 Cm using a Rotovator or Similar Construction Equipment. Waterjets Have Been Used to Cut Hard Material using a Mixture of Water and an Abrasive. If Activated Carbon is Substituted for the Abrasive, Waterjets Have the Potential to Use Surface Injection as a Replacement for Mechanical Mixing during Sediment Remediation. a Perceived Benefit of Waterjet-Based Sediment Remediation …

Evaluation Of Simultaneous Water And Gas Injection Using Co2, Shrinidhi Shetty

LSU Master's Theses

Miscible CO2 injection is the second largest contributor to global enhanced oil recovery, as it has successfully undergone extensive laboratory tests and field applications for recovering residual oil left behind after waterflooding. Prolific incremental recoveries have been obtained for some fields. Although miscible CO2 injections generally have excellent microscopic displacement efficiency they often result in poor sweep efficiency. In order to address sweep problems and maximize recoveries, other schemes of gas injection have been developed. Two such processes are water-alternating-gas (WAG) and simultaneous water-and-gas (SWAG) injection. WAG and SWAG have been successfully used to minimize poor sweep. Improved gas utilization …

Pore-Scale Lattice Boltzmann Simulations Of Inertial Flows In Realistic Porous Media: A First Principle Analysis Of The Forchheimer Relationship, Chukwudi Paul Chukwudozie

LSU Master's Theses

With recent advances in the capabilities of high performance computing (HPC) platforms and the relatively simple representation of complex geometries of porous media, lattice Boltzmann method (LBM) has gained popularity as a means of solving fluid flow and transport problems. In this work, LBM was used to obtain flow parameters of porous media, study the behavior of these parameters at varying flow conditions and quantify the effect of roughness on the parameters by relating the volume averaged flow simulation results to Darcy and Forchheimer equations respectively. To validate the method, flow was simulated on regular and random sphere arrays in …