Compositional reservoir simulation studies were performed to investigate the effect of uncertain reservoir parameters, flood design variables, and economic factors on coupled CO2 sequestration and EOR projects. Typical sandstone and carbonate reservoir properties were used to build generic reservoir models. A large number of simulations were needed to quantify the impact of all these factors and their corresponding uncertainties taking into account various combinations of the factors. The design of experiment method along with response surface methodology and Monte-Carlo simulations were utilized to maximize the information gained from each uncertainty analysis. The two objective functions were project profit in the form of $/bbl of oil produced and sequestered amount of CO2 in the reservoir. The optimized values for all objective functions predicted by design of experiment and the response surface method were found to be close to the values obtained by the simulation study, but with only a small fraction of the computational time. After the statistical analysis of the simulation results, the most to least influential factors for maximizing both profit and amount of stored CO2 are the produced gas oil ratio constraint, production and injection well types, and well spacing. For WAG injection scenarios, the Dykstra-Parsons coefficient and combinations of WAG ratio and slug size are important parameters. Also for a CO2 flood, no significant reduction of profit occurred when only the storage of CO2 was maximized. In terms of the economic parameters, it was demonstrated that the oil price dominates the CO2 EOR and storage. This study showed that sandstone reservoirs have higher probability of need for CO2i ncentives. In addition, higher CO2 credit is needed for WAG injection scenarios than continuous CO2 injection. As the second part of this study, scaling groups for miscible CO2 flooding in a three-dimensional oil reservoir were derived using inspectional analysis with special emphasis on the equations related to phase behavior. Some of these scaling groups were used to develop a new MMP correlation. This correlation was compared with published correlations using a wide range of reservoir fluids and found to give more accurate predictions of the MMP.

In this study, the co-optimization of carbon dioxide sequestration and enhanced oil recovery and the co-optimization of carbon dioxide sequestration and methane recovery studies were discussed. Carbon dioxide emissions in the atmosphere are one of the reasons of global warming and can be decreased by capturing and storing carbon dioxide. Our aim in this study is to maximize the amount of carbon dioxide sequestered to decrease carbon dioxide emissions in the atmosphere and maximize the oil or methane recovery to increase profit or to make a project profitable. Experimental design and response surface methodology are used to co-optimize the carbon dioxide sequestration and enhanced oil recovery and carbon dioxide sequestration and methane recovery. At the end of this study, under which circumstances these projects are profitable and under which circumstances carbon dioxide sequestration can be maximized, are given.

This book provides a comprehensive and detailed description of the various mechanisms of the CCS–EOR process. Whereas previous texts have primarily focused on carbon capture and storage (CCS) and enhanced oil recovery (EOR) separately, this book provides a general overview of both technologies when used together. Coupled CCS–EOR technology has become increasingly important, as it overcomes the respective shortcomings of the two technologies. The book presents an integrated numerical model including the hysteresis effect, solubility trapping, miscibility, and formation damage by asphaltene deposition. The experimental and model-based evaluation of fluid properties is also discussed. The book concludes by discussing the latest research into CO2 storage coupled with EOR, most notably performance control by including additives in CO2 injection, and CO2 injection into shale reservoirs. Ideally suited for graduate students and researchers in the fields of carbon capture, utilisation, and storage, the book shares essential insights into maximising the efficiency of CCS and EOR alike.

Increasing energy demand combined with public concern for the environment obligates the oil industry to supply oil and natural gas to the public while minimizing the carbon footprint due to its activities. Today, fossil fuels are essential in meeting the global energy needs, but have the undesirable outcome of producing carbon dioxide. Carbon dioxide (CO2) injection in reservoirs is an appealing Enhanced Oil/Gas Recovery method for increasing hydrocarbon production by using the miscible interactions between hydrocarbon and carbon dioxide. Carbon dioxide flooding is beneficial to the environment and to petroleum producers, since it can store carbon dioxide while increasing oil and natural gas production. A practical challenge in combining CO2 Sequestration with Enhanced Gas Recovery (EGR) is determining the optimal process parameters that maximize the project value. This research describes the development of a procedure to determine the best process conditions for the CO2 EGR and Sequestration process. Analysis includes experimental work that illustrates that CO2 is able to reduce the dew point pressure of wet gas fluids and that reservoir fluid phase changes can be indicated by changes in total fluid compressiblity. In addition, compositional simulation illustrates that CO2 improves condensate and natural gas recovery. Studies show that the ideal reservoir management strategy for CO2 EGR is to set the CO2 injectors' bottom hole pressure to the initial reservoir pressure. An economic model is developed that illustrates the capital investment necessary for the CO2 EGR and Sequestration process for different capture technologies and levels of captured CO2 impurity. This economic model is utilized in conjunction with an optimization algorithm to illustrate the potential profitability of theCO2 EGR and Sequestration project. To illustrate the economic risk associated with CO2 EGR and Sequestration project, probabilistic analysis is used to illustrate scenarios where the technology is successful. This work is applicable to carbonate wet gas reservoirs that have significant gas production problems associated with condensate blockage. This work is also useful in modeling the economics associated with CO2 EGR and CO2 Sequestration. The strategy developed in this work is applicable to designing process conditions that correspond to optimal CO2 EGR and optimal CO2 Sequestration. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151726

This study presents an engineering and economic analysis to estimate the financial incentives that may be required to motivate coupled enhanced oil recovery (EOR) and CO2 capture and storage (CCS) projects. Because CO2 is considered to be a major contributor to global warming, its storage in oil reservoirs could have long term economic and environmental benefits. The engineering foundations of the study are compositional reservoir simulations that accounts for all the major technical parameters, and provide data on the reservoir performance over time. In order to carry out the reservoir simulations in an efficient way, Computer Modelling Group GEM reservoir simulator was added to the UT IRSP platform. Experimental design and a project economic model were then applied to the reservoir simulation outputs to estimate the levels of CO2 credit required to motivate coupled EOR and storage. In the first part of the study, the effect of technical and economic variables on the CO2 credit was studied for the case of a mature oil reservoir. In the second part, a similar analysis was conducted for marginal (low quality) oil reservoirs. The results suggest that CO2 credit would necessarily have to be provided, in both low and high price scenarios, to motivate coupled EOR and CCS. Also, it appears that any credit scheme that is implemented must consider reservoir physical characteristics, CO2 injection method and the configuration of wells as the most significant variables.

This book addresses the feasibility of CO2-EOR and sequestration in a mature Indian oil field, pursuing for the first time a cross-disciplinary approach that combines the results from reservoir modeling and flow simulation, rock physics modeling, geomechanics, and time-lapse (4D) seismic monitoring study. The key findings presented indicate that the field under study holds great potential for enhanced oil recovery (EOR) and subsequent CO2 storage. Experts around the globe argue that storing CO2 by means of enhanced oil recovery (EOR) could support climate change mitigation by reducing the amount of CO2 emissions in the atmosphere by ca. 20%. CO2-EOR and sequestration is a cutting-edge and emerging field of research in India, and there is an urgent need to assess Indian hydrocarbon reservoirs for the feasibility of CO2-EOR and storage. Combining the fundamentals of the technique with concrete examples, the book is essential reading for all researchers, students and oil & gas professionals who want to fully understand CO2-EOR and its geologic sequestration process in mature oil fields.