A Multi-scale Approach for CO2 Accounting and Risk Analysis in CO2 Enhanced Oil Recovery Sites

Friday, 18 December 2015: 08:15
3018 (Moscone West)
Zhenxue Dai1, Hari Selvi Viswanathan2, Richard Stephen Middleton2, Feng Pan3, William Ampomah4, Changbing Yang5, Wei Jia3, Si-Yong Lee6, Brian J O L McPherson7, Reid Grigg8 and Mark D White9, (1)Los Alamos National Laboratory, Earth and Environmental Sciences, Los Alamos, NM, United States, (2)Los Alamos National Laboratory, Los Alamos, NM, United States, (3)University of Utah, Salt Lake City, UT, United States, (4)Petroleum Recovery Research Center, New Mexico Tech, Socorro, NM, United States, (5)University of Texas at Austin, Austin, TX, United States, (6)Schlumberger Carbon Services, Denver, CO, United States, (7)Univ Utah, Department of Civil and Environmental Engineering, Salt Lake City, UT, United States, (8)New Mexico Institute of Mining and Technology, Petroleum Recovery Research Center, Socorro, NM, United States, (9)Pacific Northwest Natl Lab, Richland, WA, United States
Using carbon dioxide in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce carbon sequestration costs in the absence of greenhouse gas emissions policies that include incentives for carbon capture and storage. This study develops a multi-scale approach to perform CO2 accounting and risk analysis for understanding CO2 storage potential within an EOR environment at the Farnsworth Unit of the Anadarko Basin in northern Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil-water flow and transport in the Marrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2 injection rate, CO2 first breakthrough time, CO2 production rate, cumulative net CO2 storage, cumulative oil and CH4 production, and water injection and production rates. A global sensitivity analysis indicates that reservoir permeability, porosity, and thickness are the major intrinsic reservoir parameters that control net CO2 injection/storage and oil/CH4 recovery rates. The well spacing (the distance between the injection and production wells) and the sequence of alternating CO2 and water injection are the major operational parameters for designing an effective five-spot CO2-EOR pattern. The response surface analysis shows that net CO2 injection rate increases with the increasing reservoir thickness, permeability, and porosity. The oil/CH4 production rates are positively correlated to reservoir permeability, porosity and thickness, but negatively correlated to the initial water saturation. The mean and confidence intervals are estimated for quantifying the uncertainty ranges of the risk metrics. The results from this study provide useful insights for understanding the CO2 storage potential and the corresponding risks of commercial-scale CO2-EOR fields.