CO2 SEQUESTRATION POTENTIAL OF TEXAS LOW-RANK COALS

The objectives of this project are to evaluate the feasibility of carbon dioxide (CO{sub 2}) sequestration in Texas low-rank coals and to determine the potential for enhanced coalbed methane (CBM) recovery as an added benefit of sequestration. The main objective for this reporting period was to further characterize the three areas selected as potential CO{sub 2} sequestration sites. Well-log data are critical for defining depth, thickness, number, and grouping of coal seams at the proposed sequestration sites. Thus, we purchased 12 hardcopy well logs (in addition to 15 well logs obtained during previous quarter) from a commercial source and digitized them to make coal-occurrence maps and cross sections. Detailed correlation of coal zones is important for reservoir analysis and modeling. Thus, we correlated and mapped Wilcox Group subdivisions--the Hooper, Simsboro and Calvert Bluff formations, as well as the coal-bearing intervals of the Yegua and Jackson formations in well logs. To assess cleat properties and describe coal characteristics, we made field trips to Big Brown and Martin Lake coal mines. This quarter we also received CO{sub 2} and methane sorption analyses of the Sandow Mine samples, and we are assessing the results. GEM, a compositional simulator developed by the Computer Modeling Group (CMG), was selected for performing the CO{sub 2} sequestration and enhanced CBM modeling tasks for this project. This software was used to conduct preliminary CO{sub 2} sequestration and methane production simulations in a 5-spot injection pattern. We are continuing to pursue a cooperative agreement with Anadarko Petroleum, which has already acquired significant relevant data near one of our potential sequestration sites