Carbon Dioxide Sequestration in Coal Seams: A Parametric Study and Development of a Practical Prediction/Screening Tool Using Neuro-Simulation

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractFossil fuels are a major source of the world's energy production and this is expected to be the case well into the 21 st century. Consequently, the extensive utilization of fossil fuels has measurably increased the total load of one of its byproducts, carbon dioxide (CO 2 ), in the atmosphere and concern about the effects on global warming has prompted the inception of various methods and policies geared at reducing the concentration of this green-house gas in the atmosphere. One of the more promising technologies is CO 2 sequestration which involves the capture, separation and storage of CO 2 .Production of coalbed methane is a well-developed technology, but enhanced recovery by CO 2 injection has undergone relatively limited research. Recent research suggests that CO 2 preferentially sorbs to coal, replacing the coalbed methane which can be produced and sold to offset the costs of sequestering CO 2 thereby providing a dual role for unmineable coal seams; a source of coalbed methane and a repository for the sequestration of CO 2 . Production operations from a carbon dioxide-enhanced coalbed methane recovery pilot project, in the San Juan Basin, indicate that the process is technically and economically feasible.Based on the data, results and analyses obtained from the simulations performed during the parametric study, a CO 2 performance predictor tool is developed by employing neurosimulation methods. This tool is able to predict the values of the performance indicators of the CO 2 sequestration process for a wide range of coal-seams and various production schemes within an acceptable margin of error and in a timely and efficient manner. The predictive capabilities of this tool also enables it to be used as a screening tool that has the ability to ascertain the viability of various coalbed reservoirs for the sequestration of CO 2 , as well as the optimum production scheme to be used in any given project.