Reservoir Modeling and Simulation of Carbon Dioxide Sequestration-ECBM Production in Un-mineable Coal Seams, Marshall County, WV.

摘要

Concerning the effect of increasing anthropogenic greenhouse gas emissions, especially CO2, the geological CO2 sequestration has drawn growing attention as an environmentally attractive method. Among all the geologic options, coal seam has been considered as a very promising and plausible option, especially due to its CO2 sequestration capacity at low net costs owing to its additional enhanced coal-bed methane (ECBM) production benefits as well as its potential for trapping CO2 for a long period of time.;In this work an effort has been made in order to simulate methane production, CO2 sequestration and ECBM production in un-mineable coal seams, Marshall County, West Virginia. The CO2 sequestration project is taking place in two target coal seams, namely: Pittsburgh and Upper Freeport. Methane is produced from both coal seams, while CO2 is only injected into Upper Freeport. The monitoring process is performed in the shallower one, Pittsburgh coal seam, with the intention of detecting any possible leakage of CO2.;Due to the special features and the nature of gas retention in CBM reservoirs, modeling the production and injection will have more complexity compared to conventional resources. This study attempts to address the key reservoir parameters that are germane to driving ECBM and CO2 sequestration processes in Upper Freeport coal seam through carrying out sensitivity analysis on different reservoir parameters, including cleat permeability, cleat porosity, CH4 adsorption time, CO2 adsorption time, CH4 Langmuir Isotherm, CO 2 Langmuir Isotherm and Palmer and Mansoori parameters. This paper will provide a valuable resource to engineers in order to assist them in evaluating the optimum strategy to model and match the production and injection history of CBM reserves.;Simulation results, such as history matching of production and injection, reservoir pressure distribution, CH4 and CO2 adsorption distribution at different time steps and prediction on both ECBM production and CO2 injection, have been presented and discussed.