CFD & AMP Center
Department of Mechanical & Aerospace Engineering
West Virginia University

Sequestration of Carbon Dioxide in Appalachian Coal Depositsm

Sequestration of Carbon Dioxide in Appalachian Coal Deposits
Montana State University
Dr. Andrei Smirnov
Guoxiang Liu
Montana State University
Los Alamos National Laboratory
Lawrence Berkley National Laboratory
Lawrence Livermore National Laboratory
National Energy and Technology Laboratory
Pacific Northwest National Laboratory
West Virginia University

CO2 sequestration is one way to reduce the content of carbon dioxide in the atmosphere. In this process CO2 is captured, possibly at the source of its production, like fossil fuel power plants, and pumped into underground reservoirs, such as deep saline aquifers or un-mineable coal seams. The latter can provide an additional benefit of residual methane recovery. In order to plan the CO2 sequestration operations in each particular area it is important to predict the storage capacity of a reservoir, and the feasibility of long-term containment of CO2. The purpose of this research is to conduct such feasibility study for Appalachian region using advanced computer simulations. A long term projection of CO2 transport and possible escape from deep coal seams is an important problem associated with CO2 sequestration. Many factors can affect the process of CO2 transport, such as bounding layers permeabilities, porosities, fracture densities, etc. Within this project computer simulations are conducted with the purpose of predicting CO2 transport in a multi-layer environment of typical unmineable coal seams. The San Juan, Appalachian and Powder River basins were considered as examples. TOUGH2, OpenFOAM, and COMSOL simulators were used in the study. In preliminary analysis a four layer sand-shale-coal-shale system was considered with the overlying and underlying medium to be the shales. Fracture zones might present local escape points. Locating faults and fracture zones is one of the objectives of the geophysical characterization and monitoring efforts. However, a lot of this will be site dependent. Thus, a number of different scenarios were considered: tight (low to zero permeability), seal versus leaky (higher permeability) seal, etc. The results indicate that the diffusion of CO2 may be affected by the properties of the seal layers. For tight seal shale scenarios with the reasonable assumptions used there was no considerable CO2 leakage beyond the shale layers after 50 years or more. The study can provide long term projections for the CO2 sequestration operations in known coal seams. The results of single phase, multi-component in four layers reservoir (case: CO2 concentration after 1 year injection with rate 1 kg/m3 in km3 reservoir)