Investigation into the Methane Displacement Behavior by Cyclic, Pure Carbon Dioxide Injection in Dry, Powdered, Bituminous Indian Coals

Abstract

Understanding competitive sorption effects for the carbon dioxideÀmethane system in coal is essential for the implementation of enhanced methane production with concomitant CO 2 sequestration in coal. The paper discusses the methane displacement behavior of a set of eight dry, powdered Indian bituminous coal samples when subjected to cyclic, pure CO 2 injection, employing a "huff and puff" scheme. The coal samples were partially saturated with methane, and CO 2 was then injected at a fixed pressure. This was followed by gas drainage to reduce pressure to the pre-injection level, and about 12À15 such cycles of CO 2 injection and gas drainage were carried out. In general, the process successfully displaced the adsorbed methane. The adsorption ratio of CO 2 /methane was found to be higher than pure gas sorption capacities at the same pressure. Carbon dioxide was preferentially adsorbed into the coals, and during gas drainage, preferential desorption of methane was observed for all coals. The coals also exhibited different methane displacement behavior. For three coal samples, it was possible to recover 1 mol of methane by injecting less than 1 mol of CO 2 . For the other coal samples, 1.5À2 mol of CO 2 was required for 1 mol of methane. However, no relationship could be established between the methane release characteristics of the coals and their petrographic composition.

Simulation to Enhance Shale Gas Recovery Using Carbon Dioxide in Silica Nanopores with Different Sizes

“…Horizontal drilling and high‐volume hydraulic fracturing are common techniques in shale gas extraction, however, the accompanying threats to the environment and human health are of concern, which is the bottleneck in the development . Recently, a notable technique that uses nonaqueous fracturing fluids of supercritical CO 2 to enhance the recovery of natural gas (CO 2 ‐EGR) has been recognized as a remarkable technique that could not only conquer the energy source exploitation problems but also achieve the capture and sequestration of CO 2 to thereby combine environmental and industrial benefits perfectly …”

“…[10][11][12][13][14][15] Recently,an otable techniquet hat uses nonaqueous fracturing fluidso fs upercritical CO 2 to enhance the recovery of natural gas (CO 2 -EGR) has been recognized as ar emarkablet echnique that could not only conquer the energy source exploitationp roblems but also achieve the capturea nd sequestrationo fC O 2 to thereby combine environmentala nd industrial benefitsperfectly. [16][17][18][19][20] Thev ast majority of the shale gas reserved in shale formations is in an adsorbed state in nanoscale pores,w hich includes micropores( diameter (d) < 2nm) and mesopores (d = 2-50 nm). [11,21,22] Therefore, as tudy on the microbehavior of shale gasi nn anopores with ap ore size that changes from micro-to mesopores ize is meaningful to determine the mechanisms and evaluate the potential of the recoveryo f shale gas.…”

Laboratory Studies on Permeability of Coals Using Briquettes: Understanding Underground Storage of CO2

“…Due to its sorption and structural properties, coal is a rock which is probably the most promising reservoir rock for CO 2 storage [14]. Laboratory studies of CO 2 /CH 4 exchange sorption in the context of assessing the possibility of underground storage of CO 2 in coal seams are carried out on a large scale [15][16][17][18][19][20][21][22][23][24][25]. There have also been many ECBM (Enhanced Coalbed Methane recovery) pilot/demonstration test projects in the world (e.g., in USA, Canada, China, Japan and Poland), by injecting CO 2 into coal seams [26].…”

Release of methane from nanochannels through displacement using CO2

“…Yu et al 24 built an experimental apparatus to obtain the transport characteristics of methane in nanopores and found that carbon dioxide is easier to be adsorbed by the pore surface than methane. Bhowmik et al 25 investigated the displacement behavior of methane by pure carbon dioxide in dry, powdered, bituminous Indian coals. It was also found that carbon dioxide is preferentially adsorbed by silt pores compared with methane.…”