Acoustic emission and volumetric strain induced in coal by the displacement sorption of methane and carbone dioxide

Effects of CO2adsorption on coal deformation during geological sequestration

“…In the literature, it was reported that CO 2 can lead to higher strain compared to argon, N 2 and CH 4 [ Pini et al , 2009; van Bergen et al , 2009a]. Expansion of the coal samples during CO 2 sorption was about twice that of CH 4 in the work of Majewska and Ziętek [2008]. We calculated the volumetric strain curves for methane and CO 2 adsorption under the same geological conditions.…”

“…This scenario, also known as enhanced coal bed methane (ECBM) recovery [ Mazzotti et al , 2009], is considered the most favorable because of its economic incentives [ Zarrouk and Moore , 2009]. ECBM recovery utilizes the preferential adsorption capacity of coal for carbon dioxide over methane [ Busch et al , 2006; Esteves et al , 2008; Kurniawan et al , 2006; Majewska and Ziętek , 2008; Ottiger et al , 2008a], and it has been tested in a number of field projects [ Reeves , 2004; van Bergen et al , 2009b; Wong et al , 2007]. The main fundamental problems arising during the design of CO 2 sequestration technologies include the prediction of CO 2 storage capacity and the analysis of chemical and physical processes initiated by CO 2 injection [ White et al , 2005], which affect the coal seam structure, adsorption, and transport properties, such as density, surface area, porosity, diffusion, permeability, and stability as a function of pressure and temperature.…”

“…Adsorption‐induced deformation is an interesting phenomenon, which has a significant influence on the coal bed permeability and, hence, on the recovery performance in general [ Siriwardane et al , 2009; van Bergen et al , 2009b]. Experimental investigations were performed in the past by the dilatometric method [ Ceglarska ‐ Stefanska and Czaplinski , 1993; Kelemen and Kwiatek , 2009; Reucroft and Sethuraman , 1987; Walker et al , 1988], the optical method [ Astashov et al , 2008; Day et al , 2008a; He et al , 2010; Karacan , 2007; Ottiger et al , 2008b; Pini et al , 2009; Pone et al , 2009; van Bergen et al , 2009a], the strain method [ Cui and Chikatamarla , 2007]; Majewska and Ziętek , 2008; Majewska et al , 2009; St. George and Barakat , 2001], and the acoustic emission (AE) measurement [ Majewska and Ziętek , 2008; Majewska et al , 2009]. Theoretical studies, including coupled structural deformation and variable saturation models [ Liu and Smirnov , 2009], reservoir simulation (e.g., PSU‐COALCOMP) [ Siriwardane et al , 2009], the energy balance approach [ Pan and Connell , 2007], and MC simulations [ Kowalczyk et al , 2010], were employed to study swelling and shrinkage of coal caused by the CO 2 sequestration process.…”

“…Because of competition for the adsorption sites between water and gas molecules, swelling of moisturized coals was smaller than that of dry ones [ van Bergen et al , 2009a]. In the work of Majewska and Ziętek [2008], preferential sorption/desorption of CH 4 or CO 2 in coal was investigated. They found that the injection of CO 2 into CH 4 ‐saturated coals caused considerable swelling of the coal.…”

Underground Coal Mine Methane Displacement by Injecting Low - pressure Gas into the Meta - anthracite Seam : Laboratory and Field Tests

“…However, the rapid closures of these fissures and cracks results in a decrease in permeability as the mining depth and the in situ stress increase. For a meta-anthracite seam, the residual gas pressure is 0.3 MPa after gas extraction [4] [5]. Under these conditions, methane can hardly be desorbed by the low negative extraction pressure in the drilling hole.…”