An experimental investigation of applicability of CO2 enhanced coal bed methane recovery to low rank coal

Previous studies have shown that carbon dioxide (CO2) injection can enhance CH4 production (CO2-ECBM) compared to traditionally-used methods, mainly due to the higher adsorptive capability of CO2 in coal, which desorbs the CH4 with higher sweep efficiency. Many studies have been conducted to date on the CO2-ECBM technique for high rank coals. However, there have been very few studies on low rank coal. Therefore, this study uses Victorian brown coal samples to investigate the CO2-ECBM potential of low rank coal. A series of CO2 core flooding tests was conducted on CH4 saturated meso-scale brown coal samples for various CO2 injection conditions, phases and pressures. According to the experimental findings, compared to natural recovery, CO2 flooding enhances CH4 production by creating higher production rates, and higher CO2 pressures can drive the CH4 towards the production end with almost 100% sweep efficiency. Furthermore, the rapid CO2 breakthroughs observed under higher CO2 pressures are found to be significant for super-critical CO2. Tests results show that the superior competence of super-critical CO2 in CH4 recovery is independent of coal rank or maturity. However, the greater volumetric strain created by higher CO2 pressures may, have a negative influence on long-term gas productivity with the reduction of flow ability through the seam.

[1]  S. Iglauer,et al.  CO2-wettability of low to high rank coal seams: Implications for carbon sequestration and enhanced methane recovery , 2016 .

[2]  A. A. Reznik,et al.  An analysis of the effect of CO2 injection on the recovery of in situ methane from bituminous coal: an experimental simulation , 1984 .

[3]  Stuart Day,et al.  Swelling of Australian coals in supercritical CO2 , 2008 .

[4]  David Airey,et al.  Sub- and super-critical carbon dioxide flow behavior in naturally fractured black coal: An experimental study , 2011 .

[5]  Douglas M. Ruthven,et al.  Principles of Adsorption and Adsorption Processes , 1984 .

[6]  R. T. Yang,et al.  Gas Separation by Adsorption Processes , 1987 .

[8]  L. Connell,et al.  Core flooding experiments of CO2 enhanced coalbed methane recovery , 2014 .

[9]  Grant S. Bromhal,et al.  Influence of carbon dioxide on coal permeability determined by pressure transient methods , 2009 .

[10]  Grant S. Bromhal,et al.  Matrix Shrinkage and Swelling Effects on Economics of Enhanced Coalbed Methane Production and CO2 Sequestration in Coal , 2005 .

[11]  Y. Cinar,et al.  Injecting pure N2 and CO2 to coal for enhanced coalbed methane: Experimental observations and numerical simulation , 2013 .

[12]  Scott Reeves,et al.  Geological Sequestration of CO2 in Deep, Unmineable Coalbeds: An Integrated Research and Commerical-Scale Field Demonstration Project , 2001 .

[13]  Chun-Zhu Li,et al.  Advances in the Science of Victorian Brown Coal , 2004 .

[14]  Pathegama Gamage Ranjith,et al.  Effect of coal rank on various fluid saturations creating mechanical property alterations using Australian coals , 2016 .

[15]  C. M. White,et al.  Sequestration of Carbon Dioxide in Coal with Enhanced Coalbed Methane RecoveryA Review , 2005 .

[16]  John Gale,et al.  Coal-Bed Methane Enhancement with CO2 Sequestration Worldwide Potential , 2001 .

[17]  Luke D. Connell,et al.  Laboratory characterisation of coal reservoir permeability for primary and enhanced coalbed methane recovery , 2010 .

[18]  N. I. Aziz,et al.  The effect of sorbed gas on the strength of coal – an experimental study , 1999 .

[19]  K. Wolf,et al.  Differential swelling and permeability change of coal in response to CO2 injection for ECBM , 2008 .

[20]  Anthony R. Kovscek,et al.  Laboratory and Simulation Investigation of Enhanced Coalbed Methane Recovery by Gas Injection , 2008 .

[21]  V. Vishal,et al.  A macro-scale experimental study of sub- and super-critical CO2 flow behaviour in Victorian brown coal , 2015 .

[22]  Pathegama Gamage Ranjith,et al.  Deep coal seams as a greener energy source: a review , 2014 .

[23]  Shinji Yamaguchi,et al.  CO2-ECBM field tests in the Ishikari Coal Basin of Japan , 2010 .

[24]  J. Rushing,et al.  Evaluation of the Technical and Economic Feasibility of CO2 Sequestration and Enhanced Coalbed Methane Recovery in Texas Low-Rank Coals , 2006 .

[25]  Pathegama Gamage Ranjith,et al.  A new triaxial apparatus to study the mechanical and fluid flow aspects of carbon dioxide sequestration in geological formations , 2011 .

[26]  J. P. Seidle,et al.  Review of Research Efforts in Coalbed Methane Recovery , 1991 .

[27]  Regina Sander,et al.  History matching of enhanced coal bed methane laboratory core flood tests , 2011 .

[28]  S. Durucan,et al.  Improving the CO2 well injectivity and enhanced coalbed methane production performance in coal seams , 2009 .

[30]  P. Ranjith,et al.  Super-critical CO2 saturation-induced mechanical property alterations in low rank coal: An experimental study , 2016 .

[31]  Andrzej Czapliński,et al.  Changes in mechanical properties of coal due to sorption of carbon dioxide vapour , 1982 .

[32]  A. A. Reznik,et al.  A Laboratory Investigation Of Enhanced Recovery Of Methane From Coal By Carbon Dioxide Injection , 1980 .

[33]  X. Miao,et al.  Evaluation of stress-controlled coal swelling processes , 2010 .

[34]  Jian Zhao,et al.  Optimization of enhanced coal-bed methane recovery using numerical simulation , 2015 .