1、翻译部分英文原文Simulation of CO2-geosequestration enhanced coal bed methanerecovery with a deformation-flow coupled modelWangZuo-,Wang Guo-,Rudolph ,Diniz da Costa J.,Huang Pei-minand Xin LiaSchool of Mining, State Key Lab. of Safety Mining, China University of Mining and Technology, Xuzhou 221116, CHINAbS
2、chool of Chemical Engineering, The University of Queensland, Qld 4072, AustraliacCollege of ZiJin Mining, Fuzhou University, Fuzhou 350108, ChinaAbstract:Coal bed methane (CBM) recovery and CO2 sequestration into coal seams coupled with enhanced CBM recovery have been recognized as an economically e
3、ffective and environmentally friendly technology to improve the utilization of coal reserves. However, implementation of CBM and CO2 enhanced CBM (CO2-ECBM) production involves complex deformation-flow interactions in the coal. These aspects and their fundamental understanding remain as major concer
4、ns for CBM/ECBM modeling. Increasing interest in CBM and potentially in CO2-ECBM technology requires accurate predictive modeling to minimize investment risks. This paper proposed a deformation-flow coupled model to address aspects of model improvement. This model was developed based on nonlinear el
5、astic deformation mechanics and gas percolation theory and implemented using an established computer program named F-RFPA2D - 2D Flow-coupled Rock Failure Process Analysis code. The numerical simulations of this model were carried out according to a CO2 capture and sequestration (CCS) integrated und
6、erground coal gasification (UCG) process designed for Zhongliangshan coal mine in southwest China. The individual operations comprising (1) conventional CBM recovery andCO2 sequestration into coal and (2) the integrated operation of CBM recovery with CO2 enhancement were numerically investigated, re
7、spectively. The results show that CO2 sequestration into the coal bed promotes rapid transport of CBM towards the gas producer wells with a longer production period and can enhance coal bed methane recovery by up to 80% under the conditions of using this this study.Keywords:coal bed methane (CBM); C
8、BM recovery;CO2sequestration;CO2enhanced CBM (CO2-ECBM);numerical simulation1. IntroductionCoal is one of the dominant and abundant energy sources in the world and will become even more importantwhen oil and gas sources become more expensive to produce. However, directly utilizing coal by convention
9、al technologies is causing serious concerns resulting from the high emission of CO2 which is associated with climate chang Many attempts have been made to reduce the CO2 emission from coal sourced energy by means of various new or alternative technologies. An effective possibility is to integrate CO
10、2 capture and sequestration (CCS) with coal utilization processes2-3. However, CCS is expensive and its practical application would be advantageous if equal or additional benefits are available through CO2 sequestration. Coal bed methane (CBM) is associated with CO2 injection as an enhancement agent
11、, i.e. CO2-ECBM recovery, may present an attractive option for CCS, providing an economical solution to reduce CO2 emission from coal utilization processe4-5Commonly, CBM production relies on pressure depletion in a coal reservo ir which provides the primary recovery. Because the methane is adsorbed
12、 on the coal even at low pressures, this only allows a limited amount of the gas in place to be produced and typically 30-70% of the gas resource is never recovered6,CO2sequestration into coal seam can significantly improve this, permitting access to most of the remaining gas6-9.The CO2 has a strong
13、er affinity for the coal than methane and also a greater adsorption capacity, 2 to 10 times depending on coal rank at normal reservoir pressures10and displaces the methane which is then available for recovery. Thus CO2ECBM could recover the large majority of the methane-in-place, while also having t
14、he added benefit that a large volume of greenhouse gas is sequestered in the coal.There are many factors that affect the CBM and CO2-ECBM processes. One of the most important is the dynamic response of coal bed permeability to methane production and CO2 injection11.This comes about because of the st
15、ructural deformation of the coal, caused by coal matrix shrinkage or swelling as desorption or adsorption of gases occurs12-13, and volumetric changes that occur as the system stresses respond to water drainage and gas injection/drainage14. The extent of deformation determines the dynamic permeabili
16、ty and hence the transport of gases, influencing both the rate and capacity of the coal bed reservoir to accommodate CO2 storage and provide methane production. In particular, the interaction of deformation and fluid flow in coal beds is one of the major unknowns in CBM and CO2-ECBM processes.Within China, development of unconventional natural gas from coal has become an important part of energy policy, because of its increasing demand for
