Dynamic-Change Laws of the Porosity and Permeability of Low-to Medium-Rank Coals under Heating and Pressurization Treatments in the Eastern Junggar Basin,China  

作　　者：Gang Wang Yong Qin Jian Shen Shuyuan Chen Beibei Han Xiaoting Zhou 

机构地区：[1]Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education,China University of Mining and Technology,Xuzhou 221116,China [2]Key Laboratory of Resource Survey and Research of Hebei Province,Hebei University of Engineering,Handan 056038,China [3]China Chemical Geology and Mine Bureau,Beijing 100013,China [4]Institute of Technology,East China Jiaotong University,Nanchang 330100,China

出　　处：《Journal of Earth Science》2018年第3期607-615,共9页地球科学学刊（英文版）

基　　金：funded by the National Natural Science Fundation of China(Nos.41672149,41302131,41362009);the Key Project of the National Natural Science Foundation of China(No.41530314);the Scientific Research Foundation of the Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education,China University of Mining and Technology,(No.2017-001);the National Science and Technology Major Project of the Ministry of Science and Technology of China(Nos.2016ZX05044-002,2011ZX05033,2011ZX05034);the Fundamental Research Funds for the Central Universities(No.2012QNB32)

摘　　要：Deep coalbed methane exists in high-temperature and high-pressure reservoirs. To elucidate the dynamic-change laws of the deep coal reservoir porosity and permeability characteristics in the process of coalbed methane production, based on three pieces of low- to medium-rank coal samples in the eastern Junggar Basin, Xinjiang, we analyse their mercury-injection pore structures. We measured the porosity and permeability of the coal samples at various temperatures and confining pressures by high-temperature and confining pressure testing. The results show that the porosity of a coal sample decreases exponentially with increasing effective stress. With increasing temperature, the initial porosity increases for two pieces of relatively low-rank coal samples. The increased rate of porosity decreases with increasing confining pressure. With increasing temperature, the initial porosity of a relatively high-rank coal sample decreases, and the rate of change of the porosity become faster. An exponential relationship exists between the porosity and permeability. With increasing coal rank, the initial porosity and permeability decrease. The change rate of the permeability decreases with increasing porosity.Deep coalbed methane exists in high-temperature and high-pressure reservoirs. To elucidate the dynamic-change laws of the deep coal reservoir porosity and permeability characteristics in the process of coalbed methane production, based on three pieces of low- to medium-rank coal samples in the eastern Junggar Basin, Xinjiang, we analyse their mercury-injection pore structures. We measured the porosity and permeability of the coal samples at various temperatures and confining pressures by high-temperature and confining pressure testing. The results show that the porosity of a coal sample decreases exponentially with increasing effective stress. With increasing temperature, the initial porosity increases for two pieces of relatively low-rank coal samples. The increased rate of porosity decreases with increasing confining pressure. With increasing temperature, the initial porosity of a relatively high-rank coal sample decreases, and the rate of change of the porosity become faster. An exponential relationship exists between the porosity and permeability. With increasing coal rank, the initial porosity and permeability decrease. The change rate of the permeability decreases with increasing porosity.

关 键 词：high-temperature and confining pressure coalbed methane reservoir POROSITY permeability dynamic change. 

分 类 号：P618.13[天文地球—矿床学]