This paper investigates the permeability change caused by reactions with different minerals in coal after injecting carbon dioxide for providing an experimental support for increasing the flow conductivity of the coal reservoir, and also for the improvement of the permeability based on the test of the nitrogen adsorption, the mineral composition and the permeability of medium-high rank coal (Tunlan mine and Sihe mine). The permeability change model is built based on the nonlinear regression analysis of the initial permeability, the reaction time and the improved permeability. The results indicate that the permeability of medium-high rank coal increases first and then decreases with time after injecting the carbon dioxide as a result of CO2-water-rock interaction; The permeability of the Sihe coal samples reaches the maximum value first, followed by the Tunlan coal samples, and the improving effect of permeability of the Sihe coal samples is shown to be better than that of the Tunlan coal samples; For the best improvements, the initial permeability is about 0.2×10-3 to 0.4×10-3 μm2; Finally, the reliability of the mathematical model is verified.
[1] 唐书恒, 杨起, 汤达祯, 等. 注气提高煤层甲烷采收率机理及实验研究[J]. 石油实验质, 2002, 24(6):545-549. Tang Shuheng, Yang Qi, Tang Dazhen, et al. Study on the experiment and mechanism of raising the recovery ratio of coal bed methane by gas injection[J]. Petroleum Geology & Experiment, 2002, 24(6):545-549.
[2] White C M, Smith D H, Jones K L, et al. Sequestration of carbon diox-ide in coal with enhanced coal bed methane recoverys:A review[J]. En-ergy & Fuels, 2005, 19(3):659-724.
[3] 梁卫国, 吴迪, 赵阳升. CO2驱替煤层CH4试验研究[J]. 岩石力学与工程学报, 2010, 29(4):665-673. Liang Weiguo, Wu Di, Zhao Yangsheng. Experimental study of coal beds methane replacement by carbon dioxide[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(4):665-673.
[4] Zuber M D. Production characteristics and reservoir analysis of coalbed methane reservoirs[J]. International Journal of Coal Geology, 1998, 38(1-2):27-45.
[5] Reznik A A, Aingh P K, Foley W L. Analysis of the effect of CO2 injec-tion on the recovery of in-situ methane from Bituminous coal:An exper-imental simulation[J]. SPE Journal, 1984, 24(5):521-528.
[6] 唐书恒, 马彩霞, 叶建平, 等. 注二氧化碳提高煤层甲烷采收率的实验模拟[J]. 中国矿业大学学报, 2006, 35(5):607-611. Tang Shuheng, Ma Caixia, Ye Jianping, et al. A modeling experiment of enhancing oalbed methane recovery by carbon dioxide injection[J]. Jour-nal of China University of Mining & Technology, 2006, 35(5):607-611.
[7] Gayer R, Harris I. Nature and origin of fracture in Permian coals from the Bowen Basin Queensland, Australia[J]. Coal Bed Methane and Coal Geology, 2006, 109:133-150.
[8] 傅雪海, 秦勇, 韦重韬. 煤层气地质学[M]. 徐州:中国矿业大学出版社, 2007. Fu Xuehai, Qin Yong, Wei Chongtao. Coal bed gas geology[M]. Xu-zhou:China University of Mining and Technology Press, 2007.
[9] 陶树, 王延斌, 汤达祯, 等. 沁水盆地南部煤层孔隙-裂隙系统及其对渗透率的贡献[J]. 高校地质学报, 2012, 18(3):522-527. Tao Shu, Wang Yanbin, Tang Dazhen, et al. Pore and fracture systems and their contribution to the permeability of coal reservoirs in Southern Qinshui Basin[J]. Geological Journal of China Universities, 2012, 18(3):522-527.
[10] 高莎莎, 王延斌, 倪小明, 等. CO2注入煤层中煤储层渗透率变化规律研究[J]. 煤炭科学技术, 2014, 42(2):54-57. Gao Shasha, Wang Yanbin, Ni Xiaoming, et al. Study on laws of coal seam permeability change in CO2-ECBM[J]. Coal Science and Technol-ogy, 2014, 42(2):54-57.
[11] 叶建平, 冯三利, 范志强, 等. 沁水盆地南部注CO2提高煤层气采出率微型先导性试验研究[J]. 石油学报, 2007, 28(4):77-80. Ye Jianping, Feng Sanli, Fan Zhiqiang, et al. Micro-pilot test for en-hanced coal bed methane recovery by injecting carbon dioxide in south part of Qinshui Basin[J]. Acta Petroleum Sinica, 2007, 28(4):77-80.
[12] 叶建平, 张兵, Sam Wong. 山西沁水盆地柿庄北区块3#煤层注入埋藏CO2提高煤层气采收率试验和评价[J]. 中国工程科学, 2012, 14(2):38-44. Ye Jianping, Zhang Bing, Sam Wong. Test of and evaluation on eleva-tion of coalbed methane recovery ratio by injecting and burying CO2 for 3# coal seam of north section of Shizhuang, Qingshui Basin,Shanxi[J]. Engineering Sciences, 2012, 14(2):38-44.
[13] 降文萍, 崔永君. 深部煤层封存CO2的地质主控因素探讨[J]. 中国煤炭地质, 2010, 22(11):1-6. Jiang Wenping, Cui Yongjun. A discussion on main geologic control-ling factors of CO2 sequestration in deep coal seams[J]. Coal Geology of China, 2010, 22(11):1-6.
[14] 岳立新, 孙可明, 郝志勇. 超临界CO2提高煤层渗透性的增透规律研究[J]. 中国矿业大学学报, 2014, 43(2):319-324. Yue Lixin, Sun Keming, Hao Zhiyong. Study on increased permeabili-ty law of coal seam by supercritical CO2[J]. Journal of China Universi-ty of Mining & Technology, 2014, 43(2):319-324.
[15] 孔维安, 郑水林, 白春华, 等. 膨润土在水溶液中的膨胀性能研究[J]. 非金属矿, 2010, 33(1):42-44. Kong Weian, Zheng Shuilin, Bai Chunhua, et al. Study on swelling performance of bentonite in aqueous solution[J]. Non-Metallic Mines, 2010, 33(1):42-44.
[16] Robert J R, Tamer K, James L P. Experimental Investigation of CO2-brine-rock interactions at elevated temperature and pressure:Implica-tions for CO2 sequestration in deep saline aquifers[J]. Fuel Processing Technology, 2005, 86:1581-1597.
