Pore development patterns and gas control effects of No.8 deep coal seam of Ordos Basin
黄道军许浩虎建玲董煜焦鹏帅陈世达周国晓吴小卓武衡
HUANG Daojun;XU Hao;HU Jianling;DONG Yu;JIAO Pengshuai;CHEN Shida;ZHOU Guoxiao;WU Xiaozhuo;WU Heng
中国石油长庆油田分公司 勘探开发研究院中国地质大学(北京) 能源学院中国地质大学(北京) 煤层气开发利用国家工程中心煤储层物性实验室
鄂尔多斯盆地内部深部8号煤分布广泛,煤阶跨度大,是勘探的主要目的层。然而,目前对于盆地内部深部煤储层的孔隙发育规律及其控制因素缺乏系统、全面的理解,尤其是在深部煤储层孔隙发育模式及其控气作用方面尚未进行深入研究。基于盆地内14口探井岩心测试分析数据,系统分析了煤储层的孔隙发育特征和发育模式,并探讨了其分布规律和控气作用。结果表明:随着变质程度增加,研究区8号深部煤储层微孔和介孔的孔体积均明显增高,宏孔体积逐渐降低。其中,微孔主要为气孔,尤以孔径为0.4~0.9 nm孔隙最为发育,介孔相对不发育。宏孔由中−低变质程度煤发育的胞腔孔和屑间孔转变为中−高变质程度煤发育的内生裂隙。由北到南随着变质程度的增加(
The deep No.8 coal seam in Ordos Basin is widely distributed and spans a broad range of coal ranks, making it the primary target layer for exploration. However, a systematic and comprehensive understanding of the pore development patterns and their controlling factors in deep coal reservoirs within the basin is still lacking. In particular, there has been no in-depth research conducted on the pore development models and their gas-controlling effects in these deep coal reservoirs. Focusing on core test data from 14 exploratory wells within the basin, this study systematically examines the controlling factors and development patterns of pore structures in coal reservoirs and explores their distribution patterns and gas-controlling mechanisms. The results indicate that the pore volume of micropores and mesopores in the deep No.8 coal seam reservoirs of the study area increases significantly with the progression of coal metamorphism, while the pore volume of macropores decreases gradually. Micropores are predominantly composed of gas pores, with those in the 0.4−0.9 nm range being the most developed, whereas mesopores are relatively underdeveloped. Macropores are observed to transition from cellular pores and interclast pores in coal with low to medium metamorphic degrees to endogenetic fractures in coal with medium to high metamorphic degrees. From north to south with increasing metamorphic degree (
鄂尔多斯盆地8号煤变质程度孔隙发育模式控气作用
Ordos Basin;No.8 coal seam;metamorphic degree;pore development pattern;gas controlling mechanisms
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会