准东低阶煤孔隙特征及对气体传质方式的影响

发布时间：2017-12-27 06:03

本文关键词：准东低阶煤孔隙特征及对气体传质方式的影响　出处：《煤炭学报》2016年04期 　论文类型：期刊论文

【摘要】：准东以褐煤和长焰煤为主,属于低灰、高挥发分煤;显微组分镜质组占优,惰质组次之,偶见腐泥组分;褐煤惰质组含量远大于长焰煤,且水分含量也高于后者。根据非润湿相的汞侵入毛管获得的孔隙分布和BET模型得出微小孔特征。在此基础上,并对甲烷在不同尺度孔隙中的传质方式进行探讨。结果显示:褐煤以中大孔为主,微小孔发育有限,主要储集空间孔径在0.1~2.0μm;长焰煤以微小孔为主,孔容主要来自微小孔,其单位孔容远小于褐煤。在多级孔隙配置的煤储层中划分出达西流、滑脱流、过渡流和分子扩散4种传质方式。褐煤孔隙连通性好,以达西流、滑脱渗流为主;长焰煤微小孔发育,各级孔隙连通性差,以达西流、过渡流及分子扩散为主。相比较而言,纳米级孔隙中吸附甲烷分子层厚及滑脱效应对长焰煤单孔渗流能力的影响更显著,其将会在气藏开发过程中对增产稳产提供有益的支持。
[Abstract]:The lignite long flame coal, which belongs to low ash, high volatile coal; macerals vitrinite dominated, inertinite group, occasionally sapropelinite; coal inertinite content is far greater than the long flame coal, and the moisture content is higher than the latter. The pore distribution and BET model obtained by mercury intrusion from the non wetting phase are obtained and the characteristics of small pores are obtained. On this basis, the mass transfer mode of methane in different pore sizes is discussed. The results show that lignite is mainly medium and large pores, and the development of micro pores is limited. The main storage space aperture is 0.1~2.0 m, and the long flame coal is mainly composed of tiny holes. Kong Rong mainly comes from tiny holes, and its unit Kong Rongyuan is smaller than lignite. 4 mass transfer modes of Darcy flow, slip flow, transition flow and molecular diffusion are divided in the coal reservoir with multilevel pore configuration. The pore connectivity of lignite is good, mainly based on Darcy flow and slip flow. The pores of long flame coal are well developed, and pore connectivity is poor at all levels. Darcy flow, transitional flow and molecular diffusion are the main factors. In comparison, the thickness and slippage effect of methane adsorbed on nanoscale pores have a more significant effect on the single hole percolation capacity of long flame coal, which will provide beneficial support for increasing production and stable production in the process of gas reservoir development.
【作者单位】：中国地质大学(北京)能源学院;中国地质大学(北京)煤层气国家工程中心煤储层实验室;
【基金】：中国地质调查局公益资助项目(1211302108025-4) 国家自然科学基金资助项目(41272175)
【分类号】：P618.1
【正文快照】： 准噶尔盆地东部隆起区,即准东,是准噶尔盆地中重要的一级构造单元。准东白垩系以下地震反射构造层呈凹凸相间、错落有致的棋盘状构造格局[1],包括五彩湾凹陷、木垒凹陷、梧桐窝子凹陷、吉木萨尔凹陷、纱帐断褶带及阜康断裂带东段等15个次级构造单元(图1),各次级构造受近东西和

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