摘要
深部煤岩的储层特征对深部煤岩气的富集、扩散具有控制作用。本文选取靖边地区J、Q井8#煤作为研究对象,除常规煤质和地化参数外,基于扫描电镜、气体吸附、高压压汞、核磁共振等测试手段对深部煤岩孔隙结构联合表征,并结合煤质和地球化学资料,探讨深部煤岩孔隙发育的控制因素。研究结果表明:煤样平均孔隙度为5.3%,平均渗透率为3.32×10^(-3)μm^(2),孔隙类型以气孔、胞腔孔、铸模孔为主,并含微裂缝、静压裂缝;多方法联合表征结果表明,煤孔体积的分布呈“微孔+宏孔双峰态”分布特征,其中微孔体积占比63.67%,介孔体积占比5.12%,宏孔体积占比31.2%,比表面积分布呈单峰,连通性较好,有利于游离态煤岩气运移;煤岩储层孔隙发育主要受变质程度、显微组分和灰分等因素联合控制,随着镜质组含量、变质程度和灰分含量的增加,煤岩储层微孔和介孔占比明显增加。厘清研究区本溪组8#煤孔隙结构特征及控制因素,可为煤岩气有利层位优选和勘探开发提供地质依据。
The reservoir characteristics of deep coal rock have a controlling effect on the enrichment and diffusion of deep coal-rock gas.In this paper,coal No.8 from Wells J and Q in Jingbian area was selected as the research object.In addition to conventional coal quality and geochemical parameters,the pore structure of deep coal rock was characterized based on scanning electron microscopy,gas adsorption,high pressure mercury injection,nuclear magnetic resonance and other testing methods,and the control factors of deep coal rock pore development were discussed in combination with coal quality and geochemical data.The results show that:The average porosity of coal samples is 5.3%and the average permeability is 3.32 mD.Pore types are dominated by pores,cell pores and mold pores,and contain micro-cracks and hydrostatic cracks.The combined characterization results of multiple methods show that the pore volume distribution of coal is micropore+macropore bimodal distribution,wherein micropore volume accounts for 63.67%,mesoporous volume accounts for 5.12%,and macropore volume accounts for 31.2%.The specific surface area distribution is unimodal,and the connectivity is good,which is beneficial to the free coal,rock and gas transport.The pore development of coal-rock reservoir is mainly controlled by metamorphic degree,maceral and ash content.With the increase of vitrinite content,metamorphic degree and ash content,the proportion of micropores and mesoporous pores in coal-rock reservoir increases significantly.Clarifying the pore structure characteristics and controlling factors of Benxi Formation coal No.8 in the study area can provide geological basis for the selection of favorable strata and exploration and development of coal-rock gas.
作者
侯雨庭
李勇
张涛
喻健
张海峰
王龙
胡爱平
林达飞
何智同
赵云霄
陈世加
HOU Yuting;LI Yong;ZHANG Tao;YU Jian;ZHANG Haifeng;WANG Long;HU Aiping;LIN Dafei;HE Zhitong;ZHAO Yunxiao;CHEN Shijia(PetroChina Changqing Oilfield Company,Xi′an,Shaanxi,710018,China;College of Earth Science and Technology,Southwest Petroleum University,Chengdu,Sichuan,610500,China;National Key Laboratory of Reservoir Geology and Development Engineering,Southwest Petroleum University,Chengdu,Sichuan,610500,China;Exploration Department of Changqing Oilfield Branch,PetroChina,Xi′an,Shaanxi,710018,China)
出处
《钻采工艺》
北大核心
2025年第3期189-196,共8页
Drilling & Production Technology
基金
中国石油天然气股份有限公司科技专项“深地煤岩气成藏理论与效益开发技术研究”(编号:2024DKT09)。
关键词
煤岩气
本溪组
煤储层
孔隙结构
鄂尔多斯盆地
coal-rock gas
Benxi Formation
coal reservoir
pore structure
Ordos Basin
