基于钻井液污染的煤储层类型划分及其开发特征  

Classification and development characteristics of coal reservoir types based on drilling fluid pollution

作　　者：缪欢 王延斌[1] 韩文龙[1] 吴翔[2] 赵石虎 李建红 MIAO Huan;WANG Yanbin;HAN Wenlong;WU Xiang;ZHAO Shihu;LI Jianhong(School of Geosciences and Surveying Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;China United Coalbed Methane Co.,Ltd.,Beijing 100026,China)

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [2]中联煤层气有限责任公司,北京100026

出　　处：《中国矿业》2021年第6期214-220,共7页China Mining Magazine

基　　金：国家科技重大专项项目资助(编号:2017ZX05064003-001,2016ZX05066001-002)。

摘　　要：为了研究煤储层在钻井液污染下的煤层气开发特征,以沁水盆地南部柿庄南区块为研究对象,基于渗透率损伤比计算模型,计算钻井液对煤储层的伤害程度,并在此基础上划分储层类型,分析不同煤储层的黏土含量和碎粒煤厚度占比,结合压裂资料和排采资料,分析钻井液污染后不同煤储层钻井的煤层气开发特征。研究结果表明,基于煤储层的污染程度,煤储层可划分为轻度污染、较重污染和严重污染三种类型。其中,严重污染煤储层灰分含量均值为17.69%,碎粒煤厚度占比均值为76.47%,压裂施工时,钻井油压曲线会出现大幅度的下降,稳定时所需破碎压力小,排采时单相水流阶段时间长;轻度污染型储层的灰分含量均值为10.07%,碎粒煤厚度占比均值为34.85%,油压曲线整体比较稳定,下降幅度不明显,单相水流阶段时间短;较重污染型储层的灰分含量均值为13.04%,碎粒煤厚度占比均值为59.65%,油压曲线与易伤害型钻井类似,但下降幅度小于易伤害钻井,稳定时所需的破碎压力高于易伤害型储层钻井,排采时单相水流阶段时间介于上述两者之间。In order to study the coalbed methane development characteristics of coal reservoir under the pollution of drilling fluid,taking Shizhuangnan block in the south of Qinshui basin as the research object.Based on the calculation model of permeability damage ratio,the damage degree of drilling fluid to coal reservoir is calculated.On this basis,the reservoir types are divided,and the clay content and the proportion of broken coal thickness of different coal reservoirs are analyzed.The development characteristics of coalbed methane in different coal reservoirs after drilling fluid pollution are analyzed.The results show that the coal reservoir can be divided into three types:light pollution,heavy pollution and serious pollution.The average ash content of the seriously polluted coal reservoir is 17.69%,and the average proportion of the thickness of the broken coal is 76.47%.During the fracturing operation,the drilling oil pressure curve will decline greatly,the crushing pressure is small when it is stable,and the single-phase flow stage time is long when it is discharged.The average ash content of slightly polluted reservoir is 10.07%,and the average thickness of crushed coal is 34.85%.The overall oil pressure curve is relatively stable,the decline range is not obvious,and the single-phase flow stage time is short.The average ash content of the heavily polluted reservoir is 13.04%,and the average proportion of the thickness of the broken coal is 59.65%.The oil pressure curve is similar to that of the easily damaged drilling,but the decline range is smaller than that of the easily damaged drilling,the crushing pressure required for stability is higher than that of the easily damaged reservoir drilling,and the single-phase water flow stage time during drainage is between the two.

关 键 词：柿庄南区块 煤储层类型 钻井液 煤层气开发 

分 类 号：TE254[石油与天然气工程—油气井工程] P634[天文地球—地质矿产勘探]