内蒙古自治区东部低阶煤层气地质力学特征与勘探开发技术  

Geomechanical characteristics and exploration and development technologies of low-rank coalbed methane in eastern Inner Mongolia

作　　者：陈立超 王生维[2] 孙钦平[3] 肖宇航 吕帅锋 CHEN Lichao;WANG Shengwei;SUN Qinping;XIAO Yuhang;LYU Shuaifeng(School of Resources and Environmental Engineering,Inner Mongolia University of Technology,Hohhot,Inner Mongolia 010051,China;Faculty of Earth Resources,China University of Geosciences,Wuhan,Hubei 430074,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;不详)

机构地区：[1]内蒙古工业大学资源与环境工程学院,内蒙古自治区呼和浩特市010051 [2]中国地质大学(武汉)资源学院 [3]中国石油勘探开发研究院

出　　处：《天然气工业》2024年第10期159-169,共11页Natural Gas Industry

基　　金：内蒙古自治区重点研发和成果转化计划项目“深部低透气性坚硬煤体瓦斯灾变防控关键技术研发”(编号:2023YFSH0005);内蒙古自治区科技创新引导奖励资金项目“海拉尔盆地深部煤层气资源赋存特征与开发关键技术研究”(编号:2022CXYD003)。

摘　　要：内蒙古自治区东部低阶煤层气资源丰富,具备规模开发的潜力,但区内煤层气勘探开发尚处于摸索阶段,特别是低阶煤层气地质力学特征、储层工程品质等研究程度不够,制约了煤层气资源的有效开发。为此,对内蒙古自治区东部霍林河盆地3口煤层气试验井的开发效果进行系统分析,明确了低阶煤层气资源评价及勘探开发中的关键问题,形成了一种低阶煤层气地质力学评价与勘探技术选择模式。研究结果表明:①煤储层渗透性低是该区低阶煤层气开发的关键制约地质因素,但煤层具有硬度高,刚度大,断裂韧度适中,脆性显著的力学品质,适合开展煤储层大规模体积压裂改造。②由于煤岩坚硬,洞穴完井造穴困难,不适合作为煤层气勘探开发主体技术;由于煤储层渗透性低,双U型井井控泄流面积小,试采效果差;直井水力压裂能沟通更多天然裂缝,增大了泄流面积,试采效果好。③低阶煤层气开发的关键是煤储层体积改造,水力压裂除实现储层增渗外,还具有渗吸驱替等功能,因此长水平井+体积压裂是内蒙古自治区东部低阶煤层气勘探开发的关键技术。结论认为,地质力学评价与勘探技术模式的形成为内蒙古自治区东部低阶煤层气资源的高效动用提供了科学依据。There are abundant low-rank coalbed methane(CBM)resources in the eastern Inner Mongolia,showing the potential of large-scale development.However,the CBM exploration and development in this area is still in the exploratory stage,especially the geomechanical characteristics and reservoir engineering quality of low-rank CBM are less researched,which restricts the effective development of CBM resources.In this paper,the development results of 3 CBM test wells in the Huolinhe Basin of eastern Inner Mongolia are analyzed systematically,the key problems in the resource evaluation,exploration and development of low-rank CBM are clarified,and a geomechanical evaluation and exploration technology selection model of low-rank CBM is established.The following results are obtained.First,the low permeability of coal reservoir is the key geological factor restricting the development of low-rank CBM in the eastern Inner Mongolia,but the mechanical quality of coal seam like high hardness,high stiffness,modest fracture toughness and significant brittleness makes large-scale volume fracturing suitable for coal reservoirs.Second,the coal rocks are hard enough to make it difficult to implement cave completion and cavitation,so it is not suitable to be the principal technology for CBM exploration and development.Due to the low permeability of coal reservoir,the double U-type well has a small well controlled discharge area,consequently the production test effect is poor.The vertical-well hydraulic fracturing can communicate more natural fractures to increase the discharge area,achieving a good production test effect.Third,the key to the development of low-rank CBM is volume fracturing,and hydraulic fracturing has the function of imbibition displacement besides increasing reservoir permeability,so long horizontal well+volume fracturing is the key technology for the exploration and development of low-rank CBM in the eastern Inner Mongolia.In conclusion,the geomechanical evaluation and exploration technology model provides a scientific bas

关 键 词：内蒙古自治区东部 霍林河盆地 低阶煤层气 地质力学 储层工程品质 水平井 体积压裂 

分 类 号：TE37[石油与天然气工程—油气田开发工程]