鄂尔多斯盆地东缘大吉地区山23亚段海陆过渡相页岩气富集控制因素  

Controlling factors of marine and continental transitional shale gas enrichment in Shan23 sub-member,Daji area,eastern margin of Ordos Basin

作　　者：罗力元 李勇[1,2,3,4] 李树新 何清波[4,6,7] 陈世加 李翔 李星涛[5] 路俊刚 肖正录 尹相东 LUO Liyuan;LI Yong;LI Shuxin;HE Qingbo;CHEN Shijia;LI Xiang;LI Xingtao;LU Jungang;XIAO Zhenglu;YIN Xiangdong(National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;Sichuan Natural Gas Geology Key Laboratories,Chengdu 610500,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;Key Laboratory of Unconventional Natural Gas Evaluation and Development in Complex Tectonic Areas,Ministry of Natural Resources,Guiyang 550000,China;PetroChina Coalbed Methane Co.,Ltd.,Beijing 100028,China;Guizhou Engineering Research Institute of Oil&Gas Exploration and Development,Department of Natural Resources of Guizhou Province,Guiyang 550000,China;The Laboratory of Guizhou Province of Intelligent Development and Efficient Utilization of Energy,Guiyang 550000,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室·西南石油大学,四川成都610500 [2]天然气地质四川省重点实验室,四川成都610500 [3]西南石油大学地球科学与技术学院,四川成都610500 [4]自然资源部复杂构造区非常规天然气评价与开发重点实验室,贵州贵阳550000 [5]中石油煤层气有限责任公司,北京100028 [6]贵州省油气勘查开发工程研究院,贵州贵阳550000 [7]贵州省能源智能开发与高效利用实验室,贵州贵阳550000

出　　处：《天然气地球科学》2025年第3期554-566,共13页Natural Gas Geoscience

基　　金：中国石油—西南石油大学创新联合体科技合作项目(编号:2020CX030000);自然资源部复杂构造区非常规天然气评价与开发重点实验室开放课题基金项目(编号:NRNG-202401);中国石油科技创新基金项目(编号:2022DQ02-0105)联合资助.

摘　　要：海陆过渡相页岩气是继海相页岩气商业开发后的又一重要战略接替资源。海陆过渡相页岩具有非均质性强、沉积相变快、岩性组合复杂的特征,海相页岩气地质理论不能完全适用于海陆过渡相,海陆过渡相页岩气富集控制因素认识不清,制约了高效勘探与开发。以鄂尔多斯盆地东缘大吉地区山23亚段页岩为例,通过显微组分、气体吸附、高压压汞、突破压力、扩散系数和覆压孔渗等实验分析,开展了页岩地球化学特征和储层特征研究,明确了海陆过渡相页岩气富集控制因素。结果表明:山23亚段海陆过渡相页岩具有高有机质丰度、过成熟度和以腐殖型为主的特征,孔隙类型主要以无机矿物孔为主,有机孔和微裂缝相对较少。明确了海陆过渡相页岩气富集主要受有机质丰度、孔径大小、岩性组合和构造演化共同控制:高有机质丰度增强了页岩的吸附能力,微孔为甲烷气体分子提供更多的吸附点位,页—煤和页—灰组合有利于页岩气滞留原位富集,平稳的构造和适当的埋深有利于页岩气保存,建立了大吉地区海陆过渡相页岩气储集能力和封闭能力的演化模式。研究可以为海陆过渡相页岩气甜点预测和先导试验区快速建产提供地质理论指导。Marine-terrestrial transitional shale gas is another important strategic replacement resource after the commercial development of marine shale gas.Marine-terrestrial transitional shale has the characteristics of strong heterogeneity,rapid depositional phase change,and complex lithology combination.Geological theories of marine shale gas can not be fully applied to marine-continental transitional facies,and the controlling factors of shale gas enrichment in the marine and continental transition facies are not well understood,which restricts ef⁃ficient exploration and development.Taking the Shan23 sub-member shale in the Daqi area of the eastern margin of the Ordos Basin as an example,the geochemical characteristics and reservoir characteristics of shale were in⁃vestigated through experiments such as microscopic analysis,gas adsorption,high-pressure mercury intrusion,breakthrough pressure,diffusion coefficient,and overburden pore permeability.This research elucidated the controlling factors of shale gas accumulation in marine-continental transitional facies.The research results indi⁃cate that the Shan23 sub-member shale in the marine-continental transitional facies exhibits high organic matter abundance,high maturity,and predominantly humic-type characteristics.The pore types are mainly dominated by inorganic mineral pores,with relatively fewer organic pores and microfractures.The conclusion suggests that the enrichment of marine-continental transitional facies shale gas is primarily controlled by a combination of or⁃ganic matter abundance,pore size,lithological composition,and structural evolution.High organic matter abun⁃dance enhances the adsorption capacity of shale,providing more adsorption sites for methane gas molecules in micropores.The combination of shale-coal and shale-ash favors the in-situ enrichment of shale gas.Stable tec⁃tonics and appropriate burial depth facilitate the preservation of shale gas.Furthermore,an evolutionary model for the storage and sealing capacity of marine-continental

关 键 词：页岩气 海陆过渡相 岩性组合 富集机理 大宁—吉县地区 鄂尔多斯盆地 

分 类 号：TE121.11[石油与天然气工程—油气勘探]