准噶尔盆地东部双井子地区平地泉组陆相页岩天然裂缝发育模式  

Development Model of Natural Fractures in Continental Shale of the Pingdiquan Formation in the Shuangjingzi Area,Eastern Junggar Basin

作　　者：杜晓宇 金之钧 曾联波 刘国平[1] 何文军[5] 杨森[5] 梁新平[1] 陆国青 Du Xiaoyu;Jin Zhijun;Zeng Lianbo;Liu Guoping;He Wenjun;Yang Sen;Liang Xinping;Lu Guoqing(Institute of Energy,Peking University,Beijing 100871,China;School of Earth and Space Sciences,Peking University,Beijing 100871,China;State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 100083,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China)

机构地区：[1]北京大学能源研究院,北京100871 [2]北京大学地球与空间科学学院,北京100871 [3]页岩油气富集机理与有效开发国家重点实验室,北京100083 [4]中国石油大学(北京)地球科学学院,北京102249 [5]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000

出　　处：《地球科学》2024年第9期3264-3275,共12页Earth Science

基　　金：国家自然科学基金项目(Nos.42090025,42302148);中国石油科技创新基金项目(No.2023DQ02-0103)。

摘　　要：准噶尔盆地东部二叠系平地泉组页岩油资源量丰富,天然裂缝作为烃类重要的储集空间和流体运移通道,直接影响页岩油的勘探开发效果.基于对双井子地区野外露头的精细刻画,分析了平地泉组天然裂缝的发育特征和控制因素,并在此基础上讨论了裂缝的分布模式.结果表明,准噶尔盆地双井子地区平地泉组天然裂缝包括层内裂缝、穿层裂缝和顺层裂缝3种类型,其中层内裂缝发育程度最高,分布最为广泛.天然裂缝发育受岩性、岩石力学层和构造影响,主要表现为:(1)不同岩性裂缝发育程度不同,粉砂岩和凝灰质粉砂岩中的裂缝最为发育;(2)岩石力学层控制了层内裂缝的发育,力学层厚度越小,裂缝发育程度越高;(3)断层附近存在裂缝发育带,距离断层面越近、断层上盘以及端部的裂缝越发育.不同岩层和构造部位的裂缝类型和分布特征差异较大,层内裂缝多发育在脆性较大的岩石力学层中,穿层裂缝可以切穿多套岩层,顺层裂缝则主要发育在泥质含量较高的岩层内.裂缝的形成和分布与砂岩和泥岩夹层之间的岩石力学性质差异以及泥岩夹层的厚度密切相关.The Permian Pingdiquan Formation shale oil resources in the eastern Junggar basin are abundant,however,the exploration and development of shale oil are hindered since natural fractures serve as important storage spaces and fluid migration channels for hydrocarbons there.In this paper,the development characteristics and controlling factors of natural fractures in the Pingdiquan Formation were analyzed through detailed characterization of outcrops in the Shuangjizi area,and the distribution patterns of fractures were discussed based on these findings.The results show that the natural fractures in the Pingdiquan Formation in the Shuangjizi area of the Junggar basin include three types:bed-bounded fractures,unbounded fractures,and bed-parallel fractures,with the bed-bounded fractures being the most extensively developed and distributed.The development of natural fractures is influenced by lithology,rock mechanics layers,and structures,which is mainly manifested in:(1)the degree of development of fractures in different lithologies varies,with the most developed fractures occurring in siltstone and tuffaceous siltstone;(2)the development of fractures is controlled by rock mechanics layers,with the degree of development of natural fractures being higher in thinner rock mechanical stratigraphy;and(3)there is a fracture development zone near faults,with the degree of development of fractures being higher closer to the fault plane,on the footwall and at the end of the fault.The types and distribution characteristics of fractures differ greatly in different rock layers and structural positions,with intraformational open fractures being mostly developed in rock mechanical stratigraphy with greater brittleness,transformational shear fractures can cut through multiple sets of rock layers,and bed-parallel shear fractures mainly develop in rock layers with higher mud content.The formation and distribution of fractures are closely related to the differences in rock mechanics properties between sandstone and mudstone interbeds,as

关 键 词：天然裂缝 控制因素 分布模式 陆相页岩 平地泉组 准噶尔盆地 石油地质. 

分 类 号：P618.13[天文地球—矿床学]