鄂尔多斯盆地延长组7段3亚段页岩型页岩油储层特征及勘探方向  

Reservoir characteristics and exploration direction of pure shale-type shale oil in the 3rd sub-member, 7th Member of Yanchang Formation in Ordos Basin

作　　者：李士祥[1] 郭芪恒 周新平[1] 刘元博 刘江艳[1] Li Shixiang;Guo Qiheng;Zhou Xinping;Liu Yuanbo;Liu Jiangyan(Research Institute of Exploration and Development,Petro ChinaChangqing Oilfield Company,Shaanxi Xi'an 710018,China;College of Geosciences,China University of Petroleum,Beijing 102249,China;No.1 Oil Production Plant,PetroChina Changqing Oilfield Company,Shaanxi Yan'an 716000,China)

机构地区：[1]中国石油长庆油田公司勘探开发研究院,陕西西安710018 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油长庆油田公司第一采油厂,陕西延安716000

出　　处：《石油学报》2022年第11期1509-1519,共11页Acta Petrolei Sinica

基　　金：中国石油天然气集团有限公司前瞻性基础性研究重大科技项目“鄂尔多斯盆地页岩油勘探开发理论与关键技术研究”(2021DJ1806);国家重点基础研究发展计划(973)项目“淡水湖盆细粒沉积与富有机质页岩形成机理”(2014CB239003)资助。

摘　　要：鄂尔多斯盆地三叠系延长组7段(长7段)泥页岩发育,针对其内部富集的页岩型页岩油尚未取得勘探进展,仅在少量直井的试油阶段突破出油关,但试采效果整体较差。系统梳理了长7段3亚段(长7_(3 )亚段)泥页岩的岩石学、地球化学和储层特征,优选页岩型页岩油的富集有利参数,明确了其成藏条件、勘探方向及潜力。相较于暗色泥岩,长7_(3 )亚段的黑色页岩表现为多类型纹层频繁发育、有机质丰度高、生油母质类型好、主生烃期早、含油率高的特征,是页岩型页岩油勘探的有利岩性。受水平页理缝和陆源长英质、凝灰质等相对高孔高渗纹层的复合影响,黑色页岩的水平渗透率普遍高于垂直渗透率。长7_(3 )亚段泥页岩的储集空间以刚性矿物支撑的粒间孔、粒内溶蚀孔、黏土矿物晶间孔及黄铁矿晶间孔为主,页理缝和超压微裂缝较发育。"有机质+陆源长英质纹层"、"有机质+凝灰质纹层"二元纹层组合与页理缝构成的复合单元对页岩油赋存最为有利。总有机碳(TOC)含量为4%~14%、镜质体反射率R_(o)>0.8%、页理及纹层发育、脆性矿物含量高的长英质黑色页岩是长7_(3 )亚段页岩型页岩油的有利勘探目标,黑色页岩厚度相对较大、有机质丰度适中的马岭—华池深洼区是页岩型页岩油勘探的Ⅰ类有利区。鄂尔多斯盆地长7_(3 )亚段页岩型页岩油资源丰富,有望成为盆地非常规石油勘探开发的现实性重大战略接替新领域。Mudstone and shale are developed in 7th Member of the Triassic Yanchang Formation in Ordos Basin,and there is no progress in the exploration of pure shale-type shale oil enriched inside.Oil has been produced only from a few vertical wells in the well testing stage,and the overall pilot production effect is poor.The paper systematically summarizes the petrological,geochemical and reservoir characteristics of mud shale in the 3rd sub-member of 7th Member of Yanchang Formation(Chang 7_(3 ) sub-member),optimizes the favorable parameters for the enrichment of shale type shale oil,and determines its hydrocarbon accumulation conditions,exploration direction and potential.Compared with dark mudstone,the black shale in Chang 7_(3 ) sub-member is characterized by frequent development of multi-type laminae,high abundance of organic matters,good type of parent material of source rock,early main hydrocarbon generation stage and high oil content,which are favorable lithologies for the exploration of pure shale-type shale oil.The horizontal permeability of black shale is generally higher than its vertical permeability due to the complex effect of horizontal lamellation fractures and high porosity and high permeability laminae such as terrigenous felsic and tuffaceous sandstone.The reservoir space of mud shale in Chang 7_(3 ) sub-member is mainly composed of intergranular pores,intragranular denudation pores,clay mineral intercrystalline pores and pyrite intercrystalline pores supported by rigid minerals;lamellation fractures and overpressure microfractures are developed.The composite element composed of the binary laminae combination of"organic matters+terrigenous felsic lamina"and"organic matters+tuffaceous lamina"and lamellation fractures is the most favorable for the occurrence of shale oil.Black felsic shale with the total organic carbon(TOC)content of 4%~14%,vitrinite reflectance R_(o)>0.8%,development of lamellation and laminae as well as high content of brittle minerals is a favorable exploration target for pure-shale ty

关 键 词：鄂尔多斯盆地 页岩型 页岩油 长73亚段 勘探潜力 

分 类 号：TE122.2[石油与天然气工程—油气勘探]