坳陷湖盆古地貌对沉积体系的控制作用——以准噶尔盆地中部侏罗系三工河组二段一砂组为例  

Analysing the controlling effect of palaeogeomorphology on sedimentary systems:a case study of the Jurassic Sangonghe Formation in the central Junggar basin

作　　者：厚刚福 王力宝 宋兵 曾德龙[2] 贾开富[2] 窦洋 李亚哲 彭博 郭华军 邹志文 司学强 HOU Gangfu;WANG Libao;SONG Bing;ZENG Delong;JIA Kaifu;DOU Yang;LI Yazhe;PENG Bo;GUO Huajun;ZOU Zhiwen;SI Xueqiang(PetroChina Hangzhou Research Institute of Geology,Hangzhou,Zhejiang 310023,China;Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China)

机构地区：[1]中国石油杭州地质研究院,浙江杭州310023 [2]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：《地质学报》2022年第7期2519-2531,共13页Acta Geologica Sinica

基　　金：国家科技重大专项“大型岩性油气藏形成主控因素与有利区带评价”(编号2017ZX05001-002);“岩性地层油气藏成藏规律、关键技术及目标评价”(编号2017ZX05001);中国石油天然气股份有限公司科技项目“准噶尔盆地油藏富集规律及勘探技术研究与应用”(编号2017E-0401);“大型陆相盆地砂体类型及控藏机制”(编号2019B-0309)联合资助的成果。

摘　　要：为了明确坳陷湖盆古地貌对沉积体系的控制作用,认识沉积体系展布规律,优选下一步勘探领域,以准噶尔盆地中部侏罗系三工河组二段为例,采用地层厚度法恢复了古地貌,细化了古地貌单元,并通过岩芯观察,识别了沉积微相,在此基础上,通过古地貌单元与沉积微相叠合分析,提出了坳陷湖盆沉积期古地貌对沉积体系、沉积微相和岩性圈闭的形成具有重要的控制作用。研究结果表明:准噶尔盆地中部三工河期为隆凹相间的古地貌格局,具有水下古低凸、水下古沟槽、古坡折和水下古平台等4类古地貌单元,发育湖泊-三角洲沉积体系,可进一步识别出水下分流河道、分流间湾、席状砂和砂质碎屑流微相。水下古沟槽充填水下分流河道微相砂体,水下古低凸主体部位发育分流间湾相泥岩,古坡折之下的水下古平台发育砂质碎屑流砂体。水下古低凸翼部发育的水下分流河道砂体向低凸方向超覆尖灭,水下古平台发育的砂质碎屑流砂体呈“泥包砂”结构,储层性质较优,岩性圈闭条件好,成藏条件优越,为下一步最有利勘探领域。This study,investigating the second member of the Jurassic Sangonghe Formation in the hinterland of Junggar basin as an example,aims to clarify the control of paleogeomorphology on sedimentary systems in a depression basin,implement the distribution of sedimentary systems,and optimize exploration field in future.The paleogeomorphology was restored by using the stratum thickness method,the paleogeomorphic units were refined,and the sedimentary microfacies were identified by core observation.On this basis,through the superposition analysis of paleogeomorphic units and sedimentary microfacies,it is proposed that the underwater distributary channel sand body developed in the underwater ancient trench that was conducive to the formation of updip pinch-out lithologic traps.The sandy clastic flow sandbody developed in the underwater paleo-platform area favorable for the formation of lenticular lithologic traps.The results show that:the hinterland of Juggar basin during the Sangonghe period had a paleogeomorphic pattern of uplift and depression alternation,which had four types of paleogeomorphic units:underwater paleo low uplift,underwater paleo groove,paleo slope break and underwater paleo platform.The delta sedimentary system that developed has the characteristics of relatively fine grain size,relatively deep water body and far delta extension.Sandy clastic flow sandbodies are developed in the Modong,the Shawan and the Fukang platforms,and underwater distributary channel sandbody are developed in the wings of Shinan low convex,Xiayan low convex,Sangequan low convex,Shidong low convex,Dinan low convex,Zhengshacun low convex and Mosuowan low convex,with good reservoir and lithologic trap conditions and favorable reservoir forming conditions,which are the most favorable exploration areas in future.

关 键 词：准噶尔盆地 侏罗系 三工河组 古地貌 沉积体系 岩性圈闭 

分 类 号：P618.13[天文地球—矿床学]