鄂尔多斯盆地乌审旗古隆起与中央古隆起形成演化及其对油气的控制作用  

Formation and evolution of the Wushenqi and Central paleo-uplifts,Ordos Basin and their control on hydrocarbon accumulation

作　　者：陈平 李维 周义军 裴文瑞 于小伟 韩伟 梁国平 路鹏程 王雷 CHEN Ping;LI Wei;ZHOU Yijun;PEI Wenrui;YU Xiaowei;HAN Wei;LIANG Guoping;LU Pengcheng;WANG Lei(Changqing Branch of Geophysical Research Institute,BGP Inc.,CNPC,Xi’an,Shaanxi 710021,China)

机构地区：[1]中国石油东方地球物理勘探有限责任公司研究院长庆分院,陕西西安710021

出　　处：《石油与天然气地质》2024年第6期1653-1664,共12页Oil & Gas Geology

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目(2022KT0103);中国石油东方地球物理勘探有限责任公司油气勘探新领域综合研究项目(2023YQX10111)。

摘　　要：利用鄂尔多斯盆地最新二维格架大剖面,结合高精度三维地震资料与钻井资料,重新对盆地乌审旗古隆起与中央古隆起进行了系统研究,并再次厘定了盆地寒武纪—奥陶纪沉积构造格局,明确了古隆起变迁演化历程。研究结果表明:①证实奥陶纪乌审旗古隆起具有“北高南低”的构造格局。②乌审旗古隆起对寒武系沉积控制作用明显,而中央古隆起对奥陶系沉积控制作用明显。③三维地震资料证实怀远运动期(甚至怀远运动之前),乌审旗古隆起相较中央古隆起遭受了更为严重的暴露剥蚀,前奥陶纪乌审旗古隆起更高。④乌审旗古隆起活动期为前寒武纪,逐步消隐至奥陶纪基本不再活动。中央古隆起隆升于奥陶系马家沟组沉积前,在此之前盆地西南部的庆阳古隆起与北部的伊盟古隆起独立活动,马家沟组沉积前隆升形成北达伊盟古隆起、南连庆阳古隆起的“L型”中央古隆起。⑤两大古隆起共同控制了沉积相带分布,形成了盆地中、东部有利储-盖组合,前奥陶纪风化壳型气藏、中部岩性气藏及东部断缝型气藏可能是有利勘探领域。Using the latest 2D framework section of the Ordos Basin,along with high-precision 3D seismic data and drilling data,we systematically reinvestigate the Wushenqi and Central paleo-uplifts within the basin.Accordingly,the Cambrian-Ordovician sedimentary structural framework of the basin is reestablished and the evolutionary history of these two paleo-uplifts is clarified.The results indicate that during the Ordovician,the Wushenqi paleo-uplift exhibited a structural framework characterized by high in the north and low in the south.The Wushenqi and Central paleo-uplifts produced significant controlling effects on the deposition of the Cambrian and Ordovician strata,respectively.The 3D seismic data reveal that during(or even before)the Huaiyuan movement,the Wushenqi paleo-uplift underwent greater exposure and denudation compared to the Central paleo-uplift,though remaining higher in altitude during the pre-Ordovician.The Wushenqi paleo-uplift was active during the Precambrian,followed by gradual diminishment until the Ordovician when it became largely inactive.In contrast,the Central paleo-uplift got uplifted and came into being in L shape connecting the Yimeng paleo-uplift in the north and the Qingyang paleo-uplift in the south before the deposition of the Ordovician Majiagou Formation,prior to which the Qingyang and Yimeng paleo-uplifts,located in the southwestern and northern parts of the Ordos Basin,respectively,were independently active.The Wushenqi and Central paleo-uplifts jointly govern the distribution of sedimentary facies zones,resulting in the favorable reservoir-caprock assemblages in the eastern and central Ordos Basin.Promising targets for hydrocarbon exploration in the Ordos Basin include the Pre-Ordovician gas play s in weathering crust,lithologic gas plays in the central part,and fault-fractured gas plays in the eastern part.

关 键 词：构造演化 奥陶纪 寒武纪 中央古隆起 庆阳古隆起 乌审旗古隆起 鄂尔多斯盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探]