玛湖凹陷三叠系百口泉组地层再认识与勘探潜力分析  

Recognition and Exploration Potential Analysis of Triassic Baikouquan Formation in Mahu Sag

作　　者：钟厚财 朱俊梅 林煜 邓勇 刘作强 黄友华 张珊 屈琳 Zhong Houcai;Zhu Junmei;Lin Yu;Deng Yong;Liu Zuoqiang;Huang Youhua;Zhang Shan;Qu Lin(PetroChina Oriental Geophysical Exploration Company Limited,Zhuozhou,Hebei 072750,China)

机构地区：[1]中国石油东方地球物理勘探有限责任公司,河北涿州072750

出　　处：《特种油气藏》2024年第2期28-36,共9页Special Oil & Gas Reservoirs

基　　金：中国石油重大科技专项“砾岩油藏规模增储上产与提高采收率关键技术研究”(2023zz24YJ02);中国石油东方地球物理勘探有限责任公司科研项目“陆相湖盆三角洲体系地震沉积学研究”(03-03-2023)。

摘　　要：为进一步探索玛中平台区近4000.0 km 2勘探空白区的勘探潜力,扩大玛湖凹陷百口泉组勘探潜力,实现玛湖凹陷整体突破,综合利用地质、钻井、高精度地震等资料,对玛湖凹陷百口泉组地层划分进行了细化,将玛中平台区低位域砂体划分为百口泉组零段(百零段)。在此基础上,结合区域沉积、构造背景,从烃源岩条件、疏导体系、沉积体系和成藏条件等方面对玛中平台区低位域百零段油气成藏条件及控制因素展开了综合分析。研究表明:二叠系风城组烃源岩具有碱湖双峰式生油特征,油气资源基础大,百零段更近源,更容易捕获深层油气;玛中平台区印支期走滑断裂直插深层烃源岩,搭接形成了高效的输导体系;百口泉组顶底板条件优越,百零段在大型地层超覆背景下叠置发育多期湖侵退积砂体,形成规模有效的储盖组合;百零段发育四大规模扇体,其扇三角洲平原亚相致密带、扇间泥岩、构造等值线相互配置,形成复合式多面遮挡,为扇三角洲前缘大面积成藏奠定了基础。类比研究认为,中拐扇前缘亚相上倾、侧向遮挡条件好,具有宏观整体成藏基础。该区前缘亚相有利勘探面积大,岩性目标叠置发育,落实程度高,是目前寻求百零段新层系突破的重点勘探目标。百零段的突破有望打开玛中平台区勘探局面,进而实现玛湖凹陷百口泉组整体突破。In order to further explore the exploration potential of the nearly 4000.0 km 2 exploration blank area in central platform of Mahu Sag,expand the exploration potential of Baikouquan Formation in Mahu Sag,and realize the breakthrough of Mahu Sag as a whole,the stratigraphic delineation of Baikouquan Formation in Mahu Sag has been refined by the comprehensive use of geological data,drilling data,and high-density seismic data.The sand bodies of the lowstand system tract in central platformof Mahu Sag have been defined as Baikouquan Formation 0 Member(T 1 b 0).On this basis,combined with the regional sedimentary and tectonic backgrounds,the hydrocarbon accumulation conditions and controlling factors of the lowstand system tract T 1 b 0 in Mazhong plateau area were analyzed in terms of the hydrocarbon source rock conditions,migration system,and depositional system.The study shows that the hydrocarbon source rocks of the Permian Fengcheng Formation have the bimodal characteristics of oil generation in an alkali lake conditions,the hydrocarbon potential is large,and T 1 b 0 is closer to the source and more accessible to capture the deep oil and gas.The strike-slip faults in central platform of Mahu Sag directly inserted into the deep hydrocarbon source rocks during the Indo-Chinese epoch and formed an efficient migration system;the top and bottom plates of T 1 b 0 have superior conditions,and T 1 b 0 is superimposed on a large stratigraphical superposed background and develops multiphase lake invasion and retreating sand bodies,which form a large scale and effective reservoir-caprock association.T 1 b 0 develops four large-scale fan bodies,and the tight zones,mudstones between fans,and tectonics of the fan delta plain subfacies are configured with each other to form a composite multi-faceted barrier,which lays the foundation for the large-scale formation of reservoirs in the front edge of the fan delta.The analogous study concluded that the subfacies of the leading edge of the central abduction fan has good upward-dippi

关 键 词：扇控大面积成藏 低位域 勘探潜力分析 百口泉组 玛中平台区 玛湖凹陷 

分 类 号：TE122.1[石油与天然气工程—油气勘探]