沉积古地貌恢复及古地貌对沉积体系的控制作用——以准噶尔盆地石西地区三叠系百口泉组为例  

Restoration of sedimentary paleogeography and its control on sedimentary system:A case study of the Triassic Baikouquan Formation in Shixi area of Junggar Basin

作　　者：李想 付磊 魏璞 李俊飞 徐港 曹倩倩 钟杨 王振鹏 LI Xiang;FU Lei;WEI Pu;LI Junfei;XU Gang;CAO Qianqian;ZHONG Yang;WANG Zhenpeng(The Shixi Oilfield Operation District,Xinjiang Oilfield Company of PetroChina,Karamay 834000,Xinjiang,China)

机构地区：[1]中石油新疆油田公司石西油田作业区,新疆克拉玛依834000

出　　处：《岩性油气藏》2025年第2期38-48,共11页Lithologic Reservoirs

基　　金：重庆市自然科学基金“三角洲体系物源供给的侧向差异对层序构成样式的控制”(编号:cstc2019jcyj-msxmX0719)资助。

摘　　要：综合利用三维地震资料及测井、录井数据,采用沉积古地貌恢复技术对准噶尔盆地石西地区三叠系百口泉组古地貌进行了恢复,在明确沉积相平面展布特征的基础上,对古地貌与沉积相的关系进行了探讨,并指出了油气勘探的有利区。研究结果表明:①恢复古地貌的步骤包括计算时间域下的地层厚度、计算深度域下的地层厚度、剥蚀量恢复、去压实校正和古水深恢复。石西地区百口泉组沉积时呈“西北高、东南低”的构造格局,西北部为大面积高地,中部、东部发育凸起和6条主干沟槽,相互穿插,南部则分布3个洼地,古地貌以凸起—沟槽—洼地的组合样式为主。②研究区北部、中部主要发育辫状河三角洲平原亚相,以分流河道微相为主,被分流河道间湾分割;西南部、西部主要发育辫状河三角洲前缘亚相,包含水下分流河道和水下分流河道间微相,局部区域发育河口坝和席状砂微相。③研究区古地貌控制沉积相展布,古地貌形态和特征直接影响沉积物来源、搬运路径和沉积环境,表现为东北部物源经三角洲砂体向西南部湖盆中心输送过程中,6条古沟槽为主要搬运通道,同时限制河道的频繁摆动;沟槽内水动力强,发育厚层、多期叠置的分流河道砂体;凸起地区受河道影响较小,积聚了较厚的泥岩,发育分流河道间湾微相;洼地内因河道扩展导致水动力减弱,细砂质沉积,发育大面积席状砂微相。④研究区东部沟槽区和南部洼地是储层发育有利区,也是重点勘探方向。Using 3D seismic data combined with logging and drilling data,the paleogeomorphology of the Triassic Baikouquan Formation in Shixi area of the Junggar Basin was reconstructed using sedimentary paleogeomorphology restoration techniques.Based on the clarified planar distribution characteristics of sedimentary facies,the relationship between paleogeomorphology and sedimentary facies was explored,and favorable areas for oil and gas exploration were identified.The research results show that:(1)The steps for restoring ancient landforms include calculating the thickness of the strata in the time domain,calculating the thickness of the strata in the depth domain,recovering denudation thickness of the strata,decompaction correction,and restoring the ancient water depth.During the deposition of the Baikouquan Formation,Shixi area exhibited a"northwest high,southeast low"structural pattern.The northwest was characterized by a large highland,while the central and eastern parts developed uplifts and six primary troughs,which interwove with each other.The southern part contained three depressions.The paleogeomorphology was primarily a combination of uplifts,troughs,and depressions.(2)In the northern and central parts of the study area,a braided river delta plain subfacies was predominantly developed,characterized mainly by distributary channel microfacies,segmented by interdistributary bay microfacies.In the southwestern and western regions,a braided river delta front subfacies dominated,including underwater distributary channel and interdistributary channel microfacies,with localized development of mouth bar and sheet sand microfacies.(3)The paleogeomorphology in the study area controlled the distribution of sedimentary facies.The shape and characteristics of the paleogeomorphology directly influenced sediment sources,transportation pathways,and depositional environments.Specifically,sediment from the northeastern source was transported through delta sand bodies to the southwestern lake basin center,with six paleotroughs serv

关 键 词：古地貌恢复 辫状河三角洲 席状砂 分流河道 去压实校正 百口泉组 三叠系 石西地区 准噶尔盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]