前陆盆地坡折带对沉积相的控制作用:以准噶尔盆地西北缘玛湖凹陷三工河组为例  

Control of slope break on sedimentary facies in foreland basin:a case study of Sangonghe Formation in northwestern margin of Junggar Basin

作　　者：王辉[1] 侯文锋[1] 李婷[1] 石勇[1] WANG Hui;HOU Wenfeng;LI Ting;SHI Yong(No.2 Oil Production Plant,PetroChina Xinjiang Oilfield Company,Karamay 834000,China)

机构地区：[1]中国石油新疆油田分公司采油二厂,新疆克拉玛依834000

出　　处：《中南大学学报（自然科学版）》2022年第3期1136-1145,共10页Journal of Central South University:Science and Technology

基　　金：国家“十三五”科技重大专项(2017ZX05005-001-008)。

摘　　要：为了研究前陆盆地坡折带对沉积相的控制作用,以准噶尔盆地西北缘玛湖凹陷三工河组为例,采取构造与沉积学相结合的方法,根据测井、岩性和野外剖面资料,分析三工河组沉积相特征、坡折带形成机理及其对沉积相和储层的控制作用。研究结果表明:三工河组沉积相类型包括冲积扇相和辫状河三角洲相。冲积扇相分布在三工河组下段,沉积物粒度粗,平面上分布于研究区西部和西北部等靠近物源的区域;辫状河三角洲相是三工河组主要的沉积相类型,划分为平原和前缘亚相;三工河组沉积在区域性不整合界面之上,垂向上岩性和沉积相组合指示沉积期湖平面逐渐上升;研究区坡折带为逆断层形成的构造型坡折带,划分为单断型坡折带和多断型坡折带;由于单断型坡折带长期的风化作用,在地形上并不能形成阻碍沉积物向盆地搬运的隆起;而多断型坡折带隆起的幅度较高,风化前后均能阻碍沉积物的搬运。冲积扇和辫状河三角洲平原多分布在坡折带西部和西北部等逆断层上盘,前缘亚相分布在逆断层的下盘,体现了坡折带对沉积相的控制作用;沉积分异作用使坡折带南部多沉积中砂岩,该类砂岩储层物性最好,三工河组油气显示井多分布在该区域,体现了坡折带对储层和油气成藏的控制作用。In order to study the control effect of slope break zone on sedimentary facies in foreland basin,taking Sangonghe Formation in Mahu sag on the northwest edge of Junggar Basin as an example,the characteristics of facies,the formation mechanism of slope break zone and its control effect on facies and reservoir of Sangonghe formation were analyzed by combining structure and sedimentology and according to logging,lithology and field profile data.The results show that the sedimentary facies of Sangonghe formation include alluvial fan facies and braided river delta facies.Alluvial fan facies are distributed in the lower part of Sangonghe formation,with coarse grain size,and are distributed in the west and northwest of the study area.Braided river delta facies are the main facies type of Sangonghe formation,which is divided into plain and front subfacies.Sangonghe formation is deposited on the regional unconformity interface,and the vertical lithology and facies combination indicate that the lake level rises gradually during the sedimentary period.The slope break zone in the study area is a structural type formed by reverse fault.Slope break zone can be divided into single fault slope break zone and multi fault slope break zone.Due to the long-term weathering of the single fault slope break zone,the uplift that hinders the transportation of sediments to the basin cannot be formed on the terrain.The uplift amplitude of multi fault slope break zone is high,which can hinder the transportation of sediments before and after weathering.Alluvial fan and braided river delta plain are mostly distributed in the hanging wall of reverse fault in the west and northwest of slope break zone,and the front subfacies are distributed in the footwall of reverse fault,which reflects the control of slope break zone on facies.Sedimentary differentiation makes the south of the slope break zone mostly deposit medium sandstone,which has the best physical properties.The oil and gas display wells of Sangonghe formation are mostly distributed in th

关 键 词：准噶尔盆地 前陆盆地 坡折带 沉积相 控制因素 优质储层 

分 类 号：P618.13[天文地球—矿床学]