安塞油田王窑地区长6油层沉积微相研究  

Sedimentary microfacies of the Chang-6 reservoir of Yanchang Formation in Wangyao district, Ansai oilfield

作　　者：张金亮[1] 司学强[1] 秦敬[1] 

机构地区：[1]青岛海洋大学地球科学学院,山东青岛266003

出　　处：《西北地质》2003年第3期62-71,共10页Northwestern Geology

基　　金：中国石油天然气集团公司油田开发提高采收率导向技术项目(编号:95020402)资助

摘　　要：王窑地区长6油层为湖泊河控三角洲前缘沉积,主要沉积微相为三角洲前缘水下分流河道、分流河口砂坝、前缘砂席和分流间等。水下分流河道充填沉积为向上变细的砂岩层序,分流河口砂坝可划分为向上变粗的前积式和非前积式两种沉积层序类型。水下分流河道和河口砂坝砂体相互连接,形成厚度较稳定的三角洲前缘复合体。该区三角洲沉积是安塞三角洲发育较晚的一支,也是指状砂体伸入湖区最远、发育程度最高的分支。长621沉积期,为三角洲的初始进积阶段,三角洲沉积由两支分流组成。长611沉积期三角洲前缘体系完整,砂体发育,分流带相互叠置交错。根据岩心描述结果、结合砂体形态和连井剖面对比分析,对长6油层三角洲沉积微相进行了综合表征,并提出了开发调整意见,为王窑地区特低渗透油田的高效开发奠定了地质基础。The origins of Chang-6 reservoir horizons in Wangyao district of Ansai oilfield are interpreted to be a river-dominated delta deposited in lacustrine environment. The main sedimentary microfacies of Chang-6 reservoir horizons in Wangyao district include distributary channel, distributary mouthbar, front sand sheet and interdistributary deposits. The distributary channel fills to show a finning upward sequence. The distributary mouthbar deposits consist of overall coarsing upward sequence and other homogeneous sequences. The distributary channel and distributary mouthbar sands coalesce to constitute the dominated petroleum reservoirs. Progradation of two distributaries constructed at first only a delta skeleton in the Chang-6~2_1 sandlayer. Rapid sedimentation during the period of Chang-6~1_1 lead to rapid progradation basinward of multiple distributaries. The deltaic microfacies are interpreted and delineated based on depositional sequence and sandbody geometry. Sandbody microfacies are the main factors affecting movement of oil and water. Comprehensive descriptions of sedimentary microfacies are good methods to predict reservoir performance.

关 键 词：安塞油田 河流三角洲 沉积层序 沉积微相 砂体形态 

分 类 号：P618.13[天文地球—矿床学]