塔河油田9区三叠系中上统高分辨率层序地层及沉积演化

在塔河油田9区三叠系中上统中识别出1个Ⅳ级层序界面,相应划分为5个长期基准面旋回和14个中期基准面旋回,主要目的层下油组划分为12个短期旋回,建立3种中期基准面旋回层序构型样式.结合各个层序单元的沉积相分析及层序岩相古地理图,塔河油田9区三叠系中上统发育辫状河三角洲-湖泊沉积体系,湖泊进退频繁,上、中、下油组分别为三角洲前缘及三角洲平原沉积,其间泥岩段代表了湖泛沉积.

High resolution sequence of stratigraphy and sedimentary evolution of middle-upper Trimassic in the 9th Area, Tahe Oil Field

Under the direction of theory and the technology of high resolution sequence of stratigraphy, the strata in middle-upper Trimassic in the 9th Area, Tahe oil field have been divided into fourteen 5-order sequence interfaces, which includes five long-term base-level cycles, fourteen middle-term base-level cycles and twelve short-term base-level cycles for down oil formation of primary objective reservoir. And three types of middle-term base-level cycle sequence architecture is built. Therefore by integrating into sedimentary analysis of every sequence unity and working out the old facies geographic map of sequence rock, a braided river delta-lake sedimentary system is developed, and it was found that the lake frequently advances and retreats, the upper-middle-down oil formation separates into the front edge of the delta and plant of the delta sediments. Thus the segment of mudstone delegates into floured-lake sediments.