埕岛油田馆上段高分辨率层序地层分析

High-resolution sequence stratigraphic analysis of the upper Guantao of Chengdao Oilfield

馆上段是埕岛油田的主要含油层位,曲流河沉积,砂体变化快,常规小层对比方法难以准确识别地层层序。运用Cross高分辨率层序地层学原理,在馆上段识别出3个中期旋回,12个短期旋回,中期旋回和短期旋回均为非对称旋回,以上升半旋回大于下降半旋回为主。以短期旋回为基本单元,建立了高分辨率层序地层格架,对储层进行精细对比,分析了各中期旋回储层的发育特征。

The upper Guantao formation,which belongs to fluvial facies deposition,is a main oil producing one in Chengdao Oilfield.Because of the complex reservoir change,it is difficult to identify its stratigraphic sequences using conventional sublayer correlation. Three middle-long-term cycles(MSC1-MSC3) and twelve shortterm cycles(SSC1-SSC12) were identified in the upper Guantao formation according to the concept of high-resolution sequence stratigraphy.The middle-term and short-term cycles mostly belong to asymmetric types.The uplifting semi-cycle is longer than the subsiding semi-cycle.The high-resolution sequence strati-graphic framework was established for middle-term and short-term cycles.Tracing and careful correlation of sand bodies were proceeded based on short-term cycles,and the distribution features of sand bodies were analyzed.