松辽盆地南部西斜坡高分辨率层序地层研究

HIGH-RESOLUTION SEQUENCE STRATIGRAPHIC STUDY FOR WEST SLOPE OF SOUTH SONGLIAO BASIN

根据钻井、测井及地震资料,引入沉积转换面概念,应用以多级次基准面旋回为参照面的高分辨层序地层学理论与方法,对松辽盆地南部西斜坡前缘带的青山口组一姚家组地层进行了层序地层研究。共识别出4个长期基准面旋回、8个中期基准面旋回,建立了层序划分方案,在连井剖面的层序地层对比基础上建立了地层格架;认为青山口组底部层序为盆地快速水进时期,向上至青三上层序为水退时期,至姚家组层序为另一水进初始阶段;各旋回叠加样式随基准面升降呈现有规律变化,层序格架分布样式也对油气运聚具有显著影响。

Based on the drilling, well logging and seismic data, through introduci conversion surface and applying the theory and method of high-resolution sequence grade datum level cycles as the referring interfaces, the sequence stratigraphic studi ng the concept of depositional stratigraphy taking the multi- es on the Qingshankou Forma- tion-Yaojia Formation in the front belts of West Slope of South Songliao Basin are conducted. Four long-term base level cycles and eight medium-term base level cycles are recognized altogether, and then the sequence classifying programs are established, on the basis of the sequence stratigraphic contrast of the well-commingled profiles, the stratigraphic framework is built; the studies show that Qingshankou-Formation bottom/lower sequence deposits in the period of fast water-transgression and the upper sequence of Qingshankou Formation belongs to the period of the water-regression, and moreover the upward Yaojia-Formation sequence is located in the initial stage of another wa- ter-transgression ; besides the stacked patterns of each cycle change regularly with the rise and fall of the level, the distribution types of sequence framework also possess remarkably influences on the oil and gas migration and accu- mulation.