地层学杂志

随着油气田逐渐进入开发中后期,生产实践中分层注水(气)、剩余油挖潜提高采收率等措施的实施,使得对地层划分与对比的要求精细程度越来越高。以辽河西部凹陷西斜坡南端某试验区为例,在高分辨率层序地层学理论指导下,井震结合,建立了于楼油层单层级别的高分辨率等时地层格架,为单砂体精细刻画和储层分类评价提供地质依据。于楼油层纵向上可细分为2个三级层序、12个4级层序和29个5级层序,分别对应长期基准面旋回、中期基准面旋回和短期基准面旋回。首次提出了单层对比划分的原则。研究中将高分辨率层序地层学理论与传统的地层对比方法有机结合。单井上主要通过电导率曲线,识别湖泛面,即5级层序界面;井间主要依靠测井曲线形态、地层厚度、沉积旋回组合变化、流体性质等特征,最终实现地层的等时划分与对比,建立了高分辨率等时地层格架。

As the production of oil and gas fields moves to their late stages,new measures of water or gas injection has been applied in order to improve production.The successful application of these new measures demands very fine-scale stratigraphic subdivision and correlation.Using an experimental area in the southern end of the West Depression in the Liaohe Basin as an example,this study demonstrates the importance of high-resolution sequence stratigraphy in the correlation of the Yulou reservoir.Seismic and well log data were used in this high-resolution sequence stratigraphic study.The results provide a geological basis for the correlation of single sand body and reservoir evaluation.The Yulou reservoir is divided into two third-order sequences,twelve fourth-order sequences,and twenty nine fifth-order sequences.These sequences corresponded,respectively,to long-term,mid-term,and short-term base level changes.The principles of single-bed subdivision and correlation have been laid out.The study utilizes the principles of high-resolution sequence stratigraphy and traditional stratigraphic correlation techniques to achieve better resolution in stratigraphic subdivision and correlation.Well logs of electrical conductivity were used to distinguish flooding surfaces(fifth-order sequence boundaries).Well log shape,stratigraphic thickness,sedimentary cycles,and fluid properties were used in correlation between different wells.This study shows that fine-scale stratigraphic subdivision and correlation of the Yulou reservoir can be achieved.