湖相凝缩层的发现及应用

为了寻找哈萨克斯坦A油田侏罗系中阿克沙布拉克地层中的潜力油藏，在油藏综合研究中，通过多井测井曲线对比，发现了一套几乎全区分布的、具有高自然伽马值、低电阻率等电性特征的泥岩层。应用层序地层学的观点，综合分析这套泥岩层，确定其为最大湖泛时沉积的凝缩层。根据凝缩层的横向分布特征，结合地质及地震资料，得到地层的沉积模式。分析凝缩层之上地层的沉积特征，得出在油田东部斜坡位置沉积厚度变化大，处于高水位时期并发育进积型三角洲，其前缘位置是最有利的岩性地层油气藏发育区，并在后续的钻井勘探过程中得到了很好的验证。给出了寻找湖相凝缩层的方法，提出了寻找岩性油气藏的新思路。

Discovery and Application of the Condensed Layer in Lacustrine Facies

The aim of this study was to determine potential reservoirs in the Jurassic Akshabulak Formation, located in Oil Field A in Kazakhstan. Logging curves for multiple wells were compared during a comprehensive reservoir study. A shale layer was discovered, which is distributed almost throughout the entire region, and has electrical characteristics of high natural gamma values and low resistivity. After comprehensive analysis of the shale layer via sequence stratigraphy, the condensed layer was confirmed to have been deposited during extensive flooding. The lateral distributional characteristics of the condensed layer were combined with geological and seismic data to establish a sedimentation model. Analysis of the sedimentation characteristics of the upper stratum of the condensed layer indicates substantial variations in sedimentation thickness at the eastern slope of the oil field. A prograding delta developed on this slope, which indicates the high-water mark period. Its leading edge was very favorable for the development of lithological and stratigraphic reservoirs. This observation was validated during the subsequent drilling and exploration process. A method for locating the condensed layer in lacustrine facies is proposed and provides new insights into the detection of lithological reservoirs.