源外简单斜坡区砂体的连通性及其控油作用

Connectivity of sandbody and oil control mechanism in simple slope area outside source

为定量评价源外简单斜坡区砂体连通性,明确其控油作用,以松辽盆地齐家北地区高台子油层为研究对象,应用三维地质建模技术,建立了三角洲前缘亚相砂体连通性评价模型,定量化评价了高台子油层4套砂岩组的连通性特征,并分析其对油气分布的控制作用。研究结果表明:砂地比小于0.1时砂体不连通,砂地比为0.10~0.45时砂体局部连通,砂地比大于0.45时完全连通;高Ⅲ组以砂体连通为主,高Ⅳ组以砂体局部连通为主。油气在源外简单斜坡区主要分布于砂体局部连通区带。

This paper is aimed at the quantitative evaluation of the sandbody connectivity of the delta front subfacies in the simple slope area outside the source and the clarification of its oil control mechanism.The study involves developing connectivity evaluation model for the delta front subfacies sandbody by taking the Gaotaizi oil layer in Qijiabei area of Songliao Basin as the research object and using core,logging,gas chromatography;and quantitatively evaluating the connectivity characteristics of the 4 sets of sandstone groups of the Gaotaizi oil layer,and analyzing the controlling effect of the sandbody connectivity of simple slope area outside the source on oil and gas distribution.The research results show that in the presence of the sand-to-ground ratio lower than 0.1,the sand bodies are disconnected;given the sand-to-ground ratio of 0.10-0.45,the sand bodies are locally connected;and in the case of the sand-to-ground ratio greater than 0.45,they are completely connected;the highⅢformation is dominated by the connection of sand bodies and the highⅣgroup is dominated by the local connection of sand bodies.Oil and gas are found mainly distributed in local connected areas of sandbodies in simple slope areas outside the source.