塔里木盆地前上二叠统顶面不整合特征及其控油意义

Characteristics and Oil/Gas-controlling Significances of Unconformities on the Top of Sub-upper Permian

塔里木盆地的上二叠统或中、新生界与下伏地层之间存在着不同类型的不整合,如褶皱削截(超覆)不整合、断块旋转削截超覆不整合、超覆不整合和平行不整合等。其中,褶皱削截(超覆)和断块旋转削截超覆不整合分布于巴楚、塔北、塔东、塔中等地,超覆不整合发育于麦盖提斜坡,平行不整合分布于塔西南-阿满坳陷。褶皱削截、断块旋转削截、超覆不整合发育区不仅生、储、盖组合好,而且运、聚、保条件佳,因而是控油意义最好的不整合,所以,塔北、塔中、巴楚、麦盖提等地是寻找不整合油气藏的有利靶区。

There are four types of sub-upper Permian unconformities in the Tarim basin,they are fold truncation,faulted-block-turned truncation,onlap and parallel unconformities.The fold truncation and faulted-block-turned truncation unconformities are distributed in Bachu area,and northern,eastern and central Tarim basin,the onlap unconformities in Maigaiti area,and parallel unconformities in southwestern Tarim and Aman depression.The regions in which the fold truncation,faulted-block-turned truncation and onlap unconformities are developed,are good not only in assemblances of source,reservoir and cap beds,but also in migration,accumulation and preservation conditions.Consequently,the three unconformities are best in oil/gas-controlling significance.Therefore,the northern Tarim basin,and Bachu and Maigaiti areas are advantageous targets in seeking the unconformity reservoirs.