江汉油气区发现过程之回顾与讨论

江汉盆地的油气,大都集中于沉积范围收缩的早第三纪晚期裂谷盐湖沉积系列中,由盐湖一侧发育的水下冲积扇砂体和组成旋卷构造体系的盐背斜共同控制而富集。这在国内外油区中是一种独特的类型。由于重视了区域地质研究,因而重点坳陷的确定和主要生油凹陷与目的层系的选择都很顺利。但因对岩相控油一度认识不足且缺乏相应勘探手段,在预测油田时曾走过一段弯路。

REVIEW AND DISCUSSION ON DISCOVERING OF JIANGHAN PETROLEUM PROVINCE

Most of the oil and gas reserves in Jianghan basin occurs in series of salt-lacustrine sediments deposided in a highly restricted rifting environment during the later Eogene.Their accumulation is governed both by sandstones derived from subaqueous alluvial fans at north part of the salt lake and halokinetic anticlines in a vortex structural system.This is a particular type different from any other reservoirs known.During exploration,the study of regional geology has played an important part in successful locating potential source sag and selecting main target bedds.But enough attention had not been paid to oil accumulation governed by lithofacies,and necessary means of exploration had been lacked,we had gone a wrong way for a period of time in predicting oil fields.However,as soon as the horizons of sandstones and composite components of structures necessary for oil accumulatoin have been identified,a series of oil fields which contain majority of oil reserves in the basin has been under way of discovering.According to the recognition summed up in this paper,some suggestions has been proposed for future prospecting.