潮水盆地侏罗系油气勘探前景

Petroleum Exploration Prospects of Jurassic in Chaoshui Basin

潮水盆地是河西走廊最大的侏罗系盆地,中、下侏罗统煤系和湖相泥岩生烃指标与吐哈盆地相似。中、下侏罗统青土井群属低孔低渗储集层。盆地缺少喜马拉雅运动期的背斜构造带,圈闭多以断块和断背斜为主。虽然潮水盆地的规模不如吐哈盆地,但在其中已发现了青土井小油藏,还有近2×108t的石油资源量,仍有较好的油气勘探前景。

Chaoshui basin is the largest Jurassic basin in the Gansu Corridor, in which the hydrocarbon generation indices in the MiddleLower Jurassic coal seam and lacustrine shale are similar to those in Tuha basin, but the area of hydrocarbon generating sags and the thickness of source rocks are smaller than those in Tuha basin, and its petroleum resources account for 1/5 of the total in this basin. The Qingtujing group of Middle-Lower Jurassic belongs to a low-porosity and low-permeability reservoir. Chaoshui basin is characterized by lacking of anticline structural zone formed in Himalayan movement and the fault-block and faulted anticlinal traps. Although the scale of this basin is smaller than that of Tuha basin, the Qingtujing reservoir with petroleum resources of about 2×10^8 t has been brand. It is concluded that Chaoshui basin still has good prospects for hydrocarbon exploration.