塔里木盆地古隆起斜坡对碳酸盐岩油气藏的控制作用

塔里木盆地下古生界海相碳酸盐岩油气分布不同于上覆碎屑岩,油气沿石炭纪前古隆起斜坡分布与富集。塔北、塔中、塔西南等三大前石炭纪古隆起的宽缓斜坡长期稳定发育,形成了下古生界海相碳酸盐岩大面积油气成藏的地质条件。古隆起斜坡不仅是台缘高能储集相带发育的有利部位,而且有利于风化壳岩溶储集层的发育与保存。古隆起斜坡紧邻烃源区,是多期油气运聚成藏的指向区,油气保存条件优越。海相碳酸盐岩中广泛存在喜玛拉雅晚期成藏事件,石炭纪前古隆起斜坡是海相碳酸盐岩油气富集与勘探的主攻方向。

Controlling Effects of Paleo-Uplift Slopes on Marine Carbonate Reservoirs in Tarim Basin

The hydrocarbon distribution and enrichment in marine carbonate reservoirs of the Cambro-Ordovician in Tarim basin were found along the pre-Carboniferous paleo-uplift slopes,which are different from the overlying clastic rocks.In three big pre-Carboniferous paleo-uplifts in Tabei,Tazhong and Taxinan existed wide-gentle slopes with long-term stable development forms the geologic conditions of large-area hydrocarbon accumulations in these areas.These slopes can not only be the favorable positions of high-energy facies belts in the margin of platform,but also being suitable for the development and preservation of weathering crust-type reservoirs.In addition,being very close to the source rock area,they should be the targets for multistage hydrocarbon migrations and accumulations due to their superior petroleum preservation conditions,and even as the main directions for petroleum exploration for there broadly are the hydrocarbon accumulation events of the late Himalayan movement in the marine carbonate rocks.