塔西南地区海相碳酸盐岩勘探突破新领域:寒武系白云岩

New Realm of Marine Carbonate Exploration in Southwestern Tarim Basin:Cambrian Dolomite

塔里木盆地西南地区近期勘探方向集中在奥陶系的碳酸盐岩,但成效不大,勘探也陷入迟滞。基于钻井解剖及成藏关键要素分析认为:塔西南地区奥陶系碳酸盐岩不仅储层欠发育,而且油气充注欠佳;中下寒武统白云岩储层优于奥陶系石灰岩储层,而且盐膏层盖层发育,基底卷入断裂欠发育,盐下油气保存条件较优越,有利于形成大规模的寒武系自生自储油气藏;塔西南古隆起北斜坡长期稳定发育的古构造是勘探突破的主攻方向,和田河气田周缘的古隆起斜坡区中下寒武统成藏条件优越,有望获得新的大发现。

The recent petroleum exploration in the southwest of Tarim Basin is concentrated on the Ordovician carbonate rocks, but the exploration effect is not ideal. Based on the analysis of drilling and the key elements of hydrocarbon accu-mulation, different exploration strata in the study area were evaluated. Ordovician carbonate reservoirs are underdevel-oped, and the hydrocarbon is poorly packed according to the oil and gas shows. Cambrian has a large-scale petroleum potential of self-generated and self-stored reservoir. Cambrian hydrocarbon source is abundant, and the middle-lower Cambrian dolomite reservoir is superior to the Ordovician limestone, and the salt cap layer is extensively developed with few faults involved. On the north slope of the paleo-uplift, especially in Hetianhe gas field and its periphery, it is expect-ed to get a new oil and gas breakthough in the middle-lower Cambrian dolomite.