四川盆地川东北区二叠系—三叠系天然气勘探成果与前景展望

Exploration achievements and prospects of the Permian Triassic natural gas in northeastern Sichuan basin

勘探思路从以构造圈闭为主转变为以长兴组—飞仙关组礁滩相白云岩储层构造-岩性复合圈闭为主,发现了目前国内最大的海相气田——普光气田。在总结前人40年勘探成果的基础上,结合地质与地震资料,建立了区内礁滩相沉积模式,深层碳酸盐岩优质储层发育“三元控储”机理及“复合控藏”模式;外围构造在飞仙关组三段、四段鲕滩灰岩及嘉陵江组二段白云岩也取得了勘探上的较大突破;同时,形成了海相深层碳酸盐岩天然气成藏机理理论体系及以储层综合预测为主的勘探技术系列。新的勘探成果表明区内具有多个勘探领域,是四川盆地未来重要的天然气勘探区。

The shifting of exploration target from structural traps to structural-lithologic traps （represented by dolomite reservoirs reef fiat facies in Changxing-Feixianguan Formation of） led to the discovery of Puguang gas field-China＇ s largest marine gas field so far. Based on 40 years of exploration achievements, the reef flat sedimentary model, ‘ternary reservoir controlling mechanism＇ concerning the deep carbonate reservoirs, and the ‘ compound reservoir controlling＇ model, are established by integrating the geological with seismic data. Breakthroughs are also made in the exploration of oolitic beach limestone in the third and fourth members of Feixianguan Formation and dolomite in the second member of Jialinjiang Formation in the periphery structures. Meanwhile, a theoretical system of gas pooling in deep marine carbonates is constructed, and a series of technologies aiming at integrated reservoir prediction are developed. New exploration achievements reveal that there are several potential exploration targets in the area and that Sichuan basin is an important area for future gas exploration.