准噶尔盆地腹部地区油气成藏的主控因素

Main factors for controlling formation of oil-gas reservoir in central part of Junggar Basin

准噶尔盆地腹部地区总体处于盆地负向构造单元,构造特征为南倾的单斜带和洼陷带,无特征明显的正向构造圈闭,深大断裂和区域性展布断层不发育,目的层埋深大,勘探程度低。该区处于富油气系统之中,具有高压带、断层区、沉积相、古隆起四元联合控藏的特征,具备形成“富集高产”地层和岩性油气藏的地质条件,是寻找大型油气田的重要领域。勘探部署方案是:立足富洼陷,寻找古隆起,优选沉积相,解析断层区,预测高压带,勘探叠合区。在该区部署了多口探井,均取得了勘探突破。

The central part of Junggar Basin is mainly located at subsiding structural unit of the basin with the structural features of south-dipping slope and depression. There is no obvious positive structural trap and no development of deep fracture and regional spreading fault. The area is located in the system being rich in oil and gas. The reservoir is jointly controlled by fault, pressure, facies and palaeohigh, so it possesses the geological conditions for forming rich-production stratigraphic and lithologic reservoir. It is an important area for finding the giant oil-gas fields. The basic exploration procedures include finding out palaeohigh and selecting favo rable sedimentary facies based on rich depression, analyzing fault area, forecasting high-pressure belt and exploring superimposed area. The muhi-exploratory wells deployed in this area, and a good breakthrough has been obtained.