准噶尔盆地侏罗系深部气藏勘探的有利地质条件

Favorable Geological Conditions for Gas-Pool Exploration in Jurassic Deep-Buried Basin Structure of Junggar Basin．

准噶尔盆地存在前缘坳陷和大型斜坡组成的深盆地结构。侏罗系发育陆相砂泥岩生储组合，大型三角洲体系形成了广泛发育的致密砂岩储集层。煤系地层为深盆气藏的主要气源岩，范围广、丰度高的煤系有机质普遍进入成熟—过成熟阶段。深盆气藏的的生成、运移、聚集从侏罗纪持续至今。深层侏罗系以异常高压为主，具备深盆气藏形成的有利地质条件。南缘、马桥凸起和达巴松凸起的斜坡带，为三个有利的勘探领域。预测地质储量1．5×10^(12) m^3 ．

： In Junggar basin， deep-buried basin structures are consisted of margin frontal depression and large scaleof slope structure． Continental facies mud-sandstone developed in Jurassic， thus forming source-reservoir assemblage， and the wide-spreading， and developing tight sandstone reservoir body has formed in large scale delta system． The major gas-source rocks in deep-buried basin structure gas reservoir are coal-bearing systems， with spreading in wide area． They arerich in organics， commonly in mature- and over-matured stages． The formation， migration and accumulation commence from Jurassic and continue all the way through to the time being． They are dominated with abnormal high pressure， possess favorable geological conditions needed for formation of deep-buried basin structured gas-pools． The paper indicated the favorable explorations are in three directions： south margin， Maqiao arch， Dabasong arch， and their slope area． The predicted proven geological reserves will be 1．5×1012 m3（OOIP）．