准噶尔盆地腹部深层成藏条件及勘探领域分析

An analysis of deep hydrocarbon accumulation conditions and exploratory realms in the heartland of Junggar basin

分析准噶尔盆地的热史、烃源岩热演化史、圈闭的形成史和油气的早期充注对储集层演化的影响 ,指出盆地腹部深层具有形成大型油气田的有利条件。准噶尔盆地古地温较高 ,使下二叠统烃源岩在三叠纪末大部分达到生烃高峰 ,而盆地腹部的深层圈闭在三叠纪末期或更早就已基本定型 ,与生烃史有很好的配置关系 ,因此深层油气在三叠纪末期以前就可聚集成藏 ;油气的早期充注可抑制孔隙的演化 ,由于深层具有早期成藏的特点 ,推测储集层物性应该较好。探讨了深层的油气成藏特征 ,包括油气特征、超高压和成藏模式等。图 5参 11(杨永泰摘 )

Through analyzing the effect of thermal history, thermal evolution history of hydrocarbon source rock, trap forming history and early charging of oil and gas on the reservoir evolution, it is indicated that deep strata of central Junggar basin has favourable conditions that could form a large oil field. It was considered that high palaeogeothermal system in Junggar basin caused early mature and hydrocarbon generation of Lower Permian source rocks and most of them were at hydrocarbon generation peak in the end of the Triassic, and almost at the same time, the deep traps of central Junggar basin basically falled into a pattern in the end of the Triassic or some early time before the Triassic, and in addition they were extremely matched with hydrocarbon generation history, which could result in hydrocarbon accumulation before the end of Triassic. The early charge of oil and gas could restrain pore evolution. In addition, deep strata characterized by early pool forming should have good reservoir properties. Beside, the authors discussed the pool forming characteristics in deep strata, including reservoir properties, overpressure and pool forming models, etc.