塔里木盆地阿克库勒凸起于奇地区哈拉哈塘组油气成藏机制

Forming Mechanism of Hydrocarbon Reservoirs of Halahatang Formation in Yuqi Block in Akekule Arch,Tarim Basin

于奇地区是塔里木盆地塔河油区外围重要的油气勘探地区。研究结果表明:区内哈拉哈塘组油源主要来自阿克库勒凸起南部寒武系—下奥陶统烃源岩,油源充足,具有一定的勘探潜力;原油总体具有油质较轻、含硫量较低但含蜡量较高的特点;天然气属于典型的伴生气;圈闭类型主要为低幅度的构造圈闭,油气分布主要受低幅度背斜和断层所控制;区内储层至少发生了3次油气注入成藏期,即侏罗纪—白垩纪、古近纪古新世晚期—始新世和古近纪渐新世早期—新近纪中新世;成藏机制可归结为油气多期充注和多期次生成藏,燕山期为圈闭的形成与油气藏初步建立阶段,喜山期为圈闭的定型与油气藏重建阶段,成藏模式为它源-双向排烃-多期次生成藏或古生新储-双向排烃-多期次生成藏。

Yuqi block is an important oil ＆ gas exploration target of Tahe oilfield in Akekule arch, Tarim Basin. The research results indicate that the oil ＆ gas in Yuqi block are from Cambrian to lower Ordovician source rocks in the south of the Akekule arch. Halahatang Formation in Yuqi block has definite exploration potential. The crude oil density of Halahatang Formation is low, the content of sulfur is also low, and the content of wax is high, the gas in Halahatang Formation belong to typical mixed gas. The trap types are mostly tectonicly controlled, which are low scope, the oil ＆ gas distribution is mostly fault-bounded. There are at least three episodes of oil/gas charges, i. e. , Jurassic - Cretaceous, late Palaeocene- Eocene and early Oligocene- Miocene. The oil ＆ gas accumulation model in Yuqi block is outward source-bidirectional expulsion of hydrocarbon-multistage accumulation or hydrocarbon sourced from the old rocks and preserved in the young rocks-bidirectional expulsion of hydrocarbon-multistage accumulation, and its evolution has two stages.