鄂尔多斯盆地镰刀湾地区长2油藏成因探讨

Discussion on Origin of Hydrocarbon Reservoirs of Chang 2 in Liandaowan Region of the Ordos Basin

通过鄂尔多斯盆地镰刀湾地区分析沉积、成岩、构造等圈闭形成条件,结合该区砂体分布和油气分布规律,分析各层段油藏控制因素、分布规律及成岩矿物对油气藏形成的影响。研究镰刀湾地区油气藏类型与沉积相带、成岩环境的关系,确定油藏成藏模式及规律,预测油气富集有利区。分析研究区构造-岩性复合油气藏、上倾致密遮挡油气藏及砂岩尖灭岩性油气藏的形成条件及成因。不同相带上油气藏类型有差异,岩性油气藏主要与成岩作用、砂体分布及岩相变化等地质因素有关;构造-岩性油气藏主要受构造、岩性两个因素控制,有统一的油水界面。

Base on analysis of deposition, diagenetic and structure trap, companied by spatial distribution of sandbodies and hydrocarbon distribution, summarizing on control factor and distribution rule of hydrocarbon reservoirs in each lay, and the authigenic minerals affected to hydrocarbon reservoirs forming. Make sure profitable range of accumulation pattern and rule in hydrocarbon reservoirs, forecast profitable range of hydrocarbon enriched. Origin and forming conditions for structure -petrologic combination hydrocarbon reservoirs, updip -tight screened hydrocarbon reservoirs and sandstone pinchout litho hydrocarbon reservoirs are elucidated. Differential of hydrocarbon reservoirs types is existed in different deposition facies, the petrologic hydrocarbon reservoirs are mainly associated with diagenesis, spatial distribution of sandbodies and changes of lithofacies ; structure - petrologic hydrocarbon reservoirs are controlled by structure and lithology with unified oil/water interface.