哈萨克斯坦南图尔盖盆地南肯尼斯油田油气分布特征及成藏主控因素

Hydrocarbon distribution characteristics and main controlling factors of accumulation in South Konys Oilfield in South Turgay Basin,Kazakhstan

南肯尼斯油田是哈萨克斯坦南图尔盖盆地重要的油田之一,为典型的构造—岩性地层复合型油气藏,油气成藏受大型走滑断裂带影响,其油气成藏方面的研究对扩大该区勘探、开发规模及丰富走滑裂谷盆地油气成藏理论具有重要意义。基于南肯尼斯油田的石油地质特征分析,通过油气藏解剖,总结了其油气分布特征,认为白垩系下达乌尔组M-Ⅱ层的油气分布受构造和岩性双重因素控制,主要表现为3个特征:1在构造高部位存在气顶;2油层厚度受砂体厚度和物性控制;3油藏类型为构造和岩性地层复合型油气藏。侏罗系阿克沙布拉克组J-0-1层、J-0-2层内砂体横向连续性较差,平面上存在非均质性,油气分布以薄层透镜状为主。结合研究区构造演化和断裂发育特征,对影响不同层系油气成藏的主控因素进行了探讨,认为成藏主要受3个方面因素控制:1断层活动控制白垩系上、下达乌尔组成藏组合油气成藏;2储层岩性尖灭带控制岩性油气藏平面分布;3区域性不整合面控制侏罗系岩性地层油气藏垂向发育。

The South Konys Oilfield, one of the most important oilfields in the South Turgay Basin,Kazakhstan,is a combination of structural and lithostratigraphic reservoir. The study on hydrocarbon accumulation, influenced by strike-slip faults, is of great importance on oil and gas exploration and development, enrichment of hydrocarbon accumulation theory of strike-slip basin.On the basis of the analysis of petroleum geology of the South Konys Oilfield,the author summarized the oil and gas distribution characteristics.The results show that the oil and gas distribution in M-II layers in Klln Formation was controlled by both structural and lithologic changes.The oil and gas distribution was characterized by： （1）The reservoir has a gas cap;（2）Oil column is controlled by the thickness and porosity of sandstones.（3）The South Konys Oilfield is a combination of structural and lithostratigraphic reservoir.Sandstones in the Jurassic J-0-1 ,J-0-2 layers show rapid lateral changes in thickness and oil and gas reservoirs are distributed in lenticular. Combining with the analysis of structural evolution and fault features, main controlling factors of hydrocarbon accumulation were discussed.The results show that ：（1）hydrocarbon accumulation of plays in the Klln and Klun formations is controlled by faulting activities.（2）Lateral distribution of the Jurassic lithostratigraphic reservoirs is controlled by lithologic pinch-out belts.（3）Vertical distribution of the Jurassic lithostratigraphic reservoirs is controlled by regional unconformities.