鄂尔多斯盆地麻黄山地区油气分布及成藏特征

Distribution and Accumulation of Oil and Gas in Mahuangshan Region,Western Ordos Basin

随着麻黄山地区油气开发的深入,油气分布的非均质性日益明显。通过对各区带典型井区油水分布规律的研究,采用录井、岩心及测井资料等,发现研究区油气分布、成藏组合、成藏体系在不同区带(西缘冲断带、中央凹陷带和东部凸起带)、不同层位有明显差异。油区"油源"充足,成藏条件在纵横向的配置良好,圈闭距油源的远近、运移通道、圈闭有效程度对油气藏形成的控制作用显著,成藏主要受构造影响。西缘冲断带发育断块油藏和断背斜(鼻)油藏,油藏面积小、油柱高度大;中央凹陷带主要为致密低渗岩性油藏,油藏面积大、油柱高度小;东部凸起带,主要为背斜岩性油藏。

With petroleum exploitation in Mahuangshan region, malconformation of oil and gas distribution is increasingly obvious. Based on characteristics of oil and water distribution in typical blocks, distribution and accumulation of oil and gas in different belts （i. e. western thrust belt, central depression belt and eastern convex belt） and different layers is various, in combination with well logging, core and log information. In region of sufficient petroleum, reservoir conditions were vertically and horizontally allocated as well. The petroleum accumulation was controlled by distance between petroleum source and trap, migration pathway and effectiveness of trap, but the main factor is structural activity. The main type of oil reservoir in the western thrust belt is fault-block reservoir and fault-anticline （or fault-nose） with sm^ill area and high oil column. In the central depression belt, the main type of reservoir is tight low-permeability lithologie reservoir with large area and high oil column. In contrast, the reservoir type in the eastern convex belt is antielinal-lithologic reservoir.