阳信洼陷岩性油气藏成藏控制因素分析

阳信洼陷古近系断裂发育,沉积相和沉积体系频繁变化,有效烃源岩分布广泛,为岩性油气藏的形成提供了良好的地质条件.阳信洼陷岩性油气藏主要包括砂体上倾尖灭油气藏、砂岩透镜体油气藏、断层-岩性油气藏、火成岩油气藏、构造-岩性油气藏5种类型.砂体上倾尖灭油气藏主要分布于北部陡坡带和南部斜坡带,砂岩透镜体油气藏主要分布在中部洼陷带、北部扇三角洲前缘相带和南部三角洲前缘相带,断层-岩性油气藏分布于断裂带附近,构造-岩性油气藏分布于鼻状构造带,火山岩油气藏分布于火山发育带.阳信洼陷有利的构造环境———沉积体系、充足的油气源条件、储层物性条件、断层(裂)体系的沟通或侧向遮挡、有效的直接盖层及生储盖的有机配置等优越条件是控制阳信洼陷岩性油气藏的形成与分布的主要因素.

Analysis of the factors of controlling the formation of the lithologic reservoirs in Xinyang subsag

The existence of many faults,the frequent variation of sedimentary facies and sedimentary system and the wide distribution of hydrocarbon rock in the Paleogene of Yangxin subsag all provide favorable geological conditions for the formation of the lithologic reservoirs.The lithologic reservoirs include five types: updip pinch-out sandstone reservoirs,lens-type sandstone reservoirs,fault-lithologic reservoirs,igneous reservoirs and structural-lithologic reservoirs.The updip pinch-out sandstone reservoirs mainly distribute in northern steep slope zone and southern slope zone,the lens-type sandstone reservoirs distribute mainly in central deep subsag zones,secondly in northern fan-delta front sedimentary facies zones and southern delta front sedimentary facies zones,and the fault-lithologic reservoirs mainly distribute near fault belts,the structurallithologic reservoirs mainly distribute in nose structure belts,and the igneous lithologic reservoirs mainly distributed in volcanic activity belts.The favorable structural conditions-sedimentary system,the rich oil and gas source conditions,reservoir property,the connection or side barriers of fault systems,the effective cap rocks and the good source-reservoir-caprock assemblage are all the factors of controlling the formation and distribution of the lithologic reservoirs in Yangxin subsag.