鄂尔多斯盆地林镇地区长4+5油层组油气成藏条件与机制  

Reservoir formation conditions and mechanism of Chang 4+5 oil reservoir set in Linzhen area, Ordos Basin

作　　者：夏嘉[1,2] 段毅[1] 高苑[1,2] 张晓丽[1,2] 何金先[1,2] 徐丽[1,2] 

机构地区：[1]中国科学院油气资源研究重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《岩性油气藏》2013年第4期11-16,共6页Lithologic Reservoirs

基　　金：国家自然科学基金项目"淡水湖泊环境沉积单体脂类生物标志化合物氢同位素组成特征及其成因机制研究"(编号:41272125)资助

摘　　要：在研究鄂尔多斯盆地林镇地区延长组长4+5油层组油气藏的油气生成、储层条件、运移条件、圈闭和聚集成藏等方面的基础上,综合分析了该区三叠系延长组长4+5油层组油气藏的形成条件,并总结了其形成机制。结果表明:林镇地区延长组长4+5油层组油气主要来自长7烃源岩;储层为三角洲前缘亚相各种成因类型的砂体,属于低孔、低渗储层;广泛发育的水下分流间湾暗色泥岩、致密粉砂岩以及粉砂质泥岩可形成良好的盖层;运移的动力主要来自长7泥岩形成的异常高压。长7烃源岩生成的油气在高剩余压力的驱动下,通过垂向叠合砂体与微裂缝向上运移进入长4+5储层,并沿连通的三角洲前缘砂体横向运移进入圈闭成藏,形成鼻隆构造油气藏、岩性油气藏以及构造-岩性油气藏,其形成受烃源岩、沉积相带、微裂缝、鼻隆构造以及剩余压力等因素的影响。Based on the research of hydrocarbon generation, reservoir conditions, migration, traps and accumulation, this paper systematically analyzed the forming conditions and mechanisms of Chang 4＋5 oil reservoir set in Linzhen area. The result shows that the hydrocarbon of Chang 4＋5 oil reservoir set is mainly generated from the Chang 7 source rocks, and the reservoir rocks are mostly delta front subfacies sandstone, which is considered to be low porosity and low permeability reservoir. The dark mud rock, finer siltstone and siltpelite can effectively provide top cap rock for the reservoir. The anomalous pressure formed by Chang 7 mudstone provides the force for migration. The hydrocarbon formed by Chang 7 source rocks migrated into Chang 4＋5 reservoir through the vertical folding sand bodies and micro-fractures under the high overpressure, vertically migrated into the traps along the delta front sand bodies and forming reservoir, and formed nose- shaped structural reservoir, lithologic reservoir and structural-lithologic reservoir, which are influenced by source rocks,sedimentary facies belt, micro-fractures, nose-shaped structure and overpressure.

关 键 词：长4+5油层组 油气成藏条件 油气成藏机制 林镇地区 鄂尔多斯盆地 

分 类 号：TE121[石油与天然气工程—油气勘探]