断陷湖盆滩坝砂体成因与成藏:以东营凹陷沙四上亚段为例  

Sandbody genesis and hydrocarbon accumulation mechanism of beach-bar reservoir in faulted-lacustrine-basins:A case study from the upper of the fourth member of Shahejie Formation,Dongying Sag

作　　者：王永诗[1] 刘惠民[1] 高永进[1] 田美荣[1] 唐东[1] 

机构地区：[1]中国石化胜利油田分公司地质科学研究院,山东东营257000

出　　处：《地学前缘》2012年第1期100-107,共8页Earth Science Frontiers

基　　金：国家重大科技专项"渤海湾盆地精细勘探关键技术"(2011ZX05006)

摘　　要：滩坝砂是一种发育在滨浅湖高能环境的薄互层沉积,是以往未被重视的、认识程度较低的碎屑岩储集体。围绕滩坝砂成因与成藏的难点,研究了东营凹陷沙四上亚段滩坝砂沉积特征和分布规律,明确了滩坝砂成藏要素与富集规律。提出了滩坝砂沉积受古地貌、古水动力(波浪、湖流)和古基准面控制的"三古控砂"机制和油气成藏受断裂裂隙、有效储层、烃源岩超压控制的"三元控藏"认识,指出断陷盆地中长期基准面持续上升,短期基准面频繁震荡形成了大面积分布的滨浅湖滩坝砂沉积,烃源岩生烃增压与成岩过程中耗水降压共同作用下的"压-吸充注"是滩坝砂岩大面积含油的主要原因。Beach-bar sandstone is thin and interbedded sediment that was widely developed in the high-energy shallow-shore lake environment.No enough attention has been paid to it and the exploration degree is very low.Focused on the research difficulties of beach-bar sandstone causes and oil accumulation in the upper of Es4 of Dongying Sag,this paper studies sedimentary characteristics,oil-forming factors and enriched regular pattern of beach-bar sandstone.It was suggested that the beach-bar sandstone deposition was controlled by palaeo-geomorphology,palaeo-current and palaeo-base level（three palaeo-controlling sandstone mechanism）,while oil accumulation was controlled by faults and fractures,effective reservoir and overpressure of source rocks（three factor-controlling oil accumulation mechanism）.Long-term palaeo-base level rising and short-term frequent palaeo-base level concussion formed the widespread beach-bar sandstone deposition.The＂pressuresuck filling＂caused by overpressure of source rocks and the water consumption and pressure reduction during the diagenetic process resulted in the widely bearing oils in the beach-bar sandstones.

关 键 词：断陷湖盆 滩坝砂岩 三古控砂 三元控藏 东营凹陷 

分 类 号：P618.130.2[天文地球—矿床学]