东营凹陷北带东部古近系近岸水下扇储集物性演化及其油气成藏模式  

Physical Properties Evolution and Hydrocarbon Accumulation of Paleogene Nearshore Subaqueous Fan in the Eastern North Margin of the Dongying Depression

作　　者：隋风贵[1] 操应长[2] 刘惠民[1] 王艳忠[2] 

机构地区：[1]中国石油化工股份有限公司胜利油田分公司,山东东营257015 [2]中国石油大学地球资源与信息学院,山东东营257061

出　　处：《地质学报》2010年第2期246-256,共11页Acta Geologica Sinica

基　　金：中国石化集团公司"断陷盆地早期充填层系成藏要素与油气富集"项目(编号P0708);教育部新世纪优秀人才支持计划(编号NCET-06-0604);国家油气重大专项(编号2008ZX05051-02);国家自然科学基金项目(编号40972080)资助成果

摘　　要：以东营凹陷北带东部沙河街组三段、四段近岸水下扇为例,应用多种方法求取近岸水下扇有效储层物性下限与埋藏深度的定量函数关系,以此为基础研究了近岸水下扇不同亚相的孔隙度随深度的演化及其对油气成藏的控制作用。埋藏深度小于3200m的近岸水下扇扇根、扇中、扇缘亚相均发育有效储层,主要形成"自生自储"或"古生新储"型构造油气藏或构造-岩性油气藏。埋藏深度大于3200m的近岸水下扇扇根砂砾岩物性低于有效储层物性下限,不发育有效储层,可作为油气侧向封堵层,扇中砂砾岩有效储层发育。物性变化使扇中亚相依靠扇根的侧向封堵和湖相泥岩的封盖形成"自生自储"型岩性油气藏,具有"扇缘输导、扇中富集、扇根封堵"的油气成藏特征。Taking the nearshore subaqueous fan of the third member and the forth member of the Shahejie Formation in t using multiple cutoff values o increasing In he eastern north steep slope zone in the Dongying depression for an example, this study methods obtained the quantitative functional relationship between the physical properties f the effective reservoir and the buried depth, on which the evolution of porosity with depth different suhfacies of nearshore subqueous fan and its controlling on hydrocarbon accumulation were discussed. For the nearshore subqueous fans buried less than 3200 m, their inner fan, middle-fan and outer fan can develop effective reservoirs, forming such reservoir types as ＂self-generating and self-reserving＂ or ＂generating in older formation but reserving in younger formation＂ structural reservoir and the structural-lithologie reservoirs. For the nearshore subqueous fans buried over 3200 m, the physical properties of the inner fan are lower than the cutoff, so there were no effective reservoirs developed; the sand-conglomerate of the middle-fan developed more effective reservoirs. The change of the physical properties resulted in the formation of ＂ self-generating and self-reserving＂ reservoirs which depend on lateral sealing of inner fan and covering of lacustrine mudstone, and are characterized by ＂outer fan migration, middle-fan accumulation, inner fan sealing＂, and the middle-fan formed the ＂self-generating and self-reserving＂ lithologic reservoirs.

关 键 词：近岸水下扇 物性下限 成藏模式 陡坡带 东营凹陷 地质学 

分 类 号：P618.13[天文地球—矿床学]