渤海湾盆地某油田混积岩名称厘定及储层特征

Name determination and reservoir characteristics of diamictite ina certain oilfield of Bohai Bay Basin

勘探开发实践表明,混积岩储层逐渐成为一类重要的油气储集体,但是在混积岩研究中存在着一些最基本但仍具争议的问题,比如关于混积岩的概念,一般指的是陆源碎屑岩与碳酸盐岩在沉积上的混合,但除此之外混入了火山碎屑岩或其他岩性成分后是否仍可定义为混积岩?在对渤海湾盆地某油田沙一段储层研究过程中发现了一种复杂岩性,其组分包括陆源沉积的砂砾岩、碳酸盐成因的生屑白云岩以及火山碎屑成因的沉凝灰岩,通过岩石学了特征及成因分析,将其厘定为广义的混积岩,并从储层物性、孔隙结构等方面研究了其储层特征,结果表明:混积岩储层整体表现为低孔低渗特征,但储层非均质性较强,局部发育甜点,可形成优质储层。关于混积岩名称厘定及储层特征的研究,是对混积岩基础研究的一种有效拓展和补充。

Diamictite has gradually become an important type of oil and gas reservoir through exploration and development practice.But there are some basic and controversial problems during diamictite research,such as the concept of diamictite,which generally refers to the sedimentary mixing of terrigenous clasts and carbonate.In addition,can it still be defined as the diamictite after mixing pyroclastic rock or other lithologic components?A complex lithology was discovered during the process of studying Es1 member reservoir of a certain oilfield in Bohai Bay Basin,and it was consisted of terrigenous sedimentary glutenite,bioclastic dolomite of carbonate origin and sedimentary tuff of pyroclastic origin.So,it was determined as a generalized diamictite through petrological characteristics and genetic analysis,and its reservoir characteristics were studied from the aspects of reservoir physical properties and pore structure.The results show that the reservoir is characterized by low porosity and low permeability,but the diamictite reservoir heterogeneity is strong,so it could be a high-quality reservoir with locally developed desserts.The study on the definition of the diamictite name and reservoir characteristics in this paper is an effective expansion and supplement to the basic research of diamictite.