摘要
为了揭示河口坝储层内部结构,提高剩余油描述的精度,指导油藏开发调整,以胜坨油田沙二段8砂组三角洲前缘储层为例,利用密井网条件下的构型分析方法,对河口坝储层进行了分析。研究认为,河口坝储层中发育的沉积界面可分为5级:第5级界面限定河口坝复合体,为稳定分布的泥岩,厚度较大,顶界呈水平产状,底界呈S形产状;第4级界面限定单一河口坝,主要为泥质或钙质非渗透层,在坡折带呈倾斜产状,在湖底平原呈近水平产状,单一河口坝具有S型前积结构和"同期不同体"分布特征;第3级界面限定单一河口坝内部的增生体,主要为薄泥质夹层,与第4级界面有斜交和平行两种产状,增生体具有S型和斜交型两种前积结构。特高含水后期,河口坝储层内部结构特征对剩余油分布的控制作用明显,普遍分布的S型前积结构主导了剩余油的低饱和度均匀分布,局部存在的斜交型前积结构主导了剩余油的差异分布,同期不同体结构主导了剩余油的局部富集。
In order to reveal the inner structure of debouch bar reservoir, to enhance the accuracy of remaining oil description, and to guide reservoir development and adjustment, a typical debouch bar of delta front reservoir in the Es2-8 Formation of Shengtuo Oilfield was characterized by close spacing architectural analysis. The study shows that the depositional interfaces in debouch bar can be classified into 5 levels. The fifth level interface restricts the composite debouch bar, which is thick stable mudstone. The top boundary of the fifth level interface presents a nearly horizontal attitude, and the bottom boundary presents an S shape attitude. The fourth level interface restricts the single debouch bar, which is mainly the muddy or calcareous intercalation with inclined attitude in the slope break belt, and a nearly horizontal attitude in the lake floor plain. The S shape foreset configuration and the independent sand body in contemporaneous deposit are the essential architectural features of the single debouch bar. The third level interface restricts the accretion sand body in the single debouch bar, the attitude of which is oblique or parallel with the fourth level interface. There are two kinds of foreset configuration in the accretion sand body. S shape and oblique crossing shape. At the later stage of extra-high water cut, the inner structure of the debouch bar reservoir displays a very high efficiency control effect on remaining oil distribution. The ubiquitous S shape forest configuration controls the low saturation and homogeneous distribution of the remaining oil; the regional oblique crossing shape foreset configuration controls the differential distribution of the remaining oil, and the architecture of independent sand body in contemporaneous deposit controls the sectional enrichment of the remaining oil.
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2016年第4期56-62,共7页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
国家科技重大专项(2016ZX05011)
中国博士后科学基金资助项目(2012M511542)
关键词
河口坝
沉积界面
结构单元
前积结构
剩余油
debouch bar
depositional interface
architecture unit
foreset configuration
remaining oil
