东营凹陷深层自源型油气成藏模式与勘探实践  

Deep self-source type hydrocarbon accumulation pattern and exploration practice in Dongying Sag

作　　者：杨怀宇[1,2] 张鹏飞 邱贻博[1,2] 巩建强[1] 韩同欣 Yang Huaiyu;Zhang Pengfei;Qiu Yibo;Gong Jianqiang;Han Tongxin(Research Institute of Exploration and Development,Sinopec Shengli Oilfield Company,257000;Post-doctoral Workstation,Sinopec ShengliOilfield Company)

机构地区：[1]中国石化胜利油田分公司勘探开发研究院,257000 [2]中国石化胜利油田博士后流动工作站

出　　处：《中国石油勘探》2023年第2期92-101,共10页China Petroleum Exploration

基　　金：中国石油化工股份有限公司科技攻关项目“济阳坳陷沙四—孔店组成藏条件认识及勘探方向”(P20060-1)。

摘　　要：东营凹陷深层是以“红层”为典型特征的沙河街组四段下亚段(沙四下亚段)—孔店组,该套层系沉积厚度大、储量发现少,蕴含着极大的勘探潜力。综合深层烃源岩评价、高成熟油源对比及自源型油气成藏模式的系统分析,明确了深层沙四下亚段和孔店组二段(孔二段)两套烃源岩的基本特征,落实了深层的资源潜力,同时深入剖析关键成藏要素条件,建立了自源型差异油气成藏模式。研究表明,深层孔二段烃源岩有机质类型为Ⅱ_(1)—Ⅲ型,评价为过成熟中等烃源岩;沙四下亚段烃源岩有机质类型为Ⅰ—Ⅱ_(1)型,评价为成熟优质烃源岩。利用原型盆地的井—震追踪落实烃源岩展布,进而评价出深层资源量为11.35×10^(8)t。同时,建立了两种自源型油气藏的差异成藏模式,一种是陡坡带沙四下亚段烃源岩直接对接深层砂砾岩储层,匹配形成凝析油气—常规油的纵向有序油气藏;另一种是南部斜坡带孔店组源内的“源—断—储—圈”差异油气运聚模式。分析认为,基于东营凹陷深层烃源岩品质与规模的深化认识,以及两种自源型油藏模式的认识可将勘探目的层至少下探1500m,初步估算新增圈闭资源量近2×10^(8)t,东营凹陷深层自源型油藏预计在“十四五”期间迎来重大突破。In Dongying Sag,a typical“red bed”is developed in the deep formation,lower sub member of the fourth member of Shahejie Formation-Kongdian Formation(Es_(4)^(x)-Ek2),which has a large thickness but few discovered reserves,showing a great exploration potential.Based on the comprehensive evaluation of deep source rocks,high mature source rock-oil correlation and systematic analysis of self-source type hydrocarbon accumulation pattern,characteristics of two sets of source rocks in Es_(4)^(x)-Ek2 are determined,and resource potential in the deep formation is identified.In addition,the self-sourced differential hydrocarbon accumulation pattern is established by deeply analyzing the key elements of hydrocarbon accumulation.The study results show that Ek2 source rock is dominated by TypeⅡ_(1)-Ⅲorganic matter,which is over-mature medium source rock,and Es_(4)^(x)source rock is TypeⅠ-Ⅱ_(1)organic matter,which is a set of mature high-quality source rock.The wellseismic tracking of the prototype basin is used to identify the lateral distribution of source rocks,and the estimated resources are 11.35×10^(8)t in deep formations.In addition,two types of differential hydrocarbon accumulation patterns are established.One is a vertically ordered condensate gas-conventional oil reservoir formed by direct connection between Es_(4)^(x)source rock and deep glutenite reservoir in the steep slope zone.The other is the“source rock-fault-reservoir-trap”differential hydrocarbon migration and accumulation pattern within Ek2 source rock in the southern slope zone.Based on the deepening understanding of the quality and scale of deep source rocks in Dongying Sag,as well as the two self-sourced hydrocarbon accumulation patterns,the exploration target can be extended down at least 1500m,and the preliminarily estimated new addition trap resources are nearly 2×10^(8)t.A major breakthrough is expected in the deep self-sourced oil reservoir in Dongying Sag during the 14^(th)Five-Year Plan period.

关 键 词：沙四下亚段—孔店组 深层 自源型油藏 油气藏模式 东营凹陷 勘探实践 

分 类 号：TE111.1[石油与天然气工程—油气勘探]