二连盆地洼槽区非常规油气富集模式及勘探潜力  

Enrichment model and exploration potential for unconventional oil and gas in troughs,Erlian Basin

作　　者：项鑫 黄传炎[2] 曹兰柱 曹强 江涛 张宇飞 宋宇 徐婕 XIANG Xin;HUANG Chuanyan;CAO Lanzhu;CAO Qiang;JIANG Tao;ZHANG Yufei;SONG Yu;XU Jie(PetroChina Huabei Oilfield Company,Renqiu 062552,China;School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430000,China;Mud Logging Company,BHDC,CNPC,Renqiu 062552,China)

机构地区：[1]中国石油华北油田公司,河北任丘062552 [2]中国地质大学(武汉)资源学院,湖北武汉430000 [3]中国石油渤海钻探第二录井公司,河北任丘062552

出　　处：《地学前缘》2023年第6期462-472,共11页Earth Science Frontiers

摘　　要：向湖盆中心和深层寻找油气勘探新领域已成为未来主要发展方向。二连盆地剩余油气资源量达8亿吨,主要分布于各富油凹陷洼槽区,以非常规资源形式富存,页岩油潜力巨大。本文通过对富油凹陷洼槽区非常规油气地质特征、成藏富集机理和成藏模式开展研究,总结提升断陷小湖盆洼槽区非常规油气地质理论认识。研究表明:二连盆地多个洼槽区发育互层型页岩油聚集,富集于洼槽区边缘,存在腾二期(120 Ma)未致密先成藏和赛汉期(105 Ma)边致密边成藏(先致密后成藏)两期成藏过程;高充注动力富集区,砂体规模控制页岩油富集程度,低充注动力洼槽区内甜点储层发育及规模控制页岩油富集程度;二连盆地夹层型页岩油存在两种富集机理,即“储层主控”和“生烃主控”。据此,构建了二连盆地斜坡带-洼槽区“常非共存、有序分布、满洼汇聚、差异富集”的全油藏系列成藏模式,研究成果坚定了深入湖盆内部寻找烃源灶边缘互层型页岩油及烃源灶内夹层型页岩油的勘探信心。Oil and gas exploration nowadays is increasingly directed toward the center and deep layers of lake basins.In the Erlian Basin the remaining~800 million tons of unconventional petroleum resources are mainly distributed in troughs of oil-rich depressions,with great shale oil potential.This paper seeks to summarize and improve the theoretical understanding of unconventional petroleum geology in oil-rich lake basins by studying the geological characteristics,accumulation and enrichment mechanism and accumulation model of unconventional oil and gas in the Erlian Basin.The accumulation of interbedded type shale oil in the basin occurs in multiple troughs-preferably at trough edges-via a two-stage process:“accumulation before tightening”(Tenger stage(120 Ma))and“accumulation after tightening”(Saihan stage(105 Ma)).The degree of shale oil enrichment in high-charge dynamic enrichment areas is controlled by sandbody dimensions,while in low-charge areas it is controlled by“sweet-spot”reservoirs development status.And there are two enrichment mechanisms for interlayer type shale oil:“reservoir control”and“hydrocarbon generation control.”Based on these results a hydrocarbon accumulation model is constructed for the entire oil reservoir series in slope belts and troughs of the Erlian Basin,which is summarized as“conventional/unconventional oil coexistence,hydrocarbon orderly distribution,trough-wide accumulation and differential enrichment.”Results of this study boost our confidence in finding interbedded type shale oil at source-rock edges and interlayer type shale oil within source rocks in the interior of lake basins.

关 键 词：页岩油 富集模式 洼槽区 二连盆地 勘探潜力 

分 类 号：P618.130.2[天文地球—矿床学]