致密油与页岩油形成条件与“甜点区”评价  

Formation conditions and “sweet spot” evaluation of tight oil and shale oil

作　　者：杨智[1] 侯连华[1] 陶士振[1] 崔景伟[1] 吴松涛[1] 林森虎[1] 潘松圻[1] 

机构地区：[1]中国石油勘探开发研究院

出　　处：《石油勘探与开发》2015年第5期555-565,共11页Petroleum Exploration and Development

基　　金：国家重点基础研究发展计划(973)资助项目(2014CB239000);国家油气重大专项(2011ZX05001)

摘　　要：基于国内外页岩层系液态烃勘探研究成果，对页岩层系液态烃的形成条件、聚集机理、类型划分、海陆相差异进行系统分析，进一步开展“甜点区”研究评价。通过分析北美和中国页岩层系液态烃的地质特征，指出页岩层系液态烃具有大面积连续分布、无稳定自然产能2项基本特征，且“规模区”需具备稳定构造背景、规模优质烃源岩、规模储集空间、源储共生分布等4项形成条件。揭示了页岩层系液态烃源储耦合、致密化减孔聚集机理，划分6项24种不同类型页岩层系液态烃，指出中国陆相页岩具有地热梯度较低和地层非均质性较强两项特征，须优选规模型“甜点区”来稳步推进工业上产。页岩层系液态烃“进源找油”，应着力开展地质、工程和经济“三品质”“甜点区”综合评价，成熟度是控制“甜点区”分布的首要因素。中国陆相有利页岩层系液态烃R。值为0．8％～1-3％，TOC值大于2％，岩性为纹层状页岩或致密孔隙性储集层，孔隙度较高（致密油大于8％，页岩油大于3％），脆性矿物含量高（致密储集层大于70％，页岩大于40％），含油饱和度50％-90％，原油黏度较低或地层压力较高，天然裂缝发育。页岩层系液态烃具有巨量的资源规模，增强海陆相页岩层系液态烃形成分布地质认识，对持续关注、推动这一重大领域的发展具有借鉴意义。Liquid hydrocarbons in shale strata include two kinds of resources, i.e. tight oil and shale oil. Based on the exploration and research progress of liquid hydrocarbons in shale at home and abroad, their formation condition, accumulation mechanism, classification, and differences between lacustrine and marine shale systems are examined, and ＂sweet spots＂ are evaluated further. Analysis on the geological characteristics of the liquid hydrocarbons in the shale strata in North America and China shows the liquid hydrocarbons have two basic features： large-scale continuous distribution and no stable industrial production. The massive accumulation of the liquid hydrocarbons needs four fundamental formation conditions： stable tectonic background, widespread high quality source rocks, large-scale tight reservoirs with massive reservoir space, and co-existence of source and reservoir. The study reveals the formation mechanisms of the liquid hydrocarbons： source-reservoir coupling and porosity decrease during the diagenetic tightness; and identifies 24 kinds in 6 categories of the liquid hydrocarbons. It is concluded that the geological conditions of the lacustrine shales in China are characterized by lower thermal gradient and stronger heterogeneity than those of North America, so large scale ＂sweet spots＂ have to be picked out to push up industrial production steadily. ＂Sweet spots＂ evaluation should consider the three aspects of geology, engineering and economics comprehensively, and the maturity of source rocks is first and foremost factor controlling the ＂sweet spot＂ distribution. In China, prospective shale areas should meet the following conditions： the Ro between 0.8% and 1.3%, TOC higher than 2%, laminated shales or tight porous reservoirs, higher porosity （more than 8% for tight oil, and more than 3% for shale oil）, higher content of brittle minerals （more than 70% for tight oil, and more than 40% for shale oil）, oil saturation of 50%-90%, lower crude oil viscosity or higher formati

关 键 词：致密油 页岩油 “甜点区”评价 非常规油气 细粒沉积 致密储集层 

分 类 号：TE122.1[石油与天然气工程—油气勘探]