柴北缘牛东地区古近系/侏罗系不整合结构特征及其控油气作用  

Structural Characteristics and Hydrocarbon Control Action of Paleogene/Jurassic Unconformity in Niudong Area, North Margin of Qaidam Basin

作　　者：任长青 高先志[1,2] 张永庶 王波 侯泽生 何富贵 张涛[4] REN Chang-qing;GAO Xian-zhi;ZHANG Yong-shu;WANG Bo;HOU Ze-sheng;HE Fu-gui;ZHANG Tao(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249;Research Institute of Exploration&Development of Qinghai Oilfield Company,PetroChina,Dunhuang,Gansu 736202;Geological Research Institute of the Fourth Oil Production Plant of Dagang Oilfield,Tianjin 300280)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202 [4]大港油田第四采油厂地质研究所,天津300280

出　　处：《地球学报》2019年第6期795-804,共10页Acta Geoscientica Sinica

基　　金：国家油气重大专项(编号:2016E-0106GF)资助~~

摘　　要：基于野外露头、钻井岩芯、三维地震、测井曲线、岩石薄片以及物性分析等资料,对牛东地区下侏罗统顶部不整合类型、不整合结构特征、不整合结构体物性变化规律以及其连通性进行综合研究。结果表明:牛东地区不整合整体以削截不整合为主,同时局部地区也发育断褶不整合与平行不整合;不整合在研究区分布范围广泛,具有不整合面之上底砾岩、不整合面之下风化黏土层和半风化岩石典型3层结构;不整合各层结构岩石学和测井响应特征均具有不同特征;不整合面之上底砾岩分布稳定且厚度较大,无良好盖层,属于“散失型”运移通道;不整合面之下风化黏土层物性较差为封堵层;不整合面之下半风化岩石物性特征具有明显规律性;依据其变化趋势划分为两段,且油气多分布于上段底部具有较好的储层物性的砂岩层内。根据油源、断层、不整合以及其与油气分布关系,构建了牛东地区不整合-断裂阶梯状油气运聚模式。Based on the comprehensive analysis of the outcrop observing,drilling core,3D seismic,well logging,thin section and physical property data,the type and structure characteristics of unconformity and physical property change law of unconformity structure and its connectivity in the upper Jurassic in the Niudong area were comprehensively studied.The results show that the unconformity is mainly truncated unconformity,and fault-fold unconformity and parallel unconformity are distributed in the local area in Niudong area.The unconformity is widely distributed in the study area,and it has typical three-layer structures:the rocks above the unconformity,weathered clay horizons and semi-weathered rocks;the three-layer structures of unconformity have different characteristics of the lithology and logging.The basal conglomerates above the unconformity surface is stable in distribution and thick in thickness,and has no good caprocks.It belongs to the“dispersive”migration channel.The weathered clay layer under the unconformity surface is the sealing layer due to poor physical properties.The physical characteristics of semi-weathered rocks under unconformity surface have obvious regularity.According to its changing trend,it is divided into two sections.Oil and gas are mostly distributed in sandstone layers with better reservoir performance at the bottom of the upper segment.According to the oil source,fault,unconformity and its distribution with oil and gas,the unconformity-fault step-shaped oil-gas migration and accumulation pattern is constructed in Niudong area.

关 键 词：牛东地区 下侏罗统 不整合 运聚模式 

分 类 号：P542[天文地球—构造地质学] P618[天文地球—地质学]