柴达木盆地七个泉地区渐新世沉积特征与隐蔽油藏预测  

Analysis of Oligocene sedimentary characteristics and subtle oil reservoir prediction in the Qigequan area,Qaidam Basin

作　　者：赵谦[1] 周江羽[1] 李兰斌[1] 刘馨遥[1] 张臣 光佳敏 Zhao Qian;Zhou Jiangyu;Li Lanbin;Liu Xinyao;Zhang Chen;Guang Jiamin(Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,China University of Geosciences(Wuhan),Wuhan City,Hubei Province,430074,China;Shanxi CBM Exploration and Development Branch,Huabei Oilfield Company,PetroChina,Jincheng City,Shanxi Province,048000,China)

机构地区：[1]中国地质大学(武汉)构造与油气资源教育部重点实验室,湖北武汉430074 [2]中国石油华北油田分公司山西煤层气勘探开发分公司,山西晋城048000

出　　处：《油气地质与采收率》2017年第4期22-29,共8页Petroleum Geology and Recovery Efficiency

基　　金：国家自然科学基金项目“页岩中的后油沥青孔隙体系:基本特征、形成机制与页岩油气地质意义”(41372112);“南海北部陆缘大型深水峡谷体系形成机制及充填构型对比研究”(41572109)

摘　　要：在油气开发的后期阶段，特别是构造油气藏已经不能满足生产需要的时候，利用层序精细划分和沉积微相分析等方法来寻找隐蔽油藏就显得尤为重要。通过对三维地震、钻井岩心、测井曲线等资料进行综合分析，利用三维地震资料控制沉积相空间展布，利用钻井和录井资料划分砂体小层，并将两者结合起来对柴达木盆地七个泉地区沉积相和层序进行精细刻画，同时在沉积相带内和层序格架之下研究砂体的连通性和空间展布。结果表明，在SSC5—SSC3沉积时期，研究区沉积主要以退积为主，在SSC2沉积时期经历了一次快速的水退过程之后，SSC2—SSC1沉积时期沉积基准面持续下降，后期主要以扇三角洲沉积为主。研究区渐新世下干柴沟组下段主要发育湖泊—扇三角洲和辫状河三角洲沉积。辫状河三角洲沉积发育水下分流河道、水下分流河道间、河口坝和席状砂沉积微相；扇三角洲发育扇三角洲平原和扇三角洲前缘亚相。通过对砂体展布和砂体孔渗性以及试油结果的研究，并依据沉积相与层序格架分析，预测在七32井区附近发育的斜坡带砂岩透镜体和上倾尖灭砂体是岩性油藏勘探的重点目标。It is very important to find the subtle reservoir by using the fine division of the sequence and the analysis of the sedimentary microfacies in the late stages of oil and gas exploration,especially when the structural oil-gas reservoirs are unable to meet the production needs.Through the comprehensive analysis of3D seismic,drilling core and well log data,etc.the spatial distribution of sedimentary facies was determined by using3D seismic data,layers of sandbodies were divided by drilling and log data,by which the sedimentary facies and the sequence of the Qigequan area were described finely.And then the connectivity and spatial distribution of sandbodies were studied based on the sedimentary facies and sequence framework.The results show that the retrogradation is dominant during SSC5-SSC3sedimentary period in the study area.After one regressive process occurs rapidly during SSC2,the sedimentary base level continues to decline during SSC2-SSC1sedimentary period,and the fan delta sedimentation is dominant at the later period.It is found there are fan delta sedimentary facies and braided river delta sedimentary facies in the research area of lower member of Xiaganchaigou Formation of Oligocene.The braided river delta includes microfacies of underwater distributary channel,underwater distributary interchannel,mouth bar and sheet sand.Sedimentary facies of fan delta is divided into two subfacies:fan delta plain and fan delta front.According to the distribution of sandbodies and the porosity and permeability analysis and on the basis of sedimentary facies and sequence stratigraphic analysis,it is concluded that the sandstone lens and up-dip sandstone pinchout in the slope break near Well Qi32are the key targets of reservoir exploration.

关 键 词：沉积特征 隐蔽油藏预测 下干柴沟组下段 七个泉地区 柴达木盆地 

分 类 号：TE111.3[石油与天然气工程—油气勘探]