鄂尔多斯盆地延长组长2油层组油气富集规律——以永宁油田任山区块为例  

Geological controls on hydrocarbon accumulation of Chang 2 oil reservoir in Ordos Basin:a case from Renshan area,Yongning Oilfield

作　　者：谢伟 王延锋 李红[2] XIEWei;WANG Yanfeng;LI Hong(Zhidan Oil Production Plant,Shaanxi Yanchang Oil(Group)Limited Company,Yan’an 717500,Shaanxi,China;Department of Geology,Northwest University,Xi’an 710069,China)

机构地区：[1]陕西延长油田股份有限公司志丹采油厂,陕西延安717500 [2]西北大学地质学系,西安710069

出　　处：《岩性油气藏》2017年第5期36-45,共10页Lithologic Reservoirs

基　　金：国家自然科学基金项目"中国中西部地质历史时期湖相白云岩类比研究及实验模拟"(编号:41272115)资助

摘　　要：为了探讨鄂尔多斯盆地永宁油田任山区块延长组长2油藏的富集规律,利用岩心分析测试、测井曲线以及试油等资料,对长2油层组的沉积微相、储层特征进行了系统分析。长2油层组发育曲流河沉积体系,由河道砂坝、天然堤及泛滥平原微相构成,其中河道砂坝微相由灰白色长石砂岩及岩屑长石砂岩组成。河道砂坝微相砂岩以长213小层物性最好,平均孔隙度为11.6%,渗透率变化较大,发育残余粒间孔隙和溶蚀孔隙。较为强烈的成岩作用有绿泥石薄膜胶结,自生高岭石胶结及长石、岩屑颗粒的溶解作用,自生伊利石结晶度为0.57~0.88,表明砂岩整体处于中成岩阶段A期。长2油藏的分布受局部构造和供烃条件的控制,充足的油源供应是长2油气成藏的最关键因素,本区西南部靠近长2—长7暗色泥岩发育区,是长2油气最有利富集区。To discuss the geological controls on hydrocarbon accumulation of Chang2reservoirs in Yongning Oilfield,Ordos Basin,based on testing results of fifty core samples,ninety-well logging and oil production data,Chang2sedimentary microfacies and sandstone reservoir properties were analyzed.The Chang2sedimentary system is meandering fluvial,including channel sandbars,natural levees,and flood plains.Channel sandbars are mainly composed of fine to medium grained arkose and debris-arkosic sandstones.The grain sizes of channel sandstones are fining upward and appear“two-segments”in granulation curves.Chang213sandstones is the best reservoir with average porosity of11.6%.The pores of Chang213reservoir are mainly residual intergranular pores and secondary dissolution pores.The cementation of chlorite coating,authigenic kaolinite and dissolution of feldspars and detritus are important diageneses in the sandstones.The crystallinity of authigenic illites ranges from0.57to0.88,which indicates an“A stage”of burial middle digenetic stage.According to analysis of sedimentary facies,reservoir properties,regional structures and distributions of source rocks,the hydrocarbon accumulations of Chang2reservoirs are considered to be controlled by the local nose-like structures and the distance from source rocks.Southwestern Renshan area is potential for Chang2oil exploration.

关 键 词：沉积相 储层特征 油气富集 长2油层组 鄂尔多斯盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]