鄂尔多斯盆地陇东地区洪德区块侏罗系延安组油藏富集规律  

Oil enrichment law of the Jurassic Yan’an Formation,Hongde block,Longdong area,Ordos Basin

作　　者：尹帅 邬忠虎[3] 吴晓明 刘建平 谭成仟[1] 王濡岳 袁慧 戴亚威 Yin Shuai;Wu Zhonghu;Wu Xiaoming;Liu Jianping;Tan Chengqian;Wang Ruyue;Yuan Hui;Dai Yawei(School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an,Shaanxi 710065,China;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an Shiyou University,Xi’an,Shaanxi 710065,China;College of Civil Engineering,Guizhou University,Guiyang,Guizhou 550025,China;No.7 Oil Production Plant,Changqing Oilfield Company,PetroChina,Xi’an,Shaanxi 710086,China;Changqing Oilfield Company,PetroChina,Xi’an,Shaanxi 710018,China;Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 102206,China)

机构地区：[1]西安石油大学地球科学与工程学院,陕西西安710065 [2]西安石油大学陕西省油气成藏地质学重点实验室,陕西西安710065 [3]贵州大学土木工程学院,贵州贵阳550025 [4]中国石油长庆油田分公司第七采油厂,陕西西安710086 [5]中国石油长庆油田分公司,陕西西安710018 [6]中国石化石油勘探开发研究院,北京102206

出　　处：《石油与天然气地质》2022年第5期1167-1179,共13页Oil & Gas Geology

基　　金：中国石油长庆油田分公司项目(020-CY7-F051)。

摘　　要：因邻区侏罗系有油气发现,鄂尔多斯盆地陇东地区洪德区块成为了新的勘探目标。以洪德侏罗系延安组为例,综合岩心、测井、地震和试井资料,开展了沉积体系、构造和古地貌研究,分析了古地貌、构造和沉积储层对延安组油藏的控制作用。结果表明,延安组与延长组间存在3个局部不整合面,分别介于富县组和延长组、延(延安组)10油层组和延长组及延9油层组和延长组之间。前侏罗纪古地貌可划分为5类单元,分别为古河谷、河间丘、古阶地、斜坡带和低残丘。其中,斜坡带和低残丘利于成藏;古阶地及古河谷的延10油层组也具有一定成藏潜力。此外,多支沟交汇且经河水反复冲刷的坡嘴位置,砂体泥质组分含量低,也利于成藏。油藏可见明显的油顶及油-水界面。断裂带与砂体走向在平面上互相切割;断层上盘利于成藏,而下盘因无有效封闭遮挡,往往不利于成藏;正断裂较逆断裂更容易成藏。优质沉积储层是延安组成藏的必要不充分条件。基于古地貌、构造及沉积储层三级控藏要素组合,提出了适用于洪德地区侏罗系延安组成藏的判别方法。The Jurassic in the Hongde block,Longdong area,Ordos Basin,has been less explored until some oil discoveries were made in the same system of nearby blocks.The Yan’an Formation in the Hongde block is taken as the subject of study to reveal conditions for possible oil accumulations in the formation based on relevant core,logging,seismic and testing data as well as analyses of sedimentary systems,tectonics and paleo geomorphology-the three most likely controlling factors for oil pooling.The results indicate that from the Yan’an Formation to the Yanchang Formation in the area there are three local unconformities respectively between the Fuxian Formation and the Yanchang Formation,the Yan 10 sub-member(Yan’an Formation)and Yanchang Formation,and the Yan 9 sub-member(Yan’an Formation)and Yanchang Formation.Five types of pre-Jurassic paleomorphologic units are also recognized:the paleovalley,interchannel hill,ancient terrace,slope belt and low residual hill.Among them,the slope belt and low residual hill are conducive to hydrocarbon accumulation,and the ancient terrace and valley in the Yan 10 sub-member also have certain hydrocarbon accumulation potential.In addition,favorable conditions for oil accumulation also exist in the slope mouth where sandbodies have low shale content as several tributaries converged here and washed shale away.Oil caps and oilwater contacts are easily recognized.From a plan view,fault zones are intersecting sandbodies.The hanging walls of faults form perfect traps for oil,while the footwalls,without effective sealing,are usually barren in terms of oil pool.Normal faults are comparatively better oil pool holders than reverse ones.High-quality sedimentary reservoirs are necessary but insufficient conditions for the Yan’an Formation to contain oil pools.Based on the understanding,a method for identifying reservoirs in the Jurassic Yan’an Formation in the Hongde block is proposed.

关 键 词：沉积储层 延安组 古地貌 构造 侏罗系 鄂尔多斯盆地 

分 类 号：TE122.3[石油与天然气工程—油气勘探]