鄂尔多斯盆地吴起地区古地貌对侏罗系下部油藏形成和富集控制机制分析  

ANALYSIS ON THE FORMATION AND ENRICHMENT CONTROL MECHANISM OF THE LOWER JURASSIC RESERVOIRS BY PALEO-GEOMORPHOLOGY OF WUQI AREA IN THE ORDOS BASIN

作　　者：蒋代琴 文志刚[1,2] 汤仁文 贺彤彤 JIANG Daiqin;WEN Zhigang;TANG Renwen;HE Tongtong(Key Laboratory of Oil and Gas Resources and Exploration Technology,Ministry of Education,Yangtze University,Wuhan 430100,Hubei,China;College of Resources and Environment,Yangtze University,Wuhan 430100,Hubei,China;The ninth Oil Production Plant of Changqing Oilfield Company,Yinchuan 750000,Ningxia,China)

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100 [2]长江大学资源与环境学院,湖北武汉430100 [3]长庆油田分公司第九采油厂,宁夏银川750000

出　　处：《地质力学学报》2018年第5期627-634,共8页Journal of Geomechanics

基　　金：国家科技重大专项(2011ZX05033-004)

摘　　要：为了研究吴起地区侏罗系古地貌油藏成藏主控因素,采用沉积学古地貌恢复法,依据富县组+延10地层砂体厚度刻画吴起地区侏罗系古水系分布,结合鄂尔多斯盆地前侏罗纪古地质特征,对吴起地区古地貌特征及侏罗系下部油藏成藏和富集规律进行了研究,在此基础上总结了油气成藏模式。研究表明:吴起地区发育下切河谷、斜坡带和河间丘三种古地形。前侏罗纪古地形控制着侏罗纪早期地层的沉积和油藏的分布,富县组地层与延长组之间的角度不整合剥蚀面和侵蚀河谷厚层高渗砂体是石油运移的主要通道,同时高渗砂体也是侏罗系下部油藏的主要储集体。依据侏罗系下部油藏的空间分布,结合古地貌、沉积环境、微构造特征等多方面因素总结出吴起地区侏罗系古地貌油藏的3种成藏模式:斜坡式、河间丘式和古河式,其中河间丘式油藏最为发育。In order to study the main controlling factors of the accumulation of Jurassic paleogeomorphic reservoir in Wuqi area, sedimentological paleogeomorphic restoration method was mainly used to describe the distribution of Jurassic paleodrainage system in Wuqi area according to the sand body thickness of the Fuxian Formation ＋Yan 10 Formation. Combined with the pre-Jurassic paleogeological characteristics of the Ordos Basin, the paleogeomorphic characteristics of the Wuqi area and the accumulation and enrichment of lower Jurassic were studied, and the hydrocarbon accumulation model was summarized. The results shows that there are three ancient terrains in Wuqi area： incised valley, slope zone and mound. The pre-Jurassic paleotopography controls the deposition of the early Jurassic strata and the distribution of oil reservoirs. The main channels for oil migration are the angle unconformity and the erosion between the Fuxian Formation and the Yanchang Formation and the thick high-permeable sand bodies in valley. At the same time, the high-pemleable sand bodies also the main reservoirs of the lower Jurassic oil reservoirs. According to the spatial distribution of the lower Jurassic reservoirs, combined with various factors such as paleogeomorphology, sedimentary environment and micro-structural characteristics, three types of hydrocarbon accumulation models of Jurassic paleogeomorphology reservoirs in Wuqi area are summarized： slope model, mound model and paleo-valley model, of which mound model reservoirs are the most developed.

关 键 词：成藏模式 古地貌特征 侏罗系 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]