定边地区前侏罗纪古地貌对油藏分布的影响  

Influence of pre-Jurassic palaeogeomorphology on oil reservoir distribution in Dingbian area

作　　者：黄锦绣[1,2] 杨亚娟[1,2] 张雷[1,2] 张艳[1,2] 

机构地区：[1]中国石油长庆油田分公司勘探开发研究院 [2]低渗透油气田勘探开发国家工程实验室

出　　处：《低渗透油气田》2015年第1期9-14,共6页

基　　金：基金项目：国家科技重大专项“大型油气田及煤层气开发”（编号：2011ZX05044;2011ZX05001-004）.

摘　　要：应用印模法恢复了鄂尔多斯盆地前侏罗纪古地貌形态。研究区古地貌格局由“两河夹一高地”组成，即宁陕古河、蒙陕古河和定边高地。前侏罗纪古地貌控制着下侏罗统延安组早期沉积。延10段属河流沉积环境，发育的沉积相有河床滞留亚相、边滩、心滩亚相、河漫亚相。延9段为三角洲平原亚相，其微相类型主要有分流河道微相、沼泽微相。古河谷的下切作用不仅使延安组下部与油源层的接触距离缩短，又为油气运移提供了良好的通道．如遇到有利的储集体与背斜、鼻隆等构造，即可富集成藏；同时，地层水特征表明斜坡带保存条件最好。依据已探明油田空间分布．结合古地貌形态、上覆层沉积环境、砂体展布、运移通道类型等多种因素，总结出斜坡区一河流相成藏模式和斜坡区一三角洲平原相成藏模式。The pre-Jurassic palaeogeomorphic form is restored in Ordos Basin with an impression method. The palaeogeomorphic pat- tern in the study area consists of ＂a height between two rivers＂, namely Dingbian Height between Ningxia-Shaanxi and Nei Mongolia- Shaanxi paleo-channels. The pre-Jurassic palaeogeomorphology controls the early deposition of the Lower Jurassic YanJan Formation. The Yanl0 Member is in the fluvial depositional environment. The developed sedimentary facies include retention-on-bed, point bar or marginal bank, channel bar, and aUuvial flat sub-facies. The Yah9 Member is delta plain subfacies. Its micro-facies types include mainly distributary channel micro-facies and swamp micro-facies. The down-cutting of the former river valley not only shortens the contact distance between the lower Yan＇an Formation and the source bed, but also provides a good channel for hydrocarbon migration. In case of encountering a favorable reservoir and anticline, nose or other structures it can be enriched into the reservoir. The forma- tion water feature shows that the slope area has the best conservation conditions. Based on the spatial distribution of the proven oil- fields, combined with a variety of factors such as the ancient topography, deposition environment of the overlying strata, sand-bodies distribution, types of migration channels, etc., the ramp area - fluvial facies SRCA and ramp area - delta plain facies SRCA modes are summed up.

关 键 词：定边地区 前侏罗纪 古地貌 延安组 沉积环境 油藏 

分 类 号：P534.52[天文地球—古生物学与地层学]