鄂尔多斯盆地苏里格地区奥陶系马家沟组马五_(5)亚段沉积特征  

Sedimentary characteristics of Ma 5_(5) sub-member of Ordovician Majiagou Formation in Sulige area,Ordos Basin

作　　者：杜江民 崔子豪 贾志伟[3] 张毅[3] 聂万才 龙鹏宇 刘泊远 DU Jiangmin;CUI Zihao;JIA Zhiwei;ZHANG Yi;NIEWancai;LONG Pengyu;LIU Boyuan(Hebei Key Laboratory of Strategic Critical Mineral Resources,Hebei GEO University,Shijiazhuang 050031,China;College of Earth Sciences,Hebei GEO University,Shijiazhuang 050031,China;PetroChina Southwest Oil&Gas Field Company,Chengdu 610051,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;Department of Natural Gas Evaluation Project,PetroChina Changqing Oilfield Company,Xi’an 710018,China)

机构地区：[1]河北地质大学河北省战略性关键矿产资源重点实验室,石家庄050031 [2]河北地质大学地球科学学院,石家庄050031 [3]中国石油西南油气田公司,成都610051 [4]西南石油大学地球科学与技术学院,成都610500 [5]中国石油长庆油田分公司天然气评价项目部,西安710018

出　　处：《岩性油气藏》2023年第5期37-48,共12页Lithologic Reservoirs

基　　金：河北省高等学校科学技术研究重点项目“海相碳酸盐岩储层白云岩成因机理研究”(编号:ZD2022057)资助。

摘　　要：鄂尔多斯盆地苏里格地区奥陶系马家沟组马五5亚段勘探潜力巨大。通过岩心观察、薄片鉴定、扫描电镜分析和地球化学测试,结合地球物理技术,对苏里格地区奥陶系马家沟组马五_(5)亚段沉积特征进行了系统研究,探讨了其油气地质意义。研究结果表明:(1)苏里格地区奥陶系马家沟组马五_(5)亚段属于整体海侵、晚期海退沉积背景下的向东倾斜的碳酸盐岩台地相,发育开阔台地和局限台地等亚相,可根据成分细分为云坪、灰坪和台内滩、云灰坪、灰云坪等微相。(2)研究区平面上沉积环境呈典型条带状展布,西部地区沉积水体盐度偏高,具有局限台地特征;东部地区沉积水体盐度偏低,具有开阔台地特征。(3)研究区的局限台地与开阔台地内部的低洼区域,高密度富Mg海水汇聚,为白云岩发育的有利区。(4)局限/开阔云坪相、台内滩和含膏云坪微相主要发育各种白云岩储层,连片发育白云岩的西、北部地区是潜在的油气勘探接替领域。The exploration potential of Ma 5_(5) sub-member of Ordovician Majiagou Formation in Sulige area of Ordos Basin is huge.Through core observation,thin section identification,scanning electron microscope and geochemical testing,combined with geophysical technologies,the sedimentary characteristics of Ma 5_(5) sub-member of Ordovician Majiagou Formation in Sulige area were studied,and its petroleum geological significance was discussed.The results show that:(1)The Ma 5_(5) sub-member of Ordovician Majiagou Formation in Sulige area belongs to carbonate platform facies which inclines to the east under the background of overall transgression and late regressions.Open platform and restricted platform subfacies are developed,which can be subdivided into dolomite flat,carbonate flat,and intraplatform shoal,dolomite-carbonate flat and carbonate-dolomite flat according to the composition.(2)In the plane,the sedimentary environment is typical banded distribution,the salinity of the sedimentary water in the western region is relatively high,with restricted platform characteristics,while the salinity of the sedimentary water in the eastern region is low and has the characteristics of open platform.(3)The low-lying areas within the restricted platform and the open platform in the study area,where high-density and Mg-rich seawater converges,are favorable areas for dolomite development.(4)The restricted/open dolomite flat,intraplatform shoal and gypsum-bearing dolomite flat microfacies mainly develop various kinds of dolomite reservoirs.The western and northern areas with contiguous dolomites are potential replacement areas for oil and gas exploration.

关 键 词：开阔台地 局限台地 白云岩储层 马五_(5)亚段 马家沟组 奥陶系 苏里格地区 鄂尔多斯盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]