鄂尔多斯盆地靖边气田南部马五_(4)亚段沉积相特征及演化  

Characteristics and evolution of sub-member Ma_(5)^(4) of Majiagou Formation in southern Jingbian gas field,Ordos Basin

作　　者：李百强 郭艳琴[3,4] 徐宏杰[1] 吴珍珍 王起琮[3,4] 张小莉 巨银娟[2] 李文厚 LI Baiqiang;GUO Yanqin;XU Hongjie;WU Zhenzhen;WANG Qicong;ZHANG Xiaoli;JU Yinjuan;LI Wenhou(School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,China;Department of Geology/State Key Laboratory of Continental Dynamics,Northwest University,Xi’an 710069,China;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an Shiyou University,Xi’an 710065,China;School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an 710065,China)

机构地区：[1]安徽理工大学地球与环境学院,安徽淮南232001 [2]西北大学地质学系/大陆动力学国家重点实验室,陕西西安710069 [3]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 [4]西安石油大学地球科学与工程学院,陕西西安710065

出　　处：《西北大学学报（自然科学版）》2024年第6期993-1003,共11页Journal of Northwest University（Natural Science Edition）

基　　金：安徽理工大学高层次引进人才科研启动基金(2023yjrc81);西北大学大陆动力学国家重点实验室开放基金(23LCD07);陕西省油气成藏地质学重点实验室开放基金(PAG-202401);国家“十三五”科技重大专项专题(2017ZX05005-002-04)。

摘　　要：奥陶系马家沟组五段4亚段(以下简称“马五_(4)亚段”)是靖边气田继马五5亚段之后重要的天然气接替产层之一,但其沉积微相研究相对薄弱,限制了对该气田马五_(4)亚段的碳酸盐岩储层发育及天然气分布有利区的合理、准确预测。以靖边气田南部为例,在已有区域沉积背景研究成果的基础上,通过岩心观察、薄片鉴定和沉积相测井解释,识别研究区马五_(4)亚段的沉积微相类型并刻画其平面展布特征,明确区内马五_(4)亚段各小层沉积微相纵向演化规律。结果表明,靖边气田南部马五_(4)亚段中、西部整体为局限台地亚相沉积,发育含灰云坪、灰云坪、含泥云坪、泥云坪、云泥坪以及含泥含灰云坪微相,蒸发台地主要分布于研究区东部,沉积微相类型以含膏云坪和含膏湖为主。马五_(4)^(3)小层整体发育局限台地亚相,含泥云坪和泥云坪分布面积最广;马五_(4)^(2)小层沉积时期,研究区东部蒸发台地沉积范围略有增加;马五_(4)^(1b)小层沉积时期,陆源泥质输入再次明显增加,中部地区广泛发育泥云坪沉积;马五_(4)^(1a)小层沉积时期,陆源泥质输入减少,区内广泛发育灰云坪沉积微相,局部地区发育蒸发台地亚相。沉积微相对天然气分布具有明显控制作用,灰云坪和含泥云坪为研究区马五_(4)亚段天然气分布的有利沉积微相。研究成果可以为靖边气田碳酸盐岩储层分布有利区预测及天然气勘探开发方案部署提供科学依据。As one of the critical replacement production layers following the Sub-member Ma 55 of the Ordovician Majiagou Formation in the Jingbian gas field,the sub-member Ma_(5)^(4)is limited in the reasonable and accurate prediction for the carbonate reservoir development and natural gas distribution because of the weak analysis on the sedimentary microfacies.Taking the southern Jingbian gas field as an example,the sedimentary microfacies type were identified and the planar distribution law was described,and the evolution law of sedimentary microfacies of different layers from the sub-member Ma_(5)^(4)was made clear in this paper through core observation,thin section identification and logging interpretation for sedimentary facies.The results show that the sedimentary subfacies of the sub-member Ma_(5)^(4)is dominated by restricted platform in the central and western study area,including lime-bearing dolomite flat,calciferous dolomite flat,mud-bearing dolomite flat,argillaceous dolomite flat,dolomitic mud flat,and mud-lime bearing dolomite flat.The evaporation platform is mainly distributed in the eastern study area,and dominated by gypsiferous dolomite flat and gypsiferous lake.The Ma_(5)^(4-3)layer is dominated by restricted platform,with the largest area of mud-bearing dolomite flat and mud dolomite flat development.During the sedimentary period of Ma_(5)^(4-2)layer,the evaporation platform area in the eastern study area increased.The content of terrigenous mud increases again when in the Ma_(5)^(4-1b)layer sedimentary period resulting in the extensive development of mud dolomite flat in the central study area,while decreases during the Ma_(5)^(4-1a)layer sedimentary period resulting in the extensive distribution of calciferous dolomite flat development with local development of evaporation platform.The natural gas distribution is controlled obviously by sedimentary microfacies.The calciferous dolomite flat and mud-bearing dolomite flat are the favorable sedimentary microfacies for natural gas distribution of sub-memb

关 键 词：沉积微相 碳酸盐岩 马家沟组 靖边气田 鄂尔多斯盆地 

分 类 号：P631.81[天文地球—地质矿产勘探]