鄂尔多斯盆地南部旬宜地区古生界天然气成藏条件及主控因素  

Palaeozoic gas reservoir-forming conditions and main controlling factors in Xunyi area,southern Ordos Basin

作　　者：关蕴文 苏思羽 蒲仁海[1] 王启超 闫肃杰 张仲培[3] 陈硕 梁东歌 Guan Yunwen;Su Siyu;Pu Renhai;Wang Qichao;Yan Sujie;Zhang Zhongpei;Chen Shuo;Liang Dongge(Department of Geology,Northwest University,Xi’an 710069,China;Shaanxi Coalfield Geophysical Surveying and Mapping Co.,Ltd,Xi’an 710069,China;Sinopec Petroleum Exploration and Production Research Institute,Beijing 102206,China;The Second Gas Production Plant,Changqing Oilfield Company,Yulin 719000,Shannxi,China)

机构地区：[1]西北大学地质学系,西安710069 [2]陕西省煤田物探测绘有限公司,西安710000 [3]中国石化石油勘探开发研究院,北京102206 [4]中国石油长庆油田分公司第二采气厂,陕西榆林719000

出　　处：《岩性油气藏》2024年第6期77-88,共12页Lithologic Reservoirs

基　　金：中国石化科技部项目“中西部叠合盆地重点领域成藏富集规律与突破区带评价优选”(编号:P24167)资助。

摘　　要：鄂尔多斯盆地南部古生界勘探开发前景广阔,但勘探成效不理想。基于最新钻井岩心分析测试资料、测井资料、二维/三维地震资料等,对旬宜古生界气源条件、储层质量、源储配置、断裂输导性等4个方面分别进行了评价。研究结果表明:①鄂尔多斯盆地南部旬宜地区发育太原组—山西组黑色煤岩、黑色炭质泥岩、深灰色、灰色泥岩等潜在烃源岩类型,有机质类型均为Ⅲ型,Ro为1.8%~2.5%,热演化程度较高,黑色煤岩、黑色炭质泥岩品质要高于深灰色、灰色泥岩,具有较好的生烃潜力。②研究区储层均为超低孔、超低渗储层,上古生界山西组和下石盒子组盒1段为碎屑岩储层,杂砂岩占比79%,杂基平均体积分数为29%,孔隙类型以粒间孔和次生溶孔为主,面孔率小于3%。盒1段为强胶结—弱溶蚀相,山西组为强压实—杂基强充填相。下古生界马家沟组碳酸盐岩优质储层岩性为砂屑云岩,储集空间以溶蚀孔、晶间孔和裂缝为主。③古生界源储配置关系包括下生上储、上生下储及旁生侧储,其中下古生界马家沟组主要为旁生侧储。研究区3期断裂分别发育于古生代、三叠纪、晚侏罗纪,其中晚侏罗纪的活动断裂具有良好的流体纵向输导作用。④下古生界天然气藏受控于前石炭纪古地貌,剥蚀厚度大的古洼槽东侧毗邻区是下古生界油气聚集的有利区带;上古生界气藏受控于有效输导体系,研究区北部储层物性差且缺乏开启性通源断裂是上古生界勘探失利的主要原因。The exploration and development prospects of the Paleozoic area in the southern Ordos Basin are promising,but the exploration results have been unsatisfactory.Based on the latest core analysis,data of logging and 2D/3D seismic,a comprehensive evaluation was conducted for the Palaeozoic of Xunyi area.This evaluation focused on four aspects:gas source conditions,reservoir quality,source-reservoir configuration,and fracture conductivity.The results show that:(1)In the Xunyi area,potential hydrocarbon source rock types have been identified in the Taiyuan-Shanxi formations:black coal rock,black carbonaceous mudstone,dark gray,and gray mudstone.The organic matter types are all TypeⅢ,with a vitrinite reflectance(Ro)ranging from 1.8%to 2.5%,indicating a high level of thermal maturity.The black coal rock and carbonaceous mudstone exhibit better hydrocarbon generation potential compared to the dark gray and gray mudstones.(2)The reservoirs are characterized by ultra-low porosity and ultra-low permeability.The upper Paleozoic Shanxi Formation and He 1 member consist of clastic rock reservoirs,with lithic sandstones accounting for 79%,and matrix content averaging 29%.The pore types are mainly intergranular and secondary dissolution pores,with plane porosity lower than 3%.The He 1 member is characterized by strong cementation and weak dissolution facies,while the Shanxi Formation exhibits strong compaction and matrix-rich infill facies.The high-quality carbonate reservoirs of the lower Paleozoic Majiagou Formation are dominated by sandy dolomite,with storage space mainly comprising dissolution pores,intercrystalline pores,and fractures.(3)The Paleozoic source-reservoir configurations include“lower-generation upper-storage”,“upper-generation lower-storage”,and“adjacent lateral-storage”configurations.Among these,the adjacent lateral-storage configuration is the favorable source-reservoir combination for the lower Paleozoic Majiagou Formation.The Xunyi area experienced three phases of fault development:Paleozoic,Tr

关 键 词：天然气 成藏条件 储层特征 源储配置 断裂控藏 古生界 旬宜地区 鄂尔多斯盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]