四川盆地合川-潼南地区茅二段滩相白云岩储层特征、主控因素及勘探意义  

Characteristics,controlling factors and exploration significance of shoal facies dolomite reservoirs in 2nd member of Maokou Formation in Hechuan-Tongnan area of Sichuan Basin

作　　者：印长海[1,2] 师江波 郑剑锋[3] 王显东 田小彬 鞠林波[1,2] 韦裕琳 汪海燕[1,2] 张慧君 白雪晶[1,2] YIN Changhai;SHI Jiangbo;ZHENG Jianfeng;WANG Xiandong;TIAN Xiaobin;JU Linbo;WEI Yulin;WANG Haiyan;ZHANG Huijun;BAI Xuejing(Exploration and Development Research Institute of PetroChina Daqing Oilfield Co Ltd,Daqing 163712,China;Daqing Oilfield Laboratory of CNPC Key Laboratory of Carbonate Reservoirs,Daqing 163712,China;PetroChina Hangzhou Research Institute of Geology,Hangzhou 310023,China)

机构地区：[1]中国石油大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712 [2]中国石油天然气集团有限公司碳酸盐岩储层重点实验室大庆油田研究分室,黑龙江大庆163712 [3]中国石油杭州地质研究院,浙江杭州310023

出　　处：《大庆石油地质与开发》2023年第1期1-10,共10页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油天然气股份有限公司重大科技项目“深层油气储集层形成机理与分布规律”(2018A-0103);中国石油天然气股份有限公司上游领域基础性前瞻项目“残留型海相盆地构造-岩相古地理重建技术研究”(2021DJ0501)。

摘　　要：由于四川盆地合川-潼南地区二叠系茅口组二段白云岩储层特征、主控因素认识不清,严重制约了勘探目标选择。厘清茅口组白云岩发育特征及主控因素是预测白云岩储层分布的关键,基于岩心、测井资料、岩石学、地球化学和年代学技术,开展白云岩储层的岩石类型、储集空间、储层类型、物性特征以及储层主控因素分析,并通过井震结合预测了储层分布。结果表明:茅二段白云岩储层岩性以细-中晶云岩、残余颗粒云岩为主,储集空间主要为粒内溶孔、晶间(溶)孔、溶洞及构造缝和溶缝,为低孔、低渗储层;白云岩储层主要发育在茅二段中部,横向分布稳定,在古地貌高部位的储层单层厚度大,叠置连片;古地貌背景下的滩相沉积、准同生岩溶作用、准同生白云岩化作用及构造断裂作用共同控制了茅二段白云岩储层的发育和分布;储层厚度与地震振幅呈正相关性,茅二段白云岩储层发育面积约为1250 km^(2),主要分布在矿权区中部和东北部地区,与茅二段古地貌高隆起带基本吻合。研究成果促进了川中地区茅口组勘探思路的转变,可有效支撑下一步勘探部署。Unclear understanding of characteristics and controlling factors of dolomite reservoirs in 2nd member of Permian Maokou Formation in Hechuan-Tongnan area of Sichuan Basin seriously restricts exploration target selection.Determination of dolomite development characteristics of Maokou Formation is the key for predicting dolomite reservoirs distribution.Rock types,reservoir space,reservoir types and reservoir properties are analyzed based on core and logging data,petrology,geochemistry and chronological techniques,and reservoir distribution is predicted by well-seismic tie.The results show that dolomite reservoirs in 2nd member of Maokou Formation have lithology dominated by fine-medium crystalline dolomite and residual granular dolomite,and accumulation space dominated by intergranular dissolution pores,intercrystalline(dissolution)pores,vugs,structural fractures and dissolution fractures,being low porosity and low permeability reservoirs.Dolomite reservoirs are mainly developed in middle part of 2nd member of Maokou Formation with stable lateral distribution.Reservoirs in high position of paleogeomorphology present superimposed continuous extension with large single layer thickness.The development and distribution of dolomite reservoirs in 2nd member of Maokou Formation are controlled by shoal facies deposition,penecontemporaneous karstification,penecontemporaneous dolomitization and structural faults in paleogeomorphology background.Reservoir thickness are positively correlated with seismic amplitude.Dolomite reservoirs in 2nd member of Maokou Formation are mainly distributed in central part and northeast part of loyalty area with approximate area of 1250 km^(2),being generally consistent with high-uplift zone of paleogeomorphology.The research promotes the transformation of exploration ideas and effectively supports further exploration deployment of Maokou Formation in central Sichuan area.

关 键 词：四川盆地 合川-潼南地区 茅口组 白云岩储层 主控因素 勘探意义 

分 类 号：TE122.23[石油与天然气工程—油气勘探]