渝东南地区下三叠统飞二段—飞三段鲕滩分布特征  

Distribution Characteristics of Oolitic Beach in the 2^(nd) and 3^(rd )Members of Lower Triassic Feixianguan Formation,Southeastern Chongqing

作　　者：赵玲丽 宋金民[1,2] 袁海锋[1,2] 徐国盛[1,2] 邓双林 赵聪[4] 金鑫 李立基 李朋武 任佳鑫 李柯然 冯宇翔 范建平 ZHAO Lingli;SONG Jinmin;YUAN Haifeng;XU Guaosheng;DENG Shuanglin;ZHAO Cong;JIN Xin;LI Liji;LI Pengwu;REN Jiaxin;LI Keran;FENG Yuxiang;FAN Jianping(School of Energy,Chengdu University of Technology,Chengdu,Sichuan 610059,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Chengdu University of Technology),Chengdu,Sichuan 610059,China;PetroChina Southwest Oil and Gas Company,Chengdu,Sichuan 610095,China;College of Industrial Technology,Chengdu University of Technology,Yibin,Sichuan 644000,China)

机构地区：[1]成都理工大学能源学院,四川成都610059 [2]油气藏地质及开发工程全国重点实验室(成都理工大学),四川成都610059 [3]中国石油化工股份有限公司西南油气分公司,四川成都610095 [4]成都理工大学产业技术学院,四川宜宾644000

出　　处：《现代地质》2023年第5期1208-1220,共13页Geoscience

基　　金：国家自然科学基金项目“川西地区深层雷口坡组微生物岩及其储层形成机理研究”(41872150);四川省科技厅重点研发项目(2018JZ0078)。

摘　　要：通过野外剖面实测、薄片鉴定、测井数据和地震资料分析,基于岩性-电性标志建立了渝东南地区飞仙关组地层四分的划分方案,并探讨了新方案下飞二段和飞三段的鲕滩分布规律。研究结果表明:飞一段以灰岩和泥灰岩为主,自然伽马(GR)值为80~105 API,电阻率为75~200Ω·m;飞二段以泥晶灰岩和残余砂屑鲕粒白云质(含云)灰岩为主,GR值较飞一段降低至11~31 API,电阻率值较飞一段增高至200~4205Ω·m;飞三段以鲕粒灰岩、砂屑灰岩为主,测井数值较飞二段变化不大,仅在飞三段顶、底部可见局部高GR值;飞四段发育泥质白云岩和泥质灰岩,GR值较飞三段增高至35~66 API,电阻率值降低至74~280Ω·m。在此基础上,明确飞二段滩体发育在渠县—梁平以及丰都—忠县—利川一带,飞三段滩体主要围绕垫江—梁平滩间洼地呈环带状发育,飞三段较飞二段发育的颗粒滩体厚度大、展布范围广、规模大、连通性强。研究区飞仙关期沉积模式为镶边碳酸盐岩台地,明确分层方案后认为伴随飞三期海退,台内滩体中心向东迁移。The Feixianguan Formation(FXGF)subdivision in southeastern Chongqing is established based on the lithologic-electrical identification mark by the outcrop measurement,thin-section microscopic observation,logging data and seismic data analysis.The distribution patterns of oolitic beach in the 2^(nd) and 3^(rd) members of FXGF are discussed.The results show that the stratigraphic framework of FXGF in southeastern Chongqing can be divided into four parts.The FXGF 1st Member is mainly composed of limestone with the characteristics of 80~105 API GR value and 75~200Ω·m LLD value.The FXGF 2^(nd) Member is mainly composed of micritic limestone and silty oolitic limestone.The GR value reduced to 11~31 API,and the resistivity value increased to 200~4205Ω·m compared with the FXGF 2^(nd) Member.While the FXGF 3^(rd) Member is mainly composed of oolitic limestone and silty limestone.The logging value has little change compared with the FXGF 2^(nd) Member.Only the top and bottom of the FXGF 3^(rd) Member can be seen with high GR value.Argillaceous dolomite and argillaceous limestone are developed in the FXGF 4th Member with GR value increasing to 35~66 API and resistivity decreasing to 74~280Ω·m(compared with the FXGF 3^(rd) Member).In the study area,oolitic beach in the FXGF 2^(nd) Member is developed in Quxian-Liangping and Fengdu-Zhongxian-Lichuan areas.Oolitic beaches of the FXGF 3^(rd) Member were mainly developed around the Dianjiang-Liangping intertidal depression,which were distributed in a ring belt.The oolitic beach developed in the FXGF 3^(rd) Member is thicker,more connectivity,more widely distributed,and larger in scale than that in the FXGF 2^(nd) Member.The local sedimentary model during Feixianguan period is a rimmed carbonate platform.After clarifying the stratification scheme,we considered that the beach center in the platform migrated eastward with the regression during the 3^(rd) Member of Feixianguan period.

关 键 词：渝东南 下三叠统 飞仙关组 地层划分 鲕滩 

分 类 号：P618.13[天文地球—矿床学] P588.245[天文地球—地质学]