东北石油大学学报2025，Vol.49Issue(3)：53-67,15.DOI:10.3969/j.issn.2095-4107.2025.03.005
四川盆地东部邻水-丰都地区茅二A亚段沉积演化特征及油气地质意义
Sedimentary evolution characteristics and its petroleum geological significance of subsection A of 2nd mem-ber of the Maokou Formation in the Linshui-Fengdu Area,Eastern Sichuan Basin
摘要
Abstract
Using logging,cuttings,thin-section data from cores,and geochemical test data,this study investigates the distribution characteristics,sedimentary features,and hydrocarbon accumulation condi-tions of subsection A of 2nd member of the Maokou Formation(Mao 2 A Submember)in the Eastern Si-chuan Basin(Linshui-Fengdu Area).The results show that influenced by tectonic movements,sea-level fluctuation and paleotopography,Mao 2 A Submember exhibits a platform-depression differentiation pattern.From the early to the late stages of sedimentation,the shoal bodies of each sublayer show a trend of migrating and extending to the north.The depression area gradually decreases,while the shoal area gradually increases.The hydrocarbons of Mao 2 A Submember itself can originate from the muddy limestone and organic-rich mudstone in the depression-slope area of Dianjiang.The organic carbon mass fraction ranges from 0.43％to 5.17％,and the vitrinite reflectance is between 2.08％and 2.28％,indi-cating that it is an effective hydrocarbon source rock in the over-mature deep high-temperature gas gen-eration stage.The upward-shallowing sedimentary cycles affect the vertical development of reservoirs.The reservoirs are well-developed in the shoal bodies of Mao 2 A Submember at the top of the cycles,forming fracture-pore type reservoirs.Different hydrocarbon sources and the reservoirs in the favorable facies belts of Mao 2 A Submember can be connected through migration pathways to form hydrocarbon accumulation combinations.These combinations include the lower generation and upper storage with the Silurian hydrocarbon source,the upper generation and lower storage with the Longtan Formation hydro-carbon source of the Upper Permian,and the"lateral generation and lateral storage"with the hydrocar-bon source in the depression-slope area of Mao 2 A Submember itself.These results are of guiding sig-nificance for the exploration of large-scale shoal facies in the Maokou Formation in the study area.关键词
四川盆地东部/邻水-丰都地区/茅口组/展布特征/沉积特征/成藏条件Key words
Eastern Sichuan Basin/Linshui-Fengdu Area/Maokou Formation/stratigraphic distribu-tion/sedimentary characteristics/hydrocarbon accumulation conditions分类
能源科技引用本文复制引用
徐姁,庹聪,蔡家兰,陈守春,王欣,汪飒黎,刘昇,陈卫东,唐思琪..四川盆地东部邻水-丰都地区茅二A亚段沉积演化特征及油气地质意义[J].东北石油大学学报,2025,49(3):53-67,15.基金项目
中国石油西南油气田公司重大科技专项(20230301-04) （20230301-04）
