海相油气地质2026，Vol.31Issue(2)：150-163,14.DOI:10.3969/j.issn.1672-9854.2026.02.004
蜀南地区东部上二叠统长兴组沉积特征及有利储层分布
Sedimentary characteristics and favorable reservoir distribution of the Upper Permian Changxing Formation in the eastern part of southern Sichuan Basin
摘要
Abstract
In recent years,driven by the reef-shoal hydrocarbon accumulation theory,it has been confirmed that the intra-platform shoals of the Changxing Formation in the eastern part of southern Sichuan Basin have good gas-bearing properties.However,the sedimentary system and reservoir distribution of the thick-bedded limestone reservoirs remain unclear,thus restricting the deployment of oil and gas exploration.Based on outcrop,thin section,and well-seismic data,this paper carries out sequence division and third-order framework construction of the Changxing Formation,identifies sedimentary facies by integrating lithofacies,logging facies,and seismic facies,and accordingly analyzes the dominant facies belts of high-quality reservoirs and their favorable distribution areas.The results show that:(1)Three sequence boundaries(SB1,SB2 and SB3)are identified in the Changxing Formation in the eastern part of southern Sichuan Basin,which can be further divided into two third-order sequences(Sq1 and Sq2)from bottom to top.In the early stage,carbonate deep-shallow ramp developed;in the middle-late stage,ramp-type carbonate platform developed.Among these,the intra-platform shoal subfacies of the open platform facies mainly developed during the Sq1-HST and Sq2-HST depositional periods,with the most extensive development occurring particularly in the Sq2-HST period.The shoal bodies exhibite a lateral migration trend in the planar distribution and are only locally superimposed vertically.(2)The reservoir lithology is predominantly bioclastic limestone,with pore spaces and fracture-vug systems serving as the main reservoir spaces.The formation of reservoirs is primarily controlled by sedimentary facies and dissolution processes,and favorable reservoir zones concentrated in the intra-platform shoal subfacies,displaying a scattered patchy distribution.(3)According to the sedimentary facies,the development location and thickness of shoal bodies,and the development thickness of reservoirs,three favorable reservoir development areas and two potentially favorable reservoir development areas are evaluated and predicted:the area around Z207-Z201-Z202 well area,the B28-B61 well area,the B24-G11 well area are classified as favorable reservoir development zones;the BH2-BH3 well area and F7-N49 well are the potential favorable reservoir development zones.The systematic study on the sedimentary facies and reservoir characteristics of the thick-bedded limestone of the Upper Permian Changxing Formation in the eastern part of southern Sichuan Basin provides strong guidance for the next step of oil and gas exploration in the reef-shoal field of this area.关键词
沉积特征/台内滩/储层主控因素/有利储层分布/长兴组/蜀南地区东部/四川盆地Key words
sedimentary characteristics/intra-platform shoal/main controlling factors of reservoirs/favorable reservoir distribution/Changxing Formation/eastern part of southern Sichuan Basin/Sichuan Basin分类
能源科技引用本文复制引用
王玉苗,胡忠贵,武赛军,谢武仁,陈政安,佟伟桀,赵春晖,马银银..蜀南地区东部上二叠统长兴组沉积特征及有利储层分布[J].海相油气地质,2026,31(2):150-163,14.基金项目
本文受新型油气勘探开发国家科技重大专项"四川盆地全油气系统与新领域勘探技术"(编号:2025ZD1400400)、中国石油基础性前瞻性重大科技专项"叠合盆地中下组合叠加地质构造与成因机制研究"(编号:2023ZZ0202)和中国石油天然气集团有限公司科技项目"中国石油重点地区风险勘探目标研究"(编号:2023YQX10101)联合资助 （编号:2025ZD1400400）
