【摘要】 在对四川盆地中二叠统茅口组野外剖面和钻井剖面详细研究的基础上,结合测井、地震等资料和前人的研究成果,对四川盆地中二叠统茅口组沉积相进行了分析,将中二叠统茅口组确定为碳酸盐岩台地沉积体系,进一步可划分为浅水开阔台地、较深水开阔台地、台地边缘浅滩和台地前缘斜坡等相类型。浅水开阔台地相包括台内滩和潮下亚相,台地边缘浅滩包括生屑滩和滩间等亚相,台地前缘斜坡相又可分为上斜坡和下斜坡等亚相。四川盆地在中二叠茅口期经历了一次大规模其中包括三次小规模的海侵-海退沉积旋回。将茅口组划分为茅一、茅二、茅三和茅四段,其中茅一下段-茅一上段构成第一沉积旋回,茅二下段-茅二上段组构成第二沉积旋回,茅三段-茅四段构成第三沉积旋回。综合研究表明,台地边缘浅滩为高能型生物滩是储层发展演化的最有利相带,在茅二、三、四段均有发育,且主要分布在盆地的北缘-西南缘,其厚度大、分布较广,是区内最好的勘探相带。在研究区内较深水开阔台地和台地前缘斜坡相纵向上主要分布于茅三、四段,横向上主要分布于盆地的北缘,且较有利于油气的生成与演化。更多还原

【Abstract】 Based on the detailed study of field profile and drillingl sections,combined with well logging and seismic data and previous research results,we analyzed the sedimentary facies of the Maokou formation of middle Permian in Sichuan Basin.The Maokou formation of middle Permian can be defined as carbonate platform sedimentary systems including four major sedimentary facies such as shallow open platform,deeper open platform,platform edge shallow facies and platform margin slope facies.The shallow open platform consists of inner bar and subtidal intrafacies;the platform edge shallow facies includes organic bank and interbank intrafacies;the platform margin slope facies can be divided into the upper slope and lower slope intrafacies.In the Maokou stage of middle Permian,Sichuan basin experienced a largescale and three small-scale transgressive-regressive cyclic deposition.We divided the Maokou formation into four sections such as Mao Ⅰ,Mao Ⅱ,Mao Ⅲ and Mao Ⅳ,in which the lower Mao Ⅰ-the upper Mao Ⅰ sections compose the first sedimentary cycle,the lower Mao Ⅱ-the upper Mao Ⅱ sections compose the second sedimentary cycle and the Mao Ⅲ-Mao Ⅳ sections compose the third sedimentary cycle.Comprehensive study indicates that the platform edge shallow facies with high energy organic bank is the most favorable facies belt for the evolution of the reservoirs.It develops in Mao Ⅱ,Ⅲ and Ⅳ and mainly distributes in the northern margin-southwestern margin of Sichuan basin with large thickness and wide spread.In the study area,deeper open platform and platform margin slope facies mainly distributes in Mao Ⅲ and Mao Ⅳ in vertical and northernpart of the basin in horizontal,so it is more favorable to hy drocarbon generation and evolution.更多还原