川东南地区茅口组地震相分析

Analysis of the seismic facies analysis of Maokou Formation in the southeast of Sichuan Basin

针对勘探程度不高、钻井分布不均且以二维地震资料为主的川东南地区,通过对茅口组地震相分析,发现了中高频席状地震相、中低频席状地震相、前积地震相、丘状地震相、波状地震相等多种类型。通过单井相分析和井旁地震响应模式的建立,结合区域地质背景分析并以沉积模式为指导开展了沉积相展布特征研究。认为茅口组沉积时期研究区在开阔台地相的整体背景下,局部发育的点礁、滩体、风化壳喀斯特均是有利储层发育部位,是隐蔽油气藏潜在勘探领域。

In the southeast of Sichuan Basin,the level of exporation is low,well drilling is unevenly distributed and the dominating part is 2D seismic data.By analyzing seismic facies of Maokou Formation,more than five seismic facies are identified,including the medium-high frequency mat-shaped,medium-low frequency mat-shaped,prograding structure,dome-shaped,wave seismic facies in the district.By analysing single-well facies,establishing seismic response model,and combined with the regional geological background,the authors study the sedimentary facies guided by the depositional model.They think that the open platform is the main type of sedimentary facies,and in the local area,there are patch reef,bank reservoirs and karst of weathered crust.They are favorable reservoirs and will be the next prospecting fields.This means that it is quite adapt able to carry out in the relatively low degree exploration areas of lacking drill bores,where it is very difficult to analyse plane sedimentary facies merely by drill bores.