川东北开江-梁平陆棚两侧飞仙关组储层特征

川东北环开江-梁平陆棚地区是我国重要的油气勘探区域之一,该地区储层分布极为复杂,储集性差异很大。为此,基于前人已有工作,根据高分辨率层序地层学原理,综合地震、测井、岩相、露头及薄片等资料,对飞仙关组储集地层特征进行了描述。以层序体系域为单元,在单井高频层序地层划分和对比的基础上,建立了高精度的层序地层格架,并在层序地层格架内等时、动态地揭示了滩体发育特征及控制因素。以普光、元坝两个典型区块为代表,建立了开江-梁平陆棚两侧飞仙关组储层的精细结构模式。研究表明,普光区块储层纵向上可连续发育,横向上有较好的连续性,储层的孔渗性相对较好;元坝区块储层纵向厚度较小,往往靠高频层序的上部和顶部发育,储层总体孔渗性较差。进一步在层序框架内探讨储层的发育分布,对该区域飞仙关组的油气勘探开发具有重要的指导意义。

Reservoir characteristics of the Feixianguan Formation in Kaijiang-Liangping continental shelf flanks, northeastern Sichuan Basin

Kaijiang-Liangping continental shelf in northeastern Sichuan Basin is an important area for petroleum exploration in China.Reservoir distribution is very complicated and the reservoir quality is greatly variable.Based on the previous research,this paper described the reservoir characteristics of the Ferxianguan Formation by using high-resolution sequence stratigraphy and integrating various data such as seismic,logging,lithofacies,outcrop and thin section data.On the basis of high-frequency sequence stratigraphy division and correlation of single well,a high resolution sequence framework was established with system tract as the unit.The development features and factors controlling bank facies reservoirs rocks were analyzed within the framework.Taking Puguang and Yuanba blocks as the case study,we established the fine structure pattern for reservoirs in the Feixianguan Formation.The reservoirs in the Puguang gas field are thick in vertical and continuous in lateral,and have good porosity and permeability.In contrast,the reservoirs in the Yuanba gas field are thin in vertical,commonly occur at the upper or top of the high-frequency sequences,and have poor porosity and permeability as a whole.The further study of reservoir development and distribution within the high-resolution stratigraphic framework is of great significance to the exploration and development in the Feixianguan Formation.