苏西盒8气藏气井产水成因剖析

GENESIS OF PRODUCED WATER IN HE8 RESERVOIR OF SUXI GAS FIELD

在岩性气藏开发过程中,气井产水存在多种类型,气水分布在纵向和横向上都相对复杂。根据试气、测井和生产动态资料,将苏西盒8气藏气井产水划分为纯水层、致密水层和气层产水三种类型,分析认为主要受构造条件,砂体分布,成藏环境,储层岩性与物性方面控制。除局部边底水类型的纯水层外,在盒8气藏部份井区中,孔隙中残留了大量地层水的主要原因是由于储层条件变差,气体驱替能量不足以使水大规模排驱而造成的,进而形成致密产水层和气层产少量水。

The type of underground water is quite confusing in lithologic gas reservoir,which has complex distribution of aquifer spatially.Based on wire-line logging and trial production information,the origination of produced water is classified as aquifer,tight sand aquifer and remnant water in pay zone,and the discrimination between them is also clarified.It is concluded that the distribution of sand channel,the micro-tectonics of the zone,the migration process of hydrocarbon and the heterogeneity of sand are the controlling factors of aquifer distribution in lithologic gas reservoir.Besides the normal aquifer,due to the deficiency of gas energy,the local tight zones in some parts of sand body permit the preservation of abundant formation water,the typical tight aquifer and remnant water in pay zone is formed.The classification of aquifer can be a key role in the deployment of production well and offers reference for the development of the seminal gas reservoir.