苏里格西部盒8段地层水化学特征及其地质意义

Chemical Characteristics and Geological Significance of Formation Water of He-8 Member in Western Sulige Gas Field,Ordos Basin

苏里格气田石盒子组盒8段是气田的主力产层,其地层水矿化度为0.79～99.87 g/L,水型多为CaCl2型。在盒8段同一层段的砂体中,有独立分布的气层或水层,也有气水互层和气水同层等几种分布类型。通过119口井的试气资料及地层水化验数据的分析,绘制了地层水的矿化度图、离子含量比值分布图以及变质程度图等,最终确定了地层水性质及分布与天然气富集的关系,并预测出具有天然气勘探潜力的有利区域。

The He-8 member of Shihezi formation in Sulige gas field is the main production zone,with the formation water salinity of 0.79～99.87g/L and CaCl2 water type.It is found that there exists the independent distribution of gas layer or water layer in this member,and besides,there are 3 types of distribution features,including gas/water layer,interbedded gas/water layer and same gas/water layer in sand body of one interval.Through gas test data and formation water analyses from 119 wells,the formation water salinity,the ions concentration ratio distribution and metamorphosed degree are drawn.Finally,the relationship between the formation water property and distribution and the natural gas enrichment is determined,and the favorable areas with gas exploration potentials are predicted.