东营凹陷地层水水化学纵向分带性与成岩耗水系统划分

Hydrochemical vertical zoning of formation water and petrogenic water consumption in Dongying sag

成岩作用中发生流体浓缩现象,这对地层水水化学性质及油气成藏具有重要影响。通过综合地质资料统计分析,在东营凹陷地层水水化学演化特征及成岩过程矿物蚀变耗水作用研究的基础上,对研究区成岩耗水系统进行界定,明确了地层水水化学在垂向上明显存在3个特征区带,即浅部1100m以上开放的外循环地下水系统,中部1100～2100m过渡带的复合循环地下水系统,深部2100m以下封闭的内循环地下水系统。耗水区间基本处于封闭水系统环境中,其中有效耗水区间为2100～3500m。

The phenomenon of fluid concentration during diagenesis is very important to the chemical properties of formation water and oil accumulation. Through comprehensive statistical analysis on geological data, the diagenesis systems of water consumption in Dongying sag are derived based on the studies of formation water chemical properties evolution, mineral alteration and water consumption during diagenetic stage in this paper. Vertically, there are obviously three feature zones which are the shallow open external groundwater circulatory system above 1100m, the middle transitional composite groundwater circulatory system from 1100 to 2100m, and the deep closed internal groundwater circulatory system below 2100m. The water consumption section lies in the deep enclosed internal groundwater circulatory system and the efficient water consumption section is from 2100 to 3500m.