天津市奥陶系热储层地热流体水化学特征 及其主要影响因素

天津境内在宝坻断裂以南的广大平原区, 蕴藏着丰富的中低温地热资源。在水平方向上地热流体自北东向南西矿化度逐渐增高, 水质渐趋复杂。其中奥陶系热储层是位于最上层的基岩裂隙型热储层、紧邻上覆的孔隙型热储层。其地热流体的矿化度变化范围是天津地区所有热储层中最大的、水化学类型也出现天津地区所有热储层中所独有的高硫、高钙水型：SO4?Cl-Na?Ca。本文以分布在沧县隆起区中南部的奥陶系地热井为研究重点, 通过地热流体水质检测、岩性化学分析、淋溶实验等手段, 分析了形成奥陶系水质的主要影响因素。

Hydrochemical Properties of Geothermal Fluids in Ordovician Reservoirs of Tianjin and Main Affecting Factors

Tianjin area has abundant mesothermal-epithermal geothermal resources in its vast plain area south of Baodi fault. TDS values of geothermal fluids gradually increase horizontally from northeast to southwest, with the water types becoming increasingly complex. In all these reservoirs, the Ordovician reservoir is the uppermost fractured basement rock reservoir and is adjacent to the upper porous sandstone reservoirs, and the range of its TDS values is the widest, with the water type assuming unique characteristics in all reservoirs, i.e., SO4?Cl-Na?Ca. This paper has dealt mainly with Ordovician heat wells located in the mid-south area of Congxian upheaval, and analyzed the main affecting factors for the formation of Ordovician heat fluid types by such means as geothermal water quality analysis, Lithology Component Appraising and ion elution test.