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

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.