6 Recent Hydrothermal Systems

Abstract

The investigation of recent hydrothermal systems, especially the understanding of their development and structure, is one of the main fields of application of reactive transport simulation models. The aim of numerical studies of recent hydrothermal systems is to set-up or evaluate conceptual models of geothermal areas which are able to describe the processes of fluid flow and heat transfer as well as to explain the formation of observed alteration products. This is the preliminary stage to the application of reactive transport simulation for reservoir management (compare Chap. 7) where evaluated models are used for parameter estimation in response to the exploitation of a hydrothermal system.

Within the first part of this chapter typical, currently published numerical studies of recent hydrothermal systems are summarized. The published case studies describe sophisticated numerical simulations contributing new insights to the understanding of the structure and development of hydrothermal systems. The following second part is a detailed case study of the shallow hydrothermal system of Waiwera (New Zealand). The case study evaluates the proposed conceptual model of the geothermal field and the derived natural state is used for history matching of the exploitation since 1863. Under consideration of the current conditions reservoir development is estimated until the year 2018.