Comprehensive and efficient resource management is an essential part of successful geothermal utilization, in particular to prevent over exploitation and general operational problems. It relies on the proper understanding of the geothermal system involved, which in turn depends on extensive data, information and research.
The most important data on a geothermal system’s nature and properties are obtained through careful monitoring of its response to long-term production. Such monitoring data provides the basis for geothermal reservoir modelling.
Iceland GeoSurvey offers comprehensive services related to the following aspects of geothermal resource management:
The reservoir pressure and temperature are monitored, and the mass and heat transport through wells are measured. This monitoring may be partly or fully automated, or carried out remotely.
The chemical composition of reservoir fluids is monitored by regular sampling and analysis. Changes in the fluid chemistry may provide an early indication of cold water intrusion.
Changes in the reservoir state may be detected by surface observations such as surface elevation measurements, micro-gravity observations, and micro-seismic monitoring.
Geothermal system modelling
A numerical model of a geothermal reservoir is developed. It is used to estimate the production potential of the system and to optimize utilization strategies for the field.
Reinjection research and planning
Numerical models of the reservoir are used to site reinjection wells, and tracer tests are performed to map flow paths in the system. Reinjection of geothermal effluent is generally the preferred method of disposal, but it also serves to extend the useful life of a reservoir.
Ground surface subsidence, gravity changes, the chemical composition and temperature of local ground-water, and gas emissions to the atmosphere are among the environmental parameters monitored. In this way, any adverse effects of geothermal utilization on the environment may be addressed in a timely manner.
The sustainable production potential of a geothermal system is estimated, and its sustainable utilization is planned in accord with various scenarios. Such assessments are based on the premise that the geothermal resource should last for at least 100-300 years with proper management.
Projects in Iceland: In low- and high-enthalpy systems.
Projects worldwide: China, Kenya, Costa Rica, Nicaragua, El Salvador.