Geothermal resource assessment is the process of carrying out surface exploration for geothermal resources as well as developing and updating databases of geothermal potential areas. It is key in defining areas with geothermal potential and mapping out the development strategy for geothermal fields. GDC does this in the country and offers consultancy services within the region.
The geothermal resource assessment function entails siting of wells for exploration, appraisal, production and re-injection. It also includes assessment and evaluation of geothermal resources and monitoring of any possibilities of tectonic and volcanic hazards. Once the surface studies are carried out, geothermal resource assessment experts guide the drillers during the drilling process based on the identified characteristics of the well.
Drilling takes place in three stages - exploration, appraisal and production drilling.
Exploration drilling is drilling for the first time in a geothermal prospect area. It helps the company to know the geological features of a field. The exploratory wells are used to assess if the prospect has viable commercial amounts of the geothermal resource.
Once the exploration drilling process establishes that the field has a commercially viable resource, appraisal drilling is done to understand the potential of the geothermal reservoir before commercial extraction of steam for power generation. It entails drilling several wells in a geothermal field that are used for studies to get the real estimates of a prospect.
Production drilling is done with the purpose of harvesting steam for power generation. It involves drilling many geothermal wells for electricity generation. Production wells are drilled with various objectives including flowing production, artificial lift production, well re-injection and to monitor the performance of a well.
Management of geothermal steam fields involves monitoring of how the wells behave after drilling. Our Geothermal Reservoir Management experts monitor the reservoir in various geothermal fields to ensure that the resource is not depleted during production.
After drilling is conducted successfully and steam realized, geothermal resource management experts analyze the steam being discharged, assess its quality and estimate the capacity of every geothermal well. The information obtained from the steam analysis is used in the design of a power plant.
Geothermal reservoir management takes care of monitoring of the geothermal field during steam extraction including ground subsidence rates or changes in the micro-seismic events levels. Analysis of the extracted steam is also continuously done to monitor the reservoir for any changes.
Sale of steam involves an agreement between Geothermal Development Company (GDC) and KenGen or Independent Power Producers (IPPs) that are awarded the tender for power generation. GDC ensures steady supply of steam to KenGen or IPPs who then convert it into electricity. The pricing of steam is determined by the Government from time to time on project basis.