Overview of Geothermal Development at Olkaria in Kenya
The Olkaria geothermal field has been under continuous development since 1970. A feasibility study, completed in 1976, after six wells had been drilled and tested, indicated that development of the Olkaria field was feasible. The feasibility study was followed by production drilling and the construction of three 15 MW generating units. The first unit was brought on stream in July 1981, the second in December, 1982, and the third is scheduled to be completed in early 1985. The current output of 19 productive wells is equivalent to 46 MWe. Distribution of fumaroles and resistivity surveys indicate an areal extent of some 80 km{sup 2} for the Olkaria geothermal field. Gas chemistry of fumaroles indicates comparable underground temperatures over the whole field, 200-250{degrees}C. The capacity of the resource has been estimated to be 500-1000 MW electric for a production period of 25 years. Most of the drilling has been confined to a small part of the geothermal field. Here maximum recorded downhole temperature is 339{degrees}C and temperatures follow the boiling point curve with depth. A thin steam zone at 240{degrees}C is observed in the top of the reservoir at approximately 600-700 m depth. The reservoir fluid is dilute, of the sodium chloride type, contains chloride in the range of 200-700 ppm. The reservoir rocks consist of a sequence of near horizontal lavas and tuffs of trachytic composition, but basaltic andesites have also beenidentified. The drilled rocks at Olkaria are of relatively low permeability, the average yield of wells being equivalent to about 2.5 MWe. Exploratory drilling is presently in porgress in the Olkaria field, the aim being to locate new production areas withing the field. Three holes have been completed and the forth and last hole under the present plan is being drilled.
- Research Organization:
- VIRKIR Consulting Group Ltd., Reykjavik, Iceland
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- AT03-80SF11459
- OSTI ID:
- 889482
- Report Number(s):
- SGP-TR-74-6
- Resource Relation:
- Conference: Proceedings, Ninth Workshop Geothermal Reservoir Engineering, Stanford University, Stanford Calif., December 13-15, 1983
- Country of Publication:
- United States
- Language:
- English
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