Abstract:
The Olkaria Domes Geothermal field is situated in the south of Lake Naivasha, in southern sector of
the Kenya Rift system, approximately 120 km northwest of Nairobi city. Geothermal reservoir
evaluation involves various kinds of tests, data interpretation and modelling. In this paper multistage
pressure transient data from ten deep wells obtained at well completion stage were analyzed for the
purpose of obtaining permeability structures. From the results, Injectivity Index ranged from 0.35
lps/bar to 5.56 lps/bar while Transmissivity values ranged from 7.82×109m3
/pa.s to 5.12×10-8 m3
/pa.s. Injectivity-Index and Transmisivity contours indicate higher values in the eastern regions of the
reservoir indicating good permeability and decreases southwest wards. It is recommended that more
production wells be drilled in the eastern region of the geothermal field.
