Resistivity Structure of the Eburru Geothermal Field, Kenya Depicted Through 1D Joint Inversion of MT and TEM data

Abstract

Eburru is one of the geothermal fields in Kenya, producing 2.5 MWe from one of the six exploratory wells. In order to drill production wells, a total of 36 additional MT and TEM soundings were carried out in 2013 to delineate the geothermal resource field of Eburru. This paper discusses and presents the results of the earlier soundings and soundings from 2013 which brought the total number to 43 MT and 43 TEM soundings. The TEMTD program was used for joint 1D inversion of MT and TEM data, the program calculates the shift factor. The MT data are therefore, corrected for the static shift. Data used in this report were acquired by KenGen staff team using data logger MTU-5A made by Phoenix Ltd for acquiring MT data and TerraTEM made by Monex GeoScope Ltd for acquiring TEM data. MT data were processed using SSMT 2000 and MTEditor before jointly inverted with TEM data. The results discussed in this paper present 1D joint inversion, resistivity cross-sections and iso-resistivity maps down to several kilometers. The reservoir in Eburru geothermal field is located at about 2500 m b.g.l according to the sub-surface resistivity structure.