Eburru Geothermal Prospect, Kenya - Joint 1D inversion of MT and TEM Data

Abstract

Eburru Geothermal Prospect, Kenya - Joint 1D inversion of MT and TEM Data Eburru, is a volcano that is North of Olkaria geothermal field found in the kenya rift . It is one of the geothermal fields located south of the equator and is north of Olkaria geothermal field in Kenya. The Eburru volcanic complex is known to have the highest peak in the Rift valley with elevation of about 2800m. This field has been studied actively by Kenya Electricity generating Company (KenGen) since 1987 and these studies led to drilling of 6 exploration wells. This field is currently under development of a 2.5 MW plant by KenGen. Geophysical exploration of this field has been on going and with the main aim of estimating the potential of the field for geothermal exploitation especially for direct utilization of the resource. The area hosting the resource is very important has a significant population and is very important for the development of the region. The Eburru field belongs to the complex of volcanoes -Menegai, Eburru, Olkaria, Longonot, and Suswa-that are centered on the Kenya Dome, and are already being studied to set stage for exploration drilling. Geophysical techniques employed during the campaign included transient electromagnetics (TEM), magnetotellurics (MT). These were employed to image the subsurface for the existence of electrically conductive zones that could be geothermal reservoirs while gravity method previously done in 1990, has been used before to detect the occurrence of dense bodies that are indicative of hot intrusives. the TEM was used to correct for the staic shift in the MT data. The inversion indicates the the resistivity structure of Eburru to depths in the range of kilometers and also indicate a probable reservoir located at about 1.8 km. This paper discusses the results obtained from recent interpretation of 1D inversion of MT and TEM data from Eburru and how this supplement the earlier integrated model of the geothermal system.