Preliminary reservoir analysis of Menengai geothermal field exploration wells

Abstract

Drilling in Menengai geothermal field started in February 2011 with the aim of harnessing steam for electricity power production. Three exploration wells have been completed and are still undergoing different measurements and tests. Results of 80 days of flow testing indicate that MW-1 produces two-phase fluid with an enthalpy of over 1200 kJ/kg, and a production capacity of more than 6 MWe. Temperature recovery in MW-2 has been interfered with by the upper cold feed zones. MW-2 transmissivity and storativity values are in the range 8.56×10-8 - 11.7×10-8 m3/Pa·s and 1.48×10-7 - 1.58×10-7 m/Pa, respectively. Heat-up profiles in MW-3 indicate a cold section between 1200 and 1500 m depth, with a conductive section below 1600 m. Preliminary reserve estimation, using volumetric calculation, indicates with 90% confidence that the electricity production within the Menengai caldera could reach 570 MWe for a production period of 30 years and up to 375 MWe for a period of 50 years.