MSc defence by Felix Mutugi Mwarania

Felix Mutugi Mwarania, M.Sc. Fellow in Geology at the University of Iceland will give a lecture on his MSc project on Thursday 15 May, 2014 at 14:00 in VR-II, room 157.

The title of the project is:

Reservoir Evaluation and Modelling of Eburru Geothermal Field, Kenya

Felix's supervisors are: 

Halldór Pálsson, Associate Professor, University of Iceland
Guðni Axelsson, Director of Geothermal Training, Iceland Geosurvey (ÍSOR)
Andri Arnaldsson, Geothermal Reservoir Specialist, Vatnaskil

External examiner will be Jean-Claude C. Berthet, Physicist, Vatnaskil

Everyone's welcome to attend.

Abstract

Production capacity of the Eburru geothermal system is assessed in this study using both volumetric method and numerical modelling. A conceptual reservoir model is first proposed based on the previous geoscientific research and downhole logging data. The Eburru geothermal system covers an area ranging from 1-6 km2 and is confined within the caldera region only. One upflow is exhibited with recharge into the geothermal system occurring from all directions. Volumetric method applied together with Monte Carlo calculations indicates that the reservoir can sustain 7-11 MWe by 90% probability for a period of between 30-50 years. Numerical model simulation is also presented with forward model applied in parameter estimation. The results are achieved through a single run calibration process where the system is driven to a steady-state then automatically proceed to production phase. The model is calibrated using 15kg/s of fluid with 1260kJ/kg injected into a layer above the inactive bedrock. The natural state model matches the observed and simulated response reasonably well but production history match is overestimated. Predictions from the model show that Eburru geothermal field can support 5 MWe for a period of 10 years even without reinjection. However, to double the current production, the model predicts that at least two more wells have to be added. Sensitivity analysis reveal that the reservoir rocks around well EW-06 are the most sensitive to objective function which could probably mean the numerical model is not well constrained and thus partly calibrated.