Pressure Transients Test Analysis of Well OW-918 at Olkaria Domes Geothermal Field

Evaluation of geothermal reserves involve numerous tests, information interpretation, checking and modelling. This starts from the interpretation of data gathered at the time of single wells testing to modelling of the reaction of geothermal basins to utilization for a number of years. The function of pressure transient�s tests analysis is to determine the variables of the reservoir numerically. Step-rate injection test data and heat-up data from well OW-918 the Olkaria Domes field, have been interpreted by solicitations of sophisticated and current well test interpretations procedures through derivative interpretation using the numerical Well Tester and Mathematical Laboratory (MATLAB) Software. Well OW-918�s total drilled depth is 3000m and Maximum clear depth is 2980m. Temperature reclamation, injection, and transient temperature shapes of the well exposed feeder areas at approximately 800m, 1300m, 2200m and 2700m depths. Hot fluids are encountered at around a depth of 2800m towards the bottom of the well registering temperatures in excess of 2800 C. The well Injectivity index is low around 2.1 (l/s) /bar. The vital reservoir parameter values obtained from the pressure test analysis were as follows; transmissivity (T) of, Storativity (S) of, reservoir thickness (h) of, permeability (k) of and permeability-thickness (kh) of. Therefore these key reservoir parameters reveal that well OW-918 is a good producer which can be harnessed for energy generation. They also suggest that Olkaria Domes subsector is a water dominated basin characterized by good permeability. Drilling of reinjection boreholes in the section around well OW-918 is not desirable. Finally I recommend that better drilling practices be adopted, i. e. , drilling mud need to be changed for future wells that may be drilled in this sector for wells to be stimulated and enhanced connection of the well with the adjacent reservoir.