Analysis of Deliverability Curve for Evaluating Potential Problems in the Subsurface of Geothermal Field

Abstract

In this study, the deliverability curves of several wells from two geothermal fields, namely geothermal field X and Y are evaluated. From those deliverability curves, it can be analyzed the various problems encountered in the sub-surface wellbore and/or reservoir of a geothermal field. Both qualitative and quantitative interpretations of the deliverability curves are used in the analysis. The analysis is begun with the qualitative interpretation of deliverability curves by comparing them with known typical deliverability curves. Knowing the typical of the deliverability curves, then the properties of wellbore and reservoir are inputted to the coupled wellbore-reservoir model. The suspected parameters represented the potentials problems then are taken into account to get the best matching between measured and calculated parameters, especially the mass flow rates and wellhead pressures. The results of the analysis showed that for the studied fields, the potentials problems in the sub-surface can be categorized as the reservoir pressure decrease, the permeability changes and the fluid phase changes in the reservoir.