An Analytical Decline Curve Analysis Model Applied to The Geysers Geothermal Field

Abstract

An analytical decline curve analysis model based on the theory of fluid flow mechanisms was proposed to predict steam production and reserves. Both relative permeability and capillary pressure were considered in this model. The model reveals a linear relationship between the production rate and the reciprocal of the cumulative production. The model was applied to the production data of 61 production wells in The Geysers geothermal field and the expected linear relationship was found, especially during the late period of production. Comparison with common methods to estimate reserves indicates that the new method gives a more definite estimate of reservoir behavior. The method can also calculate two constants obtained from the linear relationship that have physical significance and can be used to characterize the regional geological properties of the reservoir.