Applying Flowrate Type Curves to Geysers Steam Wells

Abstract

Dimensionless flowrate type curves were applied to steam wells at the Geysers in an attempt to quantify reservoir properties and to predict flowrate decline. Although data scatter was a problem, the flowrate data was smoothed by a normalization routine based on the back-pressure equation and the wells were modeled by dimensionless functions for a radial system with a infinite o r finite outer boundary and a constant pressure inner boundary (composite analytical empirical type curve). The "match" resulted in a unique .D. value for use in Arps' equation and k permeability-thickness product (kh) comparable to kh values obtained from pressure buildup analysis. Finally, it was shown that at least four years of data is required to obtain a unique b value.