A critical evaluation of preliminary design techniques for steam drive projects

Abstract

Preliminary design is critical for proper application of enhanced oil recovery processes. Initial estimates of overall project performance and economics are based on preliminary design calculations; these in turn establish the advisability of additional investment in the project. For steam drive projects, this design work requires models which accurately predict primary performance parameters, such as oil production schedules and oil/steam ratios ( OSR). This paper presents an evaluation study of four simple and widely used preliminary design models for steam drives: Marx and Langenheim, Myhill and Stegemeier, Gomaa, and Jones; results from these models are history matched with sixteen field projects. Each model is evaluated with respect to instantaneous oil production rate and OSR over the life of the projects. Reservoir characteristics and operating conditions for which each model accurately predicts these parameters are established. The Marx-Langenheim and Myhill-Stegemeier methods generally overpredict instantaneous oil production rates and OSR (sometimes by orders of magnitude), and should not be used in predicting project performance or making design decisions. The models of Gomaa and Jones predict oil production rates and OSR fairly well for some classes of reservoirs, but not so well for other types, and should be used with caution.