New Perspectives on Vogel Type <i>IPR</i> Models for Gas Condensate and Solution-Gas Drive Systems

Abstract In this work we propose two new Vogel-type Inflow performance Relations (or IPR ) correlations for gas condensate reservoir systems. One correlation predicts gas production the other predicts condensate production. These correlations link reservoir rock and fluid properties (dewpoint, temperature, and endpoint relative permeabilities) to the flowrate-pressure per-formance for the system. The proposed IPR relationships for compositional reservoir systems are based on data from over 3000 compositional re-servoir simulation runs with various fluid properties and rela-tive permeability curves. The resulting IPR curves for gas condensate systems are quadratic in nature like the Vogel IPR trends (the Vogel profile generally presumed for the case of a solution gas-drive reservoir system). However in the gas con-densate case the coefficients in the quadratic relationship vary significantly depending on the richness of the condensate and the relative permeability. A model to predict these coeffi-cients was developed using an alternating conditional expecta-tion approach (optimal non-parametric regression). This work also includes a discussion of the Vogel IPR for solution-gas drive systems. The original work proposed by Vogel is based on an empirical correlation of numerical simulations for a solution-gas-drive system. Our work provides a critical validation and extension of the Vogel work by esta-blishing a rigorous, yet simple formulation for flowrate-pres-sure performance in terms of effective permeabilities and pres-sure-dependent fluid properties. The direct application of this work is to predict the IPR for a given system directly from rock-fluid properties and fluid pro-perties. This formulation provides a new mechanism that can be used to couple flowrate and pressure behavior for solution-gas-drive systems and it may be possible to extend the concept to gas condensate reservoir systems.