Investigation into the capability of a modern decline curve analysis for gas condensate reservoirs

Abstract

Techniques of production data analysis for single-phase oil and gas reservoirs have advanced significantly over the past few years. These techniques range from traditional (Arps and Fetkovich) to modern (for the variation of operating conditions at the wellbore). The application of these techniques for analysis of the production data of a gas condensate reservoir may not yield reliable answers due to the fact that the flow of fluid in gas condensate reservoirs is not single-phase. This paper presents the treatment of a modern method of production data analysis (single-phase flow) to analyze the production data of a gas condensate reservoir (two-phase flow). For this purpose, a single-phase production model is presented. Using a compositional reservoir simulator, long-term production data is generated over a wide range of gas condensate reservoir parameters. Next, a comparison is made between the simulator results (gas condensate) and the corresponding single-phase gas reservoir, using a modern production analysis method. The error for each case is analyzed, and a correlation for treatment of the single-phase analysis method is developed. Our results show that the methodology developed here can be successfully applied for analysis of the production data of a gas condensate reservoir.