Well Predictive Material Balance Evaluation: A Quick Tool for Reservoir Performance Analysis

Abstract

Hydrocarbon reservoirs require steady evaluation in terms of performance prediction and resource volume estimation. These evaluations are planned and carried out from point of discovery till maturation and abandonment. Full field reservoir simulation model is the conventional tool for reservoir performance analysis via planned or existing wells. Material balance models were developed to carry out simple reservoir analysis on tank basis for resource volume estimation and prediction. Well predictive material balance model has proved to be a quick and handy tool capable of doing reservoir analysis both at reservoir and well levels. In this paper, we will be discussing the methodologies, basic workflows and technical principles of building a simple well predictive material balance model. This tool is not a replacement of more robust reservoir simulation model but a quick win in terms of time and cost. The study shows the implementation of this tool for a resource volume estimation and well performance prediction. It covered evaluation of saturated reservoirs with concurrent oil and gas production. The results were compared with reservoir simulation and conventional decline curve analysis results for robustness check. Important data such as relative permeability, well models (IPR and vertical lift curves), current fluid contact and PVT data are some of the essential data required to build a good predictive material balance model. Keys steps taken in building this model are: Data gathering and validations Model Construction History Matching/ Simulation Prediction (reservoir and well) Result analys The Results show good comparison with other methodologies (Simulation and DCA). The wells predictions were good and compare closely with actual well production.