Production Decline Analysis

This chapter presents empirical models and procedure for using these models to perform production decline data analyses. Production decline analysis is a traditional means of identifying well production problems and predicting well performance and life span based on real production data. It uses empirical decline models that have little fundamental justification. These models include exponential decline (constant fractional decline), harmonic decline, and hyperbolic decline. Although the hyperbolic decline model is more general, the other two models are degenerations of the hyperbolic decline model. The relative decline rate and production rate decline equations for the exponential decline model can be derived from volumetric reservoir model. Cumulative production expression is obtained by integrating the production rate decline equation. Computer programs can be used for model identification, model parameter determination, and production rate prediction.