A Study of Modern Decline Curve Analysis Models Based on Flow Regime Identification

Unconventional reservoirs, including tight and shale reservoirs, have become a significant source of petroleum supply in the world. Exploitation of these reservoirs is a challenge due to their very low permeability. Advanced technologies such as multi-stage hydraulic fracturing or pad drilling are necessary to enhance their productivity. Production behavior of unconventional reservoirs is characterized by long-term transient flow followed by boundary-dominated flow. Various production data analysis methods have been developed to analyze this production behavior; straight-line analysis methods are used to identify the flow- regime type while decline curve analysis methods are used to predict the future production behavior. This paper summarized flow-regime types which appear during well production in unconventional reservoirs and reviewed different decline curve analysis methods used to simulate this production behavior. A comparative study was conducting between the most used decline curve analysis models; Arps model, power-law exponential model, T-model and Duong model to determine when to use each model. A software application was written in python language to facilitate conducting this study. This software application is a powerful tool and provides reliable results.