Production Forecasting of Tight Oil Reservoirs Using Improved Decline Model

Abstract

Nzuetom Mbami Steve Wilfried

Tight oil formation has become interest for many researchers since less than 10% of the OOIP can be obtained from the primary recovery. Other thinking on how to improve the oil recovery is still done. Decline curve analysis is one of the methods commonly used to estimate the ultimate recovery and the production rate profile of tight oil reservoirs. The present work uses the Duong model to overcome the limitations of Arps’ model. This study compares the observed values from simulation results to the estimated values from Duong model over 30 years. In our previous work, we demonstrated that some key parameters such as reservoir permeability, number of fractures per stage, fracture permeability, CO2 injection rate, CO2 injection time, CO2 soaking time, number of CO2 huff-n-puff cycle have a great effect on the improve of oil recovery of tight oil reservoirs while applying CO2 huff-n-huff. This work also focused on the development of some regression equations that can help to get approximatively the oil recovery factor of any formation, the goal here is to generate a suite of diagnostic plots to estimate oil recovery. These equations have revealed that the best fit is the polynomial regression. Results show the overestimation of oil reserve by Duong model when the flow regime changes from linear flow.

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