Determining Reserves in Low Permeability and Layered Reservoirs

The minimum terminal decline rate method starts with the Arps Hyperbolic Method. The model then switches to the Exponential form of the equation at a predetermined decline rate. This procedure is widely used for estimating future production, however if the assumptions of the Arps Models- namely boundary dominated flow- are not met, the application of this methodology may not be appropriate. This monograph reviews the findings from applying the Minimum Terminal Decline Rate Method to two well types that are unlikely to satisfy this criterion: vertical layered fractured wells in tight formations and horizontal multi-fractured wells in shale formations. Both simulated and real well data are evaluated at various points throughout the life of the well and varying terminal decline rates are applied. The forecasted outcomes are compared to the known production results. This process can allow the reader to make conclusions regarding wells with similar properties.