Due to limited parking, we request attendees to carpool. Valet parking will be available.

 

For many decades, a standard method of forecasting future production in conventional oil and gas reservoirs has been to use Arps production decline equations. One of the limitations of the Arps empirical model is that stabilized (boundary-dominated) flow data are required to ensure reliable forecasts. In ultra-low permeability gas reservoirs, flow may remain transient (unstabilized) for much or all the life of a well. In such cases, the Arps model is seriously limited, and engineers have created imaginative methods to adapt the model to these unconventional reservoir conditions. An approach that may be more productive is to abandon the Arps model altogether and adopt an alternative empirical approach that is better suited to long-term transient flow in wells and in reservoirs. The “stretched exponential” model is such an approach. This model, which has been found to describe many decline processes in physics, is well suited to model production decline in ultra-low permeability gas wells with both early transient and later stabilized flow. We have applied the model successfully to production data from thousands of wells in the Barnett Shale, TravisPeak tight gas, and other reservoirs. In this presentation, we will discuss the results that we have obtained to date using the stretched exponential decline model.