An Approach to Identifying the Optimal Time to Initiate Stimulation Operations.
This research describes the application of a production economic approach which attempts to quantity stimulation treatments performed on different wells undergoing a decline phase in their production and to obtain based on the output from the model the best time during the declining phase of the wells to initiate stimulation treatments. Two different production decline models were considered in this work i.e., the exponential model and the hyperbolic model. The optimization models which are in the form of non-linear programming models combine production decline curve analysis with economic discounting concepts. The objective function of the non-linear programming problem is subject to the constraints imposed by the production facilities, reservoir productivity and the stimulation budget approved by management. The results from both optimization models show that the best time to initiate stimulation during the decline phase of a wells production should be during the periods when the current production rate is at least fifty percent of the initial production rate. The optimal discounted production for the exponential model shows that the best time to initiate stimulation is when the wells current rate is about seventy percent of the initial production rate. The results from this work can thus serve as guide for reservoir management decision making and also as a tool for communication between the economists and the reservoir engineer.