Application of box-behnken design in optimization of fracture treatment design for lower oligocene reservoir, offshore Viet Nam

Abstract

The paper presents an approach for optimizing the design of hydraulic fracture treatment in the low permeability lower Oligocene sandstone reservoir in the Cuu Long Basin, offshore Viet Nam. Several design variables including low behavior index, leak-off coefficient, pumping time, injection rate and proppant, which are generally affecting the fracture mechanics, were considered in the optimization process in order to improve oil production. The influence of those variables and interaction variables on fracture conductivity and net present value (NPV), hence, the production performance was analyzed using Box-Behnken design–based statistical modeling, which are experimental designs for response surface methodology. The results show that the maximum NPV was 50.5 million USD from optimal variables including injection rate of 36bpm, injection time of 78 minutes, slurry concentration end of the job of 9.1ppg and the leak-off coefficient of 0.0034ft/min0.5.