Prediction of Volumetric Sand Production and Wellbore Stability Analysis of a Well at Different Completion Schemes

This paper was selected for presentation by a USRMS Program Committee following review of information contained in an abstract submitted earlier by the author(s). Contents of the paper, as presented, have not been reviewed by ARMA/USRMS and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of USRMS, ARMA, their officers, or members. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of ARMA is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgement of where and by whom the paper was presented. ABSTRACT: This paper presents an oil well study subject to two types of completion schemes (perforated casing and open-hole completion) using a coupled reservoir-geomechanical model to predict the volumetric sand production and associated wellbore stability. This model is based on mixture theory with erosion mechanics, in which multiphase hydrodynamics and geomechanics are coupled in a consistent manner via principal unknowns, such as fluid saturation, pressure, porosity, and formation stress as well as displacements. A Representative Elementary Volume (REV) is chosen to comprise of five phases - solid matrix, fluidized solids, oil, water, and gas phase. The numerical model is implemented into three integrated computational modules, i.e. erosion module, reservoir module, and geomechanics module. Depending on the complexity of addressed problems, different coupling methods can be used, i.e. decoupled, explicitly coupled, iteratively coupled, and fully coupled. Numerical results show that the wellbore stability depends on the delicate interaction between geomechanics and hydromechanics processes. Formation tensile and plastic shear failures, incurred under hydrocarbon drawdown and in situ stress changes, increase the sand production potential. In return, the production of sand also weakens the formation matrix through degradation of its mechanical strength (cohesion and friction angle). The self-adjusted mechanism enables the model to compute the volumetric sand production and cavity propagation in terms of fluidized sand saturation and porosity respectively. The results of two types of completion give an insight to guide the design in different completion technique and perforation pattern in terms of optimization of the hydrocarbon production.