Flow Simulation of a Horizontal Well with Two Types of Completions in the Frame of a Wellbore–Annulus–Reservoir Model

Abstract

Well completions are generally used to connect a reservoir to the surface so that fluids can be produced from or injected into it. With these systems, pipe flows are typically established in the horizontal sections of slotted screen completions and inflow control device (ICD) completions; moreover, an annular flow exists in the region between the pipe and the borehole wall. On the basis of the principles of mass and momentum conservation, in the present study, a coupling model considering the variable mass flow of the central tubing, the variable mass flow of the annular tubing and the reservoir seepage is implemented to simulate the wellbore–annulus–reservoir behavior in the horizontal section of slotted-screen and ICD completions. In earlier models, only the central tubing variable mass flow and reservoir seepage flow were considered. The present results show that the closer the heel end, the greater is the flow per unit length in the central tubing from the annulus. When external casing packers are not considered, the predicted production rate of the slotted screen completion, which is obtained using the variable mass flow model not taking into account the annulus flow, is 9.51% higher than the rate obtained using the (complete) model with annulus flow. In addition, the incomplete model forecasts the production of ICD completion at a 70.98% higher rate. Both models show that the pressure profile and flow profile of the borehole wall are relatively uniform in the wellbore–annulus–reservoir in horizontal wells.