Screen-Inflow-Design Considerations with Inflow Control Devices in Heavy Oil

摘要

Inflow control devices (ICDs) improve oil recovery because of their capability to delay water and gas breakthrough. ICDs also can be applied to heavy oil reservoirs to help overcome the higher mobility of water, and therefore, are now frequently used in Canada’s Steam-Assisted Gravity Drainage (SAGD) heavy oil market to improve steam/oil ratio. Unfortunately, upstream flow behavior of ICDs is often ignored; however, flow through the screen-basepipe annulus can induce higher-than-expected pressure losses, and since these losses (not experienced with water) also reduce efficiency and lower performance, special attention should be given to flow-path characteristics. This paper examines pressure drops through the screen basepipe annulus of a direct wrap-on-pipe-type screen before entering the ICD. Using Computational Fluid Dynamics (CFD) simulations, the axial flow through the screen-basepipe annulus of a direct-wrap screen was simulated for three fluids. In addition, several flow rates and multiple-rib-wire-height wire types were used to cover a broad range of operations. The results of the simulations and analyses support the hypothesis that taller ribs would result in a lower pressure drop through the annulus. These simulations and analyses will show that increasing the rib height will cause the overall pressure drop in the annulus to decrease, often by as high a factor as four. These results will help determine optimum screen/base-pipe annulus spacing during screen design.