Passive flow control devices—well design and physics of their different flow regimes: A review

Abstract

As wells shift towards producing or injecting along their entire length, frictional pressure losses and reservoir heterogeneities become larger issues in completion design. There is now general agreement that passive flow control devices (PFCDs) are effective in mitigating these issues. However, the interplay of PFCDs with the reservoir, as well as their fluid mechanics have been generally treated non-rigorously. Towards providing a more scientifically rigorous understanding of PFCDs, the current work presents the following through a survey of the literature:1. The effects of frictional pressure loss and reservoir heterogeneity on wellbore performance through the lens of simplified reservoir flow equations, and how PFCDs modify these equations to combat these problems. 2. Flow theory relative to PFCDs; the significant dimensionless parameters within the different flow regimes; and PFCD performance data within the literature recast in terms of these dimensionless parameters. 3. Strategies for mitigating the erosion, corrosion and plugging of PFCDs. Broadly speaking, the review identifies that: 1. PFCDs alleviate the deleteriousness of frictional pressure loss and reservoir heterogeneity by either counteracting or overwhelming their effects. Studies recommend a PFCD flow resistance roughly equal to that of the reservoir or wellbore friction. 2. PFCD resistance is a function of the incoming flow condition and regime, and is well described using various dimensionless parameters. They are: the resistivity (κT) versus Reynolds’ number (Rex) for incompressible flows; the flow rate coefficient (Kn×Ct) versus the pressure ratio (y) for compressible flows; and the mass flow rate coefficient (G) versus the pressure ratio (y) for different gas mass fractions or qualities (x) for multiphase flows. 3. A low flow velocity will make an PFCD naturally resistant to erosion, corrosion and scaling. Other steps for improving resistance include modifying edge geometries or using resilient materials.