ICDs for Uncertainty and Heterogeneity Mitigation: Evaluation of Best Practice Design Strategies for Inflow Control Devices

Abstract

Inflow Control Devices (ICDs) are an advanced well completion device used primarily in horizontal wells to enable more efficient reservoir flow performance and to mitigate common production issues by applying an additional pressure drop to choke high productivity zones. This study aims to identify design philosophies that provide for the most robust ICD design, and to determine if ICDs can be implemented for subsurface uncertainty mitigation. As there is no ability to adjust ICD settings once installed without major recompletion, a completion design that is robust to reservoir uncertainty at and away from the wellbore is critical. While ICD design follows a basic set of guidelines, several different approaches exist for each step within this workflow. A major design aspect relates to the design of target inflow profiles (equal inflow or U-shaped inflow). The U-shaped target inflow profile hypothesis was initially proposed for homogenous wells. This study proposes a modification to the existing design philosophy to cater to heterogeneous reservoirs. There is evidence supporting the use of the less conventional U-shaped target inflow profile in ICD design over the more commonly used equal inflow profile method. Sensitivity and robustness under reservoir uncertainty and heterogeneity for each ICD design methodology was assessed using 3-dimensional numerical reservoir simulation of layered and non-layered heterogeneous block models, followed by extensive uncertainty analysis. It was found that ICD completions may be unsuitable as a method for uncertainty mitigation and use of ICDs for this reason must be thoroughly investigated using full uncertainty analysis in dynamic simulation.