Scale Risk Assessment and Novel Coating for Smart Completion: Scale Simulation and CFD Modelling Approach

Abstract

There is an increasing demand in using intelligent well completions such as ICV (Inflow Control Valve) due to increased reservoir and production complexity in subsea fields. Failure of a functional ICV due to scale deposition can cause severe production impairment, R&D efforts therefore implemented to qualify a novel coating material which will be used in ICV to prevent scale formation and adhesion. Depending on the geometry of ICV, scaling deposition risks varies; in general increased carbonate scaling are observed due to greater pressure drop gradient. This paper firstly evaluates the scaling risks over the field lifetime for a pre-salt carbonate reservoir, much increased scaling potential is identified across the region of the ICV which necessities the use of a novel coating. Special laboratory apparatus that simulate the hydrodynamic conditions is designed and tested based on CFD (Computational Fluid Dynamics) results. Intensive modelling using variety of scale software as well as CFD approach are carried out to assess scale risks over the field lifetime, identify the fluid dynamic behavior around the ICV and to investigate the scale formation and adhesion mechanisms and differences onto non-coated vs. coated surfaces. Comparative CFD modelling and laboratory testing results on coated and non-coated surfaces illustrates the much reduced scale accumulation and depositions onto coated materials. CFD modelling of the non-coated vs. coated coupon reactor indicates that the coated surface introduce higher velocity and less turbulence kinetic energy therefore reduce or eliminate surface accumulation and adhesion of scale particles. Lower velocity is observed upstream the ICV choke and around the inflow point, these areas are more prone for scale formation which leads to solid accumulation in the near wellbore region. This paper highlights the advantages of using advanced modelling techniques (including CFD and integrated PipeSim-ScaleChem models) to assist the selection of realistic testing conditions, to guide the high value test equipment design and to reveal the scaling mechanisms. The implementation of this novel technology helps to mitigate scaling problem and enhance the service longevity of smart completion tool, in particularly for severe scaling fields.