Experimental and Modelling of Barium Sulfate Formation at Turbulent Flow Conditions

The deposition, mitigation, and removal of inorganic scales that form due to the mixing of incompatible waters present a major challenge in the petroleum industry. Scale formation and deposition mechanisms are poorly understood, especially at turbulent flow conditions. Since reaction kinetics are influenced by advective transport in turbulent flows, a fundamental understanding of the complex interplay between flow characteristics and surface reaction rates is critical. In this work, we present experimental and numerical studies of barium sulfate formation kinetics. Experimental studies were carried out in a novel Taylor-Couette reactor at turbulent flow conditions (2×10⁴ < Re < 8×10⁴) and at reservoir temperatures (50-70°C). Reaction rates were obtained through effluent analyses carried out using inductively coupled plasma (ICP) spectrometry and gravimetric analysis. Computational Fluid Dynamics (CFD) simulations were used to obtain a better understanding of experimental results. These simulations combined micro-scale and macro-scale modelling methods. The micro-scale model was used to extract accurate anisotropic turbulence characteristics, and the results served as inputs to the macro-scale model. The macro-scale model implements the Reynolds Stress Tensor turbulence model to simulate slower transient properties of experiments. This combination allows for accurate investigation of turbulent transport on local saturation and reaction rates. Further, a numerical chemical model for saturation states, bulk precipitation and surface deposition has been implemented in the simulations. The combination of experimental data and simulations provide new insights into the formation kinetics of barium sulfate at reservoir conditions.