Numerical Investigation of the Fluid Mixture Velocity on Critical Sand Settling Velocity in Multiphase Fluid Flow in Horizontal Pipes

Abstract

Flow assurance studies are conducted to model the effective production and transportation of unprocessed multiphase reservoir fluids from the wellhead to the processing facilities through the pipeline systems. However, flow assurance challenges may occur due to the presence of sand particles in the fluids that are transported especially when producing from low strength sandstones reservoirs. There are also the complexities associated with changing nature of multiphase flow in pipelines, which may result in the manifestation of a number of transient flow patterns depending on the fluid properties, flow rates, pressure drop and pipe orientations.  However, some of these challenges may occur which interrupt effective pipeline transportation of unprocessed multiphase fluids. In order to avoid these challenges and ensure continuous or unhindered flow, effective management of the complexity of the transient nature of the fluids was adopted. This study presents a numerical approach to investigate fluid mixture velocity on sand transport velocity under key flow patterns such as dispersed bubble, slug, and stratified flows in multiphase fluids. To achieve this, an automated system was developed from the mathematical expression using Python 3.10, Odeint (ordinary differential equation integrator) which uses the LSODA (Livermore Solver for Differential Equation Algorithm) to solve the complex differential equation for particle transport in multiphase flow.   The effects of the fluid mixture velocity on the particle-fluid flow characteristics such as critical sand settling velocity has been numerically investigated the results showed that the critical sand settling velocity is greatly influenced by the fluid mixture velocity as well as the flow patterns. It was also observed that the in-situ position of the flow patterns; stratified, slug, and dispersed bubble flows based on the sand carrying capacity did not change as it was previously reported in the literature. Most of the investigations conducted in the literature on particle transport models for gas-liquid multiphase flow were developed based on experimental approaches with numerous limitations.