The Multiphase Flow Assurance Innovation Centre (FACE)

The suspension research activities focus on improving the prediction of particle transport in pipelines and understanding the effect that the presence of particles has in the oil and water phases in pipelines. Experiments and modelling activities will be conducted with particle properties similar to those of sand in oil pipelines with the intention having a direct industrial application of the research results. The main objective of these activities will be to significantly improve our knowledge of particle transport in pipelines and its effects on the carrier phase with special emphasis on dilute suspensions (particle mass concentration < 1%).

Detailed and controlled experiments are necessary to formulate closure relations not available in the literature. These are mainly related to the effects of drag, added mass, buoyancy effects, two-way interaction between the particles and the fluid and, to some extent, the particle-particle interactions to account for cases when higher concentrations are observed in the pipeline (e.g., near the bottom of the pipe). Channel flow experiments with water based suspension using spherical particles that resemble the density and size of sand, are ideal for this. We are able to obtain very good temporal and 2D spatial information of the flow (PIV experiments), hence increasing the robustness of closure relations. Particles with different characteristics (e.g., size and density) will be used, and experimental results will be analyzed to produce new closure relations for the macro-scale model of Activity 1.

 
Sand transport in pipelines has an added complexity introduced by the large density difference between the carrier fluid and the sand grains. This causes a strongly inhomogeneous distribution of the particle in the pipe cross-section, thereby producing rheology gradients in traditional rheometer measurements. Due to the very nonlinear effect of particle concentration on viscosity and rheology in general, the interpretation of the rheometer results are very misleading. In this activity detailed measurements of particle distribution and velocity in a rheometer will be conducted. These will be used to develop closure relations, such as modified viscosity, for the macro-scale model. Furthermore, a simple model will be developed to simulate the processes in the rheometer, with adjustable parameters that account for the rheology dependence on particle concentration. This activity will be conducted in parallel with activities 2 and 3 and will be supported by a PhD student at IFE in collaboration with the University of Oslo.