When estimating the erosion damage from passed fines through wire-wrap sand screens, variables such as approach velocity and gap velocity are often considered to be the main design considerations. Additional variables, such as the gap between the screen and base pipe, are often neglected. For the purpose of the experiments presented in this paper, two main objectives were defined. The first objective was to gain a better understanding of the location and progression of erosion in a conventional wire-wrap sand screen. In particular, inspection of the inlet and outlet surfaces of the screen was conducted in order to evaluate the erosion effects on both boundaries. The second objective was to evaluate the erosion effects of allowing flow to pass underneath the screen’s axial rib wires by introducing various standoff distances between the base pipe and the axial rib wires. The selected standoff distances were similar to a drainage layer typically included in metal-mesh type sand screens. To achieve these two objectives, eight experiments were conducted in an erosion test flow loop with varying experimental standoff geometry stack-ups. Any damage to the sand screen was quantified by calculating the specific erosion of the screen, which is the screen’s total mass loss divided by the total mass of particles passed for a given test duration. Photographs of the coupons before and after each test were used to qualitatively identify affected areas of erosion. The results of these experiments and a brief description of the testing approach are provided herein.

Computational simulation of a full-scale, horizontal liquid-liquid gravity separator has been undertaken by Southwest Research Institute® (SwRI®) to model the batch separation of oil and water flow. Separator modeling using Computational Fluid Dynamics (CFD) represents a powerful and economical option for design, but caution must be used in the setup and interpretation of data. Many examples are available in literature of poor agreement between simulation results and experimental/field data. No clear consensus on valid modeling methodology currently exists. Results require interpretation before taking them at face value due to the complexity of the various submodels that can be utilized. This work offers an evaluation of multiphase flow modeling techniques, and provides a unique comparison with experimental data that covers a broad range of flow rates, water cuts, and viscosities. The performance of a horizontal gravity separator with perforated baffles has been investigated using CFD. The simulations have been carried out using an Eulerian-Eulerian multiphase approach. These simulations were conducted using constant dispersed water droplet sizes in an oil-continuous phase. Separation efficiencies and water-cut percentages at several locations throughout the test separator were compared against experimental results for a wide range of inlet flow rates, water cuts, and oil viscosities. Computational results indicated that the horizontal liquid-liquid separator can be modeled within 10% accuracy of the local experimental separation efficiency values for the various test conditions. This effort demonstrates the capability of reliable modeling of multiphase flow fields inside of horizontal gravity separators, and offers an economical option for aiding in the design of separation equipment.