Acknowledging the serious and substantial health and business effects of COVID‑19, I sincerely hope that all JPT readers and your families, peers, and employers are safe and healthy as they read this Flow Assurance Technology Focus.
During my 20‑plus years of project experience around the world - in both onshore unconventional and offshore conventional production facilities - I have seen how flow‑assurance effects from slug‑flow design and engineering, operations, and maintenance concerns have created challenging technical issues needing safe, economical solutions. The recurring long‑term mitigation of slugging and various flow‑assurance phenomena are challenging issues that demand attention and considerable technical effort. The three papers outlined here discuss slightly different issues and approaches to slug‑flow phenomena and oil/gas fluid production flow assurance. All three have been defined by mathematical modeling and verified with actual field confirmation and use.
Paper IPTC 19769 addresses pseudo‑slug flow, characterized by short, frothy chaotic slugs with velocities less than the mixture velocity of the flowing fluids and frequently observed in pipeline and riser systems. Specifically, the paper discusses liquid and gas entrainment mechanisms within the pseudoslug body on the basis of experimental observation. Earlier experimental results show the proposed dimensionless groups, Stokes, slippage, and Poiseuille, are strongly correlated to pseudoslug‑body liquid‑holdup experimental data that describe the observed physical behavior. A linearized regression model was developed that combines the liquid holdup proportionally in both the pseudoslug body regions and correlates them to the experimentally measured total pseudoslug liquid holdup. A validation study of the proposed model with experimental data shows good agreement.