Technology Focus: Flow Assurance
Authors: Dino Galen 
Published: November 2019

Technology Focus
Flow assurance and multiphase-flow design, engineering, operations, and maintenance technical concerns have presented interesting and challenging issues requiring safe, economical solutions over my 20+ years of project experience around the world in both onshore unconventional and offshore conventional production facilities as an engineering, procurement, and construction contractor; major operator; manufacturer; and consultant. While gas-hydrate prediction and handling typically dominates the thermohydraulic design, the subsequent long-term mitigation of slugging and various flow-assurance phenomena, along with prevention of wax, erosion, asphaltenes, corrosion, and salt deposition, are all challenging issues.•
First, severe slugging, frequently observed in pipeline and riser systems, is an important flow-assurance issue. The consequences of slugging usually involve flooding of downstream pipeline and production facilities and an overall decrease in field and system productivity. On the basis of experimental observations, severe slugging prediction models were developed and verified. Second, regular intervention activities to improve flow assurance, such as frequent pigging and injection of chemical inhibitors or drag-reducing agents, all require operational expense and require safety oversight and downtime. Internal pipeline coatings and liners are available solutions that could provide long-term benefits. Third, access to real-time production data on a desktop computer could improve an operations/pipeline engineer’s efficiency and system performance greatly. A smart management system is described that is capable of retrieving and evaluating flow-assurance-related data from multiple wells. This system can allow the operator to make better-informed decisions on the basis of a consistent data set with less time spent gathering and analyzing the data. The papers presented here discuss slightly different issues and approaches to multiphase flow continuity and production flow assurance.
Severe slugging consequences typically include flooding of pipeline and production facilities and a subsequent decrease in production rate. Such severe slugging was previously thought to be limited to systems with upward, inclined pipeline or vertical, catenary or lazy-S-shaped risers. However, paper SPE 191611 presents the results of an experimental and modeling study that demonstrates the existence of severe slugging in systems with upward, inclined lateral flow paths such as a toe-down well, similar to that observed in a large-scale experimental facility specially constructed for studying flow behavior in horizontal wells.•••
Pipeline internal deposits, such as corrosion and scale, can reduce the flow efficiency and design capacity of a transport system greatly. The use of interior pipeline coatings and liners is a potential long-term design solution that could provide long-term refurbishment benefits. The work described in paper SPE 193109 involves a novel material designed to interact specifically with highly corroded and weathered pipe, thus enabling in-place application and refurbishment.••••••
Paper SPE 191951 describes a smart management system used for retrieving and evaluating all flow-assurance-related data for more than 700 wells in both onshore and offshore fields. The paper discusses system architecture, interface details, system design, functionality, visualization, application, and the benefits of the system.•
The papers presented here, including the additional reading papers on the potential novel applications of subsea tieback technology, focus on developing new analytical tools and new materials while providing safe, cost-effective, and reliable operations for flow assurance. I hope you find them as interesting as I did, and I greatly appreciate this opportunity to disseminate these new technology options to you in this and future Technology Focus sections. In addition, I invite you to join the Flow Assurance Technical Section.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 191748 Single-Flowline Tiebacks: Flow-Assurance Considerations From Appraisal to Operations by Juan I. Monge, Gate Energy, et al.
OTC 29232 Real-Time Subsea Hydrate Management in the World’s Longest Subsea Tieback by Christophe Vielliard, OneSubsea, et al.
OTC 29319 Subsea Long-Distance Tieback by Douglas Peter Wiles, TechnipFMC, et al.