Abstract
Summary Hydrates present a major flow-assurance problem because of the relatively fast timescales at which they can form, grow, agglomerate, and plug a flowline. Thermodynamic inhibitors (THIs) are a common chemical strategy for preventing hydrate formation. However, THIs can be cost prohibitive because the water content (WC) in the flowline and the seawater depth increase. Among the alternative hydrate-management strategies, there is the use of anti-agglomerants (AAs), which are active at considerably lower concentrations than THIs. AAs prevent agglomeration and allow hydrates to flow as a noninteracting slurry in subsea oil flowlines. The selection of the correct AA dosage is critical for safe and economical AA application. This work uses one model oil and two crude oils to study hydrate agglomeration in the presence of a commercial AA in a laboratory-scale autoclave equipped with particle-characterization devices. Despite known limitations, the particle-sizing probes used here provided unique insight into the hydrate-agglomeration process occurring at high pressure in crude oil systems, enabling the identification of different characteristics of a hydrate slurry based on the AA concentration and the oil phase used. For example, the droplet size before hydrate formation was a poor indicator of AA performance for the AA and oils tested. Systems with similar droplet size before hydrate formation yielded significantly different hydrate-agglomerate sizes. Similarly, increased or decreased emulsion stability did not show any correlation to AA performance. The effective AA dosage was observed to be lower for model oil systems compared with crude oil systems, which provided insight into using model oils to evaluate AA performance vs. crude oils. Results also indicated that when an effective AA dosage is applied, hydrate-agglomerate size was similar for all oil phases tested. Further parameters need to be taken into account such as impeller geometry, pressure, temperature, and WC, which may influence AA performance.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
