Hydrate Detection System for LNG and Gas Plants (24.RP1.0203)

Hydrate formation risk exists in gas/LNG processing plants when wet gas streams are cooled within the process. This can lead to blockages which impact flows, pressure drops, and can lead to potential process safety risks (e.g., overpressure due to blocked discharge). As ongoing injection of hydrate inhibitors into the gas phase is generally not practical, the standard way of managing hydrate risk is maintaining temperatures in the process 3 – 5°C above the predicted hydrate formation temperature (normally based on the most conservative composition and operating conditions). 

The downside of this conservative approach is that higher gas phase temperatures lead to adverse process impacts such as increased water loads to dehydration units leading to reduced dehydration feed capacity, and increased heavy hydrocarbon carry-through to the acid gas removal unit leading to foaming, AGRU instability, and CO2 breakthroughs. These process issues flow directly into reductions on permissible gas/LNG production rates and associated project revenues. As an alternative to operating with large safety margins on temperature, this project will explore potential for deployment of an online hydrate detection system (HDS) at key locations including but not necessarily limited to downstream of pressure letdown stations, JT valves, turboexpanders, dehydration pre-coolers, and passing valves to flare. 

Partners: The University of Western Australia, Chevron 

Project Leader: A/Prof Paul Stanwix 

Duration: 12 months