Experimental study of methane hydrate formation and agglomeration in waxy oil-in-water emulsions

Abstract

In deep-water multiphase flow pipelines, hydrate and wax agglomeration can cause blockages. To clarify the influence of wax and Tween 80 on hydrate formation and agglomeration in water-in-oil (W/O) emulsions, hydrate generation experiments were conducted in a high-pressure reactor, focusing on W/O emulsions both with and without wax and Tween 80. Additionally, the paper further explored the characteristics of hydrate formation and agglomeration in wax-containing W/O emulsions with Tween 80 under various initial pressure conditions. Results indicated that wax presence curtailed the Tween 80's dual role: inhibiting hydrate nucleation and promoting rapid hydrate growth. The interplay of waxes and Tween 80 had a synergistic impact on hydrate formation, elevating the cumulative gas consumption by 0.74 mol and augmenting the water conversion rate by 9 %. This intensifies the likelihood of hydrate blockages. Under higher initial pressures, a notable multi-step pressure decrease occurred during hydrate formation, attributed to a high water cut, wax/Tween 80 presence, and initial pressure. Torque evaluations indicate that wax-Tween 80 interactions diminish particle agglomeration, enhancing hydrate slurry liquidity.