Effects of antiagglomerants on the interactions between hydrate particles

Abstract

in Wiley InterScience (www.interscience.wiley.com).Hydrate inbibition in natural gas production by antiagglomeration is promising because of effectiveness at high subcoolings encountered in many offshore operations. There are various mechanisms that are believed to contribute to the repulsion and attraction of hydrate particles. These include: (1) steric, (2) dispersion, (3) capillary, and (4) shear forces. Some of the expressions derived, and some formulas are used from the literature to provide a theoretical analysis of the forces between two hydrate particles to examine antiagglomeration using surfactants. Results show that hydrate particle size has the most important effect on antiagglomeration. Results also show that the contact angle increase and the oil-water interfacial tension decrease will either reduce capillary forces significantly or eliminate it. Effective antiagglomerants reduce the size, decrease interfacial tension, and increase contact angle through the water phase.

Quick Assessment of Potential Hydrate Promoters for Rapid Formation

“…The increased concentration of hydrate former, favorable water structure, or both give rise to a fast growth rate. At this point, we cannot exclude that surfactant adsorption could reduce the adhesion force between hydrate particles, via increasing the net surface charge, or forming an adsorbed layer around hydrate particles, or both, lowering the possibility of agglomeration [14]. As a consequence, more small hydrate p at which the hydrate growth prefers to proceed, is higher than that in a system without surfactants, causing more guest molecules to be enclathrated in a given period.…”

Gas hydrate powder formation – Ultimate solution in natural gas flow assurance

“…Anti-agglomerants (AAs) reduce the capillary force by lowering the water-oil interfacial tension and increasing contact angle [6][7][8][9]. When the capillary force is weaker than the shearing force in the flow, hydrate particles are carried by the liquid as a slurry.…”

The effects of capillary forces on the flow properties of glass particle suspensions in mineral oil

“…It is believed that the strong adhesion is primarily due to capillary forces from liquid water bridges between particles. [2][3][4][5][6][7] Additives called antiagglomerants are being studied for their ability to control blockage formation. These additives are typically surfactants that can affect hydrate adhesion and dispersion.…”

“…These additives are typically surfactants that can affect hydrate adhesion and dispersion. 2,5,8 They also will then affect the flow behavior of the hydrate suspension. Thus, a fundamental understanding of how capillary forces and surface-active materials influence the flow properties of a suspension containing liquid bridges is of great interest.…”