(256b) Composition-Dependent Adhesion Forces Between Cyclopentane Hydrate Particles

Both anti-agglomerants and naphthenic acids are key elements of flow assurance in oil pipelines and understanding their role in hydrate agglomeration is critical to hydrate plug prediction and prevention. Adhesion forces between cyclopentane hydrates were measured at atmospheric pressure and 3.2 ˚C using an improved micromechanical apparatus. Due to the complexity of crude oil systems, a series of model oils were also prepared by adding surface-active components to 200 cP mineral oil, as analogs to the crude oil systems. After hydrate stabilization in pure cyclopentane, a variable weight percent of model oil was added to the hydrate system in order to study the isolated effects of individual naphthenic acid constituents or model anti-agglomerants in mineral oil. Addition of 1 wt% sorbitan monooleate (Span 80, a model anti-agglomerants) to mineral oil reduced particle-particle adhesion force by 37% compared to pure mineral oil. Addition of a 0.6 wt% commercial naphthenic acid mixture to mineral oil reduced particle-particle adhesion force by 79% compared to pure mineral oil. The observed reduction in adhesion force was constant between 1 and 30 wt% addition of model oil. These results indicate that both model anti-agglomerants and commercial naphthenic acid mixtures are active on the surface of hydrate particles in the organic phase, drastically reducing the agglomeration tendency between such particles.