Micromechanical Adhesion Force Measurements between Hydrate Particles in Hydrocarbon Oils and Their Modifications

Cyclopentane (CyC5) hydrate interparticle adhesion force measurements in the presence of small amounts of crude oil (up to 8 wt % in cyclopentane) were performed at 3.2 degrees C, under atmospheric pressure, using a micromechanical force apparatus. The adhesion forces obtained for cyclopentane hydrate ill small amounts of crude oil in CyC5 bulk fluid were lower than those measured for CyC5 hydrate in pure CyC5 bulk fluid. CyC5 hydrate-normalized adhesive forces were measured to be on the order of 0.5 mN/m for samples containing approximately 5-8 wt % of Caratinga and Troika crude. Hydrale-normalized adhesive forces were found to increase when the surface-active components (including acids and asphaltenes) were removed from the crude oil. These results suggest that crude oils with high contents of acids and asphaltenes may be more likely to exhibit nonplugging tendencies ill oil and gas flowlines.