Rheological characterization of cyclopentane hydrate slurries

Abstract This work presents an atmospheric-pressure protocol for generating and characterizing cyclopentane hydrate slurries. Water-in-oil emulsions containing 30 and 40% v/v water content were produced and stabilized with Span 80/AOT. Single-drop tests confirmed hydrate nucleation after a thermal shock protocol. Rheometric measurements were performed to explore the solid-like and liquid-like behaviors, before and after major structure breakdown, respectively. In this regard, elastic modulus and viscosity were captured by rotational stress sweeps, revealing that raising the water fraction increased the yield stress and the shear modulus. The critical yield strain did not vary significantly with water cut. Abrupt changes in strain and strain rate at the yielding event prevent the description of the elastic modulus as a function of strain. Hence, a dependence with respect to stress was obtained. Following this approach, we captured viscous behavior as a function of stress as well. Oscillatory frequency sweeps produced frequency-dependent crossover stresses, but nearly constant crossover strains. The resulting data set establishes a laboratory route for producing and evaluating the influence of water cut and additives on the rheology of cyclopentane hydrate slurries.