(352d) Impact of Solid Particles and Their Wettability on the Rheological Behavior of Hydrates

Flow assurance is the most important technical issue facing offshore energy development. Hydrate formation is considered as one of the most important flow assurance problems due to subsequent blockages that can form in these systems. In an oil-dominated system, emulsion stability is an important criterion for hydrate risk management. The extent to which the emulsion droplets remain segregated during hydrate formation/dissociation determines the level of hydrate plug formation. For water-in-oil emulsions stabilized using solid particles, the type of emulsions and their stability are usually influenced by the wettability of solid particles that adsorb on the oil-water interface. Thus, investigating the effect of solid particles and their wettability on hydrate formation would provide useful insights on the hydrate formation process in these systems. In addition to hydrates, scale formation is an important flow assurance problem. Scales are caused by the deposition of mineral salts that are sparingly soluble in water, and they have a significant impact on production.

In the current study, cyclopentane hydrates are studied in model oil systems using solid particles of different wettability to elucidate the effect of particle wettability on hydrate formation and the subsequent rheological behavior. In addition, the effect of scales, such as calcium carbonate and calcium sulphate, on hydrate formation will be investigated. A DHR-3 stress controlled rheometer whose temperature can be controlled between -20°C to 150°C is used to examine the rheological behavior of hydrate forming emulsions. A helical ribbon geometry is used in this work to quantify the rheological behavior of hydrates. The primary objectives of this work are to investigate the effect of solid particles and their wettability, in addition to the presence of scales, on hydrate formation and the subsequent rheological behavior.