A new predictive model for hydrate formation kinetics that captures the porous structure evolution in time is coupled with a multiphase flow mechanistic model. It is assumed that the hydrate particles behave as sponges, related to hydrate formation under flow shear. The multiphase flow is considered as a gas-liquid slug flow, where the liquid is a water-in-oil emulsion. Closure parameters for the model are thoroughly discussed and the model trend is validated against experimental results obtained in a flow loop. Mass and heat transfer limitation processes are discussed in terms of the theoretical predictions from the model.
Gas hydrates are crystals formed by the imprisonment of gas molecules in cages formed by hydrogen-bonded water molecules (1). The high pressure and low temperature conditions often found in offshore oil and gas production operations favor gas hydrate formation. The uncontrolled growth and agglomeration of these crystals can cause pipeline plugging, with production stop and related revenue losses, and thus such phenomenon is nowadays regarded as the main challenge in flow assurance (2).