Measurements of dispersant additive on hydrate/ice slurry transport

Gas hydrates are a concern for the oil and gas industry, since they can be formed in production lines and disrupt flow. Different techniques can be applied to assure that the flow will not be disrupted by hydrate formation. Recently, the use of dispersant additives known as anti-agglomerants (AAs) have been applied to transport hydrates in the form of slurry. Anti-agglomerants are assumed to act at the hydrate interface keeping hydrates dispersed in the liquid hydrocarbon phase. In particular cases in gas or gas/condensate fields, the temperature can fall below 0°C due to the Joule-Thompson cooling effect after high gas production. For these systems, a complex and poorly studied transport of ice, hydrate and liquid will occur. Despite the similarities between structures of ice and hydrate, the effect of hydrate dispersant additives to disperse ice is unknown. A new experimental apparatus, called rock-flow cell, was used in this study which allows multiphase system, works at high pressure and different flow conditions can be obtained by varying the liquid loading and rocking conditions (angle and rate). Tests of hydrate and ice formation from water and condensate dispersions were performed aiming to study the effectiveness of AAs. It was observed that certain AAs can work to disperse hydrate/ice slurry, nevertheless its effect is highly dependent on the system conditions.