Dry Flow\nTechnology as Flow Assurance in Methane Hydrate\nDevelopment

Preventing pipeline blockages caused by gas hydrate formation\nis\na critical issue for gas transportation through subsea pipelines.\nWe propose a novel approach, “dry flow”, as a means\nof preventing gas hydrate blockages in high-pressure gas pipelines.\n“Dry flow” technology comprises three stages: a separation\nprocess to remove water from gas using a separator, a conversion process\nin which any remaining water is transformed into hydrate particles,\nand a transportation process in which the hydrate particles are conveyed\nas a aerosol using pneumatic pressure. Dry flow prevents pipeline\nblockage by inhibiting the formation of a bridging structure, which\nreinforces the cohesive force of hydrate particles and adhesive force\nbetween hydrate and pipe wall. In this study, we conducted a laboratory\nexperiment using a flow loop to investigate gas flow regimes with\ndisseminated hydrate particles and verified that hydrate particles\ndo not agglomerate under dry conditions. We compared experimental\ndata with the estimation of a phenomenological model of gas–solid\nflow and numerical simulation results and found that a dilute-phase\nflow was achieved without gas hydrate agglomeration. This study verified\nour hypothesis that hydrate deposition does not occur under dry conditions\nand validated dry flow technology.