Gas Hydrate Formation in High Water Content Systems Containing Anti-Agglomerat and Salt

摘要

In this work, the effects of an anti-agglomerant (AA) and salt (sodium chloride, NaCl) on water-in-oil (w/rno) emulsion stability with and without the presence of gas hydrates is presented. The characteristics of gasrnhydrate formation and the hydrate slurry transportability were determined using a high pressure autoclaverncell, with continuous mixing. The stability of the emulsions was independently measured by performingrnbottle tests, where the stability of the emulsion was determined by observing any evidence phase coalescencernfor a period of one week after emulsification. In addition, the stability of the emulsion with hydrate formationrnand dissociation was tested using high pressure differential scanning calorimetry (DSC). From high pressurernautoclave studies, it was observed that the formation of a stable emulsion was shown to with the subjectrnoils led to transportable hydrate slurries. Note however, it was observed that for this specific oil at 75 vol.rn% water cut and the addition of both AA and salt, a highly viscous mousse with viscosity of ~100 000 cPrnformed when the emulsion was saturated with methane gas at 950 psia and 20 °C. Even without the presencernof hydrate, the formation of a highly viscous mousse may not be desirable in the field production systemrnsince it could render the system inoperable (effectively plugged).