Phase Inversion in Water鈥揙il Emulsions with and without Gas Hydrates
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- 作者：Hossein Moradpour ; Antonin Chapoy ; Bahman Tohidi
- 刊名：Energy & Fuels
- 出版年：2011
- 出版时间：December 15, 2011
- 年：2011
- 卷：25
- 期：12
- 页码：5736-5745
- 全文大小：955K
- 年卷期：v.25,no.12(December 15, 2011)
- ISSN：1520-5029
文摘
In deepwater exploration and production, where long tieback multiphase pipelines are a preferred economic option, gas hydrate blockages pose serious problems for flow assurance to produce hydrocarbons with high water cuts because the traditional techniques, such as insulation, heating, or injection of thermodynamic inhibitors, often become economically and logistically impractical. The potential for transporting hydrate particles using antiagglomerant (AA) in high water cuts could be an attractive alternative to the traditional approaches. In high water cut systems, by converting some of the water phase into the hydrate particles, the behavior of the emulsion鈥揾ydrate mixture strongly depends on the water鈥搊il emulsion which acts as a carrier fluid. Generally, AAs work as a surface active agent which influences the interface between water and oil and hence impacts the morphology of the hydrate-free emulsion (without hydrate particles) and emulsion during hydrate formation. However, information on the previous is still limited. In the present study, the phase inversion of water鈥搊il emulsions was investigated in two types of experiments: hydrate free emulsions and emulsions during hydrate formation. Experiments were performed to examine the effect of existing natural surfactants in the liquid hydrocarbon phase, AA (quaternary ammonium salt) concentration, salt (NaCl), and hydrate particles on the phase inversion of emulsions. It was concluded that the type of emulsion before hydrate formation and the initial water cut are two important factors that determine the morphology of emulsion during hydrate formation. The results also revealed that in high water cut systems, water鈥搊il emulsion, which is a binary system, is altered to a ternary water/oil/hydrate system during the hydrate formation process. These findings could lead to a better understanding of the rheological properties of the hydrate slurry flows.