Institute of Petroleum Engineering

Centre for Gas Hydrate Research Publications



Abstract 006

Gas Hydrates Modelling, Effect of Gas Solubility in Saline Water

Tohidi, B., Burgass, R. W., Danesh, A., and Todd, A. C.
International Non-Renewable Energy Sources Congress, Tehran, Iran, 26-30 December (1993).
Gas hydrates have significant importance in oil and gas industries. Major problems could arise in hydrocarbon transfer lines and processing facilities due to blockage by solid gas hydrates. For efficient, safe, and economical design as well as operation of potential hydrate forming systems, the hydrate phase boundary with or without inhibitors should be known. This paper reviews briefly hydrate prediction approaches and hydrate inhibition of injected chemicals (methanol), concentrating on the inhibiting effect of saline water and the effect of gas solubility on hydrate formation. A phase behaviour model has been used for prediction of hydrate formation in the presence of single and mixed electrolytes. The solubility of gases in saline water phase is calculated by combining a cubic equation of state with density dependent mixing rules and the Debye-Huckel electrostatic contribution. A single parameter is used to represent the gas-salt interaction, while the water-salt interaction parameter has been determined for various ionic strengths. The solubility model has been coupled with a conventional hydrate statistical thermodynamic model to predict the hydrate dissociation conditions. The predictions of the model have been compared with those of other leading published methods against experimental data.

Reprints of this article are available in Adobe Portable Document Format (.pdf). You may request a reprint by submitting an email to the webmaster with the abstract number in the subject line. To read pdf files, you will require Adobe Acrobat Reader, which can be downloaded for free at the Acrobat Reader Download Page

Submit requests to: ross.anderson@pet.hw.ac.uk