Using a Reactive Transport Simulator to Simulate CH4 Production from Bear Island Basin in the Barents Sea Utilizing the Depressurization Method†

• Published in: Energies
• Main Authors: Khadijeh Qorbani, Bjørn Kvamme, Tatiana Kuznetsova
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2017
• Subjects: methane hydrate; mixed hydrate; gas hydrate production; CO2 hydrate; CO2 storage; Technology; T; Barents Sea; Bear Island; Bjørnøya; Methane hydrate
• Online Access: https://doi.org/10.3390/en10020187; https://doaj.org/article/cf431a1b2d1d45e0913192c11b3179a6

The enormous amount of methane stored in natural gas hydrates (NGHs)worldwide offers a significant potential source of energy. NGHs will be generally unable to reach thermodynamic equilibrium at their in situ reservoir conditions due to the number of active phases involved. Lack of reliable field data makes it difficult to predict the production potential and safety of CH4 production from NGHs. While the computer simulations will never be able to replace field data, one can apply state-of-the-artmodellingtechniquestoevaluateseveralpossiblelong-termscenarios. Realistic kinetic models for hydrate dissociation and reformation will be required, as well as analysis of all phase transition routes. This work utilizes our in-house extension of RetrasoCodeBright (RCB), a reactive transport simulator, to perform a gas hydrate production case study of the Bjørnøya (Bear Island) basin, a promising field with very limited geological data reported by available field studies. The use of a reactive transport simulator allowed us to implement non-equilibrium thermodynamics for analysisofCH4 production from the gas hydrates by treating each phase transition involving hydrates as a pseudo reaction. Our results showed a rapid propagation of the pressure drop through the reservoir following the imposition of pressure drawdown at the well. Consequently, gas hydrate dissociation and CH4 production began in the early stages of the five-year simulation period.