Implementation of a multi-layer radiation propagation model for simulation of microwave heating in hydrate reservoirs

• Published in: International Journal of Numerical Methods for Heat & Fluid Flow
• Main Authors: Gupta, Akash K., Yadav, Rahul, Das, Malay K., Panigrahi, Pradipta K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Emerald 2021
• Subjects: Methane hydrate
• Online Access: http://dx.doi.org/10.1108/hff-12-2020-0822; https://www.emerald.com/insight/content/doi/10.1108/HFF-12-2020-0822/full/xml; https://www.emerald.com/insight/content/doi/10.1108/HFF-12-2020-0822/full/html

Purpose This paper aims to present the implementation of a multi-layer radiation propagation model in simulations of multi-phase flow and heat transfer, for a dissociating methane hydrate reservoir subjected to microwave heating. Design/methodology/approach To model the induced heterogeneity due to dissociation of hydrates in the reservoir, a multiple homogeneous layer approach, used in food processes modelling, is suggested. The multi-layer model is incorporated in an in-house, multi-phase, multi-component hydrate dissociation simulator based on the finite volume method. The modified simulator is validated with standard experimental results in the literature and subsequently applied to a hydrate reservoir to study the effect of water content and sand dielectric nature on radiation propagation and hydrate dissociation. Findings The comparison of the multi-layer model with experimental results show a maximum difference in temperature estimation to be less than 2.5 K. For reservoir scale simulations, three homogeneous layers are observed to be sufficient to model the induced heterogeneity. There is a significant contribution of dielectric properties of sediments and water content of the reservoir in microwave radiation attenuation and overall hydrate dissociation. A high saturation reservoir may not always provide high gas recovery by dissociation of hydrates in the case of microwave heating. Originality/value The multi-layer approach to model microwave radiation propagation is introduced and tested for the first time in dissociating hydrate reservoirs. The multi-layer model provides better control over reservoir heterogeneity and interface conditions compared to existing homogeneous models.