论文名称：Methane hydrate formation in excess water simulating marine locations and the impact of thermal stimulation on energy recovery
论文类型：期刊论文
发表刊物：APPLIED ENERGY
收录刊物：SCIE、EI、Scopus
卷号：177
页面范围：409-421
ISSN号：0306-2619
关键字：Energy recovery; Methane hydrates; Unconventional gas; Thermal stimulation; Energy efficiency ratio; Gas production
摘要：In this work, we investigated the gas and water production profiles from methane hydrates formed in an excess water environment that mimic marine locations. Instead of pressurization by the addition of gas, water was injected into the sediment to create the high pressure environment of the reservoir, thereby creating a hydrate bearing sediment of high water saturation similar to those in marine locations. A framework is introduced to determine fractions of methane converted into hydrates during hydrate formation stage taking into account the effect of density changes, solubility and the in-situ pressure and temperature conditions. As opposed to 100% conversion assumed in the previous excess water works, our quantification shows that on average, the fractional conversion of methane is around 81.5% at comparable or larger experimental time scales (76-408 h). Upon the formation of quantitatively similar hydrate bearing sediments, the dissociation of methane hydrate was done under a constant pressure of 4.5 MPa subjecting to different thermal stimulation extents from 278.7 K to 285.2 K. It was found that low temperature driving force would result in an extremely low dissociation rate, and a minimum temperature of 280.7 K (corresponding to 2.1 K temperature driving force) is required to achieve a 90% dissociation within 10 h. In addition, through a simplified estimation of energy efficiency ratio (EER) and analysis of water production profile, we demonstrated the importance of water management in developing methods to effectively recover energy from hydrate bearing sediments. (C) 2016 Elsevier Ltd. All rights reserved.
发表时间：2016-09-01