title: In-situ visual observation for the formation and dissociation of methane hydrates in porous media by magnetic resonance imaging.
abstract: In this work, magnetic resonance imaging (MRI) was employed to observe the in-situ formation and dissociation of methane hydrates in porous media. Methane hydrate was formed in a high-pressure cell with controlled temperature, and then the hydrate was dissociated by thermal injection. The process was photographed by the MRI, and the pressure was recorded. The images confirmed that the direct visual observation was achieved; these were then employed to provide detailed information of the nucleation, growth, and decomposition of the hydrate. Moreover, the saturation of methane hydrate during the dissociation was obtained from the MRI intensity data. Our results showed that the hydrate saturation initially decreased rapidly, and then slowed down; this finding is in line with predictions based only on pressure. The study clearly showed that MRI is a useful technique to investigate the process of methane hydrate formation and dissociation in porous media.
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Jiafei
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Lv
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Yanghui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Mingjun
authors.initials: M
authors.lastname: Yang
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yao
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Shenglong
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China. Electronic address: songyc@dlut.edu.cn.
authors.forename: Yongchen
authors.initials: Y
authors.lastname: Song
mesh_terms: D065966:Absorption, Physicochemical; D003460:Crystallization / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008422:Materials Testing / Q000379:methods; D008697:Methane / Q000032:analysis* / Q000737:chemistry*; D057054:Molecular Imaging / Q000379:methods*; D016062:Porosity; D011312:Pressure; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D008697:Methane
keywords: Dissociation; Formation; Magnetic resonance imaging; Methane hydrate