Keywords
Water saturation
Fractal dimension
Submitted : 2024-05-21
Accepted : 2024-06-05
Published : 2024-06-20
Abstract
The study of the hydrate formation process in porous media is of great significance for hydrate application. In this work, the formation process of methane hydrate in porous media was monitored in situ by a low-field magnetic resonance imaging (MRI) system. The formation characteristics of methane hydrate in porous media and the change of fractal dimension of pore space were studied through the change of residual water saturation and T2 relaxation time distribution. The experimental results show that the hydrate formation process is divided into two stages: fast and slow. During the formation process, the water in the pores is continuously consumed and transformed into hydrate, and the overall T2 distribution gradually shifts to the left. In the formation process of hydrate, the pore space becomes more complex, the change of fractal dimension from top to bottom of the reactor gradually increases, and the hydrate formation rate also gradually increases.
References
Chong ZR, Yang SHB, Babu P, et al., 2016, Review of Natural Gas Hydrates as an Energy Resource: Prospects and Challenges. Applied Energy, 162: 1633–1652.
Yang MJ, Song YC, Jiang LL, et al., 2014, Hydrate-Based Technology for CO2 Capture from Fossil Fuel Power Plants. Applied Energy 116: 26–40.
Hu Y, Lee BR, Sum AK, 2017, Insight into Increased Stability of Methane Hydrates at High Pressure from Phase Equilibrium Data and Molecular Structure. Fluid Phase Equilibria, 450: 24–29.
Park KN, Hong SY, Lee JW, et al., 2011, A New Apparatus for Seawater Desalination by Gas Hydrate Process and Removal Characteristics of Dissolved Minerals (Na+, Mg2+, Ca2+, K+, B3+). Desalination, 274(1–3): 91–96.
Eslamimanesh A, Mohammadi AH, Richon D, 2011, Thermodynamic Model for Predicting Phase Equilibria of Simple Clathrate Hydrates of Refrigerants. Chemical Engineering Science, 66(21): 5439–5445.
Shakerian M, Afrough A, Vashaee S, et al., 2019, Monitoring Gas Hydrate Formation with Magnetic Resonance Imaging in a Metallic Core Holder. E3S Web of Conferences, 02008.
Zhang YY, Zhao YC, Lei X, et al., 2020, Quantitatively Study on Methane Hydrate Formation/Decomposition Process in Hydrate-Bearing Sediments Using Low-Field MRI. Fuel, 262: 116555.
Zhao YC, Li M, Dong S, et al., 2023, Fractal Analysis on CO2 Hydrate-Bearing Sands During Formation and Dissociation Processes with NMR. Science of the Total Environment, 859: 160326.