Experimental research on methane hydrate formation in porous media based on the low-field NMR technique

Abstract

In the experiment, three kinds of sandy soil tests with various particle sizes and starting water substances were chosen for analysis of methane hydrate formation in porous media. In this article, low-field nuclear magnetic resonance (NMR) innovation was utilized to consider methane hydrate the kinetics and to analyse the relationship among the adjustments in water signal force, the temperature and pressure, the various qualities of the T2 relaxation time, and the substance of unhydrated water. In view of the varieties in the NMR signal intensity, the methane-hydrate formation can be separated into four phases: induction, nucleation, growth, and steadiness. In addition, for the samples with particle size of 0.25–0.5 mm, the content of unhydrated water was higher. At a similar particle size, the content of unhydrated water increments with an increasing initial water content; thusly, low unhydrated water content for the most part exists in little and moderately enormous pores.