NIUMAG
Results
- Directly and accurately measure the amount of hydrate formation
It can be seen from the figure that the formation rate of hydrate is fast at the initial stage and gradually flattens out with time. At the end of the synthesis, the saturation of water, methane and hydrate in the sample is 33%, 29% and 38% respectively.
Previous studies have confirmed that hydrate synthesis occurs only when the initial water saturation of the core is high. The experimental results also verify that hydrate synthesis stops when the saturation of liquid water is lower than 30%~40%.Therefore, the production of hydrate is not only controlled by temperature and pressure conditions, but also by liquid content.
2.Hydrates synthesize in the core pores
The highest blue line is the NMR Analyzer spectrum of saturated water, the orange line is the NMR spectrum at the beginning of hydrate formation after methane injection, and the red line is the complete NMR spectrum of hydrate formation. Comparing the blue and orange lines, it was found that the water in the macropore (T2>9ms) significantly decreased after methane injection, while the water in the macropore (T2<9ms) did not change, indicating that the gas did not enter the pores when methane was injected.
However, by comparing the orange and red lines, it was found that in the process of hydrate formation, the average amount of water in the big hole and the small hole decreased, that is, the hydrate formed in the big hole and the small hole at the same time
3.MRI
The stronger the signal (white in grayscale, red in pseudo-color), the more liquid water exists. With the formation of hydrate, the amount of water gradually decreases, and the signal gradually weakens. Moreover, the formation starts from one end and spreads to the other end, until the complete formation of hydrate, the signal is minimized.