AE monitoring-based CO2 hydrate formation and its influences to hydrate-bearing sandy sediments

An acoustic emission (AE) monitoring-based CO2 hydrate formation test and the subsequent triaxial compression on hydrate-bearing sandy sediments were performed and the results were discussed. It was found that the formation of CO2 hydrate in sediments can cause an obvious acoustic emission. The hit counts during hydrate formation in sediments grows up over tenfold with an increase of over 55% in the averaged AE energy. All the measured values of AE parameters increases as the continuation of formation, and they are smaller in CO2 injection than that in triaxial compression. Further, AE amplitude corresponding to the maximum hit counts tends to increase due to the formation of CO2 hydrate and the friction in pure sediments. AE characteristics associated with the hydrate formation and triaxial compression on hydrate-bearing sediments contribute to develop a monitoring approach on hydrate dynamics within sediments.

Automated summary

Acoustic emission monitoring is effective in detecting the formation of CO2 hydrates in sediments, with AE parameters increasing gradually during the formation process. The formation of CO2 hydrates and friction in pure sediments contribute to an increase in AE amplitude.