A comparative analysis of the mechanical behavior of carbon dioxide and methane hydrate-bearing sediments

Mechanical behaviors of permafrost-associated methane hydrate-bearing sediments under different mining methods

“…3 shows the relationship between the failure strength and confining pressure for the hydrate-bearing sediments containing ice, which dissociated by depressurization or heating method under different exhaust conditions. The results indicate that the failure strength clearly increases with increasing confining pressure, which is accordant with our previous study [26][27][28]. The reason for this behavior is that pore fissure being closed under higher confining pressures, which prevents crack propagation in the sediments.…”

Experimental Study on the Mechanical Properties of CH4 and CO2 Hydrate Remodeling Cores in Qilian Mountain

“…The mechanical properties of the hydrate-bearing sediments were extremely sensitive to temperature, confining pressure, strain rate, and porosity [24]. Considering the actual burial conditions of the hydrate-bearing sediments in reservoirs located in Qilian Mountain, the hydrate existed in layers in which the drilling depth ranged from 0 m to 400 m, the temperature ranged from about −10 • C to −1.8 • C, and the hydrate fractions in the drilling core mostly focused on 25-36%.…”

“…More CH4 hydrate was dissociated than CO2 hydrate due to their dynamic stability differences, which decreased the strength of the sample [31]. show clearly that the failure strength of the CO 2 hydrate-bearing sediments is higher than that of the CH 4 hydrate sediments under different confining pressures, and CH 4 -CO 2 replacement is beneficial to the stability of the reservoir [23,24]. Besides this, in the shear process, the strength of the hydrate-bearing sediments may consist of the strength of ice, hydrate, and sediment matrix and their interaction [29].…”

“…Liu et al [23] also found that the P-wave velocity continually decreased during all replacement processes. Hyodo et al [24] confirmed that newly formed CO 2 hydrate would keep the reservoir mechanically stable when CH 4 -CO 2 replacement took place in a relatively short period of time in sediments formed by Toyoura sand.…”

Review of natural gas hydrates as an energy resource: Prospects and challenges

“…As the CH 4 -CO 2 exchange process involves the formation of CO 2 hydrate during the exploitation, a recent work compared the difference in mechanical strength between CO 2 and CH 4 hydrate bearing sediments [232]. The preliminary study reported that the synthetic CO 2 hydrate could maintain the mechanical stability of reservoir during CH 4 -CO 2 gas exchange provided that they are well distributed in the pore space.…”