Pore pressure built-up in hydrate-bearing sediments during phase transition: A poromechanical approach

Theoretical investigation of threshold pressure gradient in hydrate-bearing clayey-silty sediments under combined stress and local thermal stimulation conditions

“…For example, experimental data from literatures [25][26][27] confirms that pore structures and permeability in HBCSS vary with effective stress. Moreover, the temperature increase due to local thermal stimulation during hydrate production causes solid particles thermal expansion and pore space compression [28][29][30], leading to the change in TPG within HBCSS. Therefore, it is important to consider that the effects of effective stress and temperature on TPG in HBCSS.…”

“…K and λ in HBCSS under various stress and local thermal stimulation conditions using Eqs. (29) and(30) EndNo  K to 274.15 K). To ensure the simulation conditions are constant with the experimental conditions, during the simulations, the effective stress peff = 2 MPa, the pore pressure ppore = 4 MPa, and the temperature difference ΔT = 9 K. In addition, σ = 0.027 N/m[36], the ratio of rmax,0 to rmin,0 is 100, θe = 149 °[43], ζ = 0.02 Pa•s, Ca = 0.002, Cpin = 5.6 mN/m, C = 2.5×10 4 [66],  = 1.93 Pa•s [74], E0 = 1000 MPa, υ = 0.3, β = 2/3, b = 750 MPa, θcs = 33 ° [53] and α = 1.5×10 -5 K -1 [75].…”