	US 12,188,908 B2
	Integrated triaxial shear and seepage experimental method for hydrate-bearing sediments and device thereof
Liang Kong, Qingdao (CN); Yapeng Zhao, Qingdao (CN); Rui Xu, Qingdao (CN); Jiaqi Liu, Qingdao (CN); Keqiang He, Qingdao (CN); and Likun Hua, Qingdao (CN)
Assigned to Qingdao University of Technology, (CN)
Appl. No. 17/753,325
Filed by Qingdao University of Technology, Qingdao (CN)
PCT Filed Oct. 29, 2021, PCT No. PCT/CN2021/127348 § 371(c)(1), (2) Date Feb. 28, 2022, PCT Pub. No. WO2022/142671, PCT Pub. Date Jul. 7, 2022.
Claims priority of application No. 202110002272.5 (CN), filed on Jan. 4, 2021.
Prior Publication US 2023/0033460 A1, Feb. 2, 2023
Int. Cl. G01N 3/12 (2006.01); G01N 3/24 (2006.01); G01N 15/08 (2006.01)

CPC G01N 3/12 (2013.01) [G01N 3/24 (2013.01); G01N 15/0826 (2013.01); G01N 2203/0025 (2013.01)]

9 Claims

1. An integrated triaxial shear and seepage experimental method for hydrate-bearing sediments, the experimental method comprising:

a step of generating a hydrate in a low-temperature and high-pressure environment comprising,

loading a sample base,

loading a lower porous stone over the sample base,

loading a sample over the lower porous stone,

loading an upper porous stone over the sample,

loading a sample cap over the upper porous stone,

tightening by using an upper rubber stirrup and a lower rubber stirrup,

adjusting heights of a transverse beam of a triaxial instrument and a dowel bar, such that a lower end of the dowel bar and the sample cap are in a critical state that the lower end and the sample cap are in contact with each other,

creating a negative pressure environment inside the sample by using the pore pressure controller when the sample is a loose matrix sample, such that the sample is in a vertical state,

applying a confining pressure to the sample,

applying a pore pressure to the sample, and

cooling the sample;

a step of preparing a shear and seepage coupling experiment comprising,

setting corresponding different stage states of one of an axial pressure controller, a confining pressure controller, a pore pressure controller, a liquid seepage pressure controller, and a nitrogen seepage pressure controller in a preset stress path, and

setting a pressure of a back pressure valve to be higher than a hydrate phase equilibrium pressure of a constant temperature gas bath at a preset temperature; and

a step of performing the shear and seepage coupling experiment comprising,

starting a device to perform the shear and seepage coupling experiment, and

recording both a sample base pressure sensor and a sample cap pressure sensor to serve as data of pressure difference in the shear and seepage coupling experiment.