Measurement method for large-displacement shear-flow of rock under high temperature and high pressure

Abstract

The invention discloses a measurement method for the large-displacement shear-flow of rock under a high temperature and a high pressure, relates to a rock mechanics test method, and solves the technical problem that measurement for the large-displacement shear-flow of rock under high temperature and high pressure cannot be carried out by the existing method. According to the measurement method disclosed by the invention, high-temperature-resistant rubber is arranged in a pressure kettle with two open ends in a sleeving manner, two semi-cylindrical rock test samples with the same section shape and dimensions and different lengths are combined and then placed into a high-temperature-resistant rubber sleeve, a pressure transfer medium fills up the space between the outer wall of the rubber sleeve and the inner wall of the pressure kettle, heating and confining pressure applying devices are configured for the pressure kettle, a pore pressure applying device is configured for an axial pressing cylinder, a pore fluid flows out through a crack surface in the middle of the combined rock test sample, and flow characteristics in a rock shear process under the high temperature and the high pressure are obtained by measuring the flow speed of the pore fluid flowing out from an axial fixed cylinder. The measurement method disclosed by the invention has the advantages of being reasonable in structure, simple in operation method, and easy to realize the measurement for the large-displacement shear-flow of the rock under high temperature and high pressure.

Description

technical field [0001] The invention belongs to the field of rock mechanics, in particular to a method for measuring large displacement shear seepage of rock under high temperature and high pressure. Background technique [0002] The shear seepage of rock is the basis for the study of major geological disasters, such as the mechanism of earthquakes and landslides, the activation mechanism of faults induced by hydraulic fracturing in the development of energy resources, etc. At present, the measurement methods of rock shear seepage include: the measurement method of direct shear flow under normal temperature and low pressure (confining pressure less than 20MPa); the measurement method of oblique shear flow under normal temperature and high pressure; the measurement method of oblique shear flow under high temperature and high pressure. The measurement method of oblique shear seepage exists: because the shear surface has a certain angle with the sample axis, the shear area chan...

AI Technical Summary

Problems solved by technology

The measurement method of oblique shear seepage exists: because the shear surface has a certain angle with the sample axis, the shear area changes during the shear slip process, and the local stress state of the sample changes; the path of the seepage fluid is irregular, resulting in Unable to accurately determine the geometric size of the seepage cross section; the shortcoming of small shear displacement, especially only about 2mm at high temperature

The direct shear seepage measurement method, although the shear displacement is large, but because the samples in the autoclave are not the same length, a blank area appears in the sealing sleeve during the shearing process of the sample. On the one hand, the sealing sleeve is easily deformed inward. Make the measurement impossible, on the other hand, the force of the long and short samples is the same, and the increase of the confining pressure will easily break the sample, resulting in the failure of the measurement

Therefore, there is no report on the method of measuring large-displacement shear (direct shear) seepage in rocks under high temperature and high pressure at present.

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