Reciprocating type rock fracture friction-seepage characteristic test device and test method

Abstract

The invention discloses a reciprocating rock fracture friction-seepage characteristic test device and test method. The test device comprises an X-axis shearing system, a Y-axis stress loading system,a Z-axis stress loading system, a servo oil source system, a pore pressure loading system and a host. The X-axis shearing system comprises an X-axis EDC controller, an upper shearing box, a lower shearing box, an X-axis left hydraulic cylinder, an X-axis right hydraulic cylinder, an X-axis left pressing head, an X-axis right pressing head, an X-axis left pressure sensor, an X-axis right pressure sensor and an X-axis displacement sensor. The pore pressure loading system comprises a gas cylinder, a pressure gauge, a pressure reducing valve, a fluid inlet pipeline, a fluid outlet pipeline and a flow meter. By the adoption of the method, the friction coefficient and the stability parameters and permeability of the fracture surface in the slippage process can be measured efficiently and accurately, simultaneous measurement of the rock fracture friction characteristic and the fracture permeability evolution law is achieved, and the mechanical property and seepage (hydraulics) characteristicof rock fractures can be represented at the same time.

Description

technical field [0001] The invention relates to the field of rock mechanics and engineering experiments, in particular to a reciprocating rock crack friction-seepage characteristic testing device and testing method. Background technique [0002] Human activities related to water injection, such as oil and gas and geothermal energy development, and sewage reinjection, may induce seismic activity and disaster risk. A large amount of high-pressure fluid is injected into the formation, which changes the in-situ stress field of the reservoir, reduces the effective stress originally acting on the fault and fracture plane, and may cause slippage of faults and fractures, resulting in earthquake phenomena. The slip stability of fault and fracture planes will directly determine whether the slip is stable creep slip or unsteady seismic slip, and the slip process will also lead to changes in the permeability of the surrounding rock mass. Similarly, there are similar engineering problem...

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Problems solved by technology

[0003] (1) The existing rock inclined shear instrument cannot simulate the triaxial stress state of the deep rock, and cannot accurately measure the friction characteristics of the rock fracture surface under the stress condition

[0004] (2) The measurement of the friction coefficient of rock fractures in the existing laboratory experiments mostly adopts the oblique shear method. During the sliding process of the oblique shear fracture, the stress concentration phenomenon caused by the end loading is difficult to ensure that the fracture slides along the direction of the fracture surface, making the upper and lower fracture surfaces Can not be fully contacted, resulting in inaccurate measurement results

[0005] (3) Existing test devices cannot simultaneously measure the friction characteristics of rock fractures and the evolution law of fracture permeability, and cannot simultaneously characterize the mechanical properties and seepage (hydraulic) characteristics of rock fractures

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