Dry-hole pressure relief valve and hydraulic fracturing crustal stress testing device

Abstract

The invention discloses a dry-hole pressure relief valve and a hydraulic fracturing crustal stress testing device, and relates to the technical field of rock mass engineering testing. A valve core of the dry-hole pressure relief valve is inserted in a valve cavity from the insertion end of a valve body, and one end of the valve core extends out of the insertion end; a plurality of pressure relief holes are formed in the end, away from the insertion end, of the valve body, the valve core is provided with a blocking part which can block the valve cavity, and the insertion end of the valve body is provided with a limit nut for limiting the length of the part, extending out of the valve body, of the valve core; the part, located between the blocking part and the limit nut, of the valve core is sleeved with a load-bearing spring; the dry-hole pressure relief valve is simple in structure and convenient to operate, and can effectively relieve pressure in a packer. A high-pressure pump of the hydraulic fracturing crustal stress testing device is communicated with the top end of a drilling hole, the bottom end of the drilling hole is communicated with the dry-hole pressure relief value, the end, extending out of the insertion end, of the valve core is communicated with a switching valve, and the switching valve is communicated with the packer. Through the adoption of the hydraulic fracturing crustal stress testing device, crustal stress tests can be conducted under the conditions of deep drilling holes and dry holes by using a hydraulic fracturing method, and the tests are stable.

Description

Technical field [0001] The invention relates to the technical field of rock mass engineering testing, in particular to a dry hole pressure relief valve and a hydraulic fracturing ground stress testing device. Background technique [0002] In-situ stress is the natural stress existing in the stratum. It is the fundamental force that causes the deformation and destruction of mine roadways and other underground projects. Therefore, the magnitude and direction of the in-situ stress directly affect the stability of the surrounding rock of the roadway. Stress, studying the stress distribution characteristics of surrounding rock is a necessary prerequisite for the stability analysis of the surrounding rock of the roadway and the realization of scientific underground engineering excavation design. At present, the testing methods of engineering rock in-situ stress modulus commonly used internationally can be summarized as: surface stress relief method, surface stress recovery method, casi...

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Problems solved by technology

[0006] 2. Double-tube pressurization, specifically, one high-pressure tube is used to pressurize the capsule (air pressure), and the other high-pressure tube is used to pressurize the test section (water pressure). The main problems of this double-tube pressurization are: the test equipment is complicated , The pressure sensor should be placed on the upper end of the packer (to reduce the pressure error)

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