Test device and test method for determining internal water pressure in cracks of water-injected coal seam

Abstract

The invention discloses a test device and a test method for determining the internal water pressure of a water injection coal seam fissure, and belongs to the technical field of pore water pressure test. It solves the technical problem that the water pressure in the coal body around the water injection borehole cannot be tested in the prior art. It includes a testing mechanism and a display mechanism. There are several water inlet holes with different apertures on the casing. Several partitions are arranged in the cylindrical cavity inside the casing. Several partitions divide the cavity into several sealed cavities. . The present invention obtains the pore diameter of the water inlet hole through the cooperation of the testing mechanism and the display mechanism, and uses the pore diameter as an intermediate quantity to calculate the amount of water in the coal seam fissure structure around the water injection drilling hole in the coal seam according to the relationship between the capillary pore diameter and the water pressure in the washburn equation. Therefore, the water pressure inside the coal body around the borehole is accurately and quantitatively calculated during the coal seam water injection process. The calculation results play an important role in adjusting the coal seam water injection parameters and improving the comprehensive disaster prevention effect of coal seam water injection.

Description

technical field [0001] The invention relates to the technical field of pore water pressure testing, in particular to a testing device and a testing method for determining the water pressure in the coal body fissure structure around a coal seam water injection borehole. Background technique [0002] Coal seam water injection is a comprehensive mine disaster prevention technology commonly used in the world. After decades of practice and development, nearly 80% of fully mechanized mining faces in my country have adopted coal seam water injection technology. In recent years, with the continuous improvement of this technology and process, the application field of coal seam water injection technology is also expanding, from the initial dust reduction, prevention of rock burst, coal and gas outburst and other disasters, to the current development to eliminate coal seam water injection technology. At the same time, it is widely used in the fields of softening hard roof and caving co...

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Problems solved by technology

[0003] In the prior art, the method for measuring the fluid pressure in the coal body around the water injection borehole is: constructing the borehole - laying the pressure measuring pipeline - sealing the hole - installing a pressure gauge at the orifice - reading, the pressure displayed by the pressure gauge in this method is gas , the combined pressure of the two phases of water, and the pressure of water cannot be accurately measured

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