Method and device for determining gas pressure of coal seam

Abstract

The invention discloses a method and a device for determining gas pressure of a coal seam. The method comprises the following steps: at an initial stage after hole drilling and hole sealing, a drilled hole gas emission rate q meets a power function relation along with time t, namely q=At-B; in the formula, a drilled hole gas emission initial speed A and an attenuation coefficient B are parameters which are changed along with the change of the gas pressure of the coal seam; and a relation is utilized to carry out rapid inversion on the gas pressure of the coal seam through a BP neural network. According to the device for determining the gas pressure disclosed by the invention, an air inlet pipe, a yellow mud hole sealing opening and an air guide pipe are arranged in a measuring room; a flow sensor is connected with the air guide pipe, a vacuum pump and a gas concentration sensor; an air outlet pipe is mounted on the vacuum pump; a signal conditioning circuit is connected with the flow sensor and the gas concentration sensor; an A / D (Analogue / Digital) converter is connected with the signal conditioning circuit; and a PC (Personal Computer) is connected with the A / D converter. The method and the device disclosed by the invention have the characteristics of solving the difficulty that the height of a function relationship for indirectly determining the gas pressure of the coal seam, and having fast inversion.

Description

technical field [0001] The invention belongs to the technical field of coal seam gas measurement, in particular to a method and device for measuring coal seam gas pressure. Background technique [0002] For decades, a lot of research and exploration have been carried out at home and abroad on how to accurately measure coal seam gas pressure, and various measurement methods have been proposed, which can be generally divided into two categories: direct method and indirect method. [0003] 1. Direct measurement method [0004] The direct measurement method is to expose the coal seam through drilling, install measuring instruments and seal the drilling, and use the principle of natural gas penetration in the coal seam to measure the gas pressure that reaches equilibrium at the drilling exposure. The hole sealing is a key process, which directly affects the accuracy of the measured gas pressure. Therefore, according to different sealing techniques, many direct pressure measurem...

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Problems solved by technology

[0010] The purpose of the embodiments of the present invention is to provide a method and device for measuring coal seam gas pressure, aiming to solve the problem that the traditional method for measuring coal seam gas pressure has a long period, and it is difficult to accurately establish a coal seam gas pressure measurement model for indirect measurement methods

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