Water-contained coal bed gas pressure measuring device and method

Abstract

The invention relates to a water-contained coal bed gas pressure measuring device and method which are suitable for a drill hole inclining upwards. The water-contained coal bed gas pressure measuring device comprises a pressure measuring pipe, a grouting pipe, a grouting pump, a water and pulp draining pipe, a sensing system and a water level and drainage pipe. The pressure measuring pipe, the water level and drainage pipe, the water and pulp draining pipe and the grouting pipe are sequentially and fixedly arranged in the drill hole through a fixed support in the vertical direction from top to bottom, and the lengths are sequentially shortened; and a water inductor and an electromagnetic valve are installed at the outer ends of the pressure measuring pipe and the water level and drainage pipe correspondingly, a drain valve is installed at the outer end of the water and pulp draining pipe, and the water inductor and the electromagnetic valve are connected with the sensing system. According to the water-contained coal bed gas pressure measuring device, the novel method for measuring water-contained coal bed drill hole gas is developed, the gas emission quantity of the water-contained coal bed gas and the water-contained coal bed drill hole gas pressure can be directly measured, and the influence of the water in a coal bed on gas pressure testing can be effectively reduced. The structure is simple, installation is convenient and rapid, operation is convenient, the measuring result is accurate, and the water-contained coal bed gas pressure measuring device can be repeatedly used.

Description

technical field [0001] The invention relates to a coal seam gas pressure measuring device, in particular to a water-bearing coal seam gas pressure measuring device and a measuring method suitable for oblique upward drilling. Background technique [0002] Coal seam gas pressure is the basic parameter that determines the amount of coal seam gas content, the level of gas flow dynamics and the potential of gas dynamic phenomena. Accurate and reliable gas pressure parameters are particularly important in the research and evaluation of gas reserves, gas gushing, gas flow, gas drainage and gas outburst. Most coal-measure formations in mines have aquifers. When the coal seam boreholes are affected by water, the accuracy of gas pressure measurement parameters will be seriously affected. The water mainly comes from the coal seam and surrounding rock, especially the sandstone water in the coal seam surrounding rock. When the water enters the coal seam gas pressure measuring device, th...

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Problems solved by technology

[0006] ① If the drilled hole is inclined upwards, the water pouring into the drilled hole from the coal seam will liquid seal part of the gas, so that the gas cannot pass through the water separation membrane, resulting in inaccurate gas pressure measurement;

[0007] ② The water-rich coal seam is mostly coal slime water, which will block the water separation membrane, affect the passage of gas and cause the measured gas pressure to be inaccurate;

[0008] ③ Unable to control the balance between the amount of water poured into the borehole and the amount of water discharged. When the amount of water poured into the borehole is greater than the amount of water discharged, the pressure in the borehole increases due to the increase in water volume, so that the gas rich in the coal seam is not easily released to the borehole. hole, resulting in inaccurate measured gas pressure;

[0009] CN 205370556 U Although it is equipped with an automatic drainage system and a pressure balance system, it is impossible to determine whether the pressure measurement junction is affected by water pressure during and after the automatic drainage of the pressure measurement device

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