The invention provides a deep
coal bed gas pressure-maintaining
coring free gas and adsorption gas content testing
system and method.The testing
system comprises a
control system, a pressure maintaining
barrel, a gas-liquid separation device, a
drying and condensing device and a flow meter, and the pressure maintaining
barrel, the gas-liquid separation device, the
drying and condensing device and the flow meter are sequentially communicated through a pipeline; and a
numerical control pressure gauge and an intelligent flow valve are mounted on the pipeline between the pressure maintaining
barrel and the gas-liquid separation device.
Free gas and adsorbed gas reach the original state of
dynamic balance through constant temperature, then the intelligent flow valve is controlled to be opened and closed through the
control system, when the pressure in the pressure maintaining barrel is lower than the
reservoir pressure, the intelligent flow valve is closed, after the pressure in the pressure maintaining barrel rises to the
reservoir pressure, the intelligent flow valve is opened, operation is circulated, and the pressure maintaining barrel is opened. After the pressure in the pressure maintaining barrel cannot rise to the
reservoir pressure,
free gas measurement is ended; in the whole process, the pressure maintaining barrel is decompressed by adopting small displacement, and the gas volume is measured by the flow meter, so that the on-site accurate gas content test of the deep
coal bed gas with high gas content and high
free gas ratio is realized.