Gas channeling judgment method based on phase change of fluid produced by gas injection effective well

A gas channeling judgment method based on phase change of output fluid of a gas injection effective well comprises the steps that the gas injection effective well is analyzed on site, and the gas injection effective well of a test object is selected; performing well flow sampling on the gas injection effective well of the test object; sampling well flow and carrying out phase state theoretical analysis and indoor experimental analysis; obtaining a phase envelope line and an equal liquid volume line according to an indoor experiment analysis result; comparing a phase state theoretical analysis result with the obtained phase envelope line and the equal liquid volume line to judge whether the precision requirement is met or not, and if not, returning to carry out the phase state theoretical analysis and the indoor experimental analysis again until the precision meets the requirement; forming a phase diagram envelope line diagram group by using a phase state theory analysis result of which the precision meets the