The invention relates to a method for evaluating the integrity of a
well cementing barrier. The method includes the following steps that 1, a simulated formation of a tubular structure with the open upper end and the closed lower end is manufactured; 2, the manufactured simulated formation is put in a
barrel; 3, a casing
pipe coated with a
drilling fluid layer is put in the simulated formation; 4, an ultrasonic probe is arranged in the middle in the casing
pipe, and the ultrasonic probe is electrically connected with an
oscilloscope, a pulse generation receiving instrument and a high-speed
transient signal acquisition instrument, wherein the
oscilloscope, the pulse generation receiving instrument and the high-speed
transient signal acquisition instrument are arranged outside; 5, water is injected into the
barrel till the water surface reaches an upper end opening of the simulated formation, and the casing
pipe is filled with water; 6,
cement paste is prepared; 7, the
cement paste is injected between the casing pipe and the inner wall of the simulated formation, after injection is completed, water is injected into the
barrel till the water surface is flush with the upper end face of the casing pipe, and waiting on
cement setting is carried out; 8, the ultrasonic probe is started, the pulse generation receiving instrument is used for measuring and acquiring a
well cementing acoustic amplitude curve of a to-be-measured time point, and the
peak value of the first wave of the
well cementing acoustic amplitude curve is read out; 9, whether the
cell cementing integrity is qualified or not is judged according to the well cementing
barrier integrity criterion.