SU824097A1 - Method of acoustic well logging apparatus calibration - Google Patents

Description

(51)) CALIBRATION METHOD FOR ACOUSTIC CARETING EQUIPMENT

The analog of the ground panel in- volves the half-wave of an acoustic signal in a window of a certain duration. Due to the difference in the duration of the half-wave of a reg signal and the signal of the simulator, a different number of half-wave signals fall into the integration window. As a result, different magnitudes of currents are recorded at the output of the amplitude channel, the difference between which and determines the attenuation calibration error.

The purpose of the invention is to increase the calibration accuracy of the acoustic logging equipment to eliminate the Errors / insertions of the non-identical signal of the electronic simulator and the real signal.

This aim is achieved in that in the method based on izmereshsh arrival time and amplitude of the acoustic signals of different kalibrovanshlh quantities po1luchensh 1x with pomsntsyu koitr0 lyshh transducers source signal caliber is set ravshsh amplitudes and m -Duration constituting its half-wave signal, in an environment with izmeren11amu known acoustic properties of the reference tube.

The drawing shows a block diagram of the individual units of the device for the implementation of the method,

 The device contains a borehole hole 1, placed in a fluid-filled pipe 2, placed on the yadstates 3, has sensors, an impedance 4 and an emitter 5. Haf (counter-mounted removable transducers b and 7 are placed with acoustic sensors on the stand S. The signal from the downhole tool 1 is fed via cable 9 to the input device .10 ground channel and then to the measuring channels P, oscilloscope i2 n recorder 13.

The signal induced in one of the removable transducers 7 is fed through the limiting amplifier 14 to calibrated transducers J5 and 16 of time and amplitude through the output stage 17 to the second control converter 6.. .

 the implementation of the method, a downhole tool with a control transducer 6 and 7 is placed in a pipe with a liquid 2, control converters

Pickers place over the outer edges of the transducers of the downhole tool inside or outside the pipe to eliminate distortion of the acoustic field. Turn on turnable

- the instrument and the instrument on the oscilloscope screen 12 have a real wave pattern, the parameters of which are determined by the properties of the reference tube imitating

o real environment. Then, using time converters 15, they move the signal induced by the electronic simulator so that both signals are observed on the oscilloscope screen - the reference tube and the reference simulator. After that, by adjusting the amplitudes and frequencies in a calibrated amplitude converter 16, set the initial calibration signal to

(j in terms of the amplitude and duration of each of the half-wave components of the signal along the reference tube.

Further, using time converters 15 and amplitudes 16

Simulator 5, by setting the initial signal by dividing the calibrated time values and damping the acoustic signal, removes the amplitude and time characteristics of the instrument under test. The robustness of working with field 5 parameters is minimal due to the elimination of error from the difference between the calibrated and real signals, due to the fact that the maximum calibration {about 1

 the signal having an arbitrary magnitude falls into an arbitrary point of the characteristic of the instrument being calibrated by the well (in the particular case in the nonlinear part) of the instrument being calibrated and,

 The waveform at the panel input depends on the shape of the characteristic of the entire path, which is determined by the non-linearity of both the instrument and the panel, and, coofBetCT, error, verification.

five

It also eliminates the possibility of an error due to the integrator determined by the cooTHOigeraieM amplitudes of the half-periods of the calibration and real signals, which is taken into account (or eliminated) only if the known ratio of the specified amplitudes for the instrument to be checked in the reference pipe is known.

The time channels are calibrated by sending a series of signals to the receiver of the device, delayed by a calibrated time relative to the time of arrival of the original signal and measuring this time by a ground panel, while the effect of the signal on the reference pipe is reduced by known methods. The result of calibration is a graph of the dependence of measured time values on calibrated.

The advantage of the method is that a maximum approximation of the conditions for verification and well is achieved. measurement, and thus eliminates the error due to the difference in waveforms during testing and measurements, and is inevitable when using the method using an electronic simulator of the medium. In addition, the method allows to obtain the characteristics of the measuring paths in the operating mode of the equipment being tested and in a wide range parameters, and with any high degree of detail, while using pipes only a limited number and values of calibrated parameters are possible. .

These advantages significantly improve the accuracy of the calibration of the equipment and the geological efficiency of its use.

Formula inventions

The method of calibration of acoustic logging equipment, based on the measurement of arrival time and amplitude of acoustic signals of various calibrated values, obtained using transducer controls, characterized in that with a circuit to improve calibration accuracy, the initial signal is set equal in amplitude and duration to each of the components its half wave is a signal measured in a medium with given properties.

Sources I {o {4atsii, taken into consideration at examination

1, USSR Author's Certificate No. 641376, cl. G 01 L / J / 40, 976.

2. Patent cm. No. 2944621, cl. NCI 340-15 5, published, 1960 (prototype).

Claims (1)

Claim A method of calibrating acoustic logging equipment based on measuring the arrival time and amplitude of acoustic signals of various calibrated · ₁₀ calibrated values obtained using control transducers, characterized in that in order to increase the calibration accuracy, the initial calibration signal is set equal in amplitude and duration to each .. making it half-waves to a signal measured in a medium with given properties.