SU443349A1 - Acoustic logging tool - Google Patents

Description

one

Acoustic logging devices that record information in digital form directly during logging and consist of a downhole probe and a ground panel are known.

However, discrete recording of information in a known device does not allow averaging of signals at the same depth, and therefore there are increased requirements to the accuracy and reliability of each individual measurement.

In order to improve the measurement accuracy in the proposed device, a quantization circuit is connected to the inputs of the counting decades, of which a number of higher bits are connected to the recorder converter.

FIG. 1 shows a block diagram of the forming, counting and recording parts of the control and recording panel; in fig. 2 - timing diagrams explaining the operation of the control and recording panel.

The input of the amplifier 1 is connected by a logging cable to the output of the downhole probe. Three emitter repeaters 2, 3 and 4 are connected in parallel to the output of the il amplifier; a phase shifter 5 is connected to the power supply voltage source. The phase shifter 5 is loaded with a meander 6 driver. Shaper multivibrator 7 is triggered by signals from the former 6.

the multivibrator 7 is connected to one of the two inputs of the coincidence circuit 8; the output of the emitter follower 2 is connected to the second input of the coincidence circuit 8. Signals from the output of the coincidence circuit 8 start the standby multivibrator 9. The output of the standby multivibrator 9 is connected to one of the two inputs of the coincidence circuit 10, the second input of the matching circuit 10 is connected to the output of the emitter follower 3. The output of the matching circuit 10 is connected to the input of the waiting multivibrator 11, the output of which, in turn, is connected to one of the inputs of the matching circuit 12. Per volt swarm input coincidence circuit 12 output emitter follower wound 4.

Outputs from coincidence circuits 8, 10, and 12 are set to the switch of measured parameters 13, which is a common

triple switch with three positions and two directions. Two inputs of the measuring trigger 14 are connected to the flip switch. Measuring trigger 14 is a normal statistical trigger.

with two separate entrances.

The output of the depth sensor is connected to one of the inputs of the resolution trigger 15. The resolution trigger 15 is a statistical trigger with separate inputs. The output of trigger multivibrator 7 is connected to the second input of trigger resolution 15. The output of trigger resolution 15 is loaded on the inputs of equalizing trigger 16 and the reset node 17. Control trigger 16 is a statistical trigger with separate inputs. The reset node 17 - shaper short pulse. The output of the control trigger 16 is connected to one of the two inputs of the matching circuit 18. The second input of this circuit receives signals from the measuring trigger 14. The output of the matching circuit 18 is connected to the inputs of the divider K 19 and the time quantizing device 20. The divider K 19 represents is a non-reversible sequential pulse number counter, performed on counting triggers. The output of the divider “K” is connected to the second input of the control trigger 16. The device of the time quantization 20 represents a generator of brand pulses. The output of the time quantization device is connected to the input of a ten-day counter (to the input of the decade "1 21). The decade counter itself consists of the number “n recalculated decades, in FIG. 1 shows the decade “1 21, the decade“ m +1 22 and the decade ”p 23. All recalculated decades of known construction are performed on four counting triggers. They are covered by feedback loops. The outputs "five to ten decades" are connected to the parallel inputs of the converter of the recorder 24, which is a buffer device for temporary storage of information. A clock generator 25 is connected to the converter of the recorder 24. The outputs of the converter of the recorder 24 are connected to the recorder 26. The device works as follows. Signals from the acoustic probe are input to the amplifier I as a sequence of packets of three identical pulses, corresponding to the parcel signal and the signals of the first entry of an elastic wave arriving at two receivers (Fig. 2, a). On amplifier 1 of these signals, standard pulses are formed with an increased steepness of the fronts. From the output of amplifier 1, the formed pulse packets arrive in parallel to the inputs of three emitter followers 2, 3, and 4. The transmitting signals of the acoustic probe are synchronized by the mains voltage. Therefore, the control and registration panel is synchronized by the network. For this purpose, an industrial frequency voltage is applied to the input of the phase shifter 5. The shaper of the meander 6 converts the sinusoidal voltage into rectangular oscillations of the same frequency (Fig. 26). The differentiated signals of the imager 6 are triggered by the waiting multivibrator 7, which outputs square pulses (Fig. 2c). By using the phase shift of the sinusoidal voltage, it is possible to vary within certain limits the starting time of the standby multivibrator 7. This is necessary so that the leading edge of the pulse of the standby multivibrator 7 is ahead of the time signal of the acoustic probe. Matching circuit 8 is designed to separate from the sequence of signals, the "send" signal. The two inputs of the coincidence circuit 8 receive, respectively, a packet of pulses from the zmitter follower 2 and the rectangular pulse of its multivibrator 7. At the output of the coincidence circuit 8, the signal appears only if both inputs of the coincidence circuit 8 have signals simultaneously (Fig. 2d). The first acoustic signals are extracted at the first receiver from the general sequence of acoustic zoid signals at the output of the coincidence circuit 10. One of the inputs of the coincidence circuit 10 from the emitter follower 3 is followed by a pulse packet of the acoustic probe, and the second input of the coincidence circuit 10 receives a square pulse the output of the waiting multivibrator 9, which is triggered by the sigpal from the output of the coincidence circuit 8. The pulse produced by the waiting multivibrator 9 has a duration of several Longer than the arrival time of the first entry of the acoustic signal at the first receiver (Fig. 2 (5). The selected first entry signal at this receiver (Fig. 2e) starts the waiting multivibrator 11, the latter generates a rectangular pulse with a duration exceeding the arrival time elastic wave at the second receiver (Fig. 2g). The signal from the output of the standby multivibrator 11 goes to one of the inputs of the coincidence circuit 12, and the second input of this circuit receives pulse packets from the emitter follower 4. At the output of the coincidence circuit 12, Signals of the moment of arrival of the first entry of the elastic wave to the second receiver (FIG. 2 h). The outputs of the three coincidence circuits 8, 10 and 12 are set to the switch of the measured parameters 13. Depending on the required measurement mode, the switch 13 switches the inputs of the measuring trigger 14 with the outputs of the coincidence circuits. The pulse duration at the trigger output is equal to the time between the arrival of signals at its inputs, i.e., equivalent to the measured time parameter Dg (Fig. 2) or ti and tz. When a probe passes a given current from the depth sensor, a triggering signal is sent to the input of the trigger of resolution 15 (Fig. 2k). The synchronizing signal of the standby multivibrator 7 resets the resolution trigger 15, and the control trigger 16 is triggered (Fig. 2m). The triggering of the control trigger 16 leads to the fact that the input of the device temporarily quantizing 20 begins to receive a series of pulses produced by the measuring

trigger 14. To do this, the signal from control trigger 16 is input to one of the two inputs of the matching circuit 18, and the second input of the matching circuit 19 receives pulses from the measuring trigger 14. With the simultaneous presence on both inputs of the output signals of the matching circuit 18, a signal fully adequate to the signal of the measuring trigger 14 (Fig. 2n).

The signal from the coincidence circuit 18 is fed to the divider "K 19, the output of which is followed by a signal only after the arrival of" K pulses (Fig. 2n). The signal from the output of the divider "K 19" returns the control trigger 16 to the initial state (Fig. 2m) and through the coincidence circuit 18, the pulses from the measuring trigger 14 no longer follow until the next signal from the resolution trigger 15 arrives on the control signal. The time quantizing device 20 is supplied to the measured pulses, the duration of each reflects the result of a single measurement of the parameter under study. These pulses on the temporary quantizer 20 device are converted into bundles of branded pulses (Fig. 2 o). The duration of the bundle of branded il pulses is equal to the pulse duration of the trigger 14, and the period of the brand pulses (time quantization step) was chosen according to the considerations given above in the present description. The number of "packages of branded silt: zeroes one after another is fed to the input of a ten-day counter consisting of decades - 23. This counter successively summarizes each brand impulse contained in

a pack. Before the beginning of each measurement cycle, all the triggers of each recalculated decade are set to the initial, zero, state by the arrival of a short pulse from the node of the reset 17 but the total discharge penalty. The reset node 17 is triggered by a pulse from the resolution trigger 15 (Fig. 2n).

The information from the "/ I - t decade of the most significant bits and in parallel arrives at the converter of the recorder 24, where it is stored until the signal arrives from the clock generator 25. With the arrival of pulses from the clock generator 25, the information is read into the recorder 26, where one or another storage medium is applied . Since most often the recorder is not able to simultaneously record the whole number in 1; the selected code, the number is recorded in parts in several stages (tact) followed successively. Therefore tact

The generator 25 for each signal from the control of the toigger 16 generates a sequence of read pulses.

Prevention and Record

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The dt acoustic logging device, the contained kva / kinny probe and the ground registration panel, including the quantizing signal; the regnator generator, the recorder, and the correction scheme are different in that, in order to improve the measurement accuracy, the kiantovaya circuit is connected to the inputs of the counting decades. which a number of CTapiuiix bits are connected to the registerpath converter.

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