RU2044878C1 - Telemetering system for monitoring rotation speed of turbodrill shaft - Google Patents

Abstract

FIELD: drilling of oil and gas wells. SUBSTANCE: telemetering system for monitoring rotation speed of turbodrill shaft has successively connected blocks of decoding, comparison of three signals located between amplifier and recording and indicating block. Decoding block is made in form of three channels each consisting of band-pass filter, detector, NAND circuit block computing pulse length τ and period of pulse spacing T, block for checking relative pulse duration c=T/c = T/τ, besides, bottom-hole transducer of information signals is made in form of resonance damper. Bottom-hole modulator is made in form of pipe with longitudinal through recess located inside the code perforated tube. Bottom-hole radiator is made in form of turbine blades of turbodrill. EFFECT: higher efficiency. 3 dwg

Description

 The invention relates to technical acoustics and can be used to obtain downhole information on a wireless communication channel and process it with ground-based equipment.

Known telemetry system used when drilling wells with a wired communication channel [1]
A disadvantage of the known telemetry system is low noise immunity and accuracy of information transfer.

 Closest to the proposed one is a telemetric system for monitoring downhole parameters of a drilling process containing downhole information signal sensors, downhole modulators, downhole emitter, drill string, receiver, amplifier, demodulator, information recording and display unit.

 A disadvantage of the known telemetric system for monitoring downhole parameters is the low noise immunity and accuracy of information transfer due to the lack of a code information signal during the formation of the measured parameter and its conversion by ground measuring equipment.

 The aim of the invention is to increase the noise immunity and accuracy of the transmission of downhole information by entering a code when generating information in the process of measuring a technological parameter and extracting it from the noise spectrum by ground-based measuring equipment.

 The goal is achieved in that the system is equipped with sequentially connected decoding units, comparing three signals located between the amplifier and the information recording and display unit, the decoding unit is made in the form of three channels, each of which consists of a band-pass filter, detector, AND-NOT logic element, the unit for calculating the pulse duration τ and their repetition period T, the unit for checking the duty cycle with T / τ; in addition, the downhole sensor of information signals is made in the form of a resonant silencer, and the downhole ulyator formed as a tube with a longitudinal through slot, disposed within the perforated tube of the code, wherein the downhole transducer is in the form of turbine blades turbodrill.

 Comparative analysis with the prototype shows that the claimed device is additionally equipped with a decoding unit and a unit for comparing three signals.

 Thus, the invention meets the criterion of "Novelty."

 Comparison of the claimed solution with other technical solutions shows that a telemetry system for controlling the number of revolutions of the turbo-drill shaft is known. However, when introducing new elements into the system, in particular, a code perforated pipe tuned to three sound absorption frequencies, when rotating the modulator, it is possible to simultaneously encode three information signals about the same technological parameter in the noise spectrum generated by turbo-blades of a turbo-drill, increasing noise immunity and accuracy of information transfer.

 In the ground part of the equipment, new elements allow, in particular, a unit for calculating the pulse duration τ and their repetition period T, with subsequent comparison of three signals, to tightly control the technological parameter in case of noisiness of one or two signals at the same time when information passes through the communication channel.

 Thus, the present invention meets the criterion of "Inventive step".

 The proposed solution can be repeatedly used in any drilling rigs until the mechanical part and the elemental base of the ground device are completely worn out during turbine drilling of oil and gas wells.

 Thus, the present invention meets the criterion of "Industrial applicability".

 Figure 1 shows a structural diagram of a telemetry system for controlling the number of revolutions of a shaft of a turbodrill; figure 2 downhole sensor resonant silencer and downhole modulator pipe with a longitudinal through groove; figure 3 spectrograms and oscillograms of the information signal.

The structural diagram of the telemetry system contains: 1 downhole emitter; 2 downhole sensor; 3 downhole modulator; 4 drill string; 5 receiver; 6 amplifier; 7 decoding unit; 8 block comparing three signals; 9 block registration and display information; 10.1 bandpass filter tuned to frequency f ₁ ; 10.2 bandpass filter tuned to frequency f ₂ ; 10.3 bandpass filter tuned to frequency f ₃ ; 11.1-11.3 detectors; 12.1-12.3 logical elements AND NOT; 13.1 unit for calculating the pulse duration τ ₁ and the period of their repetition T ₁ at a frequency f ₁ ; 13.2 unit for calculating the pulse duration τ ₂ and the period of their repetition T ₂ at a frequency f ₂ ; 13.3 unit for calculating the pulse duration τ ₃ and the period of their repetition T ₃ at a frequency f ₃ ; 14.1 block duty cycle test c ₁ T ₁ / τ ₁ for frequency f ₁ ; 14.2 block test for duty cycle c ₂ T ₂ / τ ₂ for frequency f ₂ ; 14.3 duty cycle test block c ₃ T ₃ / τ ₃ for frequency f ₃ .

The downhole sensor contains: 15 lower connecting sub; 16 shaft modulator; 17 longitudinal through groove; 18 central perforated code tube; 19 the internal cavity of the resonant silencer; 20 building; 21 upper thrust ring; 22 upper connecting sub; 23 first sound-absorbing throat at the information absorption frequency f ₁ ; 24 a second sound-absorbing throat at the information absorption frequency f ₂ ; 25 third sound-absorbing throat at the information frequency f ₃ ; 26 bottom thrust ring; 27 window for the passage of flushing fluid; 28 connecting coupling half.

 Static mode. The downhole sensor for monitoring the rotational speed of the turbo-drill shaft is located above the third section of the spindle turbo-drill of the type ZTSSh1-195 (or ZTSSh-195 TL).

 Sensor assembly: the lower thrust ring 26 is inserted into the housing 20 (Fig. 2), then the lower connecting sub 15 is screwed on. The central code perforated tube 18 is inserted into the housing 20 until it stops with the lower thrust ring 26, then the upper thrust ring 21 is inserted and the upper connecting sub 22.

 A downhole modulator shaft-modulator 16 is put on the slots of the turbo-drill shaft (not shown) by means of a connecting coupling half 28 and a downhole sensor with assembled elements is screwed onto the turbo-drill case (not shown).

где с скорость звука в трубопроводе;
V объем резонансной камеры;
F площадь зваукопоглощающего отверстия (горла);
h высота горла.The action of a resonant silencer with proper attenuation, being excited by the incident wave, selects a sufficiently large energy from the sound field in the frequency region adjacent to the natural frequency of the resonator, which is determined by the formula
f

where s is the speed of sound in the pipeline;
V volume of the resonance chamber;
F is the area of the sound-absorbing hole (throat);
h throat height.

 In order to increase noise immunity and accuracy of downhole information transmission, it is enough to transmit a controlled parameter through a communication channel simultaneously with several signals, for example, three absorbed frequencies. Then, in the case of noisy one or two signals in any combination, information about the monitored parameter is highlighted.

 This can be done as follows.

Along the generatrix of the central pipe 18 (FIG. 2), there are, for example, three sound-absorbing holes F ₁ , F ₂ , F ₃ , and each hole with one volume of the resonant silencer will absorb three frequencies f ₁ , f ₂ and f ₃ .

Then, when the shaft-modulator 16 (Fig. 2) simultaneously opens three sound-absorbing holes (throat 23-25) in the noise spectrum of the sound vibration, three frequencies f ₁ , f ₂ and f ₃ will be absorbed simultaneously. In addition, for a given width of sound-absorbing holes (with the same width of all three holes), the duty cycle will be the same, i.e. ratio of period to pulse duration.

 Thus, the constant duty cycle specified by the geometry and the three frequencies absorbed simultaneously about the same parameter is a code.

Calculation example. The inner diameter of the sub is 165 mm; the internal volume of the resonance chamber V 5000 cm ³ ; inner diameter of the chamber 105 mm; throat length h 2 cm; the area of the hole F ₁ 0.7 cm ² ; resonant absorption frequency for F ₁ , f ₁ 200 Hz; hole area F ₂ 1,58 cm ² ; resonant absorption frequency for F ₂ , f ₂ 300 Hz; hole area F ₃ = 2.8 cm ² ; resonant absorption frequency for F ₃ , f ₃ 400 Hz.

 Dynamic mode. When the mud pumps are turned on, flushing fluid through a drill string (not shown) enters the turbodrill (not shown) through the internal cavity of the modulator shaft 16 (FIG. 2) and flushing windows 27 (FIG. 2).

The rotation of the turbine shaft (not shown) through the connecting coupling half 28 (Fig. 2) drives the modulator shaft 16. For each revolution of the turbine shaft, the longitudinal through groove 17 of the modulator shaft 16 is aligned with the sound-absorbing holes 23-25 of the acoustic resonator, resulting in energy absorption occurs at frequencies f ₁ 200 Hz, f ₂ 300 Hz and f ₃ 400 Hz, performing the operation of amplitude-pulse modulation.

 Figure 3, a shows the spectrogram of the noise process generated by the turbo-drill turbines.

Figure 3, b is the same spectrogram, but with the absorbed frequency f ₁ 200 Hz from the first sound-absorbing hole F ₁ , f ₂ 300 Hz from the second sound-absorbing hole F ₂ and f ₃ 400 Hz from the third sound-absorbing hole F ₃ .

This information is distributed through the drill string 4 (FIG. 1), received by the receiver 5, amplified by the amplifier 6, fed to a band-pass filter 10.1 tuned to a frequency f ₁ 200 Hz, to a band-pass filter 10.2 tuned to a frequency f ₂ 300 Hz, and band-pass filter 10.3 tuned to a frequency f ₃ 400 Hz. All three information signals are detected by detectors 11.1, 11.2 and 11.3 and are inverted by AND-NOT 12.1, 12.2 and 12.3 elements.

In block 13.1 (Figs. 1 and 3, d), the duration of the wave pause (pulse is the frequency absorption time) generated by the downhole sensor at a frequency f ₁ 200 Hz is measured and the interval between them (periodic overlapping of the sound-absorbing hole by the modulator shaft forms a sequence of wave pauses ( for example, duty cycle selected 4).

In block 13.2 (Figs. 1 and 3, d), a computational operation is carried out, similar to the operation performed by block 13.1, but at a frequency f ₂ 300 Hz.

In block 13.3 (Fig. 1 and 3, e), a computational operation is carried out similar to the operation performed by block 13.1, but at a frequency f ₃ 400 Hz.

In block 14.1, the information signal is checked for duty cycle c ₁ T ₁ / τ ₁ for frequency f ₁ .

In block 14.2, the information signal is checked for duty cycle c ₂ T ₂ / τ ₂ for frequency f ₂ .

In block 14.3, the information signal is checked for duty cycle c ₃ T ₃ / τ ₃ for frequency f ₃ .

 In block 8 of the comparison (Fig. 1), three signals are compared and converted into a sequence of pulses proportionally to the number of revolutions (Fig. 3, k) and then enter the block 9 for recording and displaying information.

If the signal is noisy, for example, at the absorption frequency f ₂ 300 Hz (Fig. 3, c), the code information is redistributed as follows: along the frequency conversion channel f ₁ 200 Hz, at the output of block 14.1, the signal has the form shown in Fig. 3, g on the frequency conversion channel f ₂ 300 Hz; at the output of block 14.2, the signal has the form shown in FIG. 3, h; on the frequency conversion channel f ₃ 400 Hz at the output of block 14.3, the signal has the form shown in figure 3, and.

In block 8 comparison (figure 1), three signals are compared in a sequence of pulses from two signals f ₁ 200 Hz and f ₃ 400 Hz (in the absence of a signal at a frequency f ₂ 300 Hz), presented in figure 3, to and further, to block 9 registration and display of information.

If during the well drilling there will be a noise of frequencies, for example f ₁ 200 Hz and f ₃ 400 Hz (or any other combination), then the ground-based device will still show downhole information on the rotational speed of the turbo-drill shaft.

 The proposed telemetry system for controlling the number of revolutions of the turbo-drill shaft during its implementation will allow, in comparison with the known technical solutions, to increase the mechanical speed and the penetration of the bit by maintaining the specified value of the axial load along the geological and technological range.

Claims (1)

 TELEMETRIC SYSTEM FOR MONITORING THE NUMBER OF TURBO SHAFT VALVES, comprising a downhole emitter, a downhole information signal sensor connected to a downhole modulator, a receiver, amplifier and an information recording and display unit, characterized in that it is equipped with a decoding unit and a comparison unit for three signals, and a decoding unit made of three channels containing a series-connected band-pass filter, a detector, an AND-NOT element, a unit for calculating the pulse duration τ and their repetition period T and a check unit and the duty cycle C = T / τ, while the output of the receiver is connected to the input of the amplifier, the output of which is connected to the inputs of the bandpass filters, and the outputs of the test blocks for the duty cycle C = T / τ are connected to the input of the three signal comparison unit, the output of which is connected to the input unit for recording and displaying information, in addition, the downhole sensor of information signals is made in the form of a resonant silencer, the downhole modulator is made in the form of a pipe with a longitudinal through groove located inside the code perforated pipe, and the downhole emitter is tsya turbine blades turbodrill.

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