SU1606694A1 - Modulator of sonic vibration in turbo-drilling - Google Patents

Abstract

The invention relates to the oil and gas industry and is intended for drilling wells with turbo-drills. The modulator comprises a casing 1 bonded with the acoustic resonator (RA) 2 with sound absorbing throat 3 having a sound-absorbing holes 4. The opening 4 formed on an outer surface of the housing 1. The natural frequency of the AP is determined from the relationship F = C / 2φ [F / (V. H)] ^1/2 , where C is the speed of sound in the drilling fluid, F is the area of the sound-absorbing hole, V is the volume of the resonator, H is the depth of the throat. When an AR is placed in the field of a sound vibration spectrum, a wave pause is obtained at an AR frequency, which can be recorded on the spectrogram of the spectrum analyzer. When the magnitude of the sound velocity changes due to the appearance of air (gas) in the drilling mud, the wavelength shift will occur in the spectrogram of the spectrum analyzer. This will make it possible to detect the occurrence of gas in the drilling mud during the drilling process and to transfer this information to the surface. 2 Il.

Description

And-shaving refers to the oil and gas industry and ..; 1H1ChRI industry, namely to the organization for drilling wells

The purpose of the invention is to ensure that gas is detected at the well bottom when the velocity of sound propagates in a drilling fluid when it is gasified (gas

Fig. 1 shows a sound vibration modulator for turbine drilling, a longitudinal section; figure 2 - frequency spectrum,

The sound vibration modulator contains a body 1, an acoustic resonator 2 with a sound-absorbing throat 3, which has sound absorbing holes 4 “The acoustic resonator 2 is fastened to the body for 1 s. The sound-absorbing hole 4 of the acoustic resonator 2 is made on the outer surface of the casing 1 of the modulator. Bushing 5 forms together with housing 1., adapters 6 and 7, a chamber in which acoustic resonator 1 is placed. Through adapters 6 and 7, the sound vibration modulator is connected to drill pipe 8 and 9 of the drill string. In the lower part of the drill pipe string is placed turbo-drill with rock-cutting tool (not shown) „

The principle of operation of the device is as follows

Resonant absorbers in applied acoustics are understood to mean resonant mass-spring systems, called acoustic resonators, where the oscillating mass corresponds to the mass of air in a narrow hole or slit of the plate, and the spring to the elastic volume of air in the cavity;

The natural frequency of such an acoustic resonator is determined from the ratio

(one)

where C is the speed of sound;

F is the area of the sound-absorbing hole;

V is the cavity volume;

h is the depth of the throat. If such a resonator is placed in the spectrum field of a sound vibrator, a wave pause is obtained at the frequency of the resonator, which can be recorded on the spectrogram of the spectrum analyzer

0

0

five

five

When the magnitude of the sound velocity changes due to the introduction of air (gas) into the liquid with constant geometric parameters of the acoustic resonator: volume V, throat area F, depth h in the spectrogram of the spectrum analyzer. wave break pause This property of the acoustic resonator is used in a sound vibration modulator for early detection of gas content in the drilling fluid at the bottom of the well during the drilling process and simultaneous transfer of the specified information to the surface.

Example. The calculated geometrical dimensions of the device are as follows: resonator volume V 2.3 cm, depth h 496 cm, area of the sound-absorbing hole F 1 cm, resonant frequency of the acoustic resonator f 700 Hz for the speed of sound in drilling mud C 1500 m / s o

The initial absorption frequency f 700 Hz of the information signal is selected from the condition

, nz 60

(2)

where n is the number of revolutions of the shaft of the turbo-drill;

Z is the number of blades on the rotor turbine of the turbo-drill ,.

For a ZTSSh-195 turbo-drill with a flow rate of 25 l / s, the shaft rotates at 590 rpm with the number of blades on the rotary impeller Z 24 and p 590 rpm (idling the turbo-drill), the fundamental frequency is 236 Hz. The frequency of absorption, equal to 700 Hz, is the second harmonic.

In the process of drilling wells from the sound source of a turbodrill, elastic waves propagate to the wellhead through the annulus 10 ". An acoustic resonator 2 located on the propagation path of elastic waves absorbs the frequency f from the spectrum of sound vibrations. 700 Hz

At the surface of the well, a 1PA-9 type sensor (not shown) receives an acoustic signal and, via a robotron (spectrum analyzer), is fed to an AI-1024 amplitude pulse analyzer with output to a plotter. In the spectrogram (Fig. 2a)

there is no frequency f

U

 700 Hz. This indicates that there is no gas in the drilling fluid.

When a gas in the bit solution in the amount of 10% appears, the speed of sound will become equal to 1200 m / s. Therefore, the frequency of absorption according to the calculation formula (1) will be equal to) 65 Hz. . Then on the spectrogram (Fig. 2b) the absence of the frequency fy 565 Hz will be fixed,

With the appearance of 20% of the gas in the drilling fluid, the speed of sound will be equal to 1000 m / s. Consequently, the absorption frequency will be f 472 Hz, and then on the spectrogram (Fig 2 C) the absence of frequency f.g 472 Hz o

Thus, on the spectrogram of the spectrum analyzer, the presence of gas in the drilling fluid is recorded at its various contents.

Monitoring the gas content in the drilling fluid and changing its concentration value gives an idea of the downhole conditions. Such characteristics of the developing object as free gas flow rate, reservoir pressure, permeability, and others that are necessary when assessing the geological conditions of drilling in a given area are determined.

66946

With a high content of gas in the solution, which can be observed in deep wells, as a result of the burp expansion of gas at the mouth, solution emissions may occur. Therefore, a change in gas content over time is one of the signs of an immediate danger of release 10.

Determining the gas content using the device will improve the accuracy of determining the gas content of the drilling fluid directly at the 15th well bottom, without interrupting the drilling process. This will increase the drilling performance by quickly eliminating the threat of mud emissions.

20 Formula

invented

and

A sound vibration modulator for turbine drilling, containing an acoustic resonator with sound-absorbing neck attached to the housing and having sound-absorbing holes, characterized in that, in order to ensure that gas is detected at the bottom of the well when measuring the sound propagation speed in the drilling mud during its gassing, sound-absorbing hole is made on the outer surface of the modulator casing about

Claims (1)

Turbine-borne sound vibration modulator comprising an acoustic resonator fastened to the housing with a sound-absorbing neck having sound-absorbing holes, characterized in that, in order to ensure detection of gas at the bottom of the well during measurement 30 the speed of sound propagation in the drilling fluid during gas saturation, a sound-absorbing hole is made on the outer surface of the modulator body.