RU110129U1 - DEVICE FOR PREVENTION OF INJECTION OF PARTICLES OF MECHANICAL IMPURITY TO ELECTRIC CENTRIFUGAL PUMP - Google Patents

Abstract

 1. A device for preventing particles of mechanical impurity from entering an electric centrifugal pump containing quarter-wave resonators located under an electric centrifugal pump, lowered into the borehole on tubing, characterized in that under the quarter-wave resonators on the axis there is a means for noise when a stream passes through it oil and gas mixture, while the specified tool has at least one hole and is located coaxially to the tubing. ! 2. The device according to claim 1, characterized in that as a means for the occurrence of noise when a mixture flows through it, a plate or a series of plates fan-shaped in series with each other is used. ! 3. The device according to claim 1, characterized in that as a means for noise during the passage of a mixture flow through it, a rod or a series of rods, fan-shaped in series with each other, is used. ! 4. The device according to claim 1, characterized in that as a means for the occurrence of noise when a mixture flows through it, a disk or a series of disks arranged in series with each other is used. ! 5. The device according to claim 1, characterized in that a circular sector or a series of circular sectors, fan-shaped in series with each other, is used as a means for generating noise when a mixture flows through it.

Description

The utility model relates to the oil industry, in particular, to methods of controlling mechanical impurities during the operation of electric centrifugal pumps.

Known devices for protecting downhole pumping equipment, based on the separation of sand from the liquid before it enters the pump at the pump intake, for example, sand anchors / Oil production reference book / Ed. THEM. Muravyova. - M.: Gostoptekhizdat, 1959.V.2. - S.238-241.

The disadvantages of the known devices include, that sand anchors are clogged by mechanical impurities, i.e. operation of wells in conditions of intensive removal of mechanical impurities (especially when forcing production) leads to premature failure of pumping equipment.

The closest device to prevent particles of mechanical impurities from getting into the electric centrifugal pump is a device made in the form of a set of pins and quarter-wave resonators placed around the circumference along the generators in the pipe for gas purification from a dropping liquid in a separator. The rods generate large-scale vortices when they flow around with an oil-gas mixture, and the quarter-wave resonators transform the low-frequency sound into the ultrasound region, followed by the formation of standing waves in the ultrasonic frequency range. In standing waves, coagulation of liquid droplets is carried out, which, under their own weight, are deposited in the oil-water mixture / RU patent No. 2354434, B01D 19/02, publ. 2009 /.

The disadvantage of this prototype device is the dependence of the sound frequency on the flow rate, determined by the formula / Kremlevsky P.P. Flowmeters and Counters: Reference. - 4th ed., Revised. and add. - L .: Mechanical engineering. Leningra. Separation, 1989.-S.364 /

where f is the frequency of pressure pulsations as a result of periodic disruption of the vortices, υ is the flow velocity, d is the cylinder diameter, Sh is the number of the Strouhal criterion.

Currently, the most widely used electric centrifugal pumps for work in wells with casing diameters of 140, 146 and 168 mm.

When the flow rate of the well, for example, when the flow rate Q = 100 m ³ / day, the flow rate is determined from the ratio

where F is the area of the pipeline, m ² , -v is the flow velocity, m / s.

Substituting in the formula (2) the values of the area F = 0.017 m ² (F = 0.785 d ² , where d = 0.017 m ² is the diameter of the casing string 146 mm) and flow rate Q = 100 m ³ / day, the flow velocity will be v = 0.068 m /from.

With the number of Strouhal Sh = 0.2 / Abramov G.S., Barychev A.V. .Practical flow metering in the oil industry. - M.: VNIIOENG OJSC. - With 269 /) and the diameter of the rods, for example, d = 0.01 m - generated by the streamlined stream. gas mixture frequency

The wavelength λ in the liquid phase at the speed of sound C = 1500 m / s - (according to the formula / I = С / /) is 1070 m. At this frequency / = 1.4 Hz - a standing wave is not formed, and, therefore, coagulation mechanical impurities will not occur.

With the number of Strouhal Sh = 0.2 / Abramov G.S., Barychev A.V. .Practical flow metering in the oil industry. - M.: VNIIOENG OJSC. - With 269 /) and the diameter of the rods, for example, d = 0.01 m is the frequency generated by the streamlined stream of the oil-gas mixture

The wavelength λ in the liquid phase at a sound speed of C = 1500 m / s - (according to the formula λ = C / f) is 1070 m. At this frequency f = 1.4 Hz, a standing wave is not formed, and, therefore, mechanical coagulation impurities will not occur.

This disadvantage can be eliminated by increasing the frequency of sound, i.e. reducing the wavelength, in order to place it along the diameter of the casing with the subsequent formation of a standing wave.

The objective of the utility model is to ensure efficient operation of wells equipped with electric centrifugal pumps in the extraction of oil and gas mixtures with a high concentration of suspended particles.

When implementing a utility model, this problem is solved by achieving a technical result, which consists in increasing the degree of purification of the oil-gas mixture entering the electric centrifugal pump.

The specified technical result is achieved by the fact that in the device for preventing particles of mechanical impurities from entering the electric centrifugal pump containing quarter-wave resonators located under the electric centrifugal pump, which is lowered into the borehole on the tubing, a new feature is that under the quarter-wave resonators on the axis there is a means for the occurrence of noise when passing through it a stream of oil-gas mixture, while the specified tool has at least one hole and spacing It is coaxial to tubing. As a means for generating noise during the passage of an oil-gas mixture flow through it, one can use a plate or a number of plates, a rod or a number of rods, a circular sector or a series of circular sectors, fan-shaped sequentially one after another, a disk or a number of disks arranged sequentially one after another.

Comparative analysis with the prototype shows that in the inventive device to prevent the ingress of mechanical impurities into the electric centrifugal pump for generating sound by a turbulent flow, a means is used to generate noise when the oil-gas mixture flows through it, having at least one hole.

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

Those. an increase in the frequency of sound is achieved by a turbulent flow through an opening made in the means for generating noise when the oil-gas mixture flows through it. The frequency of the sound generated by the hole is determined by the formula / Savinykh Yu.A., Grachev S.I., Medvedev Yu.A., Shatalova N.V. The technology of leveling the waterflooding front // News of universities. Oil and gas. No. 6. 2010 .-- S. 58-62 /.

where f is the frequency of sound, kHz, d is the diameter of the hole, mm.

When substituting, for example, the frequency f = 200 Hz in the formula (3), taking into account the borehole diameter of 146 mm and the axis with a diameter of, for example, 20 mm, on which it is possible to place, for example, plates or rods, or disks, or circular sectors with holes with a diameter of 7.5 mm (calculated by formula 3) with a different number (for example, 6 holes).

Calculation of a quarter-wave resonator for converting a frequency of 200 Hz into a high-frequency range of frequencies to create a standing wave in the casing.

1. The sound wavelength for a borehole diameter of 146 mm is 0.25 m,

2. The length of the quarter-wave resonator is determined according to the formula / Combating noise in production: Reference book / E.Ya, Yudin, L.A. Borisov, I.V. Gorenshtein and. others; Under the total. ed. E.Ya. Yudina-M.: Mechanical Engineering, 1985. - 303 /

where n = 1, 2, 3, ...; l is the cavity length, m; s is the speed of sound in the medium, m / s.

For example, for a frequency f = 200 Hz (the main frequency at n = 1) and a speed of sound in a liquid C = 1500 m / s, according to calculation formula (4), the cavity length will be l = 1.9 m.

The main provisions of the physical essence for the implementation of the device.

1. The flow of fluid through the pipeline at any speed is accompanied by the appearance of vortices, leading to the appearance of sound. A particularly strong sound occurs when overcoming a stream of obstacles (dampers, grilles, turns, holes, etc.) [Technical Acoustics Handbook. / Ed. M.Hekla and H.A. Muller. - L .: Shipbuilding, 1980. - S.208-210].

2. The generation of low-frequency sound by the fluid flow through the hole.

3. Converting low-frequency sound into a high-frequency sound range by acoustic quarter-wave resonators. [Muzipov Kh.N., Savinykh Yu.A. New technology to increase the productivity of producing wells using ultrasound. - Oil industry, No. 12, 2004. - S.53-54 /, which are placed under the electric centrifugal pump.

4. The formation of high-frequency standing waves in the space between the acoustic quarter-wave resonators and the well.

5. The use of the phenomenon of the physical process of coagulation [Bergman L. Ultrasound and its use in science and technology. IL - M .: IL, 1957. - S.489-491] of mechanical particles in the high-frequency sound field of standing waves.

Let us show the possibility of using acoustic coagulation of particles of mechanical impurity in the oil-gas mixture by sound standing waves, followed by their deposition on the bottom of the well.

1. Waves and vibrational velocity.

The wave equation describing the elastic disturbance has the form of coagulation [Bergman L. Ultrasound and its application in science and technology. IL - M .: IL, 1957. - S. 489-491].

A particular solution to equation (5) is

where a is the displacement of a particle of the medium relative to the resting position; A is the amplitude of the bias; ω = angular frequency; t is time.

Expression (6) describes a plane harmonic wave of frequency f = ω / 2π propagating in the positive direction of the x axis.

Differentiating (6) with respect to t, we obtain for the particle velocity of the medium - the so-called vibrational velocity

Therefore, the amplitude of the vibrational velocity

The value of U determines the maximum speed with which particles move in the process of oscillation.

According to expression (8), the particle velocity fluctuates between this value and zero.

2. The interference of waves. Standing waves.

Phenomena associated with the simultaneous existence of several oscillations at some point in the medium are called interference.

Interference phenomena play an important role in the emission of sound.

A particularly important role is played by interference in the propagation of two identical waves in opposite directions. Oscillations propagating in the positive and negative directions along the x axis can be written as

Applying the addition theorem, we obtain for the resulting standing wave the expression

from which it directly follows that at the points Cos (2πx / λ) vanishes, the displacement a is identically equal to zero; this occurs when x is an odd number λ / 4. In the middle between these points, there are points at which Cos (2πx / λ) no the absolute value is maximum; here, the amplitude of the displacement in the standing wave is twice the amplitude in the initial traveling waves.

We find the expression for the vibrational velocity in a standing wave, differentiating the expression

Thus, the nodes and antinodes of the vibrational velocity are located at the same points as the nodes and antinodes of the bias.

3. Pressure in a standing wave.

We now turn to the question of the distribution of pressure in a standing wave. In a wave propagating in the direction of the x-axis forces, the pressure p is proportional to the change in displacement along x, i.e. d a / dx. Differentiating expression (11) with respect to x, we obtain

Thus, in a standing wave and sound pressure contains nodes and antinodes; however, the location of the pressure nodes coincides with the position of the displacement antinodes and vice versa. The pressure amplitude in antinodes twice exceeds the amplitude in the initial traveling waves [Bergman L. Ultrasound and its application in science and technology. IL - M .; IL, 1957.-S.489-491].

4. Acoustic coagulation.

It has long been known that under the influence of sound vibrations between particles oscillating in a sound field, attractive and repulsive forces can arise. For spherical particles, this process was experimentally and theoretically investigated by Koenig / König W., Hydrodynamisch-akustische Untersuchungen, Ann. d. Phys. (3), 42, 353, 549 (1891) / in connection with the work of Bjerkness / Bjerknes C.A. Remarques historiques sur la theori du mouvement d'un ou de plusiews corps, de formes constantes ou variables, dans un fluide incompfessible; sur les forces apparentes, qui en resultent et sur les experiences qui s'y rattachent, Compt. Rent, 84, 1222, 1309, 1375, 1446, 1493 (1867).

Partially, the appearance of dust figures in Kundt tubes is based on this phenomenon. Brandt and Freund / Brandt., Űber das Verhalten von Schwebstofen in schwingen Gasen bei Schall- und Ultraschallfrequenzen, Kolloid / Zs., 76, 272 (1936) /

and Brand and Gideman / Brandt O., Hiedenmann E., Ű ber das Verhalten von Aerosolen im akustischen Feld, Kolloid. Zs., 75, 129 (1936) / showed that under the action of ultrasonic waves in aerosols, coagulation and sedimentation of particles instantly occur.

Brandt and Freund studied the details of the process of settling particles by microphotography under illumination using the dark field method.

Based on these experiments, Brandt and Gideman distinguish two stages of coagulation. At the beginning, the particles take part in the oscillatory process and follow the motion of the fluid between the antinodes and the vibration nodes. Moreover, as a result of collisions and under the action of forces of mutual attraction, they stick together and increase in size. In the second stage, the enlarged particles no longer follow sound vibrations, but make random motions, and as a result of new mutual collisions and collisions with smaller particles, their sizes continue to increase, and then precipitate.

5. Coagulation of particles of a mechanical impurity in a standing wave.

Let an impurity particle with a radius R and density ρ be located in a fluid with a dynamic viscosity η oscillating with amplitude U _Ж and frequency f.

According to the Stokes law / Bergman L. Ultrasound and its application in science and technology. IL -M .: IL, 1957. - S. 23 - 25, 489- 491, 495 -497 / friction force acting on the particle,

where Δυ is the velocity difference between particles of a mechanical impurity and a liquid.

According to formula (14), the velocity of liquid particles

The motion of a particle of a mechanical impurity is described by the differential equation

or

The general solution of this equation has the form / Bergman L. Ultrasound and its application in science and technology. IL -M .: IL, 1957. -C. 23-25, 489- 491, 495 -497 /

A non-periodic term represents a transient. It can be neglected, since coagulation occurs after a time when the transition process no longer has any effect.

Thus, the vibration amplitude of a particle of a mechanical impurity is equal to

The degree of particle participation in the sound vibrations of the medium (the so-called drag coefficient) in the case of a standing sound wave is determined by the relation

The ratio of the amplitudes X _mp / U _w will be the smaller, the larger the radius of the particle and the higher the frequency.

Thus, for the degree of participation of a particle of a mechanical impurity in fluid oscillations, the value R ² f is decisive.

If we take the value of X _MP / U _W = 0.8 beyond the boundary to which particles of mechanical impurity are still carried away by sound vibrations, then from the relation

we get

The value of Z determines the degree of participation of particles of mechanical impurity in the oscillations of the liquid.

Thus, relation (22) allows us to calculate the frequencies necessary to create standing waves in order to coagulate particles of a mechanical impurity in front of a submersible electric centrifugal pump, followed by their precipitation.

According to the above provisions of the physical essence, acoustic coagulation of particles of a mechanical impurity in a standing sound wave is achieved.

Figure 1 presents the layout of the device under the electric centrifugal pump.

Figure 2 shows the means for the occurrence of noise when passing through it a stream of oil-gas mixture in the form of a series of plates having holes, fan-shaped on the axis.

Figure 3 shows the large-scale vortices of a turbulent flow formed by the passage of the oil-gas mixture through the holes in the means for the occurrence of noise during the passage of the oil-gas mixture flow through it.

Figure 4 shows the total high-frequency standing wave, consisting of two high-frequency waves generated by two sources - an electric centrifugal pump and quarter-wave resonators, in the annular space between the well and quarter-wave resonators.

Figure 5 shows a diagram of the movement of particles of mechanical impurities in a high-frequency standing sound pressure wave.

Figure 6 shows a diagram of the process of coagulation of particles of mechanical impurities in a high-frequency standing wave of vibrational velocity, followed by their deposition in the sump.

Figure 1 shows: 1 - well, 2 - tubing, 3 - electric centrifugal pump, 4 - quarter-wave resonators, 5 - axis, 6 - means for noise when passing through it a stream of oil-gas mixture (plates, rods, disks , circular sectors), 7 - the direction of flow of the oil-gas mixture in the well coaxially with the holes in the plates, 8 - particles of mechanical impurity, 9 - holes.

Figure 2 shows: 5 - axis, 6 - means for the occurrence of noise when passing through it a stream of oil-gas mixture in the form of a plate, 9 - holes.

Figure 3 shows: 6 - a means for generating noise when passing through a stream of oil-gas mixture in the form of a plate, 7 - a direction of flow of an oil-gas mixture in a well coaxially with the holes in the tool for generating noise when a stream of oil-gas mixture passing through it, 9 - a hole, 10 - large-scale turbulent vortices, 11 - low-frequency sound formed by large-scale vortices.

Figure 4 shows: 1 - well, 2 - tubing, 3 - electric centrifugal pump, 4 - quarter-wave resonators, 5 - axis, 6 - means for the occurrence of noise when passing through the flow of oil-gas mixture, 7 - direction of flow of oil-gas mixtures, 8 - particles of mechanical impurity, 9 - holes, 10 - large-scale turbulent vortices, 11 - low-frequency sound formed by large-scale vortices, 12 - high-frequency sound converted from low-frequency sound by quarter-wave resonators, 13 - high-frequency th sound generated by an electric centrifugal pump, 14 - total high-frequency standing sound wave formed from high-frequency sound, converted from low-frequency sound by quarter-wave resonators and high-frequency sound generated by an electric centrifugal pump,

Figure 5 shows: 1 - the well, 7 - the direction of flow of the oil-gas mixture, 8 - particles of mechanical impurity, 15 - the total pressure wave in the high-frequency standing wave, 16 - the movement of particles of mechanical impurity in the total pressure wave in the high-frequency standing wave.

Figure 6 shows: 1 - the well, 7 - the direction of flow of the oil-gas mixture, 16 - the total wave of vibrational velocity in the high-frequency standing wave, 18 - the movement of particles of mechanical impurity in the total wave of vibrational velocity in the high-frequency standing wave, 19 - coagulated particles of mechanical impurity in the total high-frequency standing wave, 20 - deposition of coagulated particles of mechanical impurity under its own weight in the sump.

A device for preventing particles of mechanical impurity from entering the electric centrifugal pump contains tubing 2, under which there is an electric centrifugal pump 3 with a quarter-wave resonator 4 attached to it. A means or a number of means are designed for causing noise on the axis 5 fixed to the resonator 4 when passing through it a stream of oil-gas mixture 6, having a hole 9 or a series of holes.

As means for the occurrence of noise when passing through it a stream of oil-gas mixture 6 can be used plate, rod, disk, circular sector. When performing means for the occurrence of noise when passing through it a stream of oil-gas mixture in the form of a series of plates, rods or circular sectors, they are placed sequentially on the axis 5 with a fan, in the form of a series of disks - they are placed sequentially on the axis 5 (figure 2, shows the implementation of the means in the form of a plate).

The assembly of the device to prevent particles of mechanical impurities from entering the electric centrifugal pump is carried out in the following sequence. Means are placed one after another on the axis 5 (FIG. 1) for causing noise when the flow of oil-gas mixture 6 (FIG. 1) passes through it with holes 9 (FIG. 1) and connected to quarter-wave resonators 4 (FIG. 1).

The assembled structure is placed at the end of the electric centrifugal pump 3 (Fig. 1) and produced on the tubing 2 (Fig. 1), the descent into the well 1 (Fig. 1).

The device operates as follows.

The flow of oil-gas mixture 7 (figure 1) with particles of mechanical impurity 8 (figure 1) rises from the bottom of the well 1 (figure 1) in the direction of the electric centrifugal pump 3 (figure 1), passes simultaneously through the holes 9 (figure 1) , forming a low-frequency sound 11 (figure 4) by large-scale vortices 10 (figure 4), and flows around the means for noise when passing through it a stream of oil-gas mixture 6 (figure 1).

Next, the low-frequency sound 11 (Fig. 4), formed by turbulent vortices 10 (Fig. 4), is transformed into the high-frequency region 12 (Fig. 4) by quarter-wave resonators 4 (Fig. 4).

The switched on electric centrifugal pump 3 (FIG. 1) generates a high-frequency sound spectrum 13 (FIG. 4), which is summed in the annular space between the quarter-wave resonators 4 (FIG. 4) and the well 1 (FIG. 4) with a high-frequency sound spectrum 12 (FIG. 4) formed by quarter-wave resonators 4 (Fig. 4).

As a result of the summation of two high-frequency sound spectra in the annular space along the length of the quarter-wave resonators 4 (Fig. 4), a total high-frequency standing wave 14 (Fig. 4) is created, which stands in the way of the oil-gas mixture 7 (Fig. 7) with particles of mechanical impurity 8 ( figure 4).

Particles of mechanical impurity 8 (Fig. 5) in the oil-gas mixture flow 7 (Fig. 5) are coagulated 18 (Fig. 6) in high-frequency standing waves 14 (Fig. 4) by moving them in a pressure wave 15 (Fig. 5) from the antinode to the site and under the influence of the wave of vibrational velocity 16 (Fig.6) as a result of collisions and under the influence of forces of mutual attraction they stick together and increase in size, and as a result of new collisions with smaller particles, their sizes continue to increase and, under their own weight, precipitate 19 ( 6).

Field tests were conducted at well No. 668 of cluster 684 of the Samotlor field. The content of solids in the extracted products decreased 3.4 times.

Claims (5)

1. A device for preventing particles of mechanical impurity from entering an electric centrifugal pump containing quarter-wave resonators located under an electric centrifugal pump, lowered into the borehole on tubing, characterized in that under the quarter-wave resonators on the axis there is a means for noise when a stream passes through it oil and gas mixture, while the specified tool has at least one hole and is located coaxially to the tubing. 2. The device according to claim 1, characterized in that as a means for the occurrence of noise when a mixture flows through it, a plate or a series of plates fan-shaped in series with each other is used. 3. The device according to claim 1, characterized in that as a means for noise during the passage of a mixture flow through it, a rod or a series of rods, fan-shaped in series with each other, is used. 4. The device according to claim 1, characterized in that as a means for the occurrence of noise when a mixture flows through it, a disk or a series of disks arranged in series with each other is used. 5. The device according to claim 1, characterized in that a circular sector or a series of circular sectors fan-shaped in series with each other is used as a means for noise when a mixture flows through it.