RU2417303C1 - Device for prevention of corrosion and sediments of paraffin in oil pipe string - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: device consists of tubes, couplings and/or subs and is made as at least one permanent magnet. The sub functions as magnetic conductor. The permanent magnet is made out of plasto-magnet and it contains at least one pair of parts with their opposite poles facing each other. The permanent magnets can be installed in a case.

EFFECT: increased service life and oil output of wells.

13 cl, 19 dwg

Description

The invention relates to the mining industry, namely to oil and gas, and can be used in the development of oil wells using casing or tubing. When oil is extracted, a significant amount of water is almost always present in it, in which salts can be dissolved and ferromagnetic particles can be present, which contribute to pipe corrosion and the deposition of paraffin-hydrated and asphalt-tar deposits (hereinafter paraffins).

A device for magnetic fluid treatment according to ed. USSR No. 190368, containing a magnetic circuit and a screw nozzle for swirling the fluid flow. The device is designed to separate ferromagnetic particles from a liquid and cannot be used in oil production.

A device for magnetic fluid treatment according to ed. USSR No. 1468868, which contains a ring and magnets installed in it, and a central core.

The disadvantage is the large dimensions of the device and clutter of the cross section of the pipe and, as a result, a decrease in the oil flow rate.

A device for magnetic processing of liquids, including oil according to the patent of the Russian Federation No. 2092444, a prototype containing a housing, inside which are installed in pairs and sequentially magnets with a magnetic circuit. According to the first embodiment, the magnetic circuit is made common for two pairs in the form of a ring. According to the second embodiment, the magnetic circuit is made in the form of two coaxially mounted rings. At both ends, the magnetic circuit has diametrically made protrusions, on the inner surface of which magnets are installed in pairs. Each pair of magnets is mounted relative to each other with an offset of 90-270 °, and the longitudinal gap between the nearest ends of the magnets is 0.1 ... 1.5 mm.

The disadvantage of this device is its low efficiency and significant clutter of the internal section of the tubing due to the large dimensions of the device, determined by the magnetic circuit. In addition, the installation of permanent magnets in the magnetic circuit leads to a mutual influence of the magnetic fields of adjacent permanent magnets and weakening the effectiveness of the magnetic flux acting on the liquid (a mixture of oil and water).

The objective of the invention is the prevention of corrosion and the reduction of paraffin deposits in the column of oil pipes.

The solution of these problems has been achieved in a device for preventing corrosion and deposition of paraffin in an oil pipe string consisting of pipes, couplings and / or sub, made in the form of at least one permanent magnet, in that the sub function performs the magnetic circuit. A permanent magnet can be made of magnetoplast and contain at least one pair of parts facing opposite poles towards each other. The device may contain several pairs of permanent magnets mounted in a clip. Permanent magnets can be installed inside the sub in radial grooves having a trapezoidal cross section. Permanent magnets can be installed in a holder, which has the form of a sleeve with radial grooves, the number of which and the shape corresponds to the number and shape of the permanent magnets. The clip may be made of non-magnetic material. The clip may be made of non-magnetic metal, for example, non-magnetic steel, or aluminum, or titanium. The clip is made of non-metal, such as plastic. An end-to-end longitudinal section may be made in the ferrule. In the cage can be performed, in addition to a through longitudinal section, additionally not through longitudinal sections. The clip can be fixed in the sub with a split ring or a retaining ring, or a sleeve inside which a locking ring is installed.

The invention is illustrated in figure 1 ... 19,

where figure 1 shows the device installed between the oil pipes,

figure 2 shows a section aa,

figure 3 shows a device made in the form of a holder with permanent magnets,

figure 4 shows the appearance of the cage with magnets,

figure 5 shows the device installed in the sub without clips,

figure 6 shows a section bB,

Fig.7 shows a device installed in the sub with a clip,

Fig.8 shows a section bb,

figure 9 shows the appearance of the cage,

figure 10 shows the appearance of the cage with radial grooves for magnets, made through in one direction,

figure 11 shows the appearance of the cage with a through cut,

on Fig shows the appearance of the cage with a through and optionally through cuts,

in Fig.13 shows the option of fixing the cage split sleeve,

Fig. 14 shows a fixing split sleeve,

in Fig.15 shows a variant of fixing the clip retaining ring,

in Fig.16 shows the option of fixing the sleeve, inside of which a locking ring is installed.

17 shows a sleeve

on Fig shown locking ring,

on Fig shows a diagram of the operation of the device.

The device (Fig. 1 ... 19) is intended for installation in a sub 1 (Fig. 1 ... 3, 5 ... 8, 13, 15, 16, 19) connecting the pipes 2 containing permanent magnets 3. The sub-circuit 1, in which Permanent magnets 3 installed.

Permanent magnets 3 can be made of magnetoplastics and contain at least one pair of parts facing opposite poles towards each other (Figs. 1 and 2), or several pairs of permanent magnets 3 can be applied, they can be stacked in grooves 4 made in clip 5 (figures 3 and 4). Permanent magnets 3 are mounted radially and in pairs, facing opposite poles N and S towards each other. Permanent magnets 3 can be installed in the radial grooves 4 of the holder 5, made of non-magnetic material. The holder 5 may be made of non-magnetic metal, for example non-magnetic steel, aluminum, or titanium, or of non-metallic material, for example, plastic. The use of non-magnetic materials for the holder 5 is necessary to eliminate the loss of magnetic flux in it and to exclude the influence of magnetic fluxes of adjacent permanent magnets, leading to the dispersion of the magnetic field and reduce its effectiveness in the working area.

Permanent magnets 3 are made in shape and size similar to radial grooves 4, which may have a trapezoidal cross section to prevent them from falling inside the tubes 2, or the shape of a regular parallelepiped.

It is necessary to ensure that the permanent magnets 3 are in contact with the sub 1 or pipes 2 that perform the function of the magnetic circuit and at the same time prevent blocking of the internal cross section of the oil pipes.

The appearance of the clip 5 is shown in Fig.9. Radial grooves 4 can be made through in one direction (figure 10).

For ease of assembly of the device, the cage 5 may have a through longitudinal section 6 (11) or one through longitudinal section 6 and several through longitudinal sections 7 (Fig.12).

The holder 5 or permanent magnets 3 in the sub 1 can be fixed with a split sleeve 8 (Fig.13 and 14), or a retaining ring 9 (Fig.15), or a sleeve 10, inside of which a locking ring 11 is installed (Fig.16 ... 18) .

During production (Fig. 19), oil almost always contains water and the ferromagnetic particles 12 and ions 13 dissolved in it, which carry positive or negative charges. A mixture of oil and water passes by permanent magnets 3 and, under the influence of a magnetic field, ferromagnetic particles 12 and ions 13 are concentrated near the axis of the tubes 2, moving away from the walls of these tubes. This prevents the deposition of tar and paraffin deposits and reduces pipe corrosion. The magnetic field is stored on the straight sections of pipes 2 at a distance of up to 400 ... 500 m, and on curved sections much less, therefore, several proposed devices can be installed in the column of oil pipes at a distance of 400 ... 500 m from each other. The effectiveness of the devices depends on the composition of the mineral particles in the oil, therefore, the effectiveness of the device for different wells may vary.

The application of the invention allowed:

1) reduce the corrosion of oil pipes;

2) to prevent the deposition of paraffinic and asphalt-tar deposits on the inner wall of oil pipes;

3) to increase the oil recovery of wells in which the proposed device is installed due to the absence of clutter in the cross section of oil pipes in comparison with devices of a similar purpose;

4) ensure the operation of oil pipes throughout the life of the well.

Claims (13)

1. Device for preventing corrosion and deposition of paraffin in a column of oil pipes, consisting of pipes, couplings and / or sub, made in the form of at least one permanent magnet, characterized in that the function of the magnetic circuit is performed by a sub. 2. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 1, characterized in that the permanent magnet is made of magnetoplast and contains at least one pair of parts facing opposite poles towards each other. 3. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 1, characterized in that it contains several pairs of permanent magnets mounted in a holder. 4. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 3, characterized in that the permanent magnets are installed inside the sub in grooves having a trapezoidal cross section. 5. A device for preventing corrosion and deposition of paraffin in an oil pipe string according to claim 3, characterized in that the permanent magnets are mounted in a ferrule, which has the form of a sleeve with through grooves, the number of which and the shape correspond to the number and shape of the permanent magnets. 6. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 3, characterized in that the clip is made of non-magnetic material. 7. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 6, characterized in that the cage is made of non-magnetic metal, for example non-magnetic steel, or aluminum, or titanium. 8. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 6, characterized in that the ferrule is made of non-metal, such as plastic. 9. A device for preventing corrosion and deposition of paraffin in an oil pipe string according to claim 3, characterized in that a through longitudinal section is made in the ferrule. 10. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 9, characterized in that additional non-through longitudinal cuts are made in the holder. 11. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 3, characterized in that the clip is fixed in the sub split sleeve. 12. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 3, characterized in that the clip is fixed in the sub retaining ring. 13. A device for preventing corrosion and deposition of paraffin in a column of oil pipes according to claim 3, characterized in that the clip is fixed in the sub by a sleeve, inside which a locking ring is installed.

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