RU2594903C1 - Frameless borehole filter - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to oil and gas industry and can be used in production of gas and oil. Device includes two nipples, at least one slot-hole filtering element between limiting rings, made of wire which is reeled up on the longitudinal elements along the spiral. Both of the nipple are welded to limiting rings. Cross section of wire which is reeled up along spiral is executed as triangular, one of wire faces is executed parallel to longitudinal axis of the filter and connected to lengthwise elements, and two lateral angle form calibrated clearance.

EFFECT: filter capacity, reliability increases, abrasive wear decreases.

16 cl, 28 dwg

Description

The invention relates to the oil and gas industry and can be used in the extraction of gas and oil.

Known slot filter according to the patent of the Russian Federation for the invention No. 2445146. The invention relates to a device for filtering liquid media and can be used in various industries where effective cleaning of low-viscosity liquid media, such as water, kerosene, gasoline, acetone, diesel fuel and others, from mechanical impurities is required. The slit filter contains a pipe, the filter section of which has perforation in the form of holes, a filter element in the form of a spiral-wound wire, and a spring. The filter element is mounted concentrically to the pipe between the fixedly fixed lower support element in the form of a cup and a movable bilateral stop in the annular gaps between the outer diameter of the pipe and the inner diameters of the lower support element and the movable bilateral stop, with support on each annular platform. A spring is installed between the movable bilateral emphasis and the upper movable emphasis in the annular gaps between the outer diameter of the pipe and the inner diameters of the supports with a support on the annular platform of each, the initial force of which exceeds the elastic deformation of the spring of the filter element, which ensures a snug fit of the coils of the wire of the filter element. The disadvantage of a slotted filter is the lack of a normalized filter gap.

Known slotted well filter according to the patent of the Russian Federation for utility model No. 68585. The filter includes a supporting frame made of a perforated pipe and a slotted filter element made of wire wound on longitudinal elements in a spiral, characterized in that a mesh filter element is installed under the longitudinal elements in the form of at least one filter mesh. The nets are fixed with a fixing wire wound in a spiral. A drainage layer is made between the filter screen and the perforated pipe. The drainage layer is made of spiral wound wire. The winding of the wire in the drainage layer differs in direction from the winding of the fixing wire. The drainage layer is made of mesh. The diameter of the wire of the drainage layer is made smaller than the height of the cross section of the wire of the slit filter element. The diameter of the wire of the filter mesh is made smaller than the diameter of the wire of the drainage layer. The drainage layer is fixed by guide rings. The filter nets and the fixing wire are fixed by guide rings. Guide rings are made of a strip of steel sheet. Boundary rings are installed at the beginning and at the end of the slit filter element. The disadvantages of the filter are low reliability and rapid wear of the filter element.

Known downhole filter according to the patent of the Russian Federation for utility model No. 70300. The filter contains a perforated pipe on which a slit filter element is installed, which, in turn, contains longitudinal support elements, on the outer surface of which a wire is wound to form gaps between the turns, characterized in that an external slit filter element is installed concentrically to the slit filter element, having a similar design, and the gap between them is filled with filter media. Between the slotted filtering elements, distance rings are installed. The gap between the turns of the external slot element is not less than the gap between the turns of the internal slot element. The external slot element is made of wire of a larger cross section than the internal slot element. The external slot element is made of wire of a larger cross section than the internal slot element. The particle size of the gravel pack exceeds the gap between the turns of the filter element by 1, 2 ... 10 times. The filter media is made of balls. Balls are made of stainless steel. Balls are made of glass. Balls are made of polymer material. The filter media is made of sand. The disadvantage of the filter is the low reliability and rapid wear of the filter element.

Known slot filter with a wire filter element according to the patent of the Russian Federation for invention No. 2378494. The invention relates to the mining industry, namely to oil and gas, and can be used in the development of oil and gas wells. The slotted filter with a wire filter element contains a perforated pipe with a nipple and coupling parts, concentric to which the filter element is made of a spiral wound wire connected to a longitudinal wire stringers. At the same time, the coil is laid in a spiral to the coil, at least on one of the contacting sides of the wire there is a tangential or intersecting notch providing a filtering gap. The technical result is to simplify manufacturing techniques and reduce filter clogging during oil or gas production. The disadvantage of the filter is its high hydraulic resistance and low throughput.

Known slotted well filter according to the patent of the Russian Federation for utility model No. 71694. The filter contains a perforated pipe on which longitudinal support elements are installed, on the outer surface of which a wire is wound to form gaps between the turns, characterized in that the wire is welded or soldered to the longitudinal elements, and the ratio of the pitch of installation of the longitudinal elements to their height is made in the range from 1 , 0 to 10. A filter screen is installed between the pipe and the longitudinal support elements. A wire is wound between the supporting longitudinal elements and the filter mesh, which acts as a drainage layer. A drainage mesh is installed between the pipe and the filter screen. Between the longitudinal support elements and the filter screen, a drainage screen is installed.

The disadvantage of the filter is the low reliability and fast abrasive wear of the filter element.

Known well filter according to the patent of the Russian Federation for the invention No. 2507384, IPC ЕВВ 43/08, publ. 02/20/2014, prototype.

This slotted well filter contains a perforated carrier pipe and a slotted filter element made of a wire wound on longitudinal elements in a spiral, the cross section of a wire wound in a spiral made five-sided, one of the faces of the wire is parallel to the longitudinal axis of the filter and forms its outer surface and each side is made with two faces, the upper ones form a filter gap, and the lower ones converge forming an acute angle.

Disadvantages: low wire strength of the filter element, which leads to a change in the gaps when lowering the downhole filter, and fast abrasive wear of the "narrowest point" of the filter element.

The solution of these problems was achieved in a frameless well filter, including two nipples and at least one slotted filter element made between the restrictive rings from a wire wound on the longitudinal elements in a spiral, characterized in that both nipples are welded to the restrictive rings, while the cross section of the wire wound in a spiral is made triangular, with one of the faces of the wire parallel to the longitudinal axis of the filter and connected to the longitudinal elements, and two side angles form a calibrated gap.

The cross section of the longitudinal elements can be made triangular. The cross section of the longitudinal elements can be made round. The cross section of the longitudinal elements can be made rectangular.

Longitudinal elements can be laid with the smaller side of the rectangle of their section along the radius of the perpendicular section of the filter. Longitudinal elements can be laid by the larger side of the rectangle of their section along the radius of the perpendicular section of the filter. Longitudinal elements can be laid with the larger side of the rectangle of their section at an angle to the radius of the perpendicular section of the filter.

The gaps between the turns of wire can be made decreasing in radius. The gaps between the turns of wire can be made constant along the radius. The gaps between the turns of the longitudinal elements can be made increasing along the radius.

On the lateral faces of the longitudinal elements, remote projections can be made on both sides. On the side faces of the longitudinal elements, remote projections can be made on one side.

Longitudinal elements can be laid on intermediate rings.

The wire may be coated.

The coating can be corrosion resistant.

The coating may be hydrophobic.

The proposed technical solution has novelty, inventive step and industrial applicability, i.e. all the criteria of the invention. The novelty of the technical solution and inventive step are confirmed by patent research. Industrial applicability is due to the fact that non-deficient materials and well-known technologies are used in the manufacture of a downhole well filter.

The invention is illustrated in FIG. 1 ... 28, where:

in FIG. 1 shows a downhole filter,

Fig. 2 shows a view A,

in FIG. 3 shows a cross section of a wire having a hexagonal cross section,

in FIG. 4 shows a cross section of a wire having a hexagonal cross section with radius fillets,

in FIG. 5 shows a trapezoidal cross-section wire, the gap between the turns decreases in radius,

in FIG. 6 shows a trapezoidal cross-section wire, the gap between the turns has a constant value,

in FIG. 7 shows a trapezoidal cross-section wire, the gap between the turns increases in radius, the smaller side of the trapezoid is made outside,

in FIG. 8 shows a trapezoidal cross-section wire, the best option,

in FIG. 9 shows a wire of triangular cross section, the first option,

in FIG. 10 shows a wire of triangular cross section, the second option,

in FIG. 11 shows a wire of rectangular cross section, the first option,

in FIG. 12 shows a wire of rectangular cross section, the second option,

in FIG. 13 shows a trapezoidal cross-sectional wire with ledges on both side faces,

in FIG. 14 shows a trapezoidal cross-section wire with ledges on one side face,

in FIG. 15 shows a filter element with intermediate power rings,

in FIG. 16 shows a section bb, the first option,

in FIG. 17 shows a section bb, the second option,

in FIG. 18 shows a section bb, the third option,

in FIG. 19 shows a section bb, the fourth option,

in FIG. 20 shows a section bb, fifth embodiment,

in FIG. 21 shows a section bb, a sixth embodiment,

in FIG. 22 shows a downhole filter with two filter elements,

in FIG. 23 shows a section CC

in FIG. 24 shows the restriction ring,

in FIG. 25 shows view C,

in FIG. 26 welding of the longitudinal element to the restrictive ring, 1 option,

in FIG. 27 welding of the longitudinal element to the restrictive ring, option 2,

in FIG. 28 shows the process of welding the wire to the longitudinal elements.

Frameless downhole filter (Fig. 1 ... 28) includes two nipples 1 and 2 and a sleeve 3 for installation in the casing or tubing string and at least one filter element 4 mounted between the restrictive rings 5 and welded to the nipples 1 and 2 welding seam 6.

The pipe for the manufacture of nipples 1 and 2 is supplied in accordance with GOST 633-80 Tubing and couplings. Technical conditions

The filter element 4 is made of a wire 8 wound on the longitudinal elements 7 in a spiral (Fig. 2) with a gap between the rows δ1 and spot welding 9 connected to the longitudinal elements 7.

Wire 8 may be coated. The coating may be corrosion resistant, for example chromium or nickel. The coating may be hydrophobic, for example fluoroplastic.

Recommended clearance value δ1

δ1 = 0.1 mm ... 2 mm.

The cross section of the wire 8, wound in a spiral, can be made round (Fig. 2) or hex (Fig. 3), while the angles of the hexagon can be rounded with a radius r (Fig. 4).

It is possible to perform longitudinal elements 7 trapezoidal (Fig. 5 ... 7).

The gap δ2 between the rows should be made larger than δ1 in order to increase the permeability of the filter element 4.

δ2 = (2 ... 10) δ1

In this case, the gap δ2 between the rows can decrease in radius (Fig. 5) or have a constant value (Fig. 6) or increase (Fig. 7).

The larger base of the trapezoid can be made in radius and facing outward (Fig. 5 and 6) or inward (Fig. 7).

In FIG. 8 shows the best option for welding a longitudinal element. In this case, the following relationships must be observed:

The radius of the larger side of the trapezoid should be equal to the outer radius of the filter

R1 = Rf

The radius of the smaller side of the sectional trapezoid should be equal to the radius of the groove of the restrictive ring

R2 = R count

In this case, it is possible to conduct better welding of the longitudinal elements 7 to the restrictive rings 5 and the wire 8 of the filter element to the longitudinal elements 7.

It is possible to make a wire 8 of a triangular cross section, while one of the sides of the triangle 10 can be parallel to the axis of the filter and forms its outer surface (Fig. 9), or one of the sides of the triangle 10 is parallel to the longitudinal axis of the filter OO and adjacent to the longitudinal elements 7 ( Fig. 10).

Perhaps the implementation of the wire 8 of a rectangular cross section (Fig. 11 and 12). In this case, two options are possible; the large side 11 of the cross section of the wire 8 is parallel to the longitudinal axis of the filter OO (Fig. 11) or perpendicular (Fig. 12).

The wire 8 can be made of carbon steel from a wire of circular cross section by cold rolling. The diameter of the source wire is from 2 to 4 mm. The gap 51 is from 0.1 mm to 2 mm.

Possible various embodiments of the longitudinal elements 7 are shown in FIG. 13 ... 18.

The longitudinal elements 7 may have contacting protrusions 12 and 13 on both sides (Fig. 19) or only 12 on one side (Fig. 20). They increase the rigidity of the filter element 4 for bending and torsion. This is important since the filter element 4 replaces the frame.

The most radical rigidity of the filter element can be increased by the use of intermediate rings 14, on which the longitudinal elements 7 are mounted (Fig. 21).

The downhole filter may have several filter elements 4 (Fig. 22), while they are bounded on both sides by restrictive rings 5, attached to them by welding seams 6, and interconnected by a weld seam 15. The longitudinal elements 7 are attached to the restriction rings 4 welding seam 16 (Fig. 23).

In FIG. 24 and 25, a distance ring 5 is provided, which comprises grooves 17 and 18 and slots 19 under the groove 18 on both sides, into which the longitudinal elements 7 are laid and welded with a weld 16 (Figs. 26 and 27). The embodiment of FIG. 27 is the most optimal from the point of view of the strength of the filter and its manufacturability, since D3 = D4, then in contact welding, there will be no deflection of the longitudinal elements 7.

The spacer ring 4 is made in the form of a cylindrical sleeve, on which, as already mentioned, grooves 17 and 18 are made on both sides from the outside, slots 19 are made below the groove 18 for laying the longitudinal elements 7 (Fig. 26). On one side of the restrictive ring 5, an inner groove 20 is made with a centering belt 21, and from the same end there is a chamfer 22 for welding (Fig. 27).

The diameter of the longitudinal elements is equal to the inner diameter of the restrictive ring 5

D4 = D3

In FIG. 28 shows the assembly of the filter element 4 using a machine, which contains a ceramic pipe 23 mounted in the cartridge 24 on the centers 24.

The machine includes a support 25, and a contact roller 26, and a sliding contact 27. In addition, a welding transformer 28 is included in the equipment, which is connected by wires 29 to the contact roller 26 and the sliding contact 27. A coil 30 with wire 8 is installed outside the machine.

Borehole Filter Operation

Frameless downhole filter works as follows (Fig. 1 ... 28).

Separate downhole filters are collected in a casing string or as part of a liner suspension, and lowered into a productive horizon. Gas or oil passes first through the gaps between the longitudinal elements δ2 (Fig. 16 ... 18), then through the filter gap δ ₁ (Fig. 2) of the filter element 4. Mechanical particles larger than the filter gap δ ₁ remain outside the filter element 4, and smaller ones or equal pass into it and with gas or oil rise to the surface.

The frameless filter has a lower weight compared to other filters.

Compared to a frame filter having a perforated frame, the permeability through slits δ2 is an order of magnitude higher. This allows you to reduce the hydraulic resistance of the downhole filter and increase the flow rate of oil or gas.

The absence of stagnant cavities in the filter elements 4 leads to the fact that the filter becomes clogged more slowly and is easily washed.

In the case of using a downhole filter with longitudinal elements 7 installed at an angle to the radial plane (Fig. 18), the produced product is swirled and foreign impurities are separated.

For backwashing, the best option is with an increase in the gap δ1 (Fig. 9) and δ2 (Fig. 6) along the radius. This contributes to the removal of foreign particles, in contrast to the traditionally used options for well filters, for example frame slotted or mesh.

When washing the slotted well filter, foreign particles exit through the gap δ1 and δ2.

The application of the invention allowed:

1. Increase the filter capacity by an order of magnitude.

2. Reduce the weight of the filter by 2 ... 3 times.

3. To increase the reliability and durability of the downhole filter compared to the prototype.

4. To provide for a long time the necessary level of filtration due to a stable gap.

5. Provide filtration of gas and oil from mechanical impurities.

6. To increase the resistance of the filter element to abrasive wear.

7. Reduce the deformation of the slit filter element when lowering the filter into the well.

8. Improve filter cleaning.

9. To make the design of the filter more technological.

Claims (16)

1. Frameless downhole filter, comprising two nipples and at least one slotted filter element made between the restrictive rings from a wire wound on the longitudinal elements in a spiral, characterized in that both nipples are welded to the restrictive rings, while the cross section of the wire wound in a spiral, made triangular, with one of the faces of the wire parallel to the longitudinal axis of the filter and connected to the longitudinal elements, and two lateral angles form a calibrated gap. 2. The frameless downhole filter according to claim 1, characterized in that the cross section of the longitudinal elements is triangular. 3. Frameless downhole filter according to claim 1, characterized in that the cross section of the longitudinal elements is made round. 4. Frameless downhole filter according to claim 1, characterized in that the cross-section of the longitudinal elements is rectangular. 5. The frameless downhole filter according to claim 4, characterized in that the longitudinal elements are stacked on the smaller side of the rectangle of their section along the radius of the perpendicular section of the filter. 6. The frameless downhole filter according to claim 4, characterized in that the longitudinal elements are laid on the greater side of the rectangle of their section along the radius of the perpendicular section of the filter. 7. The frameless downhole filter according to claim 4, characterized in that the longitudinal elements are laid on the larger side of the rectangle of their section at an angle to the radius of the perpendicular section of the filter. 8. The frameless downhole filter according to claim 1, characterized in that the gaps between the turns of wire are made decreasing in radius. 9. Frameless downhole filter according to claim 1, characterized in that the gaps between the turns of the wire elements are made constant in radius. 10. Frameless downhole filter according to claim 1, characterized in that the gaps between the turns of the longitudinal elements are made increasing in radius. 11. Frameless downhole filter according to claim 1, characterized in that on the side faces of the longitudinal elements on both sides are made remote ledges. 12. Frameless downhole filter according to claim 1, characterized in that on the side faces of the longitudinal elements on one side are made remote protrusions. 13. Frameless downhole filter according to claim 1, characterized in that the longitudinal elements are laid on the intermediate rings. 14. Frameless downhole filter according to claim 1, characterized in that the wire is coated. 15. Frameless downhole filter according to claim 1, characterized in that the coating is corrosion resistant. 16. Frameless downhole filter according to claim 1, characterized in that the coating is hydrophobic.

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