RU2603309C1 - Slit-type well filter - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, particularly to well filters. Device includes perforated supporting pipe and at least one slit-type filter element, made of wire which is wound on longitudinal elements along a spiral. At beginning and end of slit-type filter element there are restricting rings. Each slit-type filter element is connected to a supporting pipe by welding one limiting ring.

EFFECT: higher resistance of filter to abrasive wear, providing required level of filtration and flow rate for a long time, increased rigidity and strength of filter element, possibility of self-cleaning filter elements.

14 cl, 24 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 in the form of at least one filter mesh is installed under the longitudinal elements. 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 disadvantage of the filter is the 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 with the formation of gaps between the turns, characterized in that the wire is welded or soldered to the longitudinal elements, and the ratio of the installation step 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, the prototype.

This slotted well filter contains a perforated carrier tube and a slotted filter element made of a wire wound on the longitudinal elements in a spiral, with the cross section of the 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 objectives of the invention are:

- increasing the resistance of the filter to abrasion,

- ensuring the necessary level of filtration for a long time and increasing the flow rate of the extracted product,

- increase in stiffness and strength of the filter element.

The solution of these problems was achieved in a slotted well filter, including a perforated carrier pipe and at least one slotted filter element made of wire wound on the longitudinal elements in a spiral, so that restrictive rings are installed at the beginning and at the end of the slotted filter element, each slotted filter element is connected to the support pipe by welding one restrictive ring.

The cross section of the wire wound in a spiral can be made hexagonal, one of the faces of the wire is parallel to the longitudinal axis of the filter and forms its outer surface, and the two side angles form a calibrated gap. A wire having a cross section in the shape of a regular hexagon may be used. The corner connecting the faces can be rounded. Perforation in the carrier pipe can be made holes. The perforation holes in the carrier pipe can be closed with shear plugs.

Cutting plugs can be made of aluminum. Cutting plugs can be made of plastic. Shear plugs can be threaded. Cut-off plugs can be installed on glue.

Perforation in the carrier pipe can be performed with slots along the pipe. Perforation in the carrier pipe can be performed with slots across the pipe. Perforation in the carrier pipe can be performed with slots obliquely to the longitudinal axis. Slit filter elements can be installed without axial clearance between the restrictive rings of adjacent slot filter elements.

The invention is illustrated in FIG. 1 - 24, 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 with radius fillets,

in FIG. 4 shows a view A with a longitudinal section of a pipe perforated with holes,

in FIG. 5 shows a view A with a longitudinal section of a pipe perforated with slots,

in FIG. 6 shows a view A with a longitudinal section of a pipe perforated with holes made at an angle to the longitudinal axis of the filter,

in FIG. 7 shows a section bb,

in FIG. 8 shows a downhole filter with cut-off plugs, section BB,

in FIG. 9 shows a downhole filter with several filter elements installed with an axial clearance between them,

in FIG. 10 shows a downhole filter with several filter elements installed without an axial clearance between them,

in FIG. 11 shows a section CC, the first option,

in FIG. 12 shows a section CC, the second option,

in FIG. 13 shows a support perforated pipe with holes located in rows,

 in FIG. 14 shows a support perforated pipe with holes staggered,

in FIG. 15 shows a support perforated pipe with holes arranged in a spiral,

in FIG. 16 shows the remote ring,

in FIG. 17 shows a view of D,

in FIG. 18 shows the process of welding longitudinal elements,

in FIG. 19 start filter assembly,

in FIG. 20 installation of a second filter element,

in FIG. 21 centralizer installation,

in FIG. 22 assembly of the filter element,

in FIG. 23 cleaning the outside of the filter element,

in FIG. 24 cleaning the inside of the filter element.

The slotted well filter (Figs. 1-24) includes a perforated support pipe 1, on one side of which a sleeve 2 is made, and on the other, a nipple 3 for installation in a drill pipe string.

On the outer surface of the perforated carrier pipe 1, a slotted filter element 4 is concentric to it, on both sides of which restrictive rings 5 are made.

The filtering element 4 is made of wire 6. wound on the longitudinal elements 7 in a spiral, and the cross section of the wire 6, wound in a spiral, is made hexagonal, one of the faces of the wire 8 is parallel to the longitudinal axis of the filter OO and forms its outer surface, the side faces 9 form edge 10 with an angle of 120 °. The angles connecting all faces 8 and 9 can be rounded with a radius r (Fig. 3).

Perforation in the perforated carrier pipe 1 can be performed by holes 11.

Perforation can be performed with slots 12. (Fig. 5).

The holes 11 can be made at an acute angle α to the axis of the OO filter (Fig. 6) to reduce hydraulic losses during oil or gas production.

The holes 11 may not be closed (Fig. 7) or temporarily closed with cut-off plugs 13 (Fig. 8) for crimping and washing.

The cork material 13 is either aluminum or plastic.

Plugs 13 are installed in the holes 11 on the thread or on the glue.

The slotted well filter may have several filter elements 4 (Fig. 9), while they are bounded on both sides by restrictive rings 5 by welding. In FIG. 9 shows a downhole filter with several filtering elements installed with an axial clearance between them.

In FIG. 10 shows a downhole filter with several filter elements installed without an axial clearance between them.

The longitudinal elements 7 are attached to the restriction rings 4 by a weld seam 14, two restriction rings 5 to the perforated support tube 1 - by a weld seam 15, and the wire 6 to the longitudinal elements 7 - by a weld seam 16 (Fig. 11). A variant is possible (Fig. 12) when only one restrictive ring 5 is welded to the perforated support tube 1. This will allow longitudinal movements of the filter elements 4 and their self-cleaning when temperature fluctuates.

The holes 11 can be made on the perforated carrier pipe 1 in several ways. In FIG. 13 shows a support perforated pipe 1 with holes 11 arranged in rows, in FIG. 16 shows the support perforated pipe 1 with holes 11 located in a checkerboard pattern, in FIG. 15 shows the support perforated pipe 1 with holes 11 arranged in a spiral.

Parts of the support perforated pipe 17 do not have perforation.

In FIG. 16 and 17 show the spacer ring 5, which contains a groove 18 and a slot 19, into which the longitudinal elements 12 are laid and welded with a weld seam 15 (Fig. 18).

The filter assembly process is shown in FIG. 19 ... 21.

In FIG. 19 shows the start of filter assembly; FIG. 20 - installation of a second filter element, in FIG. 21 - installation of the centralizer 20 with the screw 21.

In FIG. 22 shows the assembly of the filter element 4 using a machine, which contains a ceramic pipe 22 mounted in the cartridge 23 at the centers 24.

The machine includes a support 25 and a contact roller 26 and a sliding contact 27. In addition, the 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 6 is installed outside the machine.

In FIG. 23 shows the cleaning of the outside of the filter element 5; FIG. 24 - cleaning the inside of the filter element 5,

Slot-hole filter operates as follows. Separate downhole filters are collected in a casing string or as part of a liner suspension, and lowered into a productive horizon. If there are shear plugs 13 installed in the holes 11 of the perforated carrier pipe 1, the face is flushed. After washing, the plugs are cut off and the produced product through the filter element 5 begins to flow inside the perforated carrier pipe 1. Gas or oil passes through the filter gap δ of the filter element 4. Mechanical particles larger than the filter gap δ remain outside the perforated carrier pipe 1, while smaller or equal ones pass inside it and with gas or oil rise to the surface. In this case, the abrasive particles passing through the filter gap δ abrade the side faces 8 and 9 of the profile of the wire 6 used to wind the filter element 4, increase the filter gap and change the degree of filtration. However, the corners 10 of the wire 6, having an angle of 120 °, wear out several times slower than that of the prototype, having an angle in the “bottleneck” of less than 90 °.

The presence of radius r reduces the abrasion of the wire by abrasive particles even more significantly and prevents an increase in the gap.

In addition, the hexagonal wire has greater rigidity than the trihedral or pentagonal, and is less deformed when the downhole filters are lowered into the face.

A variant is possible (Fig. 12) when only one restrictive ring 5 is welded to the perforated support tube 1. This will allow longitudinal movements of the filter elements 4 and their self-cleaning when temperature fluctuates.

The application of the invention allowed:

1. To increase the reliability and durability of the downhole filter due to the greater strength of the hexagonal wire compared to the prototype.

2. To provide for a long time the required level of filtration due to a stable gap.

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

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

5. Reduce the deformation of the filter element when lowering the filter into the well.

6. To increase the flow rate of the downhole filter by installing filter elements without a gap between them.

7. To ensure self-cleaning of the downhole filter due to the oscillatory movement of slotted filter elements welded to the support pipe.

Claims (14)

1. A slotted well filter, including a perforated support pipe and at least one slotted filter element made of wire wound on longitudinal elements in a spiral, characterized in that at the beginning and at the end of the slotted filter element there are restriction rings, each slotted filter element connected to the support pipe by welding one restrictive ring. 2. The slotted well filter according to claim 1, characterized in that the cross-section of the wire wound in a spiral is made hexagonal, one of the faces of the wire is parallel to the longitudinal axis of the filter and forms its outer surface, and two lateral angles form a calibrated gap. 3. The slotted well filter according to claim 2, characterized in that a wire is used having a regular hexagon in cross section. 4. The slotted well filter according to claim 2, characterized in that the angle connecting the faces is rounded. 5. The slotted well filter according to claim 1, characterized in that the perforation in the carrier pipe is made with holes. 6. The slotted well filter according to claim 5, characterized in that the perforation holes in the carrier pipe are closed with shear plugs. 7. The slotted well filter according to claim 6, characterized in that the shear plugs are made of aluminum. 8. The slotted well filter according to claim 6, characterized in that the shear plugs are made of plastic. 9. The slotted well filter according to claim 6, characterized in that the shear plugs are threaded. 10. The slotted well filter according to claim 6, characterized in that the shear plugs are mounted on glue. 11. The slotted well filter according to claim 1, characterized in that the perforation in the carrier pipe is made with slots along the pipe. 12. The slotted well filter according to claim 1, characterized in that the perforation in the carrier pipe is made with slots across the pipe. 13. The slotted well filter according to claim 1, characterized in that the perforation in the carrier pipe is made with slots at an angle to the longitudinal axis. 14. The slotted well filter according to claim 1, characterized in that the slotted filter elements are installed without an axial clearance between the restrictive rings of adjacent slotted filter elements.

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