RU2504644C1 - Downhole filter with flushing without surfacing - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: proposed device tail pipe fitted at pump inlet to extend through packer, mid pipe plugged from above to make with tail pipe a concentric chamber plugged from below, accumulating pipe of solid particles, cylindrical filtration element arranged between tail pipe and accumulating pipe. Concentric chamber has radial channels arranged directly above and below the packer. Horizontal perforated girths are arranged between radial channels in mid pipe, mid pipe being furnished with through holes. Spring loaded top and bottom valves rigidly connected by rod are arranged on both sides of said horizontal girths. Leaky piston is arranged above top valve spring, piston diameter being equal to top valve diameter. Elasticity of top spring exceeds that of bottom spring.

EFFECT: expanded performances.

7 dwg

Description

The invention relates to the oil industry and can be used in pumping oil with a high content of suspended solids (solids) carried out from the reservoir.

For wells producing sand-containing oil, a filter is known consisting of concentrically arranged outer, intermediate and inner pipes, the latter equipped with holes, and an adapter, while the inner pipe is equipped with a filter mesh located inside it, made in the form of a screw and attached opposite to the holes located along helix line. In addition, the outer and inner pipes in the upper part are interconnected by tangential nozzles, and the inner and intermediate pipes in the lower part are also interconnected by tangential nozzles, but oppositely oriented, with an annular gap between the intermediate and inner pipes in the upper part, and the upper and lower parts of the inner pipe are equipped with plugs, the outer pipe in the upper part is equipped with elastic rings, and in the lower part with a plug (patent for invention RU No. 2158358, IPC ЕВВ 43/08, 1999).

The advantage of this filter is the placement in the inner tube of a filter mesh made in the form of a screw and attached opposite the holes located along a helical line, while the holes are designed to transfer mechanical impurities into the annular gap between the inner and intermediate pipes, and move them under the action of gravitational forces in bottom of the filter. The disadvantage of the analogue is the abrasive wear and destruction of the filter mesh due to its blockage and slow cleaning of mechanical impurities, the disadvantage is the low separation coefficient of mechanical impurities.

A well-known self-cleaning well filter, consisting of concentrically located outer, intermediate and inner pipes, the last two provided with holes and in the upper part are connected by a pipe, while the outer pipe is connected to the intermediate pipe by annular plugs (patent RU 2305756, ЕВВ 43/08, 2007). The inner pipe is equipped with a filter element located in the interval of holes made on this pipe, the same pipe is equipped with a socket and connected with longitudinal ribs, while the socket is located with a gap relative to the intermediate pipe and is equipped with a nozzle in the lower part, in the annular gap between the inner and a filter element made in the form of a reverse truncated cone and attached to these pipes above the upper holes made in them, the middle holes being aligned with the intermediate pipes coaxially with them the intermediate pipe is made opposite the bell and is equipped with a filter element, the bell is also equipped with a centralizer. This filter has a complex structure. In case of clogging of the filter element, the liquid supply to the pump is interrupted, it becomes necessary to replace the filter.

Closest to the invention is a downhole filter, including a metal pipe with holes, provided with a plug at the bottom, placed inside the metal pipe with a gap and a filter element coaxial with it, characterized in that the filter element is made in the form of a cylindrical pipe, the alignment of the filter element is provided by centralizers, metal the pipe is equipped on top with a sleeve in which a spring-loaded valve is installed, while the sleeve has longitudinal through holes and a hydraulic channel consisting of two x half, and the first half of the channel, equipped with a ball of the valve, coincides with the axis of the downhole filter, and the second half is perpendicular to it and does not cross the longitudinal through holes, and in the lower part of the metal pipe there is a hole above the plug (RF patent No. 2355876, IPC E21B 43/08, published: 05/20/2009).

However, if the filter is clogged, it is also necessary to replace it by lifting the equipment.

The aim of the proposed invention is the provision of flushing the filter without lifting the underground equipment of the pumping unit.

This goal is achieved by the fact that in the known device, including a shank pipe installed at the pump inlet and passing through the packer, an intermediate pipe muffled from above, forming a concentric cavity muffled from below, a solid particle storage pipe, a cylindrical filter element located between the shank and the storage pipe, a spring-loaded valve located inside the intermediate pipe, the concentric cavity has radial channels located directly above and below the pack rum, under the lower radial channels in the intermediate pipe there are horizontal jumpers with holes, between which the intermediate pipe has through holes, spring-loaded upper and lower valves are rigidly connected by a rod on both sides of the horizontal jumpers, and an untight piston is located above the spring of the upper valve and is identical to the upper valve diameter, and the elasticity of the upper spring exceeds the elasticity of the lower.

Figure 1, 2, 3, 4, 5, 6 and 7 shows the schematic diagrams and various types of the proposed filter.

A pump 4 with a liner 5 connected to its intake was lowered into the well 1 on the columns of tubing 2 and rods 3. The liner 5 passes through a packer 6, to which a storage tube 7 is attached from below to collect solid suspended particles (HDTV) entering the well with the formation.

The pipe 7 is plugged from below and has openings 8 for receipt of formation products. Inside the shank 5 there is an intermediate pipe 9 forming a concentric cavity 10. Above and below the packer, radial channels 11 and 12 are made in the cavity 10, respectively, and the pipe 9 in the upper part is plugged with a jumper 13 so that the cavity 10 is in communication with the reception of the pump 4 through the outer sides of the channels 11. Below the channels 12 in the intermediate pipe 9 are horizontal jumpers 14 and 15 with through holes. Between the jumpers 14 and 15 in the intermediate pipe 9, through holes 16 are made, communicating the internal cavity of the pipe 9 with a cavity 10. A cylindrical filter element 17 is installed outside the shank 5. This element is connected to the packer 6 and, together with the cavity 10, is closed at the bottom by a jumper 18.

Inside the intermediate pipe 9 above the jumper 14 there is an leaky piston 19 with a valve 20 of the same diameter and a spring 21 between them. Under the jumper 15 there is a valve 22 with a support 23 and through-holes 24, as well as a spring 25.

Valves 20 and 22 are rigidly connected to each other by a stem 26. In the pipe 9 in front of the channels 11 there are limiters 27 for vertical movement of the leaky piston 19. At the wellhead, valves 28 for supplying fluid to the pipeline and 29 for supplying fluid to the annulus of the well are installed.

The spring 21 has a greater elasticity in comparison with the spring 25.

The filter is as follows. The pump 4 is lowered into the well 1 together with the liner 5, packer 6, pipe 7 and other filter elements. When the well is launched, the leaky design of the piston 19 and valve 20 in the pipe 9 allows the formation fluid to flow through the channels 12 and 11 into the annulus and set a predetermined dynamic level. In a working well, the formation fluid, passing through the holes 8, enters the outer surface of the filter element 17 and is freed from solid particles and is received by the pump 4 through channels 12, 16, cavity 10 and the outer sides of channels 12 and 11 (Figs. 1 and 3) . In this case, the opening of the jumper 15 is blocked by the valve 22 due to the spring 25. The piston 19 with the valve 20 in this period are in the highest position with the spring 21. The piston 19 with the valve 20 in the highest position is provided by the spring 25 through the rod 26.

The crane 28 during this period remains open, and the crane 29 is closed.

If the filter element 17 becomes clogged, the supply of pump 4 will decrease. To clean the filter from the high-frequency filter, the filter element 17 is flushed (FIGS. 2 and 4). To do this, when the pump 4 is operating, injection into the annulus of the well is carried out through the valve 29 of the flushing fluid (light oil, solvent, etc.). The flushing fluid through the channels 11 enters the piston 19 and presses it down with a high-pressure head, together with the valve 20, the stem 26, as well as the valve 22. Having reached the opening of the jumper 14, the valve 20 will block it, and the valve 22 will open the hole in the jumper 15. Further injection of the flushing fluid will compress the spring 21 and reduce the distance between the piston 19 and the valve 20. After the upper surface of the piston 19 has fallen below the upper generatrix of the channels 12, the flushing fluid will begin to flow into the channels 12 and then into the filter element 17 c his inner side. Due to the reverse fluid flow through the element 17, the latter is cleaned of the high-density particles adhering to its outer side. Next, the liquid, together with the HDTV, enters the storage pipe 7 and changes the direction of movement by 180 °, enters the intermediate pipe 9. Rotating the liquid 180 ° allows centrifugal forces to free itself from the HDTV, which under its own weight will begin to settle to the bottom of the storage pipe 7 The liquid, passing through the windows 24, the hole in the jumper 15 and the holes 16 enters the cavity 10, from where it also receives the pump 4 through the outer sides of the radial channels 12 and 11.

After washing the filter, the supply of washing liquid is stopped and the valve 29 closes. The springs 25 and 21 will cause the piston 19 and the valves 20 and 22 to return to their original upper position. Pump 4 will begin to operate in normal mode with the cleaning of liquid from the high-frequency television. When the pipe 7 is completely filled after long-term operation of the well with solid particles, washing the filter will no longer lead to its cleaning. In this case, the underground equipment is lifted in order to release the pipes 7 from the high frequency.

The technical and economic advantage of the invention is to ensure that the filter washes from the HDTV without raising the pumping equipment, as well as preventing clogging of the bottom of the well with solid rock particles carried out of the formation.

Claims (1)

A well filter with flushing without lifting the equipment, including a shank installed at the pump inlet and passing through the packer, an intermediate pipe sealed from above, forming a concentric cavity sealed from below, a storage pipe for solid particles, a cylindrical filter element located between the shank and storage pipe, a spring-loaded valve located inside the intermediate pipe, characterized in that, in order to ensure washing the filter without lifting the underground equipment installation, the concentric cavity has radial channels located directly above and below the packer, horizontal bridges with holes are located under the lower radial channels in the intermediate pipe, between which the intermediate pipe has through holes, spring-loaded upper and lower valves are located on both sides of the horizontal jumpers, rigidly connected by a rod, and above the spring of the upper valve there is an untight piston of the same diameter as the upper valve, and the elasticity of the upper zhiny exceeds the lower elasticity.

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