RU211101U1 - Device for cleaning wells from dense deposits - Google Patents

Abstract

The utility model relates to the oil and gas industry, in particular to downhole jet devices, and is designed to clean up dense deposits in directional, horizontal wells, including small diameter wells, with the ability to work in absorption wells, in wells with abnormally low formation pressures and low rates. The objective of the utility model is to create a reliable device capable of destroying and effectively removing plugs from dense deposits from a well in one trip while flushing or operating a jet pump. The technical result consists in increasing the efficiency of well operation through the use of a jet pump, a packer-throttle assembly and a drilling nozzle lowered into the production string, which allows drilling and destruction of dense deposits, the removal of deposits is carried out by flushing, and in the presence of loss with the help of a jet pump, while the removal of deposits is carried out to the surface in one descent of the device into the well. The problem is solved due to the fact that in the device for cleaning wells from dense deposits, including a jet pump installed on the tubing pipe, on the tubing pipe under the jet pump in the following order, a packer-throttle assembly and a nozzle for drilling are additionally installed, at the same time, the packer-throttling unit is equipped with throttling channels, which provide the possibility of fluid flow through the annulus from the above-packer zone to the under-packer zone. 2 ill.

Description

The utility model relates to the oil and gas industry, in particular to downhole jet devices, and is designed to clean up dense deposits in directional, horizontal wells, including small diameter wells, with the ability to work in absorption wells, in wells with abnormally low formation pressures and low rates.

A device for cleaning wells is known (see RF utility model patent No. 196747, z. 2019137093, IPC E21V 37/00, op. 03/13/2020), including a ripper nozzle connected in series from the bottom up, a sludge container with a check valve in the lower part, formed by tubing, a knock-off valve, a ripper attachment includes a body, a crown with teeth, a cutter-reamer, a screw shaft, an overrunning clutch, a nut, a spring, an internal hollow piston equipped with channels that ensure connection of the internal cavity of the piston with internal cavity of the housing, while the channels are made at an angle of 12-15° to the piston axis and not parallel to each other, the device also contains a hydraulic unit consisting of a housing, a shaft, a nut, sealing rings and shear pins.

The disadvantage of the known device is that the sludge goes through the spring, reducing the reliability and efficiency of the device.

A well-known downhole jet unit for cleaning the bottomhole of wells from sand plugs (see patent for invention No. 2393332, IPC E21V 37/00, s. 2009119598, s. tubing (CT) ejector pump, including a housing in which a nozzle and a mixing chamber with a diffuser are installed coaxially with the coiled tubing, as well as an axial channel and a transverse channel for supplying the working medium connected with it, made below the nozzle, and a channel is made parallel to the axial channel supply of the medium pumped out of the well, from the side of the upper end the axial channel is in communication with the nozzle, and from the side of the lower end the axial channel is in communication with a multi-nozzle nozzle installed under the body with the possibility of rotation around the axis of the axial channel around the axis of the axial channel, below the transverse channel on the outer side surface body, a seal is made of an elastic material, for example, rubber, consisting of at least two seals. cuffs separated by metal spacers.

The disadvantage of the known device is that the use of "pipe in pipe" technology complicates the process of cleaning the well, reducing the efficiency and reliability of the device, and increases the cost.

The closest in technical essence to the installation under consideration is a submersible ejection installation for cleaning the bottomhole of wells from sand plugs under conditions of abnormally low formation pressure (see patent for invention No. 2563896, IPC E21V 37/00, s. 09/27/2015), containing an ejector pump installed on the tubing string, including a housing in which a nozzle and a mixing chamber with a diffuser are installed coaxially with the inner tubing string, axial channels for supplying the working flow are made in the housing parallel to the mixing chamber and communicating with them radially located transverse side channels for supplying the ejected flow, from the upper end the axial channels are in communication with the annular space between the outer tubing and the inner tubing, and from the lower end - with the working chamber, in the base of the housing there is a support heel, communicated with nozzle of the ejector pump, by means of a spring-loaded pusher, with air the possibility of moving up and down under the action of the outflowing working medium and a functional insert, inside which at an angle of 30° there are at least four cavitation generators, which are a packing formed by cylindrical and conical surfaces with a channel opening angle of 6° to 7°.

The disadvantage of the installation is that the use of "pipe in pipe" technology with a cavitator complicates the process of cleaning the well, does not provide the necessary efficiency of cleaning the well and reduces the reliability of the device.

The objective of the utility model is to create a reliable device capable of destroying and effectively removing plugs from dense deposits from a well in one trip while flushing or operating a jet pump.

The technical result consists in increasing the efficiency of well operation through the use of a jet pump, a packer-throttle assembly and a drilling nozzle lowered into the production string, which allows drilling and destruction of dense deposits, the removal of deposits is carried out by flushing, and in the presence of loss with the help of a jet pump, while the removal of deposits is carried out to the surface in one descent of the device into the well.

The problem is solved due to the fact that in the device for cleaning wells from dense deposits, including a jet pump installed on the tubing pipe, on the tubing pipe under the jet pump in the following order, a packer-throttle assembly and a nozzle for drilling are additionally installed, at the same time, the packer-throttling unit is equipped with throttling channels, which provide the possibility of fluid flow through the annulus from the above-packer zone to the under-packer zone.

The use of a packer-throttle assembly allows the jet pump to operate while the device moves down, and flushing through the annulus. Provides the possibility of additional fluid supply to the under-packer zone, which allows to increase the flow rate for lifting, for example, sand through the internal space of the tubing, which significantly increases the efficiency of the device for cleaning the well, for example, with low flow rates.

The introduction of a drilling nozzle provides mechanical destruction and loosening of dense deposits (for example, sand, proppant, salts, etc.), which increases the efficiency of well cleaning, due to grinding and grinding of dense deposits, which makes it possible to wash out the destroyed deposits through a jet pump.

On fig. 1 shows a device for cleaning wells from dense deposits. On fig. 2 shows a device for cleaning wells from dense deposits with an installed jet pump insert.

The device consists of

1. Production string;

2. Tubing (required length),

3. Annulus;

4. Internal space of the tubing;

5. Jet pump body;

6. Sleeve blocking the circulation holes 7 (tubing 2 - annulus 3);

7. Circulation holes in the jet pump body;

8. Jet pump insert;

9. Mixer, mixing chamber in the jet pump insert;

10. Jet pump nozzle;

11. Suction channel in the jet pump insert;

12. Packer-throttling unit;

13. Housing of the packer-throttling unit;

14. Cup sealing cuff;

15. Throttle channels;

16. Nozzle for drilling out;

17. Drilling nozzle body;

18. Guide pin;

19. Spiral channels;

20. Spring;

21. Shaft;

22. Crown;

23. Flow channel;

24. Rotating cutter.

The nozzle for drilling and loosening dense deposits (for example, sand, proppant plugs) 16 is a rock cutting tool, consisting of a nozzle body for drilling 17, a rotating internal cutter 24, a crown 22 mounted on the nozzle body for drilling 17, which, in turn, , can be represented as a calibrator to provide a nominal passage in the production string 1.

The body of the nozzle for drilling 17 is fixedly attached to the tubing 2 and is equipped with a crown 22 in the lower part, a shaft 24 with spiral channels 19 along the length is installed coaxially inside, equipped at the end with a rotating internal cutter 24. The shaft 21 inside the body is spring-loaded by a spring 20 and has an exit outside the body for some distance. The vertical movement of the shaft 21 relative to the housing 17 is carried out along the spiral channels 19, which leads to the rotation of the cutter 24 when returning to the housing 17 and leaving it. The return to the body 17 is carried out by unloading the device against the bottom, and the exit is due to the spring 20 when the device is separated from the bottom. Also in the shaft 21 inside there is a flow channel 23 for the passage of destroyed dense deposits with reservoir and circulating fluid. The nozzle for drilling 16 can be made as a rotating bit 22, with counter-rotation of the cutter 24, and in the form of a calibrator for the nominal diameter of the production string 1.

The packer-throttling unit 12 is a packer mechanism consisting of a body 14, a cup sealing cuff 13, equipped with throttle channels 15 that provide flow through the annulus 3 from the above-packer zone to the under-packer zone, thereby providing the possibility of flushing through the annulus 3. It is also equipped the mechanism of partial or complete blocking of the throttle channels 15, which is initiated by the jet pump insert 8 or a separate mechanism discharged into the tubing 2 (not considered in this material). The annulus 3 is closed by opening the sealing cuff 13, creating a pressure drop on the cuff by pumping fluid into the annulus 3 for the operation of the jet pump 8. When the throttle channels 15 are fully open (transport position of the packer-throttling unit 12), the opening of the sealing cuff 13 is not occurs, which allows flushing through the annulus 3 with the removal of destroyed dense deposits along the tubing 2.

The jet pump is structurally designed in such a way that when the device is lowered into the tubing, only the casing 5 with the sleeve 6 is installed in the well, blocking the circulation holes 7 (tubing connection - annular space), which allows flushing along the tubing 2 and the annulus 3 (without flow restriction at the transport position of the packer-throttling unit 12). The jet pump itself in the form of insert 8 is lowered into the tubing 2, installed and fixed by creating pressure in the tubing by the pump unit from the surface (the presence of a mixer 9 in the insert 8 creates a choke, which allows you to create pressure), while the sleeve 6 is displaced in the housing 5 , opening the circulation holes 7. When the sleeve 6 is displaced, the throttling channels 15 in the packer-throttling unit 16 are completely or partially blocked. When the throttling channels 15 are partially blocked, the flow entering the annulus 3 is divided into two flows: pump 8, the second, smaller one, goes through partially closed throttling channels 15 to the under-packer zone, providing the flow rate when cuttings are sucked through the drilling nozzle 16.

The device works as follows.

The device is lowered into the well until it stops on dense deposits. The device is lowered in the following order (from bottom to top): drilling nozzle 16, tubing 2 (required length), packer-throttle assembly 12, jet pump housing 5 with a plug 6 blocking holes 7 (tubing - annular space), tubing 2 to the wellhead.

The device descends to the current face, the rotating cutter 24 rests against dense deposits, then, under the weight of the device, the shaft 21, rotating due to the spiral channel 19 and the guide pin 18, enters the body 17 and compresses the spring 20, while drilling and loosening the dense deposits. Next, the device rises, while the spring 20 pushes the shaft 21 out of the housing 17 to its original position.

Making reciprocating movements up and down, the device is unloaded on deposits and torn off for a certain distance. At the same time, throttle channels 15 are open in the packer-throttle assembly 12 for fluid flow from top to bottom along the annulus 3, excluding the effect of pistoning, which could occur due to the opening of the sealing cup cuff 13 when the device moves up. In the nozzle for drilling 16, when the device is unloaded from deposits, the cutter 24 rotates into the body of the nozzle for drilling 17, grinding/drilling dense (for example, sandy or proppant) deposits. In this case, the crown 22 (for example, made in the form of a spiral calibrator) cuts deposits from the walls of the well with its edges, showering them down for loosening with a cutter 24, providing a nominal passage in the production string 1.

In the body of the jet pump 5, the liquid circulates freely, without violating the tightness of the tubing 2 due to the blocking sleeve 6.

As the plug is being drilled out, we continuously inject into the annulus, washing out the destroyed dense deposits through tubing 2 to the surface. On the surface, the liquid with crushed deposits is cleaned. The purified liquid is fed to the intake of the pump forcing the flushing liquid into the annulus 3 for further use in circulation.

In the process of drilling out and increasing the downward passage of the device, a hydrodynamic connection with the formation will begin to appear, upon the appearance of which the absorption of the circulating drilling fluid by the formation may begin. When the circulating fluid is absorbed by the formation, it is necessary to switch to cleaning using a jet pump 8, for this, in the tubing 2 from the surface, we drop (or lower on the cable) the insert of the jet pump 8 and create pressure in the tubing 2 (by supplying fluid to the tubing, the pressure is formed due to choke with a mixer 9 in the jet pump insert 8), we open the circulation holes 7 in the jet pump housing 5 with simultaneous blocking of the throttling channels 15 in the packer-throttle assembly and fix the jet pump insert 8 in the jet pump housing 5 due to the latch on the insert 8.

Having unloaded the device on dense deposits, we start pumping the working fluid into the annulus 3. In this case, all channels 15 in the packer-throttling unit 12 are blocked. If necessary, a small flow can be left through the channels 15 in the packer-throttle unit 12 to provide the necessary volume of fluid to wash out the destroyed deposits. As the weight of the device increases, the device is lowered to the unloaded state.

At the same time, the main flow of the working fluid passes through the jet pump 8, in which, due to ejection, the destroyed deposits with formation and flushing fluid are sucked through the suction channels 11 in the insert of the jet pump 8, being mixed in the mixer 9 by the total flow, enters the tubing 2 and is carried out to surface where the liquid is cleaned from destroyed dense deposits.

In the event of an obstruction (stand on rigidly dense deposits), we stop the flow of flushing fluid into the annulus 3 (after making sure that there are no deposits at the outlet of tubing 2 on the surface) and perform reciprocating movements up and down, unloading the device on dense deposits and lifting it for some distance up, in this case, the destruction of dense deposits occurs due to the nozzle for drilling 16.

When driving 1-2 m, we start the jet pump 8 by injecting the working fluid into the annulus 3, gradually increasing the depth of descent. If an obstruction of the device occurs, repeat the procedure.

Thus, this device makes it possible to clean wells from dense deposits in directional, horizontal wells, including small-diameter wells with low formation pressures, high losses, and low flow rates. Also, if necessary, this device is applicable in an additionally lowered technical column, in case of violation of the tightness of the production string.

Claims (1)

A device for cleaning wells from dense deposits, including a jet pump installed on the tubing pipe, characterized in that a packer-throttle assembly and a nozzle for drilling are additionally installed on the tubing pipe under the jet pump in the following order, while the packer-throttle assembly equipped with throttle channels that provide the possibility of fluid flow through the annulus from the above-packer zone to the under-packer zone.

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