RU59118U1 - DEVICE FOR WASHING A WELL FROM A SAND PLUG - Google Patents

Abstract

The proposal relates to the oil industry and can be used for maintenance and overhaul of wells associated with flushing wells from sand plugs, including with absorbing formations. A device for flushing a well from a sand plug contains a pipe plugged at the bottom with radial channels at the bottom, which is concentrically mounted in a hollow body with a self-sealing cuff installed on the outer surface, pressed against the clamping nut from above. The device also contains a hollow cylindrical nozzle connected to the lower part of the hollow body. The radial channels of the pipe made with the possibility of communication pipe with the formation zone of the sand plug. The hollow body is equipped with a conical narrowing from the bottom inside and is equipped with a rigidly coaxially fixed glass with a central channel at the top under the nozzle. The pipe is made with the possibility of limited axial movement relative to the hollow body. The lower outer edge of the glass is installed with a gap - S around the perimeter relative to the lower inner edge of the hollow body. When the nozzle is axially moved relative to the hollow body, due to the rigid centralizers rigidly mounted on the outer surface of the pipe, sliding on the inner surface of the hollow body in the upper part of the latter, the device is aligned. The bottom pipe is equipped with radial holes and a cylindrical selection, in which with the possibility of axial movement along the length - L relative to the pipe, a non-return valve is installed, made in the form of a hollow sleeve mounted above the glass. The hollow sleeve in the lower position of the nozzle seals the radial holes of the nozzle. In the upper position of the nozzle, the hollow sleeve inside hermetically closes the radial channels of the nozzle, and on the outside it seals the central channel of the hollow body. By changing the slope of the conical narrowing of the hollow body, the clearance value - S is controlled, thus choosing the most optimal erosion regime of the sand plug depending on the flow and pressure of the flushing fluid. The proposed device for flushing a well from a sand plug has a simple design, in addition, it is reliable and efficient in operation due to the elimination of traction from the design of the device, which reduces the time for cleaning the well, and this leads to financial savings. 1 ill. for 1 liter

Description

The proposal relates to the oil industry and can be used for maintenance and overhaul of wells associated with flushing wells from sand plugs, including with absorbing formations.

A device for washing sand plugs (copyright certificate SU No. 857428, IPC 7 E 21 V 21/00, published in Bulletin No. 31 of 08/23/1981), comprising a housing with concentric placed in it pipe, forming with it an annular cavity.

The disadvantage of this device is that it does not prevent the absorption of washing liquid when cleaning the perforation holes of the filter from sand plugs. Therefore, as the sand plug is removed from the bottom and the filter is cleaned, the absorption rate of the washing liquid increases and the circulation and removal of the sand pulp to the surface cease. In this case, the suspended particles of sand and dirt are deposited in the wellbore, which leads to severe emergency situations: pipe sticking, long idle time of wells for overhaul. The cessation of flushing due to absorption of the liquid leads to the fact that the well remains uncleaned from the sand plug and is commissioned with a low flow rate, an increased content of mechanical impurities in the produced products or is completely idle due to the impossibility of removing the sand plug by washing.

The closest in technical essence is a device for cleaning wells from sand plugs (patent RU No. 33600, IPC 7 E 21 B 30/00, 21/00, published in Bulletin No. 30 dated 10.27.2003), containing a pipe, concentrically mounted in a hollow body on which a self-sealing sleeve is located, wherein the device is provided with a hollow cylindrical nozzle connected to the lower part of the hollow body and an installation sleeve on which the self-sealing sleeve is located, as well as a clamping nut mounted on the outer surface of the hollow body, except th, the hollow body is axially movable in a specific length (l) relative to the mounting sleeve, allowing to create a limited load at

pressing the self-sealing cuff to the walls of the well, the device is also equipped with a tip having longitudinal grooves on the outer surface and installed in the upper part of the hollow body and four bends located radially in the hollow body and communicating the inner space of the pipe muffled from below with the formation zone of the sand plug, and the device is equipped with a limiter rigidly connected to the installation sleeve with rods, which are the optimal distance for effective erosion of the sand plug L = 0.15 ÷ 0.25 m etra.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts;

- secondly, when unloading the device onto the sand plug, the traction is susceptible to curvature or breakage, and therefore the optimal distance for effective erosion of the sand plug may be violated, which generally reduces the reliability and efficiency of the device.

The objective of the utility model is to simplify the design of the device, as well as increase the reliability and efficiency of its work.

The technical set is solved by a device for flushing a well from a sand plug, containing a bottom plugged pipe with radial channels at the bottom, which is concentrically mounted in a hollow body with a self-sealing sleeve installed on the outer surface, a clamping nut pressed on top, centralizers, a hollow cylindrical nozzle connected to the lower part of the hollow case, while the radial channels are made with the possibility of communication of the pipe with the zone of formation of the sand plug.

What is new is that the hollow body is provided with a conical narrowing from the bottom inside and is equipped with a rigidly coaxially fixed glass with a central channel at the top under the pipe, which is made with the possibility of limited axial movement relative to the hollow body, the lower external edge of the glass being installed with a gap around the perimeter relative to the lower inner edge hollow body, while the pipe bottom is equipped with radial holes and an external cylindrical selection, in which with the possibility of axial movement includes flax pipe check valve, configured as a hollow sleeve mounted over the glass, wherein the hollow shank in the lower position of the sleeve sealingly covers the radial hole nozzle, wherein the upper position of the sleeve the hollow shank

from the inside, hermetically closes the radial channels of the pipe, and from the outside, hermetically closes the central channel of the hollow body.

The figure shows the proposed device in longitudinal section.

A device for flushing a well from a sand plug contains a bottom-plugged pipe 1 with radial channels 2 at the bottom, which is concentrically mounted in a hollow body 3 with a self-sealing sleeve 4 mounted on the outer surface, pressed on top by a clamping nut 5. The device also contains a hollow cylindrical nozzle 6, rigidly connected with the lower part of the hollow body 3. Radial channels 2 of the pipe 1 are made with the possibility of communication pipe 1 with the formation zone of the sand plug 7.

The hollow body 3 is provided with a conical narrowing 8 from the bottom inside and is equipped with a rigidly coaxially fixed glass 9 with a central channel 10 at the top under the pipe 1. The pipe 1 is made with the possibility of limited axial movement relative to the hollow body 3. The lower outer edge 11 of the glass 9 is installed with a clearance S perimeter relative to the lower inner edge 12 of the hollow body 3.

When the nozzle 1 is axially moved relative to the hollow body 3, due to the rigid centralizers 13 rigidly mounted on the outer surface of the nozzle 1, sliding on the inner surface of the hollow body 3 in the upper part of the latter, the device is aligned.

The pipe 1 from the bottom is equipped with radial holes 14 and an external cylindrical sample 15, in which with the possibility of axial movement by a length -L relative to the pipe 1, a check valve is installed, made in the form of a hollow sleeve 16 mounted above the glass 9.

The hollow sleeve 16 in the lower position of the pipe 1 hermetically seals the radial holes 14 of the pipe 1.

In the upper position of the pipe 1, the hollow sleeve 16 seals the radial channels 2 of the pipe 1 from the inside, and the hollow sleeve 16 seals the central channel 10 of the hollow body 3 from the outside.

The device operates as follows.

The device assembly by means of a sleeve 17 at the end of the tubing string 18 is lowered into the well 19. During the descent of the device into the well 19, a self-sealing collar 4, mounted on the outer surface of the hollow body 3 with a clamping nut 5, is in close contact with the inner wall wells 19, so the pipe 1 is rigidly connected to the tubing string 18 is in

the lower position, and the check valve made in the form of a hollow sleeve 16 is open (see Fig.), that is, it does not overlap the central channel 10 of the hollow body 3, because the hollow sleeve 16 abuts against the upper end of the outer cylindrical sample 15 of the pipe 1, and from the bottom to the glass 9, rigidly fixed inside the hollow body 1, while the liquid in the well 19, by the gap - S, gets into the device and rises from the bottom up along the annular gap between the pipe 1 and the hollow body 3 and enters the annular space 21 above the device, and that also the liquid through the radial channels 2 inside the pipe 1 enters the pipe 1 and the tubing string 18.

The descent of the device into the well 19 is continued until the toothed crown 20 of the hollow cylindrical nozzle 6 interacts with the formation zone of the sand plug 7. The tubing string 18 is completely unloaded onto the sand plug 7 and the flushing fluid is pumped into the annular space 21 of the well 19.

As a result of this, the flow of flushing fluid, since the self-sealing cuff 4 is in contact with the inner wall of the well 19 and does not allow flushing fluid from top to bottom, first enters the annular spaces of the device between the pipe 1 and the hollow body 3, and then between the hollow body 3 and the cup 9 and through the gap S gets onto the sand cork 7, eroding it.

The sand plug in the form of a water-sand mixture (not shown in the figure) washed out by the fluid flow rises from the zone of formation of the sand plug 7 and passes through the radial channels 2 into the nozzle 1, from where it is brought to the surface through the tubing string 18, which means the appearance of fluid circulation.

As the sand congestion erodes, the tubing string 18 is lowered downward, and if necessary (depending on the height of the sand congestion) it is expanded (the pipes making up the tubing string 18 are added), while the pumping of the flushing fluid into the annular space 21 of the well 19 is continued and monitored so that the tubing string 18 is constantly unloaded onto the sand plug 7. The erosion of the sand plug 7 continues until it is completely washed out or the well is deepened to the required depth.

At the end of the washing of the sand plug, the device is lifted upwards by approximately 2 meters by means of the tubing string 18, while first the nozzle 1 rises up relative to the glasses that are still motionless and rigidly interconnected

9 and the hollow body 3, and the rigid centralizers 13 of the pipe 1 slide upward along the inner surface of the hollow body 3, centering the tubing string 18 relative to the device, while the check valve, made in the form of a hollow sleeve 16, moves to the length L and is in the lower part of the outer cylindrical sample 15 of the pipe 1, where it abuts against its lower end, while the radial channels 2 of the pipe 1 are hermetically closed by the hollow sleeve 16, while the radial holes 14 of the pipe 1 open. The lifting of the tubing string 18, and hence the pipe 1, continues, while the hollow sleeve 16 is out of interaction with the upper end of the stationary cup 9 and at the lower end of the outer cylindrical sample 15 together with the pipe 1 rises up until the check valve made in the form of a hollow sleeve 16, the central channel 10 of the hollow body 3 is not hermetically blocked from the outside. As a result, the radial holes 14 of the pipe 1 are higher than the check valve made in the form of a hollow sleeve 16 and hydraulically communicate the annular space in 21 with the internal spaces of the pipe 1 and the tubing string 18, since the radial channels 2 of the pipe 1 are hermetically closed by the hollow sleeve 16.

By supplying washing liquid to the annular space 21 through the radial holes 14 of the pipe 1, the remaining sandy mixture is washed out of the internal space of the pipe 1 and the tubing string 18. Next, the device is completely removed from the well 19.

In the washing process of the sand cork, the washed-out water-sand mixture is sent to a chute or barn.

By varying the slope of the conical narrowing 8 of the hollow body 3, the clearance value S is adjusted, thereby selecting the most optimal sand erosion regime depending on the flow and pressure of the flushing fluid.

The proposed device for flushing a well from a sand plug has a simple design, in addition, it is reliable and efficient in operation by eliminating traction from the design of the device, which reduces the time for flushing a well, and this leads to financial savings.

Claims (1)

A device for flushing a well from a sand plug, containing a bottom plugged pipe with radial channels at the bottom, which is concentrically mounted in a hollow body with a self-sealing sleeve installed on the outer surface, a clamping nut pressed on top, centralizers, a hollow cylindrical nozzle connected to the lower part of the hollow body, this radial channels are made with the possibility of communication of the pipe with the zone of formation of the sand cork, characterized in that the hollow body is provided with a bottom inside a conical narrowing it and is equipped with a rigidly coaxially fixed cup with a central channel at the top under the nozzle, which is made with the possibility of limited axial movement relative to the hollow body, the lower outer edge of the cup being installed with a perimeter gap relative to the lower inner edge of the hollow body, while the nozzle is provided with radial holes from below and external cylindrical selection, in which with the possibility of axial movement relative to the nozzle mounted check valve made in the form of a hollow sleeve installed above the glass, while the hollow sleeve in the lower position of the nozzle seals the radial holes of the nozzle, and in the upper position of the nozzle the hollow sleeve seals the radial channels of the nozzle from the inside, and externally seals the central channel of the hollow body.