RU62652U1 - DEVICE FOR CLEANING AND RINSING A WELL FROM A SAND PLUG - Google Patents

Abstract

The proposal relates to the oil industry and can be used in the routine and overhaul of wells associated with flushing wells with absorbing formations from sand plugs, mud sediments, scale, etc. A device for cleaning and flushing a well from a sand plug contains a bottom plugged pipe 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 clamp nut. 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 pipe on top is provided with radial holes and a sleeve telescopically mounted externally at its upper end. The sleeve has the possibility of limited axial movement relative to the pipe and tight shutoff of the radial holes of the pipe. The hollow body is equipped with a conical narrowing from the bottom inside and a glass rigidly placed inside it, mounted on the pipe with the possibility of limited axial movement to a height - L, while the radial channels of the pipe are arranged to be located inside the glass or above it. The nozzle is made with the possibility of limited axial movement relative to the hollow body and the outside below the radial holes is equipped with a check valve, made in the form of an annular stop that seals the central channel of the hollow body in the highest position of the nozzle. 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. By varying 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 cleaning wells from sand plugs has a simple design, in addition, it is reliable in operation due to the exclusion of rods from the design of the device, and the efficiency of the device is associated with the possibility of washing out the rest of the sandy mixture from the pipe string before lifting, which generally allows high-quality cleaning of the well from sand plugs. 1 ill. for 1 liter

Description

The proposal relates to the oil industry and can be used in the routine and overhaul of wells associated with flushing wells from sand plugs, mud sediments, scale, etc.

A device for washing sand plugs (copyright certificate SU No. 857428, IPC 7 E 21 B 21/00, published in Bulletin No. 31 of 08/23/1981) is known. comprising a housing connected through a sleeve to a tubing string with a concentric pipe disposed therein, forming an annular cavity with it.

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, prolonged shutdown 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, while the device is equipped 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 against 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 using rods that are the optimal distance for the 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 of the device.

- thirdly, after the erosion of the sand cork, its residues in the form of a water-sand mixture are in the pipe string and, upon subsequent extraction of the pipe string from the well, the residues of the water-sand mixture from the pipe string are again deposited in the well, which reduces the efficiency of cleaning the well from the sand cork.

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 stated technical problem is solved by a device for cleaning and washing 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, a hollow cylindrical nozzle connected to the bottom hollow body, while the radial channels are made with the possibility of communication of the pipe with the formation zone of the sand plug.

What is new is that the nozzle on top is provided with radial holes and a sleeve telescopically mounted externally at its upper end, while the sleeve has the possibility of limited axial movement relative to the nozzle and hermetically overlapping the radial holes of the nozzle, and the hollow body is provided with a conical narrowing from the bottom inside and rigidly placed inside it a glass mounted on the nozzle with the possibility of limited axial movement, while the radial channels of the nozzle are arranged zheniya inside cups or above, wherein the nozzle is adapted for limited axial

of movement relative to the hollow body and outside below the radial holes is equipped with a check valve made in the form of an annular stop, hermetically closing the central channel of the hollow body in the upper end position of the nozzle, while the lower outer edge of the glass is installed with a gap around the perimeter relative to the lower inner edge of the hollow body.

A device for cleaning and flushing a well from a sand plug contains a pipe 1 plugged from below 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 against the clamping nut 5.

The device also contains a hollow cylindrical nozzle 6 connected to the lower part of the hollow body 3. The radial channels 2 of the pipe 1 are configured to communicate the pipe 1 with the formation zone of the sand plug 7.

The pipe 1 on top is provided with radial holes 8 and a sleeve 9, telescopically mounted externally at its upper end.

The sleeve 9 has the possibility of limited axial movement relative to the pipe 1 and sealed by means of a sealing element 10 of the overlap of the radial holes 8 of the pipe 1.

The hollow body 3 is provided with a conical narrowing 11 from the bottom inside and a glass 12 rigidly placed inside it, mounted on the pipe 1 with the possibility of limited axial movement to a height - L, while the radial channels 2 of the pipe 1 are arranged to be located inside the glass 12 or above it.

The glass 12 is rigidly fixed to the hollow body 3 by means of rigid centralizers 13 placed diametrically on its outer surface.

The pipe 1 is made with the possibility of limited axial movement relative to the hollow body 3 and the outside below the radial holes 8 is equipped with a check valve 14 made in the form of an annular stop hermetically seals the central channel 15 of the hollow body 3 in the extreme upper position of the pipe 1 relative to the hollow body 3.

The lower outer edge 16 of the glass 12 is installed with a gap - S around the perimeter relative to the lower inner edge 17 of the hollow body 3.

The device operates as follows.

The device assembly at the end of the tubing string 18 is lowered into the well 19 until the toothed crown 20 of the hollow cylindrical nozzle 6 interacts with the formation of the sand plug 7. During the descent of the device into the well 19, the self-sealing collar 4 is fixed to the outer surface

the hollow body 3, the clamping nut 5 is in tight contact with the inner wall of the well 19, as a result of which the cup 12 is in its highest position relative to the nozzle 2, while the liquid in the well 19 penetrates from the one side through the radial channels 2 into the nozzle 1 since the nozzle 1 12 is located above the radial channels 2 of the pipe 1 and further into the tubing string 18, and on the other, along the gap S, it rises from the bottom up first along the annular gap between the cup 12 and the hollow body 3 and then through the central channel 15 of the hollow body and 3 liquid enters the annular space 21 above the device. In addition, during the descent of the device into the well 19, the inner space of the tubing string 18 communicates with the annular space 21 through the radial holes 8 of the pipe 1.

The tubing string 18 is completely unloaded on the sand plug 7, while the sleeve 9 is shifted down relative to the pipe 1 and hermetically seals the radial holes 8 of the pipe 1 by means of the sealing ring 10.

Then, the flushing fluid begins to be pumped into the annular space 21 of the well 19. As a result, the flushing fluid flow, since the self-sealing cuff 5 is in close contact with the inner wall of the well 19 and does not pass the flushing fluid downward, enters the annular through the central channel 15 of the hollow body 3 the space first between the pipe 1 and the hollow body 3, and then between the hollow body 3 and the glass 12 and through the gap S gets on 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 carried out onto the surface of the tubing string 18 and sent to the barn, which means the appearance of flushing 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 19 is deepened to the required depth.

To remove the water-sand mixture remaining inside the pipe 1 and the tubing string 18, the tubing string 18 is lifted up from the wellhead, while first the sleeve 9 rises up relative to the pipe 1, while the radial

holes 8 of the pipe 1. As a result, the annular space 21 and the inner space of the tubing string 18 begin to hydraulically communicate with each other. With further lifting up of the tubing string 18 and, accordingly, the pipe 1, the valve 14 located on its outer surface below the radial openings 8, made in the form of an annular stop, seals the central channel 15 of the hollow body 3, preventing flushing liquid from entering the device. The lifting of the tubing string 18 continues, and the cup 12 already tightly closes the radial channels 2 of the pipe 1 with its inner surface, which has risen up with the tubing string 18 to a height of L. As a result, the formation zone of the sand plug 7 is hermetically cut off from the annular space 21.

By supplying flushing fluid to the annulus 21 of the well 19 through open radial channels 8 of the nozzle 1, the fluid flow enters the tubing string 18 through which it rises, since the radial channels 2 of the nozzle 1 are hermetically closed by the inner surface of the nozzle 9 and carries the sandy mixture to the surface, from where it sent to a gutter or barn.

Next, the tubing string 18 is completely removed along with the device from the well 19. By varying the slope of the conical narrowing 11 of the hollow body 3, the clearance value S is controlled, thereby choosing the most optimal erosion regime of the sand plug depending on the flow and pressure of the flushing fluid.

The proposed device for cleaning wells from sand plugs has a simple design, in addition, it is reliable in operation due to the elimination of rods from the device structure, and the device’s efficiency is associated with the possibility of washing out the rest of the sandy mixture from the pipe string before lifting it, which generally allows high-quality cleaning of the well from sand plugs.

Claims (1)

A device for cleaning and flushing a well from a sand plug, comprising 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, 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 pipe on top is provided with radial holes and telescopically mounted externally at its upper end, while the sleeve has the possibility of limited axial movement relative to the nozzle and hermetically overlapping the radial holes of the nozzle, the hollow body provided with a tapered narrowing from the bottom inside and a rigidly placed inside of it cup mounted on the nozzle with limited axial movement, the radial channels of the nozzle are arranged to be located inside the glass or above it, and the nozzle is made with the possibility of og The axial displacement relative to the hollow body and outside below the radial holes is equipped with a check valve made in the form of an annular stop that seals the central channel of the hollow body in the upper end position of the nozzle, while the lower outer edge of the glass is installed with a gap around the perimeter relative to the lower inner edge of the hollow body .