RU42262U1 - DEVICE FOR CLEANING A WELL FROM A SAND BLOCK AND ITS WASHING - Google Patents

Abstract

1. A device for cleaning a well from a sand plug and flushing it, comprising a nozzle concentrically mounted with the possibility of axial movement a certain length down in a hollow body on which a self-sealing cuff is installed, which allows the clamping nut made from the bottom up and fixed from the bottom by the mounting sleeve made with the ability to press the self-sealing cuff to the walls of the well in the working position, the tip with radial bends communicating the inner space with the formation zone of sand shells, characterized in that the hollow body is additionally provided with a lower clamping nut, upper and lower axial grooves and a lower self-sealing cuff, which passes from top to bottom and fixed with a lower mounting sleeve from above, while the self-sealing cuff and lower self-sealing cuff are located respectively below the upper axial groove and higher lower axial grooves, and the installation sleeve and lower installation sleeve are rigidly fixed relative to the hollow body, while the pipe is connected lower with a tip whose radial bends are located below, with the possibility of tight limited axial movement, sufficient to press the lower self-sealing cuff with the lower clamping nut to the walls of the well in the working position, in addition, the clamping nut and lower clamping nut are made with the possibility of axial movement relative to the hollow body and rigidly connected respectively to the nozzle and the tip of the radial guides, which are inserted respectively in the upper and lower axial grooves, length

Description

The proposal relates to the oil and gas industry and can be used for cleaning wells from sand plugs and flushing them, in particular in wells having absorbing formations or a violation in the casing with high injectivity, which do not allow cleaning or flushing of the well with the removal of contaminants to the surface.

A device for cleaning wells from sand plugs (Amirov A.D., Ovnatanov S.T., Yashin A.S. Overhaul of oil and gas wells. M., Nedra, 1975, pp. 214-216.), Containing a circulation sleeve connected to a housing in which there are radial openings. A special coupling is screwed onto the upper end of the housing. On the outer surface of the housing, a rubber self-sealing cuff is installed, which is held by a spacer ring and a clamping nut. In the middle of the circulation sleeve there is a socket, into the thread of which the lower end of the inner pipe is screwed, and its upper end is sealed from the outside with a stuffing box and packing follower, which excludes the possibility of the passage of the working fluid through the connection of the pipe with a special sleeve.

Significant disadvantages of the device are:

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

- complicated intensive removal of sludge due to different areas of the internal cross sections of the inner pipe and flushing pipes;

- damage to the self-sealing cuff due to friction against the wall of the well during its descent to the sand plug, which reduces the cleaning efficiency.

The closest in technical essence to the proposed is a device for cleaning wells from sand plugs (RF Patent for utility model No. 33600, publ. Bull. No. 30 dated 10.27.2003), containing a pipe concentrically installed with the possibility of axial movement to a certain length down in the hollow body, on which a self-sealing sleeve is installed, allowing the bottom to top and locked from below by the mounting sleeve, a clamping nut made to press the self-sealing sleeve to the walls of the well in the working

position, the tip with radial branches communicating the inner space with the zone of formation of the sand cork.

A significant drawback of the device is that it does not allow, in the presence of an absorbing layer in the well or a violation in the casing with high injectivity, to effectively clean or flush the well, since it is impossible to raise sand grains or dirt at the wellhead, since they will settle back or "go" into the reservoir or the disturbance interval, and with even greater absorption it is impossible to even circulate the flushing fluid to the surface, and as a result, there will be a low effec ktivnost cleaning or complete lack thereof.

The technical task of the utility model is to increase the efficiency of cleaning a well from a sand plug or washing it in the presence of a highly absorbing formation or a violation of the casing string with high injectivity.

The specified technical problem is solved by the proposed device for cleaning the well from sand plugs and flushing it, containing a nozzle concentrically mounted with the possibility of axial movement to a certain length down in a hollow body on which a self-sealing sleeve is installed, allowing the clamping nut to pass from the bottom up and fixed from the bottom by the mounting sleeve made with the possibility of pressing the self-sealing cuff to the walls of the borehole in the working position, a tip with radial bends communicating inside Early space with a sand cork zone.

New is the fact that the hollow body is additionally equipped with a lower clamping nut, upper and lower axial grooves and a lower self-sealing cuff, which passes from top to bottom and fixed with a lower mounting sleeve from above, while the self-sealing cuff and lower self-sealing cuff are located respectively below the upper axial groove and above the lower axial grooves, wherein the installation sleeve and lower installation sleeve are rigidly fixed relative to the hollow body, while the pipe is connected from below to a tip whose radial bends are located below, with the possibility of tight limited axial movement, sufficient to press the lower self-sealing cuff with the lower clamping nut to the walls of the well in the working position, in addition, the clamping nut and lower clamping nut are made with the possibility of axial movement relative to the hollow body and rigidly connected respectively to the nozzle and tip by radial guides, which are inserted respectively in the upper and lower axial grooves, the length of which s and

limits axial displacements, respectively, of the nozzle relative to the housing and the nozzle relative to the tip, while in the transport position the clamping nut relative to the hollow body and the tip relative to the nozzle are fixed with shear elements.

Also new is the fact that the lower clamping nut is equipped with spring centralizers.

Figure 1 shows the proposed device in longitudinal section

Figure 2 shows a section aa of the device.

A device for cleaning a well from a sand plug and flushing it (see FIG. 1) consists of a nozzle 1 concentrically mounted with the possibility of axial movement to a certain length down in a hollow body 2, on which a self-sealing cuff 3 is installed, passing from bottom to top and fixed from below the installation sleeve 4, the clamping nut 5, made with the possibility of pressing the self-sealing cuff 3 to the walls of the well b in the working position, a tip 7 having radial bends 8 from below, communicating the inner space 9 sand plug formation zone (in fig.ne shown).

The hollow body 2 is additionally equipped with a lower clamping nut 10, an upper axial groove 11 and a lower axial groove 12 (conventionally shown in FIG. 1), as well as a lower self-sealing cuff 13, which passes from top to bottom and is fixed from above by the lower mounting sleeve 14. Self-sealing cuff 3 and the lower self-sealing cuff 13 are located, respectively, below the upper axial groove 11 and above the lower axial groove 12.

The installation sleeve 4 and the lower installation sleeve 14 are rigidly fixed relative to the hollow body 2. The pipe 1 in the transport position is connected from below to the tip 7 by means of a shear element 15 with the possibility of tight limited axial movement sufficient to press the lower self-sealing sleeve 13 with the lower clamping nut 10 against the walls wells 6 in working position.

The clamping nut 5 and the lower clamping nut 10 are axially movable relative to the hollow body 2 and are rigidly connected to the pipe 1 and tip 7 by radial guides 16 and 17 (conventionally shown in FIG. 1), which are inserted respectively in the upper axial groove 11 and the lower axial groove 12, the length of which limits the axial displacements, respectively, of the pipe 1 relative to the hollow body 2 and the pipe 1 relative to the tip 7.

In the transport position, the clamping nut 5 is connected to the hollow body 2 by means of a shear element 18.

Spring centralizers 19 are mounted on the lower clamping nut 10.

The device operates as follows.

The device is selected in length so that the highly absorbing formation 20 or a violation in the casing with high throttle response (see Fig. 1) is cut off (isolated) from above and below using a self-sealing sleeve 3 and a lower self-sealing sleeve 13, respectively, and the length of the tip 7 is selected taking into account the unloading of the device on a sand cork (bottom). Next, the device on the column of washing pipes 21 (for example, a flexible pipe) is lowered into the well b to a sand plug (bottom hole).

The column of flushing pipes 21 begins to be discharged onto a sand cork (bottom), as a result of this, the shear element 15 is destroyed. The tip 7, the lower clamping nut 10, the radial guides 17 remain stationary, and the column of flushing tubes 21 with the remaining parts of the device are displaced downward, while the device moves down the lower axial groove 12 to the stop of the hollow body 2 in the lower end of the axial groove 12, in the process whereby the lower clamping nut 10, spreading the collar of the lower self-sealing cuff 13, reliably presses it against the wall of the well 6 with a certain force, limited by the length of the lower axial groove 12.

Next, the column of flushing pipes 21 with the device continues to be unloaded onto a sand cork (bottom), while the shear element 18 is destroyed, and the radial guides 16, rigidly connected to the pipe 1 and the clamping nut 5 (see Fig. 2) move down the upper axial groove 11 until the radial guides 16 stop in the lower end of the axial groove 11, in the process, the clamping nut 5, by expanding the collar of the self-sealing collar 3, reliably presses it against the wall of the well 6 with a certain force limited by the length of the upper axial groove 11.

After that, the wellhead is sealed with an oil seal 22 (see Fig. 1) and a working fluid (for example, industrial water with surfactants) is supplied under a certain pressure and flow rate into the annulus of the well. As a result, the working fluid rushes into the zone of formation of the sand plug, eroding it, or to the bottom of the well, washing its walls. A mixture of washed sand plugs and dirt from the walls of the borehole with the working fluid enters through the radial bends 8 of the tip 7 into the inner space 9 and then through the pipe 1 and the pipe string 21 is carried to the day surface.

As erosion and removal of sludge and dirt onto the day surface increases the pressure and flow rate of the working fluid into the annulus of the well to the allowable for this production string.

The completion of the process of cleaning and washing the well is evidenced by the absence of suspended sand grains of sludge and dirt in the pipes 21 carried along the pipe string to the surface of the working fluid.

In the proposed device, due to reliable cutting off of a highly absorbing formation or disturbances in the casing with high throttle response using self-sealing cuffs by mechanically pressing them to the walls of the production casing of the well, the efficiency of cleaning the well from the sand plug and its washing increases, which means that the time for work is reduced, which allows save material and financial resources.

Claims (2)

1. A device for cleaning a well from a sand plug and flushing it, comprising a nozzle concentrically mounted with the possibility of axial movement a certain length down in a hollow body on which a self-sealing cuff is installed, which allows the clamping nut made from the bottom up and fixed from the bottom by the mounting sleeve made with the ability to press the self-sealing cuff to the walls of the well in the working position, the tip with radial bends communicating the inner space with the formation zone of sand shells, characterized in that the hollow body is additionally provided with a lower clamping nut, upper and lower axial grooves and a lower self-sealing cuff, which passes from top to bottom and fixed with a lower mounting sleeve from above, while the self-sealing cuff and lower self-sealing cuff are located respectively below the upper axial groove and higher lower axial grooves, and the installation sleeve and lower installation sleeve are rigidly fixed relative to the hollow body, while the pipe is connected lower with a tip whose radial bends are located below, with the possibility of tight limited axial movement sufficient to press the lower self-sealing cuff with the lower clamping nut to the walls of the well in the working position, in addition, the clamping nut and lower clamping nut are made with the possibility of axial movement relative to the hollow body and rigidly connected respectively to the nozzle and the tip of the radial guides, which are inserted respectively in the upper and lower axial grooves, length otorrhea and limits the axial movement of tube respectively relative to the housing and relative to the nozzle tip, while in the transport position the clamping nut relative to the hollow body and the nozzle tip fixed with respect to shear elements. 2. The device according to claim 1, characterized in that the lower clamping nut is equipped with a spring centralizer.