RU54081U1 - WELL WASHING AND CLEANING DEVICE - 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 a well from a sand plug contains a pipe string, a nozzle plugged at the bottom and concentrically mounted in a hollow body, which is equipped with a cylindrical nozzle mounted on the lower end of the hollow body, taps connecting the inner space of the pipe with the sand plug formation zone, a self-sealing cuff with a clamp a nut, a stop and an installation sleeve with a central channel. On the inner surface of the limiter, a hollow body is concentrically placed, above and below which annular protrusions are made, restricting the movement of the hollow body relative to the limiter. Below the installation sleeve, but above the bends, there is a plug made with the possibility of tight interaction with the central channel of the installation sleeve. The installation sleeve is equipped with a self-sealing cuff and side channels located above the lower seal of the self-sealing cuff, made in the form of an inflatable sleeve. The upper end of the inflatable sleeve is rigidly and hermetically fixed with a clamping nut. The limiter is rigidly attached from below to the installation sleeve and covers the hollow body from the outside, with the possibility of tight axial movement. The upper end of the pipe interacts with the possibility of limited tight axial movement with the technological sleeve, rigidly connected to the pipe string and equipped with radial channels, which are configured to communicate with the interior of the pipe string or hermetic overlap pipe. The proposed device for cleaning wells from sand plugs has a simple structure and a more durable limiter, in addition, it is effective especially in wells having absorbing formations, due to cutting off the latter with subsequent washing out of the sandy mixture from the pipe string, thereby reducing the time for cleaning the well and financial savings.

Description

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 washing sand plugs (Av. St. SU No. 857428, IPC 7 E 21 B 21/00, published in BI No. 31 of 08/23/1981), comprising a casing connected through a sleeve to a tubing string a pipe concentrically placed in it, 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 plug is removed from the bottom and the filter is cleaned, the absorption rate of the washing liquid increases and the circulation and the removal of sand pulp to the surface cease. In this case, 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 unpurified from the plug and is put into operation with a low flow rate, an increased content of mechanical impurities in the produced products, which leads to premature failure of the pumping equipment or standstill of the well due to the inability to remove cork flushing.

A device for washing sand plugs (Av. St. SU No. 1081334, IPC 7 E 21 B 21/00, published in BI No. 11 of 03/23/1984), comprising a casing connected through a sleeve to a tubing string a pipe concentrically placed in it, forming an annular cavity with it, two elastic cuffs installed in the upper and lower parts of the housing, and the coupling has radial channels for communicating the annular cavity formed by the housing and the pipe with the annulus.

The disadvantages of this device is that the cuffs are in constant contact with the walls of the well, resulting in friction, which

leads to gradual wear of the cuffs during the descent of the device to the sand plug, especially in deep wells, which leads to a decrease in tightness during the washing of the sand plug and, as a result, to an increase in the flow rate of the washing fluid in the absorbing wells; in addition, in paraffin wells during the descent process, due to tight contact, the cuff may break, which reduces the efficiency of the device.

The closest in technical essence is a device for cleaning wells from sand plugs (patent RU No. 33600, IPC 7 E 21 B 37/00, 21/00, published in BI No. 30 dated 10.27.2003), containing a pipe concentrically mounted in a hollow body on which a self-sealing sleeve is installed, while it is provided with a hollow cylindrical nozzle connected to the lower part of the hollow body, provided with an installation sleeve on which the self-sealing sleeve is located, and a clamping nut mounted on the outer surface of the body, in addition, the hollow to the housing has the possibility of axial movement by a certain length relative to the installation sleeve, which allows you to create a limited load when pressing the self-sealing cuff to the walls of the well, equipped with a tip having longitudinal grooves on the outer surface and installed in the upper part of the body, equipped with four bends located radially in the hollow body and communicating the inner space of the bottom plugged with a sand plug formation zone.

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 can be bent or broken, and therefore the optimal distance for effective erosion of the sand plug can be violated, and this reduces the reliability of the device;

- thirdly, in the process of cleaning a well from a sand plug, the pressure of the flushing fluid above and below the self-sealing cuff is approximately equal, as a result of which the wells are absorbed by the formations in the wells with low reservoir pressure, and therefore the outflow stops

eroded sand cork to the surface, which reduces the efficiency of the device in such wells.

The technical task of the utility model is to simplify the design of the device, as well as to increase the reliability and efficiency of the device in wells with absorbing formations having low reservoir pressure.

The technical problem is solved by a device for washing and cleaning a well, comprising a pipe string, a nozzle plugged from below and concentrically mounted in a hollow body, which is equipped with a cylindrical nozzle mounted on the lower end of the hollow body, and bends connecting the inner space of the pipe with the sand plug formation zone, self-sealing cuff with a clamping nut, a stopper and a mounting sleeve with a central channel, made with the possibility of limited axial movement relative to the polo about housing.

New is that the pipe is additionally equipped with a check valve above the taps, and below the installation sleeve, but above the taps, with a plug made with the possibility of tight interaction with the central channel of the installation sleeve, while the installation sleeve is equipped with a self-sealing cuff and side channels located above the lower terminations of a self-sealing cuff made in the form of an inflatable sleeve, the upper end of which is rigidly and hermetically fixed with a clamping nut above the side channels of the installation sleeve ki, and the stopper is rigidly attached from below to the installation sleeve and externally encloses a hollow body having the possibility of limited axial movement relative to the stopper by means of annular protrusions made on the inner surface of the stopper above and below the hollow body, while the upper end of the nozzle interacts with the possibility of limited tight axial movement with a technological sleeve rigidly connected to the pipe string and equipped with radial channels, which are made with the possibility of Strongly communication with the interior of the tubing string or pipe sealingly overlap.

The figure shows the proposed device in longitudinal section in the working position.

The device for washing and cleaning the well contains a pipe string 1, a pipe 2, plugged from the bottom and concentrically mounted in the hollow body 3, which is equipped with a cylindrical nozzle 4 mounted on the lower end of the hollow body 3, bends 5 connecting the inner space of the pipe 2 with the formation zone

a sand plug (not shown in FIG.), a self-sealing collar 6 with a clamping nut 7, a limiter 8 and an installation sleeve 9 with a central channel 10. The installation sleeve 9 is made with the possibility of limited axial movement relative to the hollow body 3.

The pipe 2 is additionally equipped with a check valve 11 above the taps 4. The hollow body 3 is concentrically placed on the inner surface of the stop 8, annular projections 12 are made above and below, restricting the movement of the hollow body 3 relative to the stop 8. Below the installation sleeve 9, but above the taps 5, - a plug 13 made with the possibility of tight interaction with the Central channel 10 of the installation sleeve 9. The installation sleeve 9 is equipped with a self-sealing cuff 6 and side channels 14 located above the lower the case of the self-sealing cuff 6, made in the form of an inflatable sleeve 15. The upper end of the inflatable sleeve 15 is rigidly and hermetically fixed with a clamping nut 7 above the side channels 14 of the installation sleeve 9.

The limiter 8 is rigidly attached from below to the installation sleeve 9 and encloses the hollow body 3 with the possibility of tight axial movement from the outside. The upper end of the nozzle 2 interacts with the possibility of limited tight axial movement with the process sleeve 16, rigidly connected to the pipe string 1 and equipped with radial channels 17, which made with the possibility of communication with the inner space of the pipe string 1 or tight shutoff pipe 2.

Unauthorized fluid flows on mating surfaces are eliminated by O-rings 18. 19.

The device operates as follows.

The device is assembled in the transport position on the pipe string 1 (for example, the tubing string) is lowered into the well before the device interacts with a toothed crown 20, which is equipped with a stop 8 from the bottom with a sand plug in the well, while in the process of lowering the device located in the well the liquid through the radial channels 17 of the technological sleeve 16 enters the pipe string 1.

Next, unload the pipe string 1 with the device at the end onto the sand plug to be cleaned (control is carried out by the weight indicator installed on the mouth

wells), while the pipe 2 rises up relative to the process sleeve 16 and hermetically seals from the inside its radial channels 17.

Unloading of the device is continued, while the technological sleeve 16, falling down, acts from above on the pipe 2, which together with the hollow body 3 moves downward relative to the installation sleeve 9 and the limiter 9 rigidly connected to it until the hollow body 3 is placed concentrically in the limiter 8 does not abut below the annular protrusion 12, made on the inner surface of the stop 8 below the hollow body 3. The tooth crown 20 of the stop 8 fixes the device relative to the sand cork. Then, flushing fluid begins to be pumped into the annulus of the well (not shown in the figure).

The fluid flow from the annulus of the well flows from above into the central channel 10 of the installation sleeve 9, and then into the annular space between the pipe 2 and the installation sleeve 9 and then through the hollow body 3 through its cylindrical nozzle 4 enters the sand plug, eroding it. At the same time, the fluid flow entering the central channel 10 of the installation sleeve 9 through the side channels 14 of the installation sleeve 9 inflates from the inside the inflatable sleeve 15, which is pressed against the inner walls of the well, while the pressure drop above and below the inflatable sleeve 15 additionally compresses the latter to the walls wells, hermetically separating the annulus of the well.

Further, a 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 and falls into branches 5 and further into the pipe 2 and is carried to the surface by pipe string 1.

As the sand plug is eroded, the pipe string 1 is lowered downwards, and if necessary (depending on the height of the sand plug) they increase, while the pumping of the flushing fluid into the annulus of the well continues. The erosion of the sand plug continues until the flow of the sandy mixture washed out of the well visually decreases or the circulation ceases. This means that the sand plug is washed out to the formation, which began to absorb the flushing fluid and therefore the flow of fluid in the device no longer ensures that the sandy mixture in the pipe string 1 will rise to the surface.

To remove the water-sand mixture located inside the pipe string 1 above the check valve 11 of the device, the pipe string 1 is raised from the wellhead by about 2-3 meters, first the process sleeve 16 goes out of contact with the ribs 13, then the process sleeve 16 is rigidly connected to the pipe string 1, rises upward relative to the pipe 2, while opening the radial channels 17 of the process sleeve 16. At the same time, the process sleeve 16 pulls the pipe 2 and the hollow body rigidly connected to it mustache 3, causing limited axial movement of the latter until the hollow body 3 on top rests against the annular protrusion 12, made on the inner surface of the limiter 8 above the hollow body 3, while the plug 13 mounted on the pipe 2 will seal the central channel 10 of the installation sleeve 9, while the fluid flow through the side channels 14 of the installation sleeve 9 continues to act on the inflatable sleeve 15, continuing to press it against the walls of the well due to the pressure difference above and below it. As a result, the formation zone of the sand plug and the formation are hermetically cut off from the well space located above the device.

By supplying flushing fluid to the annulus of the well through open radial channels 17 of the process sleeve 16, the fluid flow enters the pipe string 1 above the check valve 11, which prevents the fluid from flowing down into the sand plug formation zone, from where the sandy water mixture is washed to the surface in a gutter or barn.

To continue cleaning the well from the sand plug, the pipe string 1 is lowered down until the device is unloaded onto the sand plug, after which the whole cycle of work described above is repeated. At the end of the well cleaning from the sand plug, the device is removed from the well.

The proposed device for cleaning wells from sand plugs has a simple structure and a more durable limiter, in addition, it is effective especially in wells having absorbing formations, due to cutting off the latter with subsequent washing out of the sandy mixture from the pipe string, thereby reducing the time for cleaning the well and financial savings.

Claims (1)

A device for flushing and cleaning a well from a sand plug, containing a pipe string, a nozzle plugged from below and concentrically mounted in a hollow body that is equipped with a cylindrical nozzle mounted at the lower end of the hollow body, and bends connecting the inside of the pipe to the sand plug formation zone, a self-sealing cuff with a clamping nut, a stopper and an installation sleeve with a central channel, made with the possibility of limited axial movement relative to the hollow body, characterized in that the pipe is additionally equipped with a check valve above the taps, and below the installation sleeve, but above the taps, with a plug made with the possibility of tight interaction with the central channel of the installation sleeve, while the installation sleeve is equipped with a self-sealing sleeve and side channels located above the lower seal self-sealing cuff made in the form of an inflatable sleeve, the upper end of which is rigidly and hermetically fixed with a clamping nut above the side channels of the installation sleeve and, moreover, the stopper is rigidly attached from below to the installation sleeve and encloses the hollow body from the outside, having the possibility of limited axial movement relative to the stopper by means of annular protrusions made on the inner surface of the stopper above and below the hollow body, while the upper end of the nozzle interacts with the possibility of limited tight axial movement with a technological sleeve rigidly connected to the pipe string and equipped with radial channels, which are made with the possibility of ü communication with the interior of the pipe string or tight shutoff pipe.