RU52913U1 - DEVICE FOR CLEANING A WELL FROM A SAND STOCK - 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 consists of a nozzle concentrically mounted in a hollow body, a hollow cylindrical nozzle mounted on the lower end of the hollow body, taps located in the hollow body and connecting the inner space of the pipe plugged from below with the formation zone of the sand plug, self-sealing cuff and clamping nut. A limiter made in the form of a hollow cylinder equipped with a toothed crown at the lower end is rigidly attached to the lower end of the hollow body. A hollow rod concentrically mounted on top of the outside surface of the nozzle has through holes and is fixed relative to the nozzle by a shear element in the initial position. The pipe is equipped with radial holes, below which on the outer surface of the pipe a shaped groove is made in the form of alternating long and short sections. In a shaped groove with the ability to move along long and short sections during the reciprocating movement of the hollow rod relative to the nozzle, a guide pin is placed rigidly connected to the hollow rod. The radial holes of the nozzle and the through holes of the hollow rod, in the initial position, are hermetically cut off from each other. Bottom of the hollow rod is equipped with a sealing element that isolates the formation zone of the sand plug when the hollow rod is axially moved down relative to the nozzle and the radial holes of the nozzle and the through holes of the rod are aligned with each other. Inside the pipe, a check valve is installed above the taps. The proposed device for cleaning wells from sand plugs has a simple structure, more durable limiter and is quite effective when cleaning sand plugs in wells having low reservoir pressure, leading to the absorption of drilling fluid by the formations, due to cutting off the latter, with

the subsequent washing out of the water-sand mixture from the tubing string, in connection with which the time for cleaning the well is reduced and financial and material costs are saved.

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. 1081334, IPC 7 E 21 B 21/00, publ. 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 plugs, and as a result, to an increase in the flow rate of flushing fluid in 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. 33599, IPC 7 E 21 B 37/00, 21/00, publ. In BI No. 30 dated 10.27.2003), containing a pipe concentrically mounted in a hollow body, a self-sealing cuff and a clamping nut, the device is equipped with a locking element in the form of a rubber ball with a grate and a hollow cylindrical nozzle, on the inner surface of which there is a conical bore, in which a rubber ball is fixed, fixed in it by a grate, while tsilin The nozzle is connected to the lower part of the hollow body, and the device is equipped with four taps located radially in the hollow body and

communicating the inner space of the bottom of the pipe plugged with a sand plug formation zone, and the device is equipped with a limiter rigidly connected to the hollow body by means of rods, while the optimal distance for the effective erosion of the sand plug is L = 0.15 ÷ 0.25 meters.

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 may be bent or broken, and therefore the optimal distance for effective erosion of the sand plug may be violated, in addition, during the cleaning of the well from the sand plug, the pressure of the flushing fluid above and below the self-sealing cuff is approximately equal, as a result of which wells with low reservoir pressure absorb the flushing fluid by the layers, and as a result, all this reduces the efficiency of the device in such kvazhinah.

The objective of the utility model is to simplify the design of the device, as well as increase the efficiency of the device in wells with low reservoir pressure.

A device for cleaning a well from a sand plug includes a nozzle concentrically installed in the hollow body, a hollow cylindrical nozzle mounted on the lower end of the hollow body, taps located in the hollow body and connecting the inner space of the pipe plugged from the bottom with the sand plug formation zone, a self-sealing cuff, and a clamp a nut and limiter rigidly connected to the hollow body.

What is new is that on top of the outer surface of the nozzle a hollow rod concentrically installed has through holes and is fixed in its initial position relative to the nozzle by a shear element, while the nozzle is provided with radial holes, below which on the outer surface of the nozzle a shaped groove is made in the form of alternating long and short sections, and in a figured groove with the ability to move along its sections with the reciprocating movement of the hollow rod relative to the nozzle is placed guide p alet rigidly connected to the hollow rod, while the radial holes of the nozzle and through

the holes of the hollow rod in the initial position are hermetically cut off from each other, and the bottom of the hollow rod is equipped with a sealing element that isolates the formation zone of the sand plug when the hollow rod is axially moved downward relative to the nozzle and the radial holes of the nozzle and the through holes of the hollow rod are aligned with each other, while the limiter is made in the form of a hollow cylinder equipped with a gear crown at the lower end, and a check valve is installed inside the pipe above the taps.

Figure 1 shows the proposed device in longitudinal section.

Figure 2 shows a scan of the curly groove.

A device for cleaning a well from a sand plug consists of a pipe 1 (see FIG. 1), concentrically mounted in a hollow body 2, a hollow cylindrical nozzle 3 installed on the lower end of the hollow body 2, taps 4 located in the hollow body 2 and connecting the inner the space muffled from the bottom of the pipe 1 with the formation zone of the sand cork (not shown in Figs. 1 and 2). Self-sealing cuff 5 is located on the outer surface 6 of the hollow body 2 and is secured by a clamping nut 7.

To the lower end of the hollow body 2 (see Fig. 1), a restrictor 8 is made rigidly attached, made in the form of a hollow cylinder equipped with a toothed crown 9 at the lower end, while the optimal distance established during practical studies from the lower end of the hollow cylindrical nozzle to the zone of formation of the sand plug for the effective erosion of the sand plug is L = 0.15 ÷ 0.25 meters. On top of the outer surface of the pipe 1, a hollow rod 10 is concentrically mounted, having through holes 11 and fixed relative to the pipe by a shear element 12 in its initial position. The pipe 1 is provided with radial holes 13, below which on the outer surface of the pipe 1 there is a shaped groove 14 (see figure 2) in the form of alternating long 15 and short 16 sections.

In the figured groove 14 with the ability to move along the long 15 and short 16 sections with the reciprocating movement of the hollow rod 10 (see figure 1) relative to the pipe 1 there is a guide pin 17, rigidly connected to the hollow rod 10. Radial holes 13 of the pipe 1 and the through holes 11 of the hollow rod 10, in the initial position, are hermetically cut off from each other. Bottom hollow stem

10 is equipped with a sealing element 18 that isolates the zone of formation of the sand plug 5 when the hollow rod 10 is axially moved downward relative to the nozzle 1 and the radial holes 13 of the nozzle 1 and the through holes 11 of the hollow rod 10 are aligned together. Inside the nozzle 1, a check valve 19 is installed above the branches 4.

In order to exclude unauthorized fluid flows, the mating surfaces of the pipe 1 and the hollow rod 10 are provided with o-rings 20 and 21.

The device operates as follows.

The assembled device, as shown in FIG. 1, is lowered into the well on the tubing string 22 until the tooth crown 9 of the device limiter 8 interacts with the sand plug in the well (not shown in FIGS. 1 and 2).

Then the tubing string 22 is unloaded onto the sand plug by about 30-40 kN (control is carried out by the weight indicator installed at the wellhead), while the shear element 12 remains in its original position, fixing the nozzle 1 relative to the hollow rod 10. Then, the flushing fluid is pumped into the annular space of the well (not shown in FIGS. 1 and 2). Under the pressure of the injection, the collar of the self-sealing sleeve 5 mounted on the outer surface 6 of the hollow body 2 and the fixed clamping nut 7 is pressed against the inner walls of the well and seals the space between the device and the well below the self-sealing sleeve 5. As a result, the fluid flow first enters the annular space between the pipe 1 and the hollow body 2, from where, through the hollow cylindrical nozzle 3, it enters the sand cork, eroding it. Further, the sand plug in the form of a sandy mixture (not shown in Figs. 1 and 2), washed out by the fluid flow, rises from the zone of formation of the sand plug and enters bends 4 and further into the pipe 1, through the hollow rod 10 and through the tubing string 22 is carried to the day surface , and this means the appearance of fluid circulation. As the sand plug is eroded, the tubing string 22 is lowered downward, and if necessary (depending on the height of the sand plug) it is increased, while the pumping of flushing fluid into the annulus of the well continues and make sure that the tubing string 22 is not unloaded with the device on the sand plug exceeded 30-40 kN. 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 altogether. This means that, erosion

sand plug reached the formation in the well, which began to absorb the flushing fluid and therefore the pressure in the device no longer provides the rise, located in the tubing string 22 of the sandy mixture to the surface.

To remove the sandy mixture located in the device above the check valve 19 and inside the tubing string 22 and to continue further cleaning the well from the sand plug, the tubing string 22 is unloaded by about 50-60 kN, and the shear element 12 is destroyed and the hollow pipe 10 is shifted down relative to pipe 1, and the guide pin 17 (see figure 2), located in the initial position in the upper part of the short section 16 of the figured groove 14 is shifted down to its lower part. Then, from the wellhead, the tubing string 22 is lifted (see FIG. 1) about 1 meter up and down, as a result, the guide pin 17 from the bottom of the short section 16 falls into the upper part of the long section 15 of the figured groove 14 (when lifting), and then (during descent) from the upper part of the long section 15 to its lower part, and the hollow rod 10 moves downward relative to the nozzle 1 and by its sealing elements 18 isolates the formation zone of the sand plug, while the nozzle 1 concentrically installed in the hollow body 2 remains stationary relative to the hollow rod 10, due to the fixation of the device by the tooth crown 9 of the limiter 8 in a washable sand cork. The result is a combination of the radial holes 13 of the pipe 1 and the through holes 11 of the hollow rod 10. The fluid is supplied to the annulus of the well through the interconnected radial holes 13 of the pipe 1 and the through holes 11 of the hollow rod 10 and further through the internal spaces of the pipe 1 above the return valve 19, preventing the flow of liquid down into the formation zone of the sand plug and hollow rod 10 up the tubing string 22 is washed out, located in the tubing string 22 and in the device above the check valve 19 vodopeschanuyu mixture on the surface where it is withdrawn in channel capacity or barn (Figures 1 and 2 are not shown).

To continue cleaning the well from the sand plug, the tubing string 22 is lifted up about 2 meters up and down, while lifting, the guide finger moves from the bottom of the long section 15 of the figured groove 14 to the upper part of the short section 16, and when lowering, the guide finger 17 moves from the upper part of the short section 16 to its lower part. As a result

the hollow rod 10 rises upward relative to the nozzle 1, and its sealing element 18 comes out of contact with the hollow body 2, hydraulically connecting the annular space of the well through the hollow body 2 and the hollow cylindrical nozzle 3 with the formation zone of the sand plug.

Further, the cleaning of the well from sand plugs continues, repeating the entire cycle described above. 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, more durable limiter and is quite effective when cleaning sand plugs in wells with low reservoir pressure, leading to the absorption of drilling fluid by the formations, due to cutting off the latter, followed by washing out the sandy mixture from the tubing string, in connection with which the time for well cleaning is reduced and financial and material costs are saved.

Claims (1)

A device for cleaning a well from a sand plug, comprising a nozzle concentrically mounted in the hollow body, a hollow cylindrical nozzle mounted on the lower end of the hollow body, taps located in the hollow body and connecting the interior of the pipe plugged from the bottom with the sand plug formation zone, a self-sealing cuff, a clamping nut and a limiter rigidly connected to the hollow body, characterized in that a hollow rod having a well is concentrically mounted on top of the outer surface of the nozzle ozny holes and a shear element fixed in the initial position relative to the nozzle, while the nozzle is provided with radial holes, below which on the outer surface of the nozzle there is a shaped groove in the form of alternating long and short sections, and in the shaped groove with the ability to move along its sections with reciprocating the movement of the hollow rod relative to the nozzle is placed guide pin, rigidly connected to the hollow rod, while the radial holes of the nozzle and through holes of the hollow piece ka, in the initial position, are hermetically cut off from each other, and the bottom of the hollow rod is equipped with a sealing element that isolates the formation zone of the sand plug when the hollow rod is axially moved down relative to the nozzle and the radial holes of the nozzle and through holes of the hollow rod are aligned with each other, while the limiter is made in the form of a hollow cylinder equipped with a gear crown at the lower end, and a check valve is installed inside the pipe above the taps.