RU56467U1 - WELL CLEANING DEVICE - Google Patents

Abstract

The utility model relates to the oil industry and can be used as equipment for cleaning the bottomhole formation zone and borehole bottom from sludge and other hard to recover deposits, including in wells with low reservoir pressure and high injection rate. A well cleaning device comprises a hollow rod connected with a pipe string with an annular protrusion and radial channels, a sleeve overlapping the radial channels of the hollow rod in the initial position, a packer, a knockdown valve, a body with a check valve and sealing elements. In this case, the upper part of the housing is equipped with stops, between which an annular protrusion of the hollow rod is placed, connected to the housing with the possibility of only axial movement relative to the housing. The sleeve is rigidly connected to the housing and is provided with radial channels that are aligned with the radial channels of the hollow rod only in the middle of its axial movement relative to the housing. The packer is made in the form of a self-sealing cuff and is located above the body and below the whipping valve. In the lower part of the stem and in the upper part of the housing there are drain valves. A working tip is installed under the body check valve. The use of a device for cleaning a well allows one team of ORSs to perform a single set of operations for a single descent of the device: cleaning the bottom of the well, destroying and removing the slurry plug, cleaning the bottom-hole zone of the formation with depressive pulses and draining fluid from the formation into the well, which increases the efficiency of well cleaning and reduces cost of work performed.

Description

The utility model relates to the oil industry and can be used as equipment for cleaning the bottomhole formation zone and borehole bottom from sludge and other hard to recover deposits, including in wells with low reservoir pressure and high injection rate.

A device for cleaning a well is known (patent RU No. 2068079, MKI E 21 B 37/00, 21/00, publ. Bull. No. 29 for 10/20/96), containing a hollow rod with an annular protrusion and a whipping valve mounted on it and a compression spring, a housing with a check valve connected to the shank and the packer, and the rod and shank are made with radial channels, shear and sealing elements.

The disadvantage of this device is the inability to achieve multiple pulses of depression, which reduces the efficiency of cleaning the bottom-hole zone of the formation, as well as the inability to destroy and remove slurry plugs from the bottom of the well.

The closest in technical essence is a device for cleaning wells (patent RU No. 2186947, MKI E 21 B 37/00, publ. Bull. No. 22 of 08/10/2002), containing a hollow rod with an annular protrusion and radial channels, in the original position overlapped by a sleeve, housing with a check valve connected to the shank, packer, knockdown valve and sealing elements.

The disadvantage of this device is its low reliability, since the personnel working with the device, in order to ensure the cyclical nature of the depressive effect, need to navigate in a few seconds with the estimated height of the pipe string and raise the pipe string to a predetermined height. Moreover, if the rise is less than the calculated value, then the depressive effect will not be interrupted, and if the rise of the pipe string is higher than the calculated value, the rod will exit

from the cone and the cessation of the depressive effect, since to displace the sleeve and open the holes, it is necessary that the rod re-enter the counter hole of the cone, which is practically impossible. In addition, the device does not allow to destroy sludge plugs at the bottom of the well.

The technical task of the utility model is to expand the functionality of the device due to the possibility of destruction and extraction of slurry plugs from the bottom, increasing the reliability of operations by simplifying operations performed on the well when creating a multi-pulse depressive effect on the bottom-hole zone of the well and the formation.

The specified technical problem is solved by the proposed device comprising a hollow rod connected with a pipe string with an annular protrusion and radial channels, a sleeve that covers the radial channels of the hollow rod in the initial position, a packer, a knock-off valve, a housing with a non-return valve and sealing elements.

What is new is that the casing is equipped with stops between which an annular protrusion of the hollow rod is placed, connected to the casing with the possibility of only axial movement relative to the casing, the sleeve is rigidly connected to the casing and is provided with radial channels that are aligned with the radial channels of the hollow rod only in the middle of its axial displacement relative to the casing, the packer, made in the form of a self-sealing cuff, is located above the casing and below the knockdown valve; Willow valves, and a working tip is installed under the check valve of the housing.

Figure 1 shows a longitudinal section of the device in its original position; figure 2 - cross section aa pairing of the upper part of the stem and the upper stop in figure 1; figure 3 - the device in the middle of the movement of the rod relative to the housing (in the working position); figure 4 - the device in the final position, when the annular protrusion of the rod interacts with the lower emphasis of the housing.

The device (see Fig. 1) comprises a hollow rod 2 connected to the pipe string 1 with an annular protrusion 3 and radial channels 4, a sleeve 5 overlapping the radial channels 4 of the hollow rod 2 in the initial position, the packer 6,

knock-off valve 7, the housing 8 with a check valve 9 and sealing elements 10, eliminating unauthorized fluid flow.

The housing 8 is equipped with stops 11 and 12, between which an annular protrusion 3 of the hollow rod 2 is placed. The hollow rod 2 is connected to the housing 8 with the possibility of axial movement without rotation relative to it, which is achieved by performing the outer section surface of the upper part 13 of the hollow rod 2 located above the annular the protrusion 3 and the mating inner surface of the cross section of the hole of the stop 11, for example, in the form of polyhedra (see Figure 2). The sleeve 5 (see Figure 1) is rigidly connected to the housing 8 and is equipped with radial channels 14 that are aligned with the radial channels 4 of the hollow rod 2 (see Figure 3) only in the middle of its axial movement relative to the housing 8. Packer 6 (see Figure 1), made in the form of a self-sealing cuff, is located above the body 8 and below the knocking valve 7. A drain valve 15 is placed in the lower part of the hollow stem 5, a drain valve 16 is placed in the upper part of the body 8 below the stop 12, and under the check valve 9 body 8 installed working tip 17.

The device operates as follows.

The device in its initial position on the pipe string 1 is lowered into the well 18, while the annular protrusion 3 of the hollow rod 2 interacts with the abutment 11 of the housing 8, the sleeve 5 overlaps the radial channels 4. The cavity 19 of the pipe string 1 is at atmospheric pressure and is a depression chamber. In this position, the device lowers to the bottom 20 of the well 18. The housing 8 with the working tip 17 abuts against the bottom 20, and the hollow rod 2 connected to the pipe string 1 continues to move downward relative to the housing 8 and the sleeve 5 rigidly connected to it. In the middle of the movement (see Figure 3) of the hollow rod 2 relative to the sleeve 5, the radial channels 4 of the hollow rod 2 are aligned with the radial channels 14 of the sleeve 5. In this case, the cavity 19 of the pipe string 1 communicates with the cavity 21 of the housing 8. There is a pulsed depressive effect on the bottom-hole zone 22 of the well 18 and ma (not shown) as the fluid column pressure in the well 18, a packer 6 takes disposed above the reservoir, and the pressure in the cavity 19 of the column pipe 1 is equal to atmospheric.

In this case, the sludge located at the bottom through the opened check valve 9 is carried away by a high-speed fluid flow into the cavity 21 of the housing 8.

With further movement (see Figure 4) of the hollow rod 2 down relative to the housing 8 to the stop 12, the radial channels 4 of the hollow rod 2 are again blocked by the sleeve 5. The cavity 19 of the pipe string 1 is cut off from the cavity 21 of the housing 8. The pulse of the depressive effect stops. The non-return valve 9 closes, preventing the exit of sludge from the cavity 21 of the housing 8. The annular protrusion 3 of the hollow rod 2 interacts with the abutment 12 of the housing 8, while the working tip 17 is introduced into the sludge plug (not shown) by the weight of the pipe string 1 and destroys it.

To create the next impulse of depressive effects, the pipe string 1 is raised. In this case, the hollow rod 2 connected to the pipe string 1 moves upward relative to the housing 8. The radial channels 4 of the hollow rod 2 are again aligned with the radial channels 14 of the sleeve 5 (see FIG. 3). Another depressive effect occurs on the bottom-hole zone 22 of the well 18 and the formation, and the particles of the collapsing sludge plug with a high-speed fluid flow through the opened check valve 9 are carried into the cavity 21 of the housing 8.

With further rise, the hollow rod 2 returns to its original position (see Figure 1) relative to the housing 8, the cavity 19 of the pipe string 1 is again cut off from the cavity 21 of the housing 8. The check valve 9 closes. The device is ready for the next pulse of depression.

The execution of the outer surface of the cross section of the upper part 13 of the hollow rod 2, located above the annular protrusion 3, and the internal surface of the cross section of the hole of the stop 11 in the form of a polyhedron mating with it (see Fig. 2) allows you to rotate the working tool by rotating the pipe string 1 at the mouth 17, which increases the rate of destruction of sludge plugs.

Further cycles are repeated.

A cyclic depressive effect on the bottom-hole zone of the formation and cleaning of the bottom of the well are carried out until the pressure in the pipe string is equal to the pressure under the packer. Sludge removed from the bottom of the well is

in the cavity 21 of the housing 8 and is held there by a closed check valve 2.

Before lifting the device (see Figure 1), a load (not shown) is dropped into the pipe string and the knock-off valve 7 is destroyed. Then the device is lifted.

When lifting the device, the liquid located in the annular space 23 above the packer 6 flows through the destroyed knockout valve 7 into the cavity 19 of the pipe string 1. The fluid pressure in the cavity 19 of the pipe string 1 will exceed the fluid pressure in the annular space 22 under the packer 6, while the drain open valves 15 and 16. The fluid from the cavity 19 of the pipe string 1 will flow into the cavity 22 of the well 18, and the sludge located in the cavity 21 of the housing 8 is removed to the surface.

During the lifting of the pipe string 1, the packer 6, made in the form of a self-sealing element, acts as a swab along the production casing of the well, gradually reducing the pressure in the bottom-hole zone of the well. The decrease in pressure leads to drainage of fluid from the formation into the well, which is an additional effect on the bottom-hole zone of the formation, increasing the efficiency of cleaning the bottom-hole zone of the formation.

The degree of depressive effect on the formation created by the device can be controlled by changing the distance of the location of the packer 6 on the pipe string 1 relative to the perforation interval. The closer the packer 6 is located to the perforation interval, the stronger the degree of depressive effect on the formation. Thus, depending on the properties and condition of the reservoirs of the wells, it is possible to individually select the most effective exposure regimen for each well.

The absence of shear elements reduces the time and laboriousness of preparing the device for operation, since there is no need to extract the remains of the destroyed elements, prepare holes and install new shear elements. Preparation for work consists in replacing the destroyed knockdown valve 7 and emptying the cavity 21 of the device body 8 from the sludge.

The design of the device allows for a single descent into the well to produce multiple pulsed depressive effects on the bottomhole

the zone of the well and reservoir and at the same time to destroy sludge plugs and clean the bottom of the sludge. Significantly simplified operations to create pulses of depressive effects, because for this it is only necessary to lower the device all the way to the bottom and raise it to a certain height, which reduces the complexity and facilitates the work.

Using the proposed device for cleaning a well allows one team of PRS for a single descent of the device to carry out a whole range of works: cleaning the bottom of the well, destroying and removing the slurry plug, cleaning the bottom-hole zone of the formation with depressive pulses and draining fluid from the formation into the well, which increases the efficiency of cleaning the well and reduces the cost of the work performed.

Claims (1)

A device for cleaning a well, comprising a hollow rod connected with a pipe string with an annular protrusion and radial channels, a sleeve overlapping the radial channels of the hollow rod in the initial position, a packer, a knockout valve, a body with a check valve and sealing elements, characterized in that the upper part of the body equipped with stops between which an annular protrusion of a hollow rod is placed, connected to the housing with the possibility of only axial movement relative to the housing, the sleeve is rigidly connected to the housing and provided with radial channels compatible with the radial channels of the hollow rod only in the middle of its axial movement relative to the body, the packer, made in the form of a self-sealing cuff, is located above the body and below the knockdown valve, drain valves are located in the lower part of the rod and in the upper part of the body, and under the check valve Housing mounted working tip.