RU2289679C1 - Device for cleaning wells - Google Patents

Abstract

FIELD: oil extractive industry, possible use as equipment for cleaning face-adjacent zone of bed and well bottom from slurry, sand, paraffin, tar and other sedimentations hard to remove by washing.

SUBSTANCE: device contains face cutter, including elastic collar and expanding cone, shaft with conic section on top, provided with profiled groove on external surface, and also a shell mounted on the shaft together with guiding pin, spring-loaded sockets, expanding cone and shaft, which are connected by shear elements, check valve, mounting tool, including body with transverse wall and lower-positioned channels. In accordance to invention, check valve of face cutter is mounted in valve box with longitudinal slits and circular recess in external upper part. Valve box is hermetically inserted into expanding cone. Radial channels in the body of mounting tool are positioned at same level with saddle of check valve. In transverse wall, locking valve is positioned, made in form of two interconnected cylindrical rods of larger diameter in upper part and lesser - in lower part with supporting head on top and supporting transverse limiter at the bottom. Body of mounting tool and expanding cone are connected by shear elements. Shell of face cutter shaft is provided with spring localizers. Sockets are held on levers connected to the shell.

EFFECT: high serviceability, simple construction with low metal costs.

4 dwg

Description

The invention relates to the oil industry and can be used as equipment for cleaning the bottom-hole zone of the formation and the bottom of the well from sludge, sand, paraffin, resins and other deposits difficult to remove by washing.

A device for cleaning a well is known, consisting of a hollow rod made with two rows of radial channels separated by a blank transverse partition and in the initial position blocked by a movable spring-loaded sleeve with a cylindrical selection inside. The rod is connected - with the expansion cone of the packer. The housing has a check valve and a shank and is connected to the expansion cone of the packer. The hollow stem is equipped with a whipping valve (RF Patent No. 2186947, IPC 7 E 21 V 37/00, 2002).

The closest in technical essence to the proposed one is a device for cleaning a well, comprising a downhole cutter, including an elastic cuff and an expanding cone, a trunk with a conical section at the top, equipped with a figured groove on the outer surface with longitudinal short and long sections, as well as a clip with a guide pin, the free end of which is placed in a curly groove, and spring-loaded slips, an expanding cone and the barrel are connected by shear elements and a check valve, a landing valve trument comprising a body with a transverse partition disposed below and radial channels (utility model patent №37142, IPC 7 E 21 B 37/00, 2004 YG).

Devices, both by analogy and by prototype, have low working capacity, due to the fact that dirt will accumulate in the area of the check valve above and below it during the cleaning process, as a result of which it will be leaky during subsequent muffling. In addition, in the process of implosion in the presence of large pieces of mud and sludge from the formation, the labyrinth channel formed by radial channels in the rod and a cylindrical sample in the movable sleeve may clog. The devices are structurally complex and metal-intensive. The presence of a long shank in the analogue will lead to the fact that the sand washed out of the reservoir will fill the shank and will not allow to remove the cutter from the well in the future. In this case, it is impossible to carry out operations related to the injection of fluids into the reservoir.

The technical task of the invention is the creation of a device for cleaning wells with high efficiency, simple in design and low metal consumption.

The technical problem is solved by the proposed device for cleaning a well, comprising a downhole cutter, including an elastic cuff and an expanding cone of the barrel with a tapered section at the top, equipped with a figured groove on the outer surface with longitudinal short and long sections, as well as a clip with a guide pin mounted on the barrel, free end which is placed in a figured groove, spring-loaded slips, an expanding cone and a barrel, which are connected by shear elements, a check valve, a landing tool, including Corps with a transverse bulkhead and located below the radial channels.

New is that the downhole check valve is installed in a valve box with longitudinal cuts and an annular sample from the top above, and the valve box is hermetically inserted into the expansion cone with the possibility of forced extraction, and the radial channels in the landing tool body are flush with the check valve seat ; in the transverse baffle there is a shut-off valve made in the form of two connected cylindrical rods of a larger diameter in the upper part and a smaller one in the lower part with a support head at the top and a supporting transverse stop at the bottom, fixed in the initial position by a shear element and interacting with the valve in the working position downhole check valve box; the landing tool body and the expanding cone are connected by shear elements; the barrel holder of the bottomhole cutter is equipped with spring centralizers, and the slips are mounted on levers associated with the holder.

Figure 1 - shows the proposed device in longitudinal section, lowered into the well.

Figure 2 is the same at the time of cleaning the well.

Figure 3 - downhole cutter in the well after lifting the landing tool.

Figure 4 is a scan of a shaped groove on the barrel of a face cutter.

The device consists of a downhole shut-off device (Fig. 1), which includes an elastic cuff 1 mounted on an expansion cone 2, which is connected by shear elements 3 to the barrel 4 with a conical section 5 provided with a figured groove 6 (Fig. 4) on the outer surface with a short 7 and 8 long sections. On the barrel 4 (FIG. 1), a ferrule 9 is installed with a guide pin 10, the free end of which is located in the figured groove 6. Spring ferrules 11 are mounted on the ferrule 9, and above them are the clips 12 on the levers 13 connected by the ferrule 9. The reverse clan 14 the bottom hole cutter is installed in the valve box 15 with the longitudinal slots 16 and the annular selection 17 from the outside at the top. The valve box 15 is hermetically inserted into the expansion cone 2 with the possibility of forced extraction.

A housing 19 of a landing tool is connected to the upper part of the expanding cone 2 by shear elements 18, inside of which there is a transverse partition 20 with a shut-off valve 21 made in the form of two connected cylindrical rods of a larger diameter 22 in the upper part and a smaller 23 in the lower part with a support the head 24 at the top and the supporting transverse stop 25 at the bottom, in the initial position, fixed by a shear element 26 and interacting in the working position with the valve box 15 of the check valve 14 of the bottomhole tsekatelya. In the lower part of the housing 19 at the level of the seat of the check valve 14 there are radial channels 27, the purpose of which is to facilitate the flushing of this valve. The mating surfaces of the parts are provided with o-rings 28. The housing 19 with the tubing string 29 form a depression chamber 30 under atmospheric pressure. Inside the bottom pipe of the tubing string 29 is a knockdown valve 31.

The device operates as follows.

The device on the tubing string 29 is lowered into the well so that the slips 12, and therefore the elastic sleeve 1, are higher than the perforated holes of the reservoir, and the guide pin 10 is in the position shown in FIG. 4. Then the device is lifted by about 1 meter and lowered again, as a result, the guide pin 10 moves to a long section of the figured groove 6, and the conical section 5 (Fig. 1) of the barrel 4 runs into the slots 12, which come into contact with the casing 32 and the bottom hole cutter is fixed relative to it. The tubing string 29 is unloaded, the shear elements 3 are destroyed and the expanding cone 2 is lowered, stretches and presses the elastic sleeve 1 against the walls of the casing 32, thereby separating the downhole space. With further unloading of the tubing, the shear elements 18 are destroyed, and the box 15 comes into contact with the shut-off valve 21 and lifts it until the transverse stop 25 contacts the transverse baffle 20. As a result, the inner space of the housing 19 and the depression chamber 30 of the tubing string 29 are connected with the space wells under the bottomhole cutter. And since the pressure inside the tubing string 29 is atmospheric, a significant depression is created on the formation. Under the influence of the difference in the pressure of contamination and sludge from the reservoir from the bottom and from the walls of the well through the bore 4, cone 2, longitudinal grooves 16 of the check valve 14, the hole 33 in the transverse partition 20 fall into the upper part of the housing 19 of the planting tool and then into the tubing string 29.

To avoid spontaneous removal of the valve box 15 from the expansion cone 2, they are fixed relative to each other by a locking mechanism 34 (for example, a spring ring), which opens when the calculated load is exceeded, which is higher than the load acting on the valve box 15 when creating a depression. After a certain period of time (this time for each well and each formation is different and depends on the reservoir pressure, porosity, permeability and degree of contamination of the formation, it is determined experimentally). The tubing 29 with the planting tool is raised to the surface, while the valve 21 is closed, so that all contaminants from the well will be inside the tubing 29. The downhole cutter remains in the well.

To drain the fluid from the tubing 29 before lifting into the string of tubing 29 dump the load (in Fig. Not shown) and destroy the knockdown valve 31.

Depression on the formation can be controlled by pouring the calculated volume of fluid into the tubing. Then, a pump is lowered into the well (not shown in figures 1, 2, 3 and 4) and development and operation are carried out in the usual manner.

If it is necessary to pump the process fluid into the formation located under the bottomhole cutter, a pump is removed from the well and an outer tube (not shown in Fig.) Is lowered, which grasps valve box 15 by ring sample 17 and removes valve box 15 with check valve 14 from the expansion cone 2, overcoming the force of the locking mechanism 34 (see figure 3). Then you can carry out any technological operations with the reservoir. For further operation of the reservoir, the valve box 15 with the check valve 14 is installed in the expansion cone 2, the pump is lowered and further development is carried out.

The proposed device is simpler in design than the known ones, and, therefore, less metal-intensive and more efficient and functional, since the check valve in the bottomhole cutter is located in its upper part, which prevents clogging of the cutter with dirt and sludge when cleaning the reservoir, and its valve box made extractable, which allows for the injection of process fluids into the reservoir. A positive role is also played by the fact that there are no labyrinth zones in the downhole cutter and in the planting tool along the path of pollution and sludge movement.

Claims (1)

A device for cleaning a well, comprising a downhole cutter comprising an elastic cuff and an expanding cone, a trunk with a conical section at the top, provided with a figured groove on the outer surface with longitudinal short and long sections, and also a clip mounted on the barrel with a guide pin, the free end of which is placed in a figured groove, spring-loaded slips, an expanding cone and a barrel that are connected by shear elements, a check valve, a landing tool, including a housing with a transverse partition and below by positioned channels, characterized in that the downhole check valve is installed in a valve box with longitudinal cuts and an annular sample from the top upward, and the valve box is hermetically inserted into the expansion cone with the possibility of forced extraction, the radial channels in the landing tool housing being flush with the seat check valve; in the transverse baffle there is a shut-off valve made in the form of two connected cylindrical rods of a larger diameter in the upper part and a smaller one in the lower part with a support head at the top and a supporting transverse stop at the bottom, fixed in the initial position by a shear element and interacting with the valve in working position downhole check valve box; the landing tool body and the expanding cone are connected by shear elements; the barrel holder of the bottomhole cutter is equipped with spring centralizers, and the slips are mounted on levers associated with the holder.

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