RU2244099C1 - Device for cleaning bed and maintaining bed productiveness - Google Patents

Abstract

FIELD: oil extractive industry.

SUBSTANCE: device has pit-face cutting valve and mounting tool. Cutting valve has body, packer with check valve and perforated tail. Mounting tool has hollow rod, connected by shear elements to expanding cone of packer, lower and upper bodies. Lower body is provided with self-compacting collar, and upper - through tubing string of limited volume and sleeve is connected to drop valve cylinder. Valve rod is connected to rope, on which device is lowered into well. Hollow rod and tubing string form depression chamber being at constant atmospheric pressure. Rod has upper and lower shelves. On shelf of upper body expander of self-compacting collar having longitudinal grooves is mounted. After raising of mounting tool from well packer, body with tail and check valve remain in it. Then a pump is lowered into well.

EFFECT: lower costs.

3 dwg

Description

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

A device for cleaning a well is known, comprising a hollow rod with an annular protrusion and a knock-off valve and a compression spring mounted on it, a body with a check valve connected to the liner and the packer, the rod and liner being made with radial channels, shear and sealing elements (see patent RF №2068079, MKI 6 E 21 V 37/00, 21/00, 1996).

The disadvantages of the device:

- the complexity of the design and its insufficient rigidity;

- low efficiency of well cleaning, due to the fact that the communication of the sub-packer space with the internal space of the tubing (tubing) will occur before the final packing of the well is achieved, as a result of which the tubing will be filled with the borehole fluid, and not with the contamination of the formation and formation fluid;

- the device allows to achieve a temporary effect, because after it is lifted along with the packer, the contaminants in the wellbore will again enter the pores and channels of the reservoir and reduce its permeability.

The closest in technical essence to the proposed one is a device for cleaning a well, comprising a downhole cutter, comprising a body with a check valve connected to a perforated shank, and a packer consisting of a cuff and an expanding cone, a planting tool including a hollow stem, muffled from below, with radial the channels above the plugs, the expanding cone and the body are connected by shear elements, and the lower end of the hollow rod is mounted telescopically in the expanding cone (see RF patent No. 2186947, MKI 7 E 21 V 38/00, 2002).

The use of the known device leads to significant operational costs due to the fact that it is lowered into the well on the tubing, and this process is time-consuming and lengthy.

The objective of the invention is to provide a device having a relatively low operating costs.

This problem is solved by the proposed device, comprising a downhole cutter, comprising a housing with a check valve connected to a perforated shank and a packer consisting of a sleeve and an expansion cone, a landing tool including a hollow rod, muffled from below with radial channels above the plug, the expanding cone and the housing are connected shear elements, and the lower end of the hollow rod is mounted telescopically in the expansion cone.

New is that the landing tool is equipped with a lower body mounted telescopically on the stem and connected with shear elements with an expanding cone, in the outer groove of which a self-sealing cuff with a stop is installed along the perimeter, it is also equipped with an upper body connected to the hollow stem and tubing string of limited volume, on the ledge of which is fixedly installed extender self-sealing cuff with longitudinal grooves, and the tubing string through a sleeve connected to a cylinder of the relief valve, the stem of which, nabzhenny upper and lower ledges, is connected with the cylinder through the shear elements.

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

In Fig.2 - the same in a sealed state.

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

The device consists of two nodes: a bottomhole cutter and a landing tool.

The downhole shut-off device (Fig. 1) consists of a housing 1 with an inner ledge 2, on which a check valve 3, a perforated shank 4, a packer including a sleeve 5 and an expanding cone 6 connected to the housing 1 by shear elements 7 are installed.

The landing tool includes a hollow stem 8 with a plug 9 and radial channels 10. A lower housing 11 is telescopically mounted on the hollow stem 8, in the outer groove of which a self-sealing sleeve 12 with a stop 13 is installed around the perimeter. The upper end of the hollow stem 8 is connected to the upper housing 14, on ledge 15 which has an expander 16 for a self-sealing sleeve 12 with longitudinal grooves, preloaded by a nut 17. The upper housing 14 is connected to the tubing string 18, which consists of three to four pipes, which, in turn, is connected to the cylinder through a sleeve 19 m 20 of the relief valve 21, inside of which the rod 22 is installed with the lower 23 and upper 24 ledges, connected to the cylinder by shear elements 25.

The device is lowered into the well on a rope 26, which is attached to the stem 22. The mating surfaces of the parts are provided with o-rings 27.

Rod 8 with tubing 18 form a depression chamber 28, which is under atmospheric pressure. The length of the shank 4 is taken from the calculation so that its upper holes are at a distance of 5-10 m from the bottom of the reservoir, and the lower end of the cuff 5 is at a distance of 5-10 m from the roof of the reservoir.

The device operates as follows.

The device on the rope 26 is lowered into the well until it stops at the bottom and unloaded. In this case, the upper part of the planting tool with a hollow rod continues to move down until the lower end of the upper body 14 sits on the upper end of the stop 13, and the expander 16 enters the inside of the self-sealing collar 12. After that, the wellhead is sealed and inside the casing 29 excess pressure, under the influence of which shear elements 30 are destroyed. The landing tool lowers down, the end face 31 of the lower case 11 sits on the expansion cone 6, after which the medium is destroyed under the influence of the load knowing elements 7. The expanding cone 6 moves down, stretches and tightly presses the cuff 5 against the walls of the casing 29, thereby separating the downhole space from the reservoir.

Simultaneously with the expanding cone 6, the hollow rod 8 also moves downward, the radial holes 10 of which exit from the expanding cone during the sealing process (Fig. 2). At this moment, the inner space of the hollow rod 8 and tubing 18 are connected with the inner space under the packer. And since the pressure inside the rod and tubing is atmospheric, significant depression is created on the reservoir. Under the influence of the difference in pressure of pollution and sludge from the reservoir through the liner 4, the housing 1 and the radial channels 10 fall into the hollow rod 8 and then into the tubing 18.

After completion of the operation to clean the reservoir, the rope 26 is stretched, while the shear elements 25 of the valve 21 are destroyed, the rod 22 is lifted in the cylinder 20, the downhole space communicates with the space inside the device and the pressure is equalized. With a further tension of the rope, the upper part of the planting tool rises, so that the expander 16 disengages from the self-sealing cuff 12, after which the planting tool is lifted from the well. In the well remain a packer, a housing with a liner and a check valve (Fig.3).

Then a pump is lowered into the well and development and operation are carried out in the usual manner.

Due to the fact that the proposed device is lowered into the well on a rope, the need to use tubing to the entire depth of the well is eliminated, the process of lowering and raising the device is accelerated, which, ultimately, will save significant material resources.

Claims (1)

A device for cleaning and maintaining reservoir productivity, comprising a downhole cutter comprising a body with a non-return valve connected to a perforated shank, a packer consisting of a cuff and an expanding cone connected by shear elements to the body, and a planting tool including a hollow stem with radial plugged from the bottom with a plug channels above the plugs, the lower end mounted telescopically in the expanding cone, the tubing string (tubing) and the relief valve, characterized in that The first tool is equipped with a lower casing with an outer groove around the perimeter and an upper casing with a ledge, the tubing string has a limited volume, the relief valve is made in the form of a cylinder connected by means of a coupling with a tubing string of a limited volume, and a rod with upper and lower ledges connected to the cylinder through shear elements and made with the possibility of fastening to the rope, while the lower case has a self-sealing collar installed in the outer groove along the perimeter, mounted telescopically on the hollow stem and connected to expands it shear cone elements, the upper housing is coupled with the hollow rod and the tubing limited volume, and on the ledge of the upper housing rigidly mounted dilator having longitudinal slots self-sealing cuff.

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