RU2258796C1 - Casing pipe repair device - Google Patents

Abstract

FIELD: oil production industry, particularly means to provide recovery of casing pipe air-tightness.

SUBSTANCE: device has connection pipe rigidly connected to pipe string and expanding cone. Connection pipe is provided with expanded parts located from top and bottom ends thereof. Expanding cone may press connection pipe to casing pipe and has diameter of the base less than inner diameter of the connection pipe installed in its working position. Circulation valve is arranged in lower expanded part and opens flow in top-bottom direction. Valve body is air-tightly connected to the connection pipe with shear screws. Expanding cone is inserted in upper expanded part and has seat for droppable valve. Connected to expandable cone is collar self-sealing in top-down direction. Connection pipe plasticity exceeds that of pipe string. Elastic shell is connected to outer connection pipe surface.

EFFECT: increased isolation of damaged part and reduced material consumption.

3 cl, 3 dwg

Description

The invention relates to the oil industry, and in particular to means for restoring the tightness of casing strings.

It is known "Device for installing adhesives in the casing" (patent RU No. 2154149, E 21 B 29/10, publ. BI No. 22 of 08/10/2000), containing a circular valve, a movable hydraulic power pusher, consisting of a cylinder, a piston and a hollow stem, a core with collet stops and a patch placed on it between the head of the head and the stop, while the bottom stop is made in the form of a cone with grooves in which the stop plates of the patch are located on hinges with spring-loaded petals, while in working condition they occupy the position perpendicular forming the patch, in contact with one end with its lower end, and with the other with the feet of the grooves of the conical stop.

The disadvantages of this device are the complexity of the design and assembly before launching, since the thrust is located inside the patch, if it is necessary to overlap large sections with a length of more than one pipe, the patch is assembled by welding at the wellhead, all this requires the use of highly qualified specialists and time-consuming preparation of equipment to work, and when flailing the patch along the entire length, great efforts of flailing, all this together require large material costs, and Reliability of isolation due to the lack of insulating material to compensate for irregularities in the casing.

The closest in technical essence and the achieved result is a "Device for repairing a casing string" (ed. St. SU No. 1627663, E 21 V 29/10, publ. BI No. 6 of 02.15.91), including an expanding cone with a drive its movement and a nozzle located on the expanding cone, while the expanding cone is made with an angle at the apex of 25-60 ° with a base diameter less than the inner diameter of the nozzle in the working position by no more than an amount determined in accordance with the following relationship:

где

Where

Δd is the increase in the inner diameter of the pipe in the working position over the diameter of the base of the expanding cone, m;

d is the diameter of the base of the expanding cone, m;

α is the angle at the apex of the expanding cone, rad.

The disadvantages of this device are the complexity of the design and assembly before launching, since the thrust is located inside the patch, if it is necessary to overlap large sections with a length of more than one pipe, the patch is assembled by welding at the wellhead, all this requires the use of highly qualified specialists and time-consuming preparation of equipment to work, and when flailing the patch along the entire length, great efforts of flailing, all this together require large material costs, and the reliability of the insulation due to the lack of insulating material, compensating for irregularities in the casing, the possibility of emergency situations in case of jamming of the cone in the pipe.

The technical task of the invention is to simplify the design by reducing the parts lowered into the well, reducing the landing force when isolating large intervals of damage to the casing string by using the bursting force of the in-pipe pressure and reducing the expansion distance of the pipe, improving the reliability of isolation, eliminating emergency situations and welding work wellhead and, as a result, reduction of material costs for assembly, descent and landing.

The technical problem is solved by a device for repairing a casing string, consisting of a pipe extending a cone with an angle at the apex sufficient to tightly press the pipe against the walls of the casing, and with a base diameter smaller than the internal diameter of the pipe in the working position.

What is new is that the pipe is rigidly attached to the pipe string on top, and is equipped with extensions on the top and bottom, while a circulation valve is installed in the lower extension, passing from bottom to top, the casing of which is tightly attached to the pipe with shear screws, and on the outer surface of the pipe there is an elastic shell and an expansion cone having an opening with a seat for a valve discharged from the mouth is inserted into the upper extension of the nozzle, while a self-sealing top end is rigidly attached to the expanding cone of the cuff, the tube more ductile than the tubing string.

Also new is the fact that the pipe between the upper and lower extensions is equipped with longitudinal corrugations.

Also new is the fact that the expansion cone and the circulation valve housing are made of easily drilled materials.

Analysis of the known similar solutions allows us to conclude that they lack features similar to the distinctive features in the claimed device, i.e. on the compliance of the proposed solutions to the criteria of "novelty" and "inventive step".

Figure 1 shows a longitudinal section of the device.

Figure 2 shows a cross section aa of the device.

Figure 3 shows a longitudinal section of the device during isolation.

A device for repairing a casing string 1 (see FIG. 1), consisting of a nozzle 2, an expanding cone 3 with an angle of 4 (see FIG. 3) with an apex sufficient to tightly press the nozzle 2 against the walls of the casing 1, and with a diameter base 5, smaller than the inner diameter 6 of the pipe 2 in the working position. On top of the pipe 2 is rigidly attached to the pipe string 7, and on top and bottom it is equipped with extensions 8 and 9, while in the lower extension 9 is installed a circulation valve 10, passing from bottom to top, the housing 11 of which is hermetically attached to the pipe 2 with shear screws 12. On the outer surface 13 of the pipe 2, an elastic shell 14 is located, and in the upper extension 8 of the pipe 2 an expansion cone 3 is inserted, having an opening 15 with a seat 16 for a valve 17 discharged from the mouth 17. A self-sealing top-down cuff 18 is rigidly attached to the expansion cone 3 The pipe 2 is more plastic than the pipe string 7.

The pipe 2 between the upper and lower extensions 8 and 9 may be provided with longitudinal corrugations 19 (see Figure 2) to facilitate expansion of the pipe.

The expanding cone 3 (see Figure 1) and the casing 11 of the circulation valve 10 can be made of easily drilled materials, if necessary, further drilling.

The device operates as follows.

A device for repairing the casing string 1 assembly (see FIG. 1) on the pipe string 7 is lowered into the well below the violations of the casing string 1. In this case, the pipe string 7 is filled through the circulation valve 10, through which, if necessary, the well is flushed, lower expansion 9 does not allow the elastic shell 14 to be washed off and peeled off. After that, the pipe string 7 is fixed and sealed at the mouth (not shown in Fig.) And an overpressure is created inside, which only pipe 2 distributes beforehand, approximating the cross section to the inner the diameter of the casing 1, since the pipe 2 is more ductile than the pipe string 7. If the pipe 2 is equipped with longitudinal corrugations 19 (see Figure 2), then they are straightened under pressure, approaching the cross section of the inner diameter of the casing 1. The excess pressure is raised in the pipe string 7 until the shear screws 12 are destroyed and the circulation valve 10, which falls to the bottom of the well, is released from the pipe 2 of the body 11 (in FIG. not shown). Then, a valve 17 (for example, a ball) is dropped from the mouth, which sits in the seat 16 of the expansion cone 3, blocking the hole 15. Then, overpressure is again created in the pipe string 7, as a result of the expansion cone 3 (see Figure 3) out of the expansion 8 and moves down, booster pipe 2 after expansion by pressure. Due to the angle 4 at the apex of the expanding cone 3, the nozzle 2 is finally firmly pressed against the casing 1, and the elastic shell 14 located on the outer surface 13 of the nozzle 2 fills all the irregularities of the casing 1, excluding fluid overflows from the disturbances 20 into the pipe string 7. From - due to the fact that the diameter of the base 5 of the expanding cone 3 is less than the inner diameter 6 of the pipe 2 in the working position, the inner diameter 21 of the pipe string 7 is smaller than the internal diameter 6 of the pipe 2 in the working position, which subsequently does not udnit descent necessary equipment (in FIG. not shown) for subsequent operation of the well. The self-sealing cuff 18, mounted on the expansion cone 3, eliminates unauthorized flows from top to bottom when the expansion cone 3 is moved due to overpressure in the pipe string 7. After passage of the pipe 2, the expansion cone 3 with the self-sealing cuff 18 and valve 17 fall to the bottom. Work to restore the tightness of the casing 1 is completed.

In cases where further deepening of the well is necessary, cutting of additional boreholes or jamming of the expansion cone 3 in the pipe 2 is possible (for example, in cases of critical violation of the geometry of the inner section of the casing 1), the housing 11 of the circulation valve 10 and the expansion cone 3 are made of easily drilled materials (e.g. cast iron), excluding emergency situations.

The use of the proposed device when isolating large intervals of damage to the casing string allows to increase the reliability of isolation, to eliminate emergency situations and welding work at the wellhead, to reduce material costs for assembly, descent and landing by simplifying the design, reducing parts lowered into the well, and reducing landing forces when isolation, reducing the expansion distance of the pipe, sufficient for insulation.

Claims (3)

1. A device for repairing a casing string, consisting of a nozzle, an expanding cone, made with the possibility of pressing the nozzle to the casing and with a base diameter smaller than the inner diameter of the nozzle in its working position, characterized in that the nozzle is rigidly attached to the pipe string from above, and above and below it is equipped with extensions, while a circulation valve is installed in the lower extension, passing from bottom to top, the body of which is hermetically attached to the pipe with shear screws, the expansion cone is inserted into the top It nozzle extension and adapted to seat at the mouth of the valve with the disposable, with the expanding cone fixedly secured downward self-sealing cuff tube made more ductile than the tubing string and the outer surface of the shell is elastic. 2. The device according to claim 1, characterized in that the pipe between the upper and lower extensions is equipped with longitudinal corrugations. 3. The device according to claim 1 or 2, characterized in that the expanding cone and the body of the circulation valve are made of easily drilled materials.

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