RU2154149C2 - Device for installation of patch in casing string - Google Patents

Abstract

FIELD: equipment for well repairs, particularly, devices for installation of corrugated metal patches for reconditioning of tightness of casing strings of oil, water and gas wells. SUBSTANCE: device consists of circulation valve, movable force pusher including cylinder, piston and hollow rod. Located on core with clamping stops is patch between mandrelling head and stop. Lower stop is made in the form of cone with slots in which patch stopping plates are located on hinges with spring-loaded lugs. In operating state, plates assume position perpendicular to patch generating lines and coming in contact by its one end with patch lower end and by its other end with steps of slots of conical stop. Building up of excessive pressure in system results in cycle of forcing of mandrelling head through patch. Cycles are repeated until mandrelling head comes out of patch. EFFECT: higher reliability, servicing efficiency factor and serviceability of device. 4 dwg

Description

 The invention relates to techniques for underground well repair, to devices for installing corrugated metal adhesives to restore the tightness of casing pipes of oil, water and gas wells.

 A device is known, consisting of a hollow rod, at the lower end of which is placed a dormant hydraulic head, at the upper end - an anchor, and between them on the rod between the stops there is a patch (1).

 This device has the disadvantage that the expanding head, when expanding the patch to mate with the casing, is pulled through the patch from bottom to top by axial load on the tool (tubing). In this case, the tubing is subjected to a double load: hydraulic pressure and axial tension, which does not exclude the rupture of the pipes during tension during installation of the patch at great depths. In addition, jamming of the mandrel head in the patch is not excluded in cases when a solid body (cement stone, rock, metal objects) between the casing and the patch in the process of expansion expands from the defect or from the mouth.

 As a result of these shortcomings, casing sealing is not achieved and, moreover, an emergency situation is created: the head of the collar at the left lapel falls to the bottom, the unexpanded upper part of the patch is out of phase, fishing operations and additional work to restore the sealing are carried out. Cases of decommissioning of the well are not excluded.

 The closest technical solution to the proposed invention is a device for installing the patch in the casing (2).

 This device contains a circulation valve, a movable hydraulic power pusher consisting of a cylinder, a piston and a hollow rod, a core with collet stops and a patch placed on it between the mandrel head and the stop.

 The known device is unreliable in operation, which reduces the success rate of repair and operability of the device.

 The task of the invention is to increase the reliability, success rate of repair and operability of the device.

 The problem is solved in that in a device for installing adhesives in a casing pipe containing a circulation valve, a movable hydraulic power pusher consisting of a cylinder, a piston and a hollow rod, a core with collet stops, and a patch placed on it between the cutting head and the stop, lower the emphasis is made in the form of a cone with grooves in which the thrust plates of the patch are located on hinges with spring-loaded petals, while in working condition they occupy a position perpendicular to the patch forming with one end with its lower end, and with the other with the steps of the grooves of the conical stop.

Figure 1 shows a General view of the device assembly with a patch, lowered into the well to the place of casing pipe defect;
figure 2 - lower conical emphasis of the patch with thrust plates in the working position;
figure 3 - lower conical emphasis of the patch with thrust plates in the transport position;
in FIG. 4 - lower conical emphasis, performing the role of expanding the patch from the bottom up when lifting the tool.

 The device contains a circulation valve 1; movable hydraulic power pusher 2, consisting of a cylinder 3, a piston 4 and a hollow rod 5 with a hole 6; movable mandrel hydraulic head 7; hollow core 8 with collet stops 9 fixed thereon; conical emphasis 10, consisting of a cone 11 with grooves 12, spring tabs 13 and thrust plates 14.

 The device operates as follows.

 The device assembly with the patch 15 is lowered into the well on pipes (tubing, drill) 16 to the place of the defect 17 of the casing 18. The middle of the patch 15 is oriented to the defect 17. An excessive hydraulic pressure is created in the system. The liquid under pressure enters the power pusher 2 and through the hole 6 of the rod 5 creates a force on the pistons 4, driving the cylinders 3, connected to a movable hydraulic head dormant 7.

 Pressing the patch 15 to the inner wall of the casing 18 to close the defect 17 is carried out by pushing the head of the head 7 through the patch 15 with a power pusher 2 on the length of the working stroke L from top to bottom.

 At the end of the first pass, the plunger head 7 of the working stroke L relieves the hydraulic pressure in the system, the power pusher 2 is deposited (charged) by lowering the pipes 16 by the size of the working stroke L. In this case, the next collet stop 9 leaves the plaster and contacts its end with its ledges, acting as an intermediate stop. At the same time, the thrust plates 14 of the conical stop 10, having freed themselves from contact with the lower end of the patch 15, automatically, under the action of the spring lobes 13, occupy their transport position in the grooves 12 of the cone 11. After the plunger 2 is deposited by the working stroke L, hydraulic pressure is created in the system and the process is repeated punching the mandrel head in the patch.

 So the cycles of forcing the mandrel head through the patch are repeated until the head exits the patch.

 In the event of a failure in the operation of the power follower 2 or other malfunctions, the continuation of the installation of the patch 15 in the casing 18 is continued due to the presence of a conical stop 10 in the device, which with its cone-punch 11 expands the remaining part of the patch from the bottom up when lifting the tool. In this case, the pressure in the system is relieved. Then, under pressure, the turning head 7 is pulled through the patch (calibration) both from top to bottom by the weight of the tool and from bottom to top by lifting the tool. This operation is repeated several times if necessary.

 If the patch calibration fails due to the lack of preservation of excess pressure in the system, the device is removed to the surface, its problems are eliminated and the patch calibration operation is repeated.

 The liquid is filled with pipes during the descent and its discharge during the ascent through the circulation valve 1.

 From premature expansion of the patch when it is lowered into the well, the head of the device is equipped with a locking shear pin.

 Thrust plates, which play the role of an abutment of the patch, are in the perpendicular position only at the first stage of expansion of the patch, then when the force pusher is deposited, they automatically occupy a position in the grooves of the cone under the action of spring-loaded petals. This allows you to, if necessary, pull the cone through the patch by lifting the tool from the bottom up, then carry out further operations to calibrate the patch until it is fully and properly mated with the casing. In this case, there is no need to have shear pins (left lapels) and to leave any elements of the device in the well in emergency situations.

The proposed device in comparison with the existing has the following advantages:
- increases the success rate of repairs;
- excludes emergency work in the well during the installation of the patch in case of failure of the device;
- increases the efficiency of the device;
- eliminates the abandonment of the elements of the device in the well.

Sources of information:
1. SU 562636, publ. 1977

 2. RU 2026956, publ. 1995 year

Claims (1)

 A device for installing a patch in a casing pipe, containing a circulation valve, a movable hydraulic power pusher consisting of a cylinder, a piston and a hollow rod, a core with collet stops and a patch placed on it between the head and the stop, characterized in that the lower stop is made in the form cones with grooves in which thrust plates of the patch are located on hinges with spring-loaded petals, while in working condition they occupy a position perpendicular to the patch forming, contacting one con tsom with its lower end, and another - with the steps of the grooves of the conical emphasis.

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