SU1550088A1 - Device for repairing leaky pipe string in well - Google Patents

Abstract

The invention relates to the oil and gas industry. The goal is to simplify the design of the device. For this purpose, the delivery unit of the sealing material 4 to the leakage place is made in the form of a chamber with powder charge 5 placed in the lower part of the body 1 of the chamber. The upper wall of the chamber is formed by a floating annular piston 6 and a school type igniter. The latter has an initiator 8 located in the hole of the piston 6. The igniter of the school type has a rod 7 mounted concentrically in the housing 1. The upper end of the rod 7 is located above the housing and the diameter of the rod is less than the diameter of the hole of the piston 6. With the vertical movement of the piston 6, the hole for the initiator 8 fits onto the rod 7, as a result of which the rod 7 does not impede the movement of the piston 6. Once in the pores and cracks of the annulus, the molten sealing material cools down, again acquiring viscosity. At the same time, it reliably isolates pores and cracks from falling into them through the leakage of the reagent column. 1 hp f-ly, 1 ill.

Description

The invention relates to the oil and gas industry and can be used to locate leaks in casing strings and eliminate leaks.

The purpose of the invention is to simplify the design of the device.

The drawing shows a device for repairing a pipe string in a well.

The device consists of a hollow body 1 made of upper and lower cups placed in the upper part of the body of the sealing element 2 with radial openings 3, which can be made, for example, in the form of slots arranged at least in two rows to close the sealing perimeter element. Holes 3 provide a change in the direction of flow, create the necessary pressure drop to stop the device and allow to eliminate casing leakage. In the cavity of the housing 1 there is a low-melting sealing material 4 (for example, paraffin) and its delivery unit to the leakage place, made in the form of a chamber with powder charge 5 with a phlegmatizer located in the lower part of the housing body, the upper wall of which is formed by a floating annular piston 6, and igniter type of school. The igniter is made in the form of a rod 7 concentrically mounted in the body, the upper part of which is located above the body and the diameter is smaller than the diameter of the aperture of the annular floating piston 6. The igniter also contains

the initiator 8, located in the hole of the annular floating piston 6, the stop 9 and the spring 10 installed in the housing. To prevent

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sticking to the rod 7 of the low-melting sealing material the rod has a sleeve 11 made of readily destructive material, such as cardboard, concentrically placed on its surface.

The upper part of the stem 7 is connected with the device delivery device to the well — a cable 12. There are openings 13 with check valves in the upper part of the body, and a load 14 is located in the lower part. The device is placed in the casing 15, which has leakage into the annulus 16, and connected to the surface of the cable 17, on which set the detonating sleeve 18 with a diagonal cut under the cable 17.

The device works as follows.

The device is lowered into the casing 15 at a speed equal to the speed of the fluid pumped by the pump (not shown). When the device reaches the level of the leak, the fluid moves through the holes 13 and through the hole 3 combined with the leakage goes into the annular space 16. When the hole 3 coincides with the leakage place, the pressure drop increases, which affects the inner surface of the sealing element 2 and deforms the latter , presses it to the side surface of the casing 15, thereby stopping the further movement of the device.

When the movement is stopped during the injection process, the cable 12 is slightly tensioned (with a force of lesser rigidity of the spring 10) and the sleeve 18 is put on the cable 12 through the diagonal cut 17 and lowered into the casing 15. Impact on the rod 7,

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the sleeve 18 strikes the initiator 8, as a result of which the powder charge 5 ignites and the combustion process begins, accompanied by gas evolution, an increase in temperature and pressure. In this case, under the action of heat, the low-melting sealing material dissolves, acquiring low viscosity, and under the action of gas pressure, the annular floating piston 6 moves upwards, removing the sleeve 11 and squeezing out the molten sealing material through the holes 3 and the defect of the casing 15 into the annulus 16. the vertical movement of the annular floating piston 6 a hole under the initiator 8 is mounted on the rod 7 (the spent initiator falls off)

as a result, the rod 7 does not interfere with the movement of the annular floating piston 6. The straightened sealing material cools into the pores and cracks of the annular space 16, again acquires viscosity (hardens), while it reliably isolates the pores and cracks of the annular space 16 from falling in them through the leakage of the column 15 of the reagent.

Claims (2)

1. A device for the repair of an untight pipe string in a well, including 6 the piston A hollow body with a means of transporting it in a well, a sealing element placed on the body in its upper part, a low-melting sealing material located in the body cavity and its delivery unit to the cross of leakage, so that the delivery unit of the low-melting sealing material to the place of leakage is made in the form of a chamber with a powder charge placed in the lower part of the housing body, the upper wall of which is formed by a floating annular piston And igniter nakolnogo type initiator which is placed in the bore of the annular floating piston and rod type igniter nakolnogo concentrically mounted in the housing, and its upper end is positioned above the body and the stem diameter smaller than the diameter of the annular openings swim the piston 2. The device according to claim 1, characterized in that the stock-type igniter rod has an easily-destroyed sleeve, concentrically placed on the outer surface of the stem.