RU2351743C1 - Pipe string holder - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil and gas industry and can be implemented for well casing and additional suspended strings in wells with defects of leakproofness of production well and also for sealing tubular space. The holder contains a case, and a cylinder bushing installed therein, designed to axial displacement and divided with a horizontal partition. At the lower end of the bushing pushers are assembled resting on the end of the piston located above a telescopic cone and a telescopic collet with die-heads. The invention facilitates performing two functions: sealing tube space and suspending lowered string on holder at repair works allowing lowering sunk string of smaller diameter. There is achieved increased reliability of device due to cylinder bushing with exterior diameter equal to diameter of tube space.

EFFECT: increased reliability of device due to cylinder bushing with exterior diameter equal to diameter of tube space.

2 dwg

Description

The invention relates to the oil and gas industry during the attachment of wells and can be used for lowering and attaching additional suspension columns in previously drilled wells with violations of the tightness of the production string. The device is designed to seal the pipe space and hold the hanging casing in the required interval without unloading the face or cement bridge.

It is known "Device for suspension of countersunk casing strings", SU No. 1578316, ЕВВ 33/14, 43/10, dated 04.07.88, publ. 07/15/90, comprising a housing with through-cuts and a bearing barrel with through-cuts. The latter are located opposite the through slots of the housing. A movable sleeve is mounted on the carrier barrel. The device also comprises a disconnect assembly with a left nut. On the housing are dies associated with a sleeve having a groove, a spring preloaded and a fixed movable sleeve. To keep the dies in the initial position, a lock is located in the through-cuts of the housing in the bore of the sleeve. The lock is made in the form of levers placed on the axes in the slots of the bearing barrel.

The movable sleeve has pins included in the through-cuts of the bearing barrel, interacting with the lock levers when it is triggered. To suspend a countersunk column, you must move the device down. In this case, the dies cut into the inner surface of the pipe of the intermediate column, and the mass of the countersunk column is transferred from the coupling to the housing, the dies and the intermediate column. The invention provides for the fastening of deep wells in small annular gaps, the management of technological operations when turning off the lock, cementing the secret column and packing.

The closest in technical essence is the "Device for suspension and sealing a casing collar" according to patent RU No. 2206713 C1, E21 B33 / 14, E21B 17/06, from 16.10.2001, publ. 2003.06.20, comprising a hollow housing, a piston-piston assembly and a pressure-tight assembly. The piston piston assembly contains a hollow piston. The hollow piston is installed in the casing and is connected by a collet with wedge-shaped dies. Wedge-shaped dies are arranged to move along a cone-shaped supporting surface. The rectangular protrusion of the hollow body of the sealing-pressing unit has a cylindrical groove having a slope towards the base of the groove to its outer side surface.

Both the analog and the prototype, with large zenith angles of the wellbore due to the insignificant area of the piston acting on the cone, it is difficult to advance the wedge-shaped dies with teeth along the conical surface into the gap between the device body and the inner surface of the production string.

The objective of the proposed technical solution is to create a device that simultaneously performs two functions: sealing the tube space and suspension of the descent column on the holder, with increasing the reliability of the device.

The problem is solved due to the fact that the holder of the pipe string contains a housing with a conical groove for the retaining ring and a casing and a barrel connected inseparably to the housing, while a cylindrical sleeve with an external diameter equal to the diameter of the pipe space is installed with axial movement in which there is a horizontal partition dividing the sleeve into two cavities; in the sleeve above the baffle, upper circulation openings are provided, equipped with seats for seating the sealing balls, and below the baffle, lower circulation openings are made; on the lower end of the sleeve are installed, with the possibility of axial movement along the guide slots of the barrel, pushers that rely on the end face of the piston located between the barrel and the casing above the expanding cone and the sliding collet.

A cylindrical sleeve mounted in the housing, with the possibility of axial movement, with an external diameter equal to the diameter of the tube space, in which there is a horizontal partition dividing the sleeve into two cavities, above which there are upper circulation holes equipped with seats for seating the sealing balls, and below the partition made lower circulation holes, allows you to seal the tubing space of the casing and create maximum axial force, by increasing to internally column diameter of the area to which the internal pressure in the pipe string.

The installation on the lower end of the sleeve, with the possibility of axial movement along the guide slots of the barrel, pushers that rely on the end of the piston located between the barrel and the casing above the spreading cone and the sliding collet, allows you to convert the axial force into a radial force sufficient to introduce the collet teeth into the wall production casing and holding the casing, even without using the load from the weight of the carrier and the descent.

The holder of the pipe string is shown in the drawings, where Fig. 1 shows a device before actuation, and Fig. 2 shows a device after actuation.

Figure 1 and figure 2 shows the housing 1, a tapered groove 2, a retaining ring 3, a cylindrical sleeve 4, a baffle 5 of the sleeve, shear screws 6, upper circulation holes 7, seat seats 8, lower circulation holes 9, connecting screws 10, holding cone 11, central hole 12, pushers 13, barrel 14, casing 15, piston 16, slots 17, shear screws 18, sliding cone 19, collet 20, circlip 21, stopper 22 with slots, lower sub 23, sealing balls 24 , console 25, die 26 with teeth, wall 27 of the production casing.

The holder of the pipe string is as follows.

The holder of the pipe string is placed in the production string 27, contains a housing 1 with a tapered groove 2 for the retaining ring 3, the casing 15 and the barrel 14, arranged concentrically and connected inseparably by connecting screws 10. In the housing 1 is mounted and fixed with shear screws 6 with the possibility of axial displacement of the cylindrical sleeve 4 with an external diameter equal to the inner diameter of the tube space, in which a horizontal partition 5 is placed, dividing the sleeve into two cavities. In the bushing 4, above the baffle 5, there are upper circulation openings 7 provided with seats 8 for seating the sealing balls 24, and below the baffle 5 there are lower circulation bores 9. At the lower end of the bushing 4, pushers 13 are mounted axially moving along the guide slots 17, which rely on the end face of the piston 16 located between the barrel 14 and the casing 15 above the spreading cone 19 and the sliding collet 20, which is fixed on the casing 15 with shear screws 18. On the upper end of the sleeve 4 is installed holding cone 11 with a central hole 12. The piston 16 is supported by the lower end on the spreading cone 19, in which the circlip 21 is mounted. The cone 19 contacts its conical surface with the sliding collet 20, having dies 26 with teeth and elastic consoles 25. On the lower sub 23, a stopper 22 is placed, in the slot of which, after the operation of the holder, the elastic arms 25 enter.

The holder of the pipe string operates as follows.

The device is installed in the lower part of the descent secret column, above the shoe of the descent column, under all elements of technological equipment installed on the descent column.

After the descent of the column and flushing, a viscoelastic separator with sealing balls 24 is introduced into the well, which are pressed by the squeezing fluid to the holder.

The upper circulation holes 7, equipped with seats 8, overlap balls 24, sealing the casing pipe space. The pressure rises above the working one, the screws 6 are cut off, the sleeve 4 with an external diameter equal to the diameter of the pipe space, separating the pipe space into two cavities, due to the placement of a horizontal partition 5 in the sleeve 4, it allows to create the maximum axial force, which is pushers 13 mounted on the lower the end face of the sleeve 4, along the guide slots 17 of the barrel 14 is transmitted to the end face of the piston 16, and the expanding cone 19 through the dies 26, the collet 20 converts the axial force into radial, pushing the dies until the teeth contact the walls of the assembly column 27.

The axial force on the cone 19 and the collet 20 increases significantly, due to the equality of the outer diameter of the cylindrical sleeve 4 to the diameter of the tube space, in comparison with analogues and prototype, where the pressure affects only the area of the piston. The cone 19 and the collet 20, after triggering and holding the column, are fixed in the final position by the locking ring 21 from the reverse stroke.

The elastic consoles 25 of the collet 20 are placed in the slots of the stopper 22, rigidly connected with the lower sub 23, which prevents the rotation of the column when carrying out work on the separation of the devices lowered from the bearing column and drilling the internal parts of the devices lowered into the well when the well is put into operation.

The technical result is the creation of a device that simultaneously performs two functions: sealing the tube space and suspension of the descent column on the holder during repair work, with the descent of a countersunk column of small diameter, with an increase in the reliability of the device due to the cylindrical sleeve mounted in the housing with axial movement, with an external diameter equal to the diameter of the tube space in which the horizontal partition is placed, dividing the sleeve into two cavities, above which the upper circulation holes are provided with seats for seating the sealing balls, and lower circulation holes are made below the baffle, and pushers are mounted on the lower end of the sleeve, with the possibility of axial movement along the guide slots of the barrel, which are supported by the end of the piston located between the barrel and the casing above spreading cone and sliding collet.

Claims (1)

A pipe string holder comprising a housing with a tapered groove for the retaining ring and a casing and a barrel connected inseparably to the housing, characterized in that a cylindrical sleeve with an external diameter equal to the diameter of the pipe space in which the horizontal partition separating is arranged is axially movable the sleeve into two cavities, in the sleeve above the baffle there are upper circulation holes provided with seats for seating the sealing balls, and below the baffle there are made ie circulation openings on the lower end of the sleeve mounted for axial movement along the guide slots barrel lifters which rely on the piston end face located between the barrel and the casing are moved apart over the cone and collet extensible.

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