RU2225496C2 - Pipe cutting device - Google Patents

Abstract

FIELD: well maintenance equipment. SUBSTANCE: device has body, cutters, drive, shaft with yoke for carriages, and anchoring assembly. Drive is electromechanical with possibility of feeding current of one polarity to electrical engine, increasing power and inverting polarity. Anchoring assembly consists of billets, master cam and cams. Carriages are moveable in the yoke with possibility of supporting balance of torque on the shaft and cutting moment. EFFECT: decreased cutting time and excluded pipe geometry disruption. 5 dwg

Description

The invention relates to the field of oil and gas industry, in particular to the restoration and repair of wells by cutting and subsequent lifting of pipes.

Known are devices for cutting pipes in a well, comprising a housing with windows rigidly connected to the housing, an adapter for connecting to the pipe string and a filter tube, cutters installed in the windows of the housing, articulated with the housing and spring-loaded relative to it, a glass with radial valves, balls in them, a piston placed under the cutters with peripheral holes [1].

The disadvantages of this device are the complexity and length of time of the process; the need to attract special equipment, a downhole motor or a turbodrill, the descent of the device on the tubing string. The preparation and conduct of the cutting process takes from 2 to 3 days.

Closest to the proposed invention in technical essence is a device for cutting pipes and extracting pipes from a well (prototype) [2], including a pipe cutter with a drive in the form of a downhole motor connected to the lower end of the pipe string, and a tube rigidly connected to the upper end of the pipes .

The disadvantage of this device is that the cutting technology requires a lot of labor and a long time to complete the cutting process from 4 to 6 days; preparatory work (delivery of tubing, downhole motor and the use of a special unit).

The objective of the invention is to reduce the timing of the pipe cutting process, reduce the cost and eliminate violation of the geometry of the pipe.

In the proposed invention, the projectile for cutting and removing pipes carries out the cutting process in the shortest time and without high costs.

Figure 1 presents the invention in a static state.

Figure 2 is a view along arrow A (operating position of the ratchet when moving to the left).

Figure 3 - projectile for cutting pipes in the working position during cutting mode.

Figure 4 is a view along arrow B (the working position of the ratchet when moving to the right).

Figure 5 - projectile for cutting pipes after the end of the cutting process.

In Fig.1, a projectile for cutting and removing pipes from wells, including a housing (5), a drive in which an electric motor (1), a magnetic coupling (2) and a gearbox (3), a shaft (4) are located. The drive is electromechanical with the possibility of supplying an electric current of one polarity to its electric motor, increasing the strength and reversing the polarity of the current. The pipe (6), movably connected to the housing (5) by means of a spline connection (7), a ratchet mechanism (8) with a spring (9) and a propeller (10) located on the central shaft (4), and an anchor unit made with the possibility of neutralizing the reactive moment when cutting with cutters and consisting of cams (11) with a copier (12) having a conical surface, dies (13) movably connected to the copier (12) using a dovetail and nut (14) connection, supporting cam mechanism. At the end of the shaft (4), a ferrule (15) is located, on which the carriages (16) are movably located with the possibility of balancing the torque on the shaft and the moment of cutting with cutting elements (17). The holder (15) is fixed to the shaft (4) motionless with the help of dowels (18). The carriages (16) are pulled together by a spring (19). Between the copier (12) and the housing (5) are leaf springs (20). The housing (5) and the pipe (6) are fixed to each other by shear pins (21). On the pipe (6) there are windows (22) for circulating the well fluid. The dies (13) are locked using shear screws (23). The projectile descends on the cable-rope (24), on the body (5) a “herringbone” (25) is provided for capture by the tube.

A device for cutting and removing pipes works as follows: a projectile descends into the well on a cable-rope (24) and is fixed on the wall at a certain interval.

An electric current of one polarity (direct) is supplied to the electric motor (1) via a cable-rope (24), while the electric motor torque is transmitted through a magnetic coupling (2), a gearbox (3) and a shaft (4) to a ratchet mechanism (8), the teeth of which are connected to the teeth on the end face of the cams (11) and are pressed using a spring (9). (Figure 2 is a view along arrow A). In this case, the cams (11) begin to rotate to the left, the copiers (12) and dies (13) under the action of the protrusion of the cams (11) move in the radial direction, are pressed to the column and remain fixed. With further rotation of the shaft (increase in torque), the ratchet (8) slides along the end of the cam, since the spring (9) is depressed.

Figure 3 - projectile for cutting pipes in the working position during cutting mode.

After landing the projectile on the column, the current strength of the same polarity is increased through the control panel. The revolutions of the electric motor (1) increase, respectively, the revolutions of the shaft (4) increase. The carriages (16), located movably on the cage (15), are moved apart in the radial direction under the action of centrifugal force, and the cutting elements (17) - cutters cut into the column wall and begin to cut, while the springs (19) are stretched. If the cutting force is large and the torque created by the electric motor (1) is insufficient, the shaft speed (4) decreases, and the centrifugal force of pressing the cutting elements-cutters (17) against the wall and its feed depth decrease accordingly.

Thus, a sufficient balance of the torque on the shaft (4) is maintained by the time of cutting, within 10-15 minutes of operation of the electric motor, the column wall is cut off with a thickness of 10 mm.

In the cutting mode at high speeds on the shaft (4), the ratchet mechanism (8) will be disconnected from the cam tooth due to the axial force created by the propeller (10).

To extract the projectile from the well, the electric motor (1) is turned off, while the carriages (16) and the cutting elements (17) occupy the initial positions under the action of the spring (19). When an electric current of reverse polarity is applied to the electric motor (1), the central shaft (4) starts to rotate to the left, and the ratchet mechanism (8) rotates the cams (11) to the right. Figure 4 is a view along the arrow (B). When sufficient torque is reached on the shaft (4), the cams move away from the copier (12), the dies (13) move radially to the shaft under the action of a leaf spring (20). The projectile is freed from the wall of the column. There is an emergency failure of the projectile in case of failure of the motor (1) or breakage of the cable-rope (24).

Lower the tube and catch it for the “Christmas tree" (25). After being captured by the tube, the projectile is pulled upward, while the axial force from the body (5) is transmitted to the shear pin (21), it is cut off, then the force is transmitted to the shear screw (23) on the die (13), and it is cut off. The housing (5), the central shaft (4), the copier move upward relative to the nozzle (6), the dies (13) move radially towards the center (shaft), and the dies (13) are disengaged from the column walls. The housing (5) along the spline connection (7) moves upward relative to the nozzle until the yoke (15) abuts against the nozzle (6) (Fig. 5)

Thus, the use of this device reduces material costs and the timing of the pipe cutting process, which is completed within one hour, while the preparatory work (transportation of tubing, downhole motor) is excluded and there is no need to use a special unit.

Sources of information

1. RF patent No. 2012771, E 21 In 29/00, 1994.

2. Auto USSR No. 1783110, Е 21 В 29/00, 1992.

Claims (1)

A projectile for cutting pipes, including a housing, cutters and a drive, characterized in that it is provided with a shaft with a cage in which the carriages are located and an anchor unit, the drive is electromechanical with the possibility of supplying an electric current of one polarity to its electric motor, increasing the force and changing polarity reverse current, while the anchoring unit is made with the possibility of neutralizing the reactive moment when cutting with cutters and consists of dies, a copier and cams, and the carriages are mounted movably in the holder with the possibility of providing the balance of the torque on the shaft and the moment of cutting.

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