RU56931U1 - DEVICE FOR CUTTING A PART OF A PIPE COLUMN IN A WELL - Google Patents

Abstract

The utility model relates to the oil and gas industry, in particular to cutting casing strings and creating technological windows in them by completely destroying the body of the casing strings (strings) in a predetermined interval during drilling while drilling additional shafts, overhaul wells, etc. Known devices used for this purpose have a number of disadvantages, namely: - the inability to determine the end of the process of cutting the column on the wellhead parameters of the washing liquid; - unreliability of the constructive solution of the return of the incisors to the transport position. The technical result of the proposed utility model is to expand the technological capabilities of the device while increasing the reliability of its operation. The technical result is achieved by solving a technical problem aimed at ensuring the determination of the moment of completion of the process of cutting the string and the reliability of the fixation of the cutters when trimming the section of the casing. The stated technical problem is solved due to the fact that in the known device comprising a housing with grooves with retractable cutters pivotally mounted therein, arranged to be locked in extended and transport positions, a cutter extension assembly including a piston with wedge pushers located below the retractable cutters, radial cylindrical channels in the device body, the tool return unit, and the nozzle-nozzle located in the lower part of the device, wedge pushers are made with ball valves, the prun node a further return of the incisors to the transport position, located at the top of the device and includes

a piston, a thrust clutch and cylindrical bypass channels made in the device’s body, a telescopic channel for circulating the working fluid is made along the axis of the housing, retractable cutters are equipped with earrings attached to the device’s body and cutters with the help of cylindrical axes, the device is also equipped with a locking assembly connecting the upper cutters with a housing made in the form of a spring-loaded ball retainer and screw. Using the proposed utility model provides the following advantages: - it becomes possible to determine the end of the process of cutting the pipe string by the wellhead pressure of the flushing fluid. This will reduce the duration of work, to avoid emergencies associated with the failure of the device inside the pipe string, bending of the cutters and the device spell, present when using the prototype; - the possibility of a reliable forced return of the incisors to the transport position has been decided, which, unlike the prototype, eliminates possible complications (tightening, wedging) when removing the device from the well; - increased reliability of the fixation of the cutters when trimming the section of the casing string, which allows you to work in wells cased with two or more columns. At the same time, reliable fixation of the incisors eliminates vibrational loads, thereby increasing the life of the incisors. The estimated economic effect of using the proposed device, depending on the depth of the work, the design of the well and the mechanical strength of the casing, will be from 0.5 to 2.0 million rubles.

Description

The utility model relates to the oil and gas industry, in particular, to cutting casing strings and creating technological windows in them by completely destroying the body of the casing strings (strings) in a given interval during drilling while drilling additional shafts, overhaul wells, removing strings, in case of emergency and dismantling, as well as the creation of fluid-resistant grouting tires during well abandonment.

A device according to A.S. USSR No. 717279 for cutting pipes in a well, containing a housing with sub, inside which is located the drive of the cutters, made in the form of a spring-loaded piston with a rod, which is installed with the ability to interact with cutters placed in the radial channels of the housing, the rod is made with grooves, and the drive of the cutters equipped with elastic elements and a sleeve mounted on the rod, the upper ends of the elastic elements are rigidly connected with the cutters, the lower ones are placed in the grooves of the rod with the possibility of interaction with the sleeve.

The disadvantages of this device include:

- the inability to determine the end of the process of cutting the column on the wellhead parameters of the washing fluid;

- the impossibility of complete destruction of the body of the casing string (trimming) in a given interval due to the design of the cutters;

- unreliability of the constructive decision to return the cutters to the transport position, since the probability of breaking one of the six elastic plates is very high, which can lead to an emergency, due to the inability to remove the device from the well.

A device for cutting a section of a pipe string in a well according to A.S. THE USSR. No. 1481375, comprising a housing with grooves and cutters pivotally mounted in them with cutting edges, a hydraulic drive for moving the cutters located in the housing, made in the form of a spring-loaded piston with a rod, the end part of the outer surface of which has the form of a wedge for

interaction with the inner surface of the cutters, is equipped with additional hydraulic drives for moving the cutters, made similar to the main one, while the main and additional drives are placed under each of the cutters with the possibility of interaction in the working position of the wedge outer surface of the rod with the surface of the cutter in the plane of the cutting edge of the latter, perpendicular to the axis of the device and each hydraulic drive for moving the cutters is equipped with a roller connected to the wedge surface of the rod by means of a hinge and installed with the possibility of interaction with the inner surface of the cutter in the extreme extended position of the latter, and the axis of the hinge of the roller is offset relative to the axis of the hinge of the cutter in the direction of the axis of the device.

The disadvantages of the device include:

- the inability to determine the end of the process of cutting the column on the wellhead parameters of the washing fluid;

- there is no constructive solution for the forced return of incisors to the transport position;

- the unreliability of the fixation of the incisors when trimming the section of the casing string of pipes.

The closest technical solution to the proposed utility model is a device for cutting a section of a pipe string in a well according to patent RU No. 2110665, comprising a housing with grooves pivotally mounted in them with retractable cutters, a hydraulic drive located below the retractable cutters with the possibility of interaction with the surface of the retractable cutters in the plane of the cutting edge of the latter, perpendicular to the axis of the device, and in the housing in the plane of extension of the cutters made radial channels directed into the cutting zone, retractable cut The pins are made with the possibility of their fixation in the extreme extended and transport positions due to the presence of upper and lower supporting planes and an annular spring installed in a groove made in the housing and retractable cutters in the zone of their extension, the hydraulic drive piston is made in the form of a hollow cylinder with a shoulder and ends with a wedge surface, the latter having a cutout for the supporting plane of the cutter.

This device has the following disadvantages:

- the impossibility (fixation) of determining the end of the process of cutting the string (s) by wellhead parameters (pressure, flow rate) of the flushing fluid to go to the process of trimming the section of casing pipes.

This in most cases, especially when working with alloyed columns of increased strength, leads to a sharp increase in the duration of work, and often to emergency situations due to bending, breakage of cutters and device splices, which, without cutting the column, will milling its inner surface ( from the inside), to which this device is not intended;

- unreliability of the constructive solution of the return of the incisors to the transport position.

This is due to the fact that metal shavings in the process of cutting will inevitably curl in a spiral and accumulate in the gaps in the movement of the cutters, even in the presence of washing channels, jamming and preventing them from returning to the transport position. The efforts of the annular spring, which can not exceed several kg / s, in this case will be insufficient, it requires a force exceeding several hundred (100-300) kg / s;

- the unreliability of the fixation of the incisors when trimming the section of the casing string of pipes.

This is due to the fact that when the flushing fluid is supplied by existing and commonly used reciprocating pump units, there is always a pulsation of excess pressure in the pressure pipes, which leads to vertical movements of the spring-loaded piston, and with it the wedge pusher of the cutters. In this case, when facing the pipe string, unstable and vibro-variable loads arise on the cutting edge of the cutters, which leads to their rapid wear and breakdown.

In addition, in the event of an emergency stop of the supply of flushing fluid, the cutters will move from the end surface and fall into the inside of the pipe string with the ensuing negative consequences (increase in the duration of work, emergency situations).

The technical result of the proposed utility model is to expand the technological capabilities of the device while increasing the reliability of its operation.

The technical result is achieved by solving a technical problem aimed at ensuring the determination of the moment of completion of the process of cutting the string and the reliability of the fixation of the cutters when trimming the section of the casing.

The stated technical problem is solved due to the fact that in the known device comprising a housing with grooves with retractable cutters pivotally mounted therein, arranged to be locked in extended and transport positions, a cutter extension assembly including a piston with wedge pushers located below the retractable cutters, radial cylindrical channels in the device body, the tool return unit and the nozzle-nozzle located in the lower part of the device, wedge pushers are made with check ball valves, The green of the forced return of the cutters to the transport position is located at the top of the device and includes a piston, a thrust clutch and cylindrical bypass channels made in the device’s body, a telescopic channel for circulating the working fluid is made along the axis of the device, the retractable tools are equipped with earrings attached to the device’s body and cutters using cylindrical axes, the device is also equipped with a locking assembly connecting the upper part of the cutters with the housing, made in the form of a spring-loaded ball fix ora and screws.

The proposed device is illustrated by drawings of figure 1, figure 2, figure 3.

The device consists of a housing 1 with grooves for pivotally mounting retractable cutters 2. In the lower part of the device is a knot for extending cutters, consisting of a figured cylindrical base 3, piston 4, wedge pushers 5 and cylindrical bypass channels 6. In the upper part of the device there is a node for the forced return of the cutters 2 to the transport position, including a piston 7, a thrust clutch 8 and cylindrical bypass channels 9, made in the housing of the device 1.

Along the axis of the housing 1 and the cylindrical base 3 there is a telescopic channel 10 for circulating the working fluid (solution, process water, etc.).

In the lower part of the cylindrical base 3 there is a removable calibrated nozzle-nozzle 11.

Departure of the cutters 2 with the cutting surface 14 and their main fixation in the trimming mode is provided by the earrings 15. The earrings 15 are attached to the housing 1 (see figure 2) and the cutters 2 by means of cylindrical axes 16 and 17.

Additional fixation of the cutters 2 from moving them down is provided by the locking assembly (see figure 3), consisting of a ball retainer 18, a spring 19 and a screw 20.

The essence of the proposed utility model is that the inclusion of the earring 15 and the locking assembly in the design allows reliable fixation of the cutters 2 in the extremely extended position for trimming the pipe string, even in case of emergency interruption of the supply of flushing fluid and the lateral pressure of the destructible medium (cement, rock, etc.). ) behind the column.

The presence in the device of non-return ball valves 12 and flushing channels 13 allows you to receive at the wellhead a reliable signal about the end of the process of cutting the pipe string due to a sharp drop in pressure of the flushing fluid at a constant flow rate. In addition, the channels 13 and valves 12 provide a flow of flushing fluid through them sufficient to remove metal chips from the grooves of the device and the well itself.

Pistons 4 and 7 are used to bring the device to its working position when cutting the pipe string, cutting it and forcing the cutters to return to the transport position.

Cutting the section of the pipe string in the well is as follows.

The device through the thrust clutch 8 is rigidly attached to the column of pressure pipes, lowered to a predetermined depth and put into rotation by the rotor of the drilling rig. When pumping a flushing fluid through the device, the latter, passing through the opening of the calibrated nozzle-nozzle 11, creates a pressure differential between the inner part

device and well. At the same time, the flushing fluid passing through the bypass channels 6 creates (excessive) pressure on the pistons 4, under the action of which they move upwards, and the wedge pushers 5, rigidly connected with the pistons 4, extend the cutters 2 from the grooves of the body that cut through the pipe wall. After the cutters 2 cut through the pipe wall, the pistons 4 with wedge pushers 5 will completely open the cutters 2. In this case, the check ball valves 12 will be located opposite the washing channels 13 of the housing 1 and most of the washing liquid will begin to flow through them into the well, which in turn will lead to a sharp drop in pressure at the mouth to 3-10 MPa. A drop in the pressure of the flushing fluid at the mouth, at a constant flow rate, will indicate the end of the process of cutting the pipe string, since the maximum diameter of the cutters 2 will be larger than the diameter of the cut column.

At the end of the cutting, the columns proceed to the process of trimming the given pipe section by creating a vertical load on the cutters of 2 to 1-2 tons, due to the partial unloading of the weight of the pressure pipes. At the same time, the cutters 2 held by the earrings 15, describing the arc, move upward, firmly abut the upper part in the housing of the device 1, the piston body 7 and are additionally fixed by the locking assembly (see figure 3). Feeding the device down, the pipe is trimmed to a predetermined depth.

After the end of the trimming process, the rotor is stopped, the well is thoroughly washed from metal shavings, the device is raised 0.2-0.5 m and the pressure differential across the device is created by pumping the flushing fluid and the annulus between the pressure head and casing.

When flushing fluid is pumped into the annulus, the non-return ball valves 12 are closed and due to the nozzle nozzle 11, less pressure is provided inside the device than in the well, which leads to downward movement of the pistons 4 and 7, which in turn forcefully return the wedge pushers 5 and cutters 2. At the same time, depending on the pressure drop, they can reach 2000 kg / s or more, which is quite enough to destroy the spiral metal chips, unlike the prototype.

The closure of ball valves 12 is recorded by increasing wellhead annular pressure of the flushing fluid to 3-10 MPa. After increasing the pressure in the annulus, to guarantee, the pumping fluid is pumped for another 5-10 minutes, then the pump units are stopped and the pressure pipe string is removed along with the device from the well to the surface.

Using the proposed utility model provides the following advantages:

- it becomes possible to determine the end of the process of cutting the pipe string by the wellhead pressure of the flushing fluid. This will reduce the duration of work, to avoid emergencies associated with the failure of the device inside the pipe string, bending of the cutters and the device spell, present when using the prototype;

- the possibility of a reliable forced return of the incisors to the transport position has been decided, which, unlike the prototype, eliminates possible complications (tightening, wedging) when removing the device from the well;

- increased reliability of the fixation of the cutters when trimming the section of the casing string, which allows you to work in wells cased with two or more columns.

At the same time, reliable fixation of the incisors eliminates vibrational loads, thereby increasing the life of the incisors.

The estimated economic effect of using the proposed device, depending on the depth of the work, the design of the well and the mechanical strength of the casing, will be from 0.5 to 2.0 million rubles.

Claims (1)

A device for cutting a section of a pipe string in a well, comprising a housing with grooves with retractable cutters pivotally mounted therein, arranged to be locked in extended and transport positions, a cutter extension assembly including a piston with wedge pushers located below the retractable cutters, radial cylindrical channels in the device body, the tool return unit and the nozzle-nozzle located in the lower part of the device, characterized in that the wedge pushers are made with check ball valves, the forced return of the cutters to the transport position is located at the top of the device and includes a piston, a thrust clutch and cylindrical bypass channels made in the device body, along with the axis of the body there is a telescopic channel for circulating the working fluid, retractable cutters are equipped with earrings attached to the device body and cutters when using cylindrical axes, the device is also equipped with a locking assembly connecting the upper part of the cutters with the housing, made in the form of a spring-loaded ball retainer and screw.