RU2791767C1 - Casing string drilling device - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: used in drilling operations, in particular for drilling wells on a casing string. Device for drilling on a casing string includes a hollow cylindrical body with a top sub having an internal thread for connection with the top power drive of the drilling rig, a sealing collar. The body is equipped with longitudinal grooves on the outside, in which rams with cutters, spring-loaded in the working position, are installed with the possibility of limited rotation on the axes and wedging in the inner wall of the casing to transmit torque when the upper power drive rotates to the right. At least two sealing collars are installed in the grooves of the top sub, which is equipped with an annular ledge in the upper part with a groove from below under the upper end of the guide funnel, placed inside the casing pipe coupling.

EFFECT: transmission of the torque both during rotation by the top power drive, and keeping the torque when drilling with a bottom-hole motor, the device is easy to manufacture and allows to effectively walk and unscrew stuck assemblies.

1 cl, 2 dwg

Description

The invention relates to the mining industry and can be used in drilling operations, in particular for drilling wells on a casing string.

An overshot is known (patent RU No. 149992, IPC E21V 31/18, publ. 27.01.2015, Bull. No. 3), containing a hollow body connected to a sub for threaded connection with a pipe string, inside the body with the possibility of axial movement is installed through collet, made in the form of a springy split sleeve with an outer cone interacting with an inner cone, made from the side of the lower end of the body, on the working surface of the collet there are teeth in contact with the outer surface of the body of the catch pipe, an additional cone is made from the lower end of the body, for entry pipes. The axial movement of the collet is limited by a retaining ring mounted on the outer surface of the collet and included in a wide annular groove made in the body, and the upper end of the retaining ring and the stop surface of the wide annular groove are made conical, and above the installation of the collet, a narrow annular groove is made to fix the collet when released from the pipe.

Device disadvantages:

- the impossibility to keep the torque that occurs both when drilling with a top power drive, and when using a downhole motor;

- the seal at the end of the pipe will be destroyed under axial load from top to bottom when drilling on casing pipes;

- collet grip damages the outer part of the thin-walled casing pipe, which in turn locally reduces the strength characteristics of the pipe itself;

- the lack of the possibility of capturing the casing directly by the coupling part.

The closest in technical essence to the proposed invention is a sealing device for drilling on a casing string (patent RU No. 2773187, IPC E21V 33/02, E21V 23/02, E21V 31/18, publ. 31.05.2022, bull. No. 16 ), including a hollow cylindrical body with a through top sub having an internal thread for connection with the top power drive of the drilling rig. The body outside is equipped with at least three lugs symmetrically located on the surface of the body, on the axis of which spring-loaded clamping feet are installed, inside the body in the lower part there is a radial ledge with a conical design in the lower part and a straight platform on top, the lower part of the upper sub is made in in the form of a straight ledge, on which a thrust washer is installed, and on the outer side of the lower part of the top sub, a radial protrusion is made along the entire diameter, while a rubber cuff is installed between the top sub and the device body, made with a characteristic depression on top, coinciding with the radial protrusion made on top translator.

Device disadvantages:

- the impossibility to keep the torque that occurs both when drilling with a top power drive, and when using a downhole motor;

- the assembly for holding the weight of the casing string, consisting of spring-loaded clamping legs installed in the lugs on the axles, is not intended for reciprocation, extraction with rotation of stuck assemblies;

- non-standard, complex configuration of the sealing cuff and, as a result, high material costs for its manufacture;

- large dimensions of the device will lead to contact of the eyes with the elevator links and, as a result, they may be damaged.

The technical tasks are to create a device that allows you to transmit torque both during rotation by the top power drive, and to hold torque when drilling with a downhole motor, easy to manufacture through the use of standard sealing collars, which allows you to walk and unscrew stuck assemblies through the use for lowering and raising standard elevator.

Technical problems are solved by a device for drilling on a casing string, including a hollow cylindrical body with a top sub having an internal thread for connection with the top power drive of the drilling rig, a sealing cuff.

What is new is that the housing is equipped on the outside with longitudinal grooves in which dies with teeth, spring-loaded in the working position, are installed with the possibility of limited rotation on the axes and wedging in the inner wall of the casing to transmit torque when the upper power drive rotates to the right, while the sealing collars in the amount at least two are installed in the grooves of the upper sub, which in the upper part is provided with an annular protrusion with a groove from below under the upper end of the funnel placed inside the casing pipe coupling.

Figure 1 shows a General view of the device for drilling on the casing string in the working position.

In FIG. 2 shows section A-A.

The casing drilling device includes a hollow cylindrical body 1 (Fig. 1) with an upper sub 2 having an internal thread 3 for connection with the upper power drive of the drilling rig 4, sealing cuffs 5. The body 1 of the device is equipped with longitudinal grooves 6 on the outside (Fig. 1 and 2), in which spring-loaded springs 7 (Fig. 2) are installed in the working position of the die 8 (Fig. 2), with milled teeth 9 (Fig. 1 and 2), having the possibility of limited rotation on the axes 10 (Fig. 2 ), and jamming in the inner wall of the casing 11 for transmitting torque during rotation of the upper power drive 4 (Fig. 1), to the right. At least two sealing collars 5 are installed in the grooves 12 of the upper sub 2. The upper sub 2 in the upper part is provided with an annular protrusion 13 with a groove 14 from below under the upper end 15 of the guide funnel 16 placed inside the sleeve 17 of the casing pipe 11.

The device works in the following order.

In the assembled form, the device is screwed onto the nipple end of the upper power drive of the drilling rig 4 by means of an internal thread 3 (Fig. 1), the upper sub 2. 2 is not shown), the next casing pipe 11 is captured by the sleeve, a funnel 16 is installed in its sleeve and rises to the height of the pipe above the rotor table, then the raised casing pipe 11 is screwed with a string of pipes already lowered into the well using traditional technology (Fig. not shown). After turning the casing on the string, the upper power drive 4 of the drilling rig, without releasing the pipe from the elevator 18, is smoothly fed down until the stop of the annular protrusion 13 into the end of the coupling 17. pipes 11, without riding up on the thread of the coupling 20, without damaging the thread of the coupling 20 and hermetically cover the space below the device, and the rams 8, spring-loaded by springs 7 (Fig. 2), are pressed against the walls of the casing pipe 11. Next, the drilling pump is started, the drilling fluid is pumped through the hollow cylindrical body 1 (Fig. 2), a load is created on the end of the casing pipe 11 through the annular protrusion 13 and the drilling process begins. Drilling can be carried out by the assembly - bit, reamer, downhole motor, with subsequent disconnection of the assembly at the end of drilling and its extraction through the casing using a known disconnect device. In this case, the device for drilling on the casing string seals the interior of the casing pipe 11 while pumping the drilling fluid with sealing collars 5 installed in the grooves 12 of the upper sub 2, and the dies 8, cutting into the body of the pipe with milled teeth 9 (Fig. 1 and 2), prevent rotation of the casing from the reactive moment created by the downhole motor during drilling. Upon completion of drilling for the length of one pipe, with the rotation of the upper power drive 4 (Fig. 1), to the left, the dies 8 installed on the axes 10 (Fig. 2), in the longitudinal grooves 6 of the body 1, compress the springs 7 and the device is released from the casing columns.

It is also possible to drill on the casing string by transmitting torque to the casing pipe directly using the device through the upper power drive 4 (Fig. 1). In this case, the casing drilling device also seals the interior of the casing pipe 11 while pumping the drilling fluid with sealing collars 5, and the slips 8 transmit torque from the upper power drive 4 to the casing string. After a well has been drilled for the length of one pipe, the column is installed on wedges in the rotor of the drilling rig. The device for drilling on the casing string is removed from the casing pipe 11, the next pipe is taken from the bridges of the drilling rig and the operation is repeated anew.

The proposed device allows you to transmit torque both during rotation by the top power drive, and to keep the torque when drilling with a downhole motor, easy to manufacture through the use of standard sealing collars, which allows you to walk and unscrew stuck assemblies through the use of a standard elevator for lowering and lifting.

Claims (1)

Device for casing drilling, including a hollow cylindrical body with a top sub having an internal thread for connection with the top power drive of the drilling rig, a sealing collar, characterized in that the body is equipped on the outside with longitudinal grooves, in which rams with teeth, spring-loaded in the working position, are installed with the possibility of limited rotation on the axes and wedging in the inner wall of the casing to transmit torque when the top power drive rotates to the right, while at least two sealing collars are installed in the grooves of the top sub, which in the upper part is equipped with an annular protrusion with a groove from below under the upper end of the guide funnel, located inside the casing sleeve.

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