RU2779682C1 - Casing reamer bit - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to drilling equipment for the oil and gas industry, in particular to devices for increasing the diameter of a well with simultaneous drilling on a casing string in a given interval. The reamer bit for casing drilling includes a body, a sleeve movably mounted on the body. Rock-cutting elements with gauge and cutting parts are placed in the support windows of the coupling and side grooves with body guides. The sleeve is rigidly connected to the pilot bit from below. The upper part of the body is oval in cross section, interacting with the oval hole of the coupling plug, forming a hydraulic chamber with the upper part of the body and the inner part of the coupling, connected to the central channel of the body by an opening. The body above the side grooves with guides is made in the form of a piston and is hermetically mounted relative to the inner part of the coupling. The inner part of the coupling in the place of the supporting windows is made conical. The cutting part of the rock cutting elements is made with a curved outer surface and is equipped with PDC cutters. The body is equipped on the top with a sub with locking thread for connection with the downhole motor, and on the bottom - with a removable rod, hermetically installed in the bore of the coupling. The pilot bit is made in the form of a drill head equipped with PDC cutters.

EFFECT: reliability and durability of the structure, drilling and expansion with loads arising during simultaneous drilling and expansion of the well at the required mechanical speed are ensured, a calibrated diameter of the wellbore is provided, as well as the exclusion of a wedge and sliming of the internal cavity of the device.

1 cl, 4 dwg

Description

The invention relates to drilling equipment for the oil and gas industry, in particular to devices for increasing the diameter of a well with simultaneous drilling on a casing string in a given interval.

A well expander is known (patent No. 189648, IPC E21B 7/28, E21B 10/26, publ. 05/29/2019, bull. No. 16), including a bit with main cutters, a body connected to a drill string, rock-cutting bodies - movable incisors fixed in the lower - transport state by shear elements and made with the possibility of moving along the guides, which are made diverging upward from the expander axis. The body is rigidly connected to the bit, and the guides are placed between the main cutters. The diameter of the circumscribed circle and the lower cutting edges of the movable cutters in the transport position are respectively less than the diameter of the circumscribed circle and below the cutting edges of the main cutters.

The disadvantages of the device are:

- the impossibility of using the expander in directional and horizontal wells, since the drill string is located on the wall of the well, as a result, the axial force does not reach the shear elements;

- unreliable design of the expander, as there is a possibility of falling out of the movable cutters due to the destruction of the fasteners holding the movable cutters;

- when expanding in the cavernous areas, the required diameter is not provided, since the movable cutters occupy their working position only when in contact with the bottom of the well;

- the impossibility of using the expander for simultaneous drilling and expansion on the casing string, since the expansion range of the expander does not provide the required expansion diameter.

The closest in technical essence and the achieved result is a downhole expander (patent No. 2315849, IPC E21B 7/28, E21B 10/26, publ. on the body of the coupling, placed in the supporting windows of the coupling and the side grooves of the body with guide rock-cutting bodies. The body is made as a leading liner, and the coupling is rigidly connected to the pilot bit and suspended by means of a sub to the body, the side grooves of the body with guides are engaged with the rock-cutting bodies by the lower part in the transport position of the expander. The housing and the coupling are made with seating areas for mating in the working position of the expander. Rock cutting tools are made with calibrating and conical cutting parts, the taper angle is equal to the angle of inclination of the side grooves of the body with guides.

The disadvantages of the device are:

- low resource of the device due to the destruction of the side grooves of the body with guides and guide rock-cutting elements when applying loads that occur during drilling, since the body has the ability to rotate relative to the coupling;

- deformation of the supporting windows of the coupling, when applying loads arising in the process of drilling and expanding the well, since it is made in the form of a pipe with a small contact surface with rock-cutting bodies;

- when drilling and expanding in cavernous areas, the required diameter is not provided, since the movable cutters take up their working position only when they come into contact with the bottom of the well;

- the conical working part of the blades leads to a high torque, blades and vibrations during operation;

- due to the fact that the housing and the coupling are made with landing areas for mating only in the working position of the expander, in the transport position and during tripping operations, the inner part of the grooves is not sealed, they are sludged;

- cone pilot bit significantly reduces the mechanical speed while drilling and reaming the hole.

The technical objectives of the proposed device are to create a reliable, durable design of a reaming bit for casing drilling with the necessary resource under loads that occur during simultaneous drilling and reaming of the well at the required mechanical speed, ensuring a calibrated diameter of the wellbore, as well as eliminating the sub-blade and sludge of the internal cavity of the device.

Technical problems are solved with a reaming bit for casing drilling, including a body, a sleeve movably mounted on the body, rock-cutting elements with calibrating and cutting parts are placed in the support windows of the sleeve and side grooves of the body with guides, the sleeve is rigidly connected to the pilot bit from below.

What is new is that the upper part of the housing is oval in cross section, interacting with the oval hole of the coupling plug, forming a hydraulic chamber with the upper part of the housing and the inner part of the coupling, connected to the central channel of the housing by a hole, while the housing above the side grooves with guides is made in the form of a piston and is installed hermetically relative to the inner part of the coupling, and the inner part of the coupling in the place of the supporting windows is made conical, the cutting part of the rock-cutting elements is made with a bend of the outer surface and is equipped with PDC cutters, also the body is equipped with a sub with locking thread for connection to the downhole motor, and from the bottom - removable rod hermetically installed in the bore of the coupling, and the pilot bit is made in the form of a drilling head equipped with PDC cutters.

In FIG. 1 shows a casing reamer bit in working position.

In FIG. 2 shows a reamer bit for drilling on a casing string in a transport position.

In FIG. 3 - section A-A.

In FIG. 4 - section B-B.

The reamer bit for casing drilling includes a body 1 (Fig. 1, 2, 4), a sleeve 2 movably mounted on the body 1. Rock-cutting elements 3 with a gauge 4 and a cutting part 5 are placed in the support windows 6 of the sleeve 2 and side slots 7 with guides 8 of the body 1. The sleeve 2 is rigidly connected from the bottom with the pilot bit 9. The upper part 10 of the body 1 is oval in cross section (Fig. part 13 of the clutch 2 hydrochamber 14 connected to the Central channel 15 of the housing 1 hole 16. The housing 1 above the side grooves 7 with guides 8 is made in the form of a piston 17 and is installed tightly relative to the inner part 13 of the clutch 2. The inner part 18 of the clutch 7 in the place of the supporting windows 6 is made conical. The cutting part 5 of the rock cutting elements 3 is made with a bend of the outer surface and is equipped with PDC cutters 19. The body 1 is equipped on top with a sub 20 with locking thread 21 for connection to the downhole motor (not shown in Fig.), and on the bottom it is equipped with a removable rod 22 hermetically installed in the through passage hole 23 of the coupling 2. The pilot bit 9 is made in the form of a drill head 24 equipped with PDC 25 cutters.

Reamer bit for drilling on casing works as follows.

The reamer bit assembly, a screw downhole motor with a skew angle for controlled drilling, a telesystem, then a drilling tool connecting unit are assembled (for example, Pat. RU No. 2663856, IPC E21V 7/20, E21V 7/28, publ. , bul. No. 22), which in turn is already connected to the casing string (not shown in Fig.). Due to the fact that the housing 1 is equipped on top with a sub 20 with a locking thread 21 for connection to the downhole motor, additional subs are excluded that extend the layout below the downhole motor, which allows you to control the trajectory during drilling. The assembly is lowered into the well, the mud pump is turned on and a pressure drop is created, at the same time, the screw downhole motor starts to rotate and the process of simultaneous drilling and expansion begins. Due to the presence of the hydraulic chamber 14, the hole 16 and the body 1 made in the form of a piston 17 during drilling, a pressure drop is created due to the flushing fluid and the reaming bit is constantly in the working position, which provides the required diameter during drilling and expansion, including in cavernous areas. Due to the fact that the upper part 10 of the body 1 is made oval in cross section, interacting with the oval hole 11 of the plug of the coupling 12, the torque does not affect and does not destroy the side grooves 7 with guides 8 of the body 1. At the same time, the lateral load that occurs during drilling and expansion , perceive the supporting windows 6 of the coupling 2 made reinforced due to the fact that the inner part 18 of the coupling 2 in the place of the supporting windows 6 is made conical. Due to the fact that the cutting part 5 of the rock cutting elements 3 is made with a bend of the outer surface and equipped with PDC 19 cutters, and the pilot bit 9 is made in the form of a drill head 24 equipped with PDC 25 cutters, the mechanical speed during drilling and expansion significantly increases. Due to the fact that the housing 1 from below is equipped with a removable rod 22 hermetically installed in the through hole 23 of the coupling 2, there is no sludge in the internal cavity of the device. Upon reaching the design bottomhole, the well is flushed and the drilling pump is turned off. Then, a tool is lowered on the drill pipe string, which is fixed for the extractable part of the connecting unit. The lifting assembly is removed, while the reamer bit assumes a transport position, and the casing string is cemented in a known manner.

The proposed reamer bit for casing drilling is a reliable, durable design with the necessary resource, which allows drilling and reaming with the loads that occur during simultaneous drilling and reaming of the well at the required mechanical speed, to ensure a calibrated diameter of the wellbore, and also to exclude wedges and cuttings the interior of the device.

Claims (1)

Reamer bit for casing drilling, including a body, a sleeve movably mounted on the body, rock-breaking elements with calibrating and cutting parts are placed in the support windows of the sleeve and side grooves of the body with guides, the sleeve is rigidly connected to the pilot bit from below, characterized in that that the upper part of the housing is oval in cross section, interacting with the oval hole of the coupling plug, forming a hydraulic chamber with the upper part of the housing and the inner part of the coupling, connected to the central channel of the housing by a hole, while the housing above the side grooves with guides is made in the form of a piston and is installed hermetically against the inner part of the coupling, and the inner part of the coupling in the place of the supporting windows is made conical, the cutting part of the rock-cutting elements is made with a bend of the outer surface and is equipped with PDC cutters, the body is also equipped with a sub with locking thread for connection to the downhole motor, and at the bottom - with a removable rod, hermetically tired in the bore of the coupling, and the pilot bit is made in the form of a drill head equipped with PDC cutters.

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