RU2790628C1 - Device for simultaneous drilling and fixing of sloughing zones and collapses when drilling a well - Google Patents

Abstract

FIELD: oil and gas industry; drilling of oil and gas wells.

SUBSTANCE: device for simultaneous drilling and fastening of sloughing zones and collapses during drilling of a well includes a retrievable expanding bit connected to a casing string of multi-beam expandable pipes with the possibility of straightening them with excessive pressure and fixing relative to the walls of the well, lowered on a landing sub, connected so that they can be disconnected with a drill pipe string followed by retrieval of the landing sub with the drill pipe string. The retrievable sliding bit is fixed in the working position by a shear element that fixes the rod with the drill head relative to the bit body. The retrievable sliding bit is made in such a way that it assumes a transport position when the ball is seated in the rod seat and excess pressure is created. The internal thread of the body of the retrievable sliding bit is provided with grooves for the locking rings of the calibrating tool. The landing sub is equipped with spikes inserted into the beams of the shaped part of the upper end of the upper multipath casing. The landing sub is also equipped with a groove with a cone for narrowing the cylindrical end of the upper multi-beam casing, on which a guide funnel is made, sealed with an elastic sealant.

EFFECT: proposed device allows drilling and its installation in directional and horizontal wells, transmitting the necessary torque for drilling, eliminating non-expanded areas during drilling, as well as eliminating emergencies associated with sliming of the upper part of the string of shaped pipes, turning and falling of the retrievable sliding bit when retrieving it.

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Description

The invention relates to the oil and gas industry, and in particular to the drilling of oil and gas wells with simultaneous isolation of areas of shedding and collapses when drilling a string of pipes.

A device is known for simultaneous drilling and fastening of zones of shedding and collapses when drilling a well (patent RU No. 2753428, IPC E21V 7/20, publ. The rock-breaking element is made in the form of a drilling bit screwed to the lower end of the casing string on a thrust tapered thread and equipped with a ball seat. In the upper part of the casing there is a hermetically sealed sub with keys inserted into the mating grooves made on the upper end of the casing. The sub is equipped at the bottom with a bit with a hole for the passage of the ball, and at the top with a groove inserted into the narrowing of the casing, while the taper angle of the chamfer of the groove of the sub is made to provide additional expansion when exiting through the narrowing of the casing, in addition, the sub is equipped with a thread on top for connection with the drill string . Outside, the narrowing of the casing is provided with an elastic element with an outer diameter equal to the diameter of the casing, while the diameter of the casing is 10-15% less than the diameter of the bit being drilled.

The disadvantages of the device are:

- high probability of jamming of the sub with the bit when leaving the upper end of the casing, since at the same time the elastic element is compressed and, as a result, the axial force increases significantly;

- a large narrowing of the wellbore after installing this device, since the diameter of the casing string is 10-15% less than the diameter of the well and, as a result, a reduced bit must be used to drill to the target bottom.

The closest in technical essence to the claimed is a method implemented by a device for the simultaneous opening and fastening of unstable rocks during well drilling (patent RU No. 2437997, IPC E21V 7/20, publ. a casing string in the form of a multi-beam expandable pipe with the possibility of straightening it with excess pressure with its fixation relative to the walls of the well with a length exceeding the length of the shedding and collapse zone, a retractable expandable bit for drilling a well connected to a string of multi-beam expandable pipes lowered on the drill pipe string with subsequent retrieval of the drill string, a sizing tool with a catcher at the lower end for grabbing, detaching and retrieving the expandable bit when interacting with it.

The disadvantages of the device are:

- the sub installed in the landing pipe does not transmit torque for drilling the well;

- the connection of the landing sub with the pipe string by the thread does not allow distortion, which occurs in directional and horizontal wells, and, as a result, the thread jams and creates an emergency;

- during simultaneous drilling and expansion, due to pulsations in the flow rate of the flushing fluid of the pump, it is not guaranteed that the bit will move to the working position and, as a result, it is impossible to expand the profile pipes to the full extent, which can lead to an emergency;

- due to the lack of locking when removing the retrievable expandable bit with a calibrating tool, there is a high probability of turning and falling of the extractable expandable bit.

The technical task is to create a device for simultaneous drilling and fastening of zones of shedding and collapses during drilling of a well, reliable in operation, allowing to transmit the necessary torque for drilling, to drill and install the device in directional and horizontal wells, to exclude non-expanded areas during drilling, and so also exclude emergencies associated with sliming of the upper part of the column of profile pipes, lapel and fall of the extracted sliding bit.

The technical problem is solved by a device for simultaneous drilling and fastening of zones of shedding and collapses during drilling of a well, including a retrievable sliding bit connected to a casing string of multi-beam expandable pipes with the possibility of straightening them with excessive pressure with fixation relative to the walls of the well, lowered on a landing sub, connected with the possibility of disconnection with the drill pipe string, followed by the extraction of the landing sub with the drill pipe string.

What is new is that the extractable expandable bit is fixed in the working position by a shear element that fixes the rod with the drill head relative to the bit body and is made in such a way that it assumes a transport position when the ball is seated in the rod seat and excess pressure is created, in addition, the internal thread of the body of the extractable expandable the bits are provided with grooves for locking rings of the sizing tool; also, the landing sub, equipped with spikes inserted into the profile part of the upper end of the multi-beam casing string, is equipped with a groove with a cone for narrowing the cylindrical end of the upper multi-beam casing pipe, on which a guide funnel is made, sealed with an elastic sealant .

In FIG. 1 shows a device with an axial longitudinal section while drilling a well.

In FIG. 2 shows the device with an axial longitudinal section after expansion of multi-beam shaped tubes by hydraulic pressure and removal of the landing sub.

In FIG. 3 shows the device with an axial longitudinal section after calibrating multi-beam profile pipes with a calibrating tool in the process of lifting a recoverable expandable bit.

The device for simultaneous drilling and fixing of the zones of shedding and collapses during drilling of a well includes a retrievable sliding bit 1 (Fig. 1) connected to a casing string of multi-beam expandable pipes 2 with the possibility of straightening them with excess pressure with fixation relative to the walls of the well, lowered on the landing sub 3, connected with the possibility of disconnection with the drill pipe string (not shown in Fig. 1, 2, 3) with subsequent extraction of the landing sub 3 with the drill pipe string.

The extractable sliding bit 1 is fixed in the working position by a shear element 4 (Fig. 1), which fixes the rod 5 with the drill head 6 relative to the body of the bit 7. The extractable sliding bit 1 is made in such a way that it assumes a transport position when the ball 8 is seated in the saddle 9 of the rod 5 and creating overpressure. The internal thread 10 (Fig. 3) of the body 7 of the extractable sliding bit 1 is provided with grooves 11 for the retaining rings 12 of the sizing tool 13. 3 is equipped with a groove 18 with a cone 19 for narrowing 20 of the cylindrical end 21 of the upper multibeam casing pipe 17, on which a guide funnel 22 is made, sealed with an elastic sealant 23.

The device works as follows.

Drilling to the roof of the zone of shedding and collapses is carried out on a drill string according to known technology. Next, they collect at the wellhead and lower the device assembly, screwed along the thread 24 with a drill string (not shown in the figure), into the well. Drilling is carried out with flushing with flushing fluid. Due to the fact that the extractable sliding bit 1 is fixed in the working position by the shear element 4, which fixes the rod 5 with the drill head 6 relative to the body 7, non-expanded sections of the wellbore are excluded. Due to the fact that the landing sub 3 is equipped with spikes 14 inserted into the beams of the profile part 15 of the upper end 16 of the upper multipath casing pipe 17, the necessary torque for drilling the well is transmitted from the drill string. After the opening of the entire zone of shedding and collapses, drilling is stopped. A ball 8 is thrown from the wellhead into the drill string, which passes through the drilling pipes, the sub 3 with the flushing fluid, the multibeam expandable pipes 2 cover the seat 9 of the extractable expandable bit 1. Next, a pressure drop is created, for example, 12 MPa, while the elements 4 are sheared ( Fig. 2), the movement of the rod 5 with the drill head 6 into the transport position and the bit 1 occupies the transport position. After that, a pressure drop is created, for example, 18 MPa, while the multi-beam expandable pipes 2 are straightened by excess pressure and fixed relative to the walls of the well. With a further increase in pressure, for example, up to 20 MPa, the landing sub 3 with a cone 19 expands the narrowing 20 of the cylindrical end 21 and exits the column of multi-beam expandable pipes 2, while, thanks to the elastic sealant 23, there is no sludge formation between the landing sub 3 and the cylindrical end 21. At the same time, the landing sub 3 with a cone 19 expands the guide funnel 22, which eliminates sludge between the cylindrical end 21 and the borehole wall, after which the calibrating tool 13 freely enters the upper cylindrical end 21 and, with rotation and axial load, expands it and expandable pipes 2 along the entire length. Upon reaching the extractable sliding bit 1, the picking device 25 of the sizing tool 13 is turned up to the stop. In this case, the locking rings 12 of the calibrating tool 13 are fixed in the grooves 11 of the body 7 of the extractable expandable bit 1, preventing the lapel and fall of the extractable expandable bit 1. the required axial load is expanded until the sizing tool 13 exits the multi-beam expandable tubes 2. After that, the sizing tool 13 with the retractable sliding bit 1 is removed.

The proposed device for simultaneous drilling and fastening of areas of shedding and collapses during well drilling is reliable in operation, allows drilling and installation of the device in directional and horizontal wells, transmitting the necessary torque for drilling, eliminating non-expanded areas during drilling, and also eliminating emergency situations associated with the sludge of the upper part of the column of profile pipes, the lapel and the fall of the extracted sliding bit during its extraction.

Claims (1)

A device for simultaneous drilling and fixing of zones of shedding and collapses during drilling of a well, including a retrievable extendable bit connected to a casing string of multi-beam expandable pipes with the possibility of straightening them with excessive pressure with fixation relative to the walls of the well, lowered on a landing sub, connected with the possibility of disconnection with a drilling string pipes with subsequent extraction of the landing sub with the drill string, characterized in that the extractable sliding bit is fixed in the working position by a shear element that fixes the rod with the drill head relative to the bit body and is made so that it assumes a transport position when the ball is seated in the rod seat and created excess pressure, in addition, the internal thread of the body of the retrievable expanding bit is provided with grooves for the locking rings of the sizing tool, as well as the landing sub, equipped with spikes inserted into the profile part of the upper end casing strings of multi-beam profile pipes is equipped with a groove with a cone for narrowing the cylindrical end of the upper multi-beam casing pipe, on which a guide funnel is made, sealed with an elastic sealant.

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