RU101076U1 - DEVICE FOR FORMING AXIAL LOAD ON THE CHISEL - Google Patents

Abstract

 A device for forming an axial load on a bit containing a drill string and a downhole motor with an axial support attached to it by an adapter, an additional flowing axial support with a thrust bearing, an elastic element in the form of a steel coil spring for coaxially mounted between the shaft of the downhole motor and the drill string above the engine, coaxially smooth transmission of axial forces from the drill string to the upper end of the shaft of the downhole motor; sleeve for rigid transmission of axial vibrations to the drill string from the upper end of the shaft a, and configured as a poppet generator axial hydraulic force transmitted to the upper end of the shaft of a downhole motor, characterized in that the generator of the axial hydraulic force has several poppet valves, plates which are in the form of carbide sleeves with a skirt and mounted to traverse carbide saddles.

Description

The utility model relates to the field of mechanical engineering, mainly to drilling wells with hydraulic downhole motors (HWD), and, in particular, to drilling directionally curved wells with large zenith angles and with horizontal sections of their bore.

In deep hole drilling, electromagnetic, mechanical, and hydromechanical devices are known for generating axial load on a bit.

A device is known that is installed between the drill string and the downhole motor [Izosimov A.M. Device for creating axial load on the bit. // Drilling and oil. - 2008. - No. 1. - P.46-47.] The device consists of a housing inside which an electromagnetic coil is placed, a hollow square rod with a non-magnetic lower part, a spring that softens possible sudden movements of the rod, seals, contact coupling, contact rod, with valves fixed to it, saddles and power anchors. The operation of the device is based on the supply of electricity with the necessary voltage and current to the electric drive armature, which extends and contacts the borehole walls, sensing the reaction force of the bottom hole, and an electromagnetic coil, which moves the rod due to electromagnetic forces and creates an axial load on the bit. The device has its certain disadvantages: the process of forming the load on the bit does not occur continuously - after the stroke has been generated, the device turns off, the bit feed regulator moves the drill string with the device body towards the bottom, after which the process repeats; there is no mechanism for transmitting axial vibrations of the drill bit, which is necessary to reduce the friction forces of the drilling tool lying on the bottom wall of the well; in the device, in addition to the flushing unit of the bit, there are no mechanisms for the formation of axial hydraulic force on the bit, in connection with which, between the feeds to the bottom of the bottom end of the column, the axial load on the bit after developing the stroke of the rod can be reduced to zero; the formation of the axial load on the bit is difficult due to the complexity of the structural design of weighted pipes, in which it is necessary to embed an electric cable.

To implement the formation of axial load on the bit when drilling directional and horizontal wells, a device is known that is installed between the shaft of the downhole motor and the bit [G. Luzyanin, V. Galichenko, V. Razuvaev, L. Matveenko, Gordeev Yu.P., Smirnov V.N. The results of field tests of the amplifier load on the bit. // Oil industry. - 1994. - No. 12. - S.26-29.], Which consists of a housing formed by two screw-in adapters with connecting threads, with a grill installed in it and a partition with a side hole, between which there is a thrust sleeve, in the cavity of which there is a massive ball. The ball, rolling on the inner surface of the sleeve due to the rotation of the device, periodically partially blocks the bore hole, resulting in a partial hydraulic shock, the pressure of which gives a force applied suddenly in the direction of the bottom and helps to overcome the friction force of the drill string against the borehole wall and transfer the load to the bit.

Despite the structural simplicity and reliability of the device, it also has certain disadvantages: to ensure the operation of the device, it is necessary to roll the ball on the inner surface of the sleeve, and this is possible only when the drill string is rotated; the response frequency of the device is directly dependent on the rotation frequency of the drill string; the device does not have a mechanism for transmitting axial vibrations of the drill bit.

It is also known [RU 2124617 C1, IPC 6 ЕВВ 4/02, 19/08, publ. 1999] a device for forming an axial load on a bit installed between a drill string and a downhole motor, consisting of a sub, in which an additional flow axial sliding support is coaxially mounted, an elastic element, such as a steel coil spring, for smooth transmission of axial forces from the string to the upper end face downhole motor shaft, steel sleeve for rigid transmission of axial vibrations from the upper end of the shaft to the drill string, and also a generator, for example a poppet valve, axial hydraulic force I, transferred to the upper end face of the shaft of the downhole motor, while the thrust bearing of the additional axial support is made in the form of a cup and mounted on the upper end of the shaft of the downhole motor, the heel is made in the form of an interchangeable rod with a spherical working surface and installed in the heel body, the spring and the sleeve are mounted a traverse with holes for the flow of flushing fluid with a poppet valve integrated in the traverse to generate a pressure drop in the heel body, above the spring and the sleeve, and the valve plate mounted on a rod that is rigidly embedded in the protrusion on the upper central part of the heel body, the sleeve is made with holes for free flow of flushing fluid from under the valve to the holes in the heel body, while a gap is made between the upper end of the sleeve and the traverse, the size of which is regulated by rings located above the traverse, while the rings are pressed by the working sub.

The disadvantage of this device is the low wear resistance of the additional axial support, in which the friction of the rotating thrust bearing and the fixed heel occurs at high contact loads.

The closest technical solution adopted for the prototype [RU 77329 U1, IPC 6 Е21В 4/02, 19/08, publ. 2008], is a device for forming an axial load on a bit installed between a drill string and a downhole motor, consisting of a sub in which an additional flow axial sliding bearing is coaxially mounted, an elastic element, such as a steel coil spring, for smooth transmission of axial forces from the string to the upper end of the shaft of the downhole motor, a steel sleeve for rigid transmission of axial vibrations from the upper end of the shaft to the drill string and an axial hydraulic generator made in the form of a poppet valve force transmitted to the upper end of the shaft of the downhole motor, with the thrust bearing of the additional flow axial sliding bearing made in the form of a sleeve and two disks, fixed with a nut on the upper end of the shaft of the downhole motor, the heel is made in the form of a ring with rubberized contacting surfaces and installed in the housing, with the ability to move in the axial direction along the key relative to the housing of the device.

The disadvantage of this device is the narrow range of regulation of the differential pressure, as well as low wear resistance of the poppet valve and sleeve.

The problem to which the claimed utility model is directed is to increase the rate of penetration of wells and reduce the cost of 1 m of drilling. The problem is solved by achieving a technical result, which consists in increasing the control range of the differential pressure and increasing the reliability of the device by changing the number and shape of the poppet valve and increase the wear resistance of the poppet valve using plates and seats made of carbide.

The specified technical result is achieved by the fact that in the known device for forming an axial load on a bit containing a drill string and a downhole motor with an axial support connected to it by an adapter, an additional flowing axial support with a thrust bearing is coaxially installed between the shaft of the downhole motor and the drill string above the engine in the sub , an elastic element in the form of a steel coil spring for a smooth transmission of axial forces from the drill string to the upper end of the shaft of the downhole motor, sleeve for rigidly transmitting axial vibrations to the drill string from the upper end of the shaft of the downhole motor, and an axial hydraulic force generator configured as a poppet valve transmitted to the upper end of the shaft of the downhole motor, it is new that the axial hydraulic force generator has several poppet valves, the plates of which are made in the form carbide bushings with a skirt and carbide saddles installed in the traverse.

The device shown in the drawing.

A device for forming an axial load on a bit contains an additional flowing axial support arranged coaxially between the drill string and the downhole motor and contains a thrust bearing made in the form of a sleeve 1 and two disks 2 secured by a spring washer 3 and a nut 4 on the upper end of the shaft 5 of the downhole motor , heel 6, made in the form of a ring with rubberized contact surfaces, fixed in the housing 7 with a split nut 8 with a locking screw 9, holes 10 in the housing 7, a key 11 mounted between the housing 7 and a sub 12 to accommodate the proposed device, an elastic element, such as a steel coil spring 13, for smooth transmission of axial forces from the drill string to the upper end of the shaft 5 of the downhole motor sleeve 14 with holes 15 for hard transmission of the axial vibration of the drill string from the upper end shaft 5, two rods 16 for mounting plates 17 of the valves, made in the form of carbide bushings with a skirt, using a ring 18, a spring ring 19 and a nut 20, the upper beam 21 with holes 22 and with carbide grades embedded in it lamas 23, acting as a generator of axial hydraulic force transmitted to the shaft of the downhole motor, a working sub 24, adjusting rings 25, seals 26 and the housing 27 of the downhole motor.

The device operates as follows.

After installing the thrust bearing, made in the form of a sleeve 1 and two disks 2, fixed with a spring washer 3 and a nut 4 on the upper end of the shaft 5 of the downhole motor and the entire device on the casing 27 of the downhole motor, the spring 13 is pressed by the rings 25 and the sub 24 to its axial size with the formation of the calculated value of the gap between the upper end of the sleeve 14 and the traverse 21 for transmission from the shaft 5 to the drill string necessary for the parameters of axial vibrations coming from the bit. Simultaneously with the preloading of the spring 13, the initial position of the valve plate 17 in the hole of the valve seat 23 installed in the traverse 21 is established to ensure the average design pressure drop in the holes 22 and the valve integrated in the traverse 21, and, therefore, to provide the initial calculated value of the additional hydraulic axial force on the upper end of the shaft 5. Next, we will consider the operation of the device for forming the axial load on the bit for the case of drilling a well in its horizontal or inclined sections.

During the supply of the column to the bottom due to the axial force transmitted from the column through the sub 24 and the ring 25, the yoke 21 moves towards the shaft 5 of the hydraulic downhole motor, the spring 13 is compressed, the gap between the yoke 21 and the sleeve 14 is reduced, simultaneously with this process through the disks 2 of the thrust bearing, the heel 6, the housing 7, the sleeve 14, the yoke 21 and the rings 25, the transmission of axial vibrations from the motor shaft to the drill string is intensified, as a result of which the friction forces of the string against the borehole walls are reduced, and the drill string it moves freely and quickly to the bottom is formed the design value of the axial load on the bit. At the end of the supply of the column to the bottom, the valve plate 17 is in its upper position relative to the yoke 21, and the clearance between the sleeve 14 and the yoke 21 and the hydraulic axial force on the motor shaft from the pressure drop in the column become minimal. At this time, the widest range of axial vibrations transmitted from the upper end of the shaft 5 to the drill string, and the axial load on the bit is maximum and is transmitted to it with higher efficiency than in the absence of the proposed device.

As the bottom hole collapses in the interval between the column feeds to the bottom, the stem 16 and valve plate 17 moves toward the bottom, the spring 13 unclenches, the gap between the crosshead 21 and the sleeve 14 increases, and the range of vibrations transmitted to the column from the end of the motor shaft narrows but the indicated vibrations continue to act on the column lying on the bottom wall of the well mainly with increased amplitudes, while the lower part of the column continues to shift towards the bottom, loading the bit with axial force. At a time between the feeds of the column, when the rod 16 is displaced to the bottom of the valve plate 17, the clearance area for the fluid to flow through the valve decreases, and the hydraulic axial force on the beam 21 and then on the motor shaft 5 increases, and with increased ripple due to the rigid the connection plate 17 with the fifth 6 of the device.

Claims (1)

A device for forming an axial load on a bit containing a drill string and a downhole motor with an axial support attached to it by an adapter, an additional flowing axial support with a thrust bearing, an elastic element in the form of a steel coil spring for coaxially mounted between the shaft of the downhole motor and the drill string above the engine, coaxially smooth transmission of axial forces from the drill string to the upper end of the shaft of the downhole motor; sleeve for rigid transmission of axial vibrations to the drill string from the upper end of the shaft a, and configured as a poppet generator axial hydraulic force transmitted to the upper end of the shaft of a downhole motor, characterized in that the generator of the axial hydraulic force has several poppet valves, plates which are in the form of carbide sleeves with a skirt and mounted to traverse carbide saddles.