WO2018160095A1

WO2018160095A1 - Stop sub (variants)

Info

Publication number: WO2018160095A1
Application number: PCT/RU2017/000772
Authority: WO
Inventors: Андрей Васильевич БАБИКОВ; Николай Дмитриевич ДЕРКАЧ; Илья Валериевич ЗЛОБИН; Дмитрий Леонидович СЕЛЯНСКИЙ; Алексей Сергеевич АБЫЗОВ; Андрей Михайлович ГУРКИН
Original assignee: Закрытое акционерное общество "НГТ"
Priority date: 2017-03-01
Filing date: 2017-10-23
Publication date: 2018-09-07
Also published as: RU2648369C1

Abstract

The group of inventions relates to the field of drilling equipment. A sub stop mechanism is fastened between bearings and comprises a tubular stopping member, the cavity of which contains an annular insert with stop recesses. Each recess has a pivotable spring-loaded pawl disposed therein. Splines are provided on the outer surface of a shaft. Rings having apertures which receive the ends of the pivot pins of the pawls, are connected to the tubular stopping member and abut the end faces of the annular insert from two sides, said annular insert having splines on the inner surface thereof, which are seated on the splines of the shaft. An upper conical connection of a housing is configured in the form of an outwardly flared conical socket with a screw thread on its inner surface. The outer surface of a lower conical connection of the housing is provided with an external screw thread. According to a first variant, the lower surface of each pawl consists of two portions, one shorter than the other, forming an outward facing apex. In a working position, the long surface of a pawl impinges on the surface of a recess of the annular insert. In a non-working position, the short surface of the pawl impinges on the surface of the recess; with the pawl in this position, a continuous annular gap is formed between the upper surface of the pawl and the surface of the annular insert. According to a second variant, the lower surface of each pawl is flat; when the pawl is in a working position, its lower flat surface impinges on the surface of a recess of the annular insert. In a non-working position, a continuous annular gap is formed between the lower flat surface of the pawl and the surface of the annular insert, and the depth of a recess of the tubular stopping member is greater than the thickness of the pawl disposed therein. This provides an increase in the lifespan of the stop sub.

Description

Locking sub (options)

These technical solutions relate to drilling equipment, in particular to drill columns equipped with turbodrills and means of protecting shafts from breakage. Technical solutions relate to the means of connecting the stator of the engine with its rotor, which selectively transmit torque from the stator of the downhole tool to the rotor and eliminate breakdowns in cases of sticking of the drill bit, and also provide effective release of the bit from the stick.

The locking sub is a separate unit that is mounted on top of the turbine section of the turbo-drill and is connected to the upper part of the turbo-drill shaft (turbine section), while the shaft of the locking sub is connected to the shaft of the turbine section through a conical-splined coupling. The locking mechanism of the sub allows the shaft to rotate in one right direction. In case of sticking the bit, when the drill pipe rotates in the indicated direction, the shaft of the sub of the locking mechanism is blocked. In this case, the rotation of the shaft of the turbine section is carried out through the locking mechanism, the torsion bar and the spindle shaft and, further, the rotation is transmitted to the bit, while the sticking of the bit is eliminated.

In case of sticking the bit, shaft breakage is excluded by introducing protection, which is located in the locking sub. Protection provides rotation of the locking mechanism in the housing of the locking sub when the maximum torque on the shaft is reached.

Known locking clutch for the selective transmission of torque from the stator of the downhole tool to the rotor of the downhole tool, containing at least one locking dog a ratchet mechanism located on the rotor, wherein at least one locking dog of the ratchet mechanism comprises a loading path, at least one pivot axis and a center of mass. At the same time, at least one locking dog of the ratchet mechanism is adapted to be biased into the engaged position by the biasing mechanism, while at least one locking dog of the ratchet mechanism transmits force from the stator to the rotor when they are in the engaged position and the centrifugal the force compresses at least one locking dog of the ratchet mechanism to the disengaged position when the rotor rotates at a speed above the disengagement speed. At least one locking dog of the ratchet mechanism is rotatable from an engaged position to an uncoupled position around at least one pivot axis. At least one locking dog of the ratchet mechanism is configured to be in an engaged position when the total rotor speed is not greater than the stator rotation speed and less than the trip speed. At least one locking dog of the ratchet mechanism is configured to delay the movement of the ratchet mechanism when the total rotor speed is greater than the stator rotation speed and less than the disengagement speed, while the clutch speed can be the same with the disengagement speed, while the clutch speed is less than the disengagement speed. The locking clutch has a biasing mechanism containing torsion springs. In the locking sleeve, torsion springs are selected to move at least one locking dog of the ratchet mechanism to the engaged position when the rotor rotates more slowly than the clutch speed. In the stop clutch, the biasing mechanism may comprise a fluid flow directed across, at least one stop dog ratchet mechanism. In this case, the downhole tool may be a hydraulic downhole motor or a turbine hydraulic downhole motor or an electric motor. In this case, the stator can be mounted on the drill string in the retainer for rotation with it. In the stop clutch, the rotor comprises a plurality of corresponding recesses adapted to receive the stop dogs of the ratchet mechanism when they are in the engaged position. In the lock sleeve, the inner diameter of the stator comprises a plurality of lock V-grooves configured to receive the front end of at least one lock dog of the ratchet mechanism. In the locking sleeve, the front end of the at least one locking dog of the ratchet mechanism is configured to inhibit the movement of the ratchet mechanism across the locking V-grooves when the rotor rotates at a speed greater than the stator speed, but less than the trip speed. In the locking sleeve, the front end of the at least one locking dog of the ratchet mechanism is adapted to engage with one of the locking V-grooves when the rotor rotates at a speed less than or equal to the speed of rotation of the stator. In the locking sleeve, at least one locking dog of the ratchet mechanism contains material with a density higher than that of steel. In the locking sleeve, the locking dog of the ratchet mechanism comprises a dynamic (movable) pivot axis. In the locking clutch, the dynamic axis of rotation moves from the first position to the second position based on the change in rotor speed (RU 2471954 C2, 10.20.2012 - prototype).

Patent RU 2471954 C2 provides a method for selectively transmitting torque from a stator of a downhole drilling motor to a rotor downhole drilling motor, the method presented in the claims essentially describes the operation of the locking clutch. The method is characterized by a sequence of actions: first, a clutch is placed between the stator and the rotor, while the clutch contains at least one ratchet locking dog that rotates around the axis of rotation between the engaged position and the disengaged position. Next, rotate at least one locking dog of the ratchet mechanism from the engaged position to the disengaged position under the action of centrifugal force when the rotor speed exceeds the disengagement speed. Then, at least one locking dog of the ratchet is rotated from the disengaged position to the engaged position when the rotor speed falls below the disengagement speed. The torque is transmitted from the stator to the rotor of the downhole drilling motor through the loading path of at least one stop dog of the ratchet mechanism when it is in the working position. In the method, the biasing elements push at least one locking dog of the ratchet mechanism into an engaged working position (RU 2471954 C2, 10.20.2012 - prototype). A similar device is described in patents US 8776915, 07.15.2014 on the application US 20110214963 A1, 09/08/2011.

In the patent RU 2471954 C2, an analysis of well drilling methods is presented, the disadvantage of drilling with a hydraulic downhole motor is mentioned when the rotation of the drill string is seized (stopped by rotation resistance) and the movement of the drill string continues using the hydraulic bottom hole motor. During such periods, the drill string slides in the wellbore as it drills and has no rotation to prevent sticking columns in the reservoir. The drill string can rotate at a relatively low speed to prevent the drill string from sticking in the wellbore, and the drive shaft of the hydraulic downhole motor (rotor) mounted above the assembly can drive the drill bit at high speed. In this case, the hydraulic downhole motor converts the energy of the drilling fluid under high pressure into the mechanical energy of rotation of the drill bit, an example of which is given in the patent US 4187918. In a screw downhole motor, drilling fluids under pressure passing through the stem of the drill string come into contact with the stator and rotor so that create the resulting torque on the rotor, which is then transmitted to the drill bit. Hydraulic downhole motors are characterized by low speed and high torque transmitted to the drill bit. Such motors are suitable for use with cone and chisel bits with polycrystalline diamond inserts.

In turbine hydraulic downhole motors, one or more turbine power sections are used to generate torque on the drill bit. Each power section consists of fixed stator vanes and a rotor assembly containing rotating vanes mechanically connected to the rotor shaft. Preferably, the force sections are configured such that the blades of the stator stages direct the flow of drilling fluid to the respective rotor blades to create rotation. The rotor shaft, which may be monoblock or may contain two or more connected shafts, such as a flexible shaft and an output shaft, is connected to the bit by the end and drives it. High-speed mud flow to the rotor blades creates rotation rotor and drill bit relative to the stator. Turbine hydraulic downhole motors are characterized by high speed and low torque transmitted to the drill bit. Due to the high speed, the output of the turbine hydraulic downhole motor is suitable for diamond bits. In this case, the stator of the drill string motor is connected to the string and rotates at the same speed with it.

However, since turbine hydraulic motors have low output torque, drill bits attached to them are more prone to sticking when they come across some formations. This happens when the resistance to rotation of the bit becomes greater than the torque that the engine blades are capable of creating. In the case of sticking the drill bit during the "rotary" drilling, in which the drill string is rotated and used to drive the bit. It is common practice to apply high torque to the drill string to release the drill bit. However, in drill strings using downhole motors, rotation between the rotor and stator can prevent the transmission of torque from the drill string to the drill bit. As a result, the only torque that can be transmitted to the stuck drill bit to release the bit is the torque that the hydraulic downhole motor can create. Because turbine hydraulic downhole motors produce relatively low torque, they may not be able to rotate a stuck drill bit.

The prototype essentially represents a one-way coupling having means for automatically connecting the rotor to the stator when the body rotates, and the bit gets stuck, and the specified tool provide free rotation of the rotor when the speed of the bit is greater than the speed of the stator. This device, however, does not prevent the locking means from rubbing against the rotor or stator during normal operation - when the bit is not stuck and the shaft rotates at a faster speed than the motor housing. In this case, the locking agent is subject to rapid abrasion and loss of functionality, if not isolated from the external environment and at the same time not protected from the abrasive effects of the drilling fluid at relatively high speeds of turbines and some high-speed hydraulic downhole motors.

In the invention RU 2471954 C2, a method and means are provided for preventing sticking of a drill bit and its release from sticking. It is possible to use torque from the drill string to the stator of the downhole motor and then from the stator of the motor to the rotor, while additional actions with the drill string and flow rate of the solution are excluded. As a result, if the bit is tacked and the stator is free to rotate, then the stator is connected with the rotor of the engine using a special tool, and when the rotor rotates at a speed exceeding the speed of rotation of the stator. The specified means disconnect the stator from the rotor. To perform these actions, the invention RU 2471954 C2 used a lock-up clutch for selectively transmitting torque from the stator to a rotor connected to the downhole tool. The coupling contains locking dogs rotatably mounted on the rotor, each dog having a loading direction, a pivot axis and a center of mass thereof, under the influence of which the moment of its rotation relative to the center of mass is applied to the dog. Each dog deviates into an interlocked position by a mechanism its rotation relative to the axis of rotation, it transfers the force of the moment of rotation from the stator to the rotor in the direction of loading, when it is in a locked position. When the locking sleeve rotates, the centrifugal force rotates each locking dog relative to the axis of its attachment and puts it in the disengaged position when the rotor rotates at a speed that overcomes the dog’s adhesion to the rotor and stator. In this position, the dog disengages from the stator.

In the patent RU 2471954 C2, in the case of a sticking of a bit in the well, the stop sub does not exclude the need for turning the bit by external force, since it is made integral with the turbodrill body and its shaft, which is associated with the great complexity of putting the turbodrill into operation. Moreover, these actions lead to the inability to install and replace the turbodrill with a drill. In the known locking sub, the locking mechanism is an integral part of the downhole motor. Such a locking mechanism cannot be removed and replaced with a drill, and to replace the sub, complete disassembly of the downhole motor and sub is necessary, which reduces their resource. Mentioned operations also significantly increase the complexity of installation and dismantling.

In the patent RU 2471954 C2 at the location of the locking sub, the latter has a negative impact on the reliability of the device and its resource, since the entry of each dog into engagement with the housing and its disengagement is associated with significant wear on the dogs and their working surfaces in contact, which leads to the need for frequent replacement and dismantling of the column. The specified wear occurs as a result of a relatively high concentration of stresses at peak loads in the areas of the recesses in the housing under the dogs located in them and in the areas where the dogs are attached to the rings (flanges 206 and 234) of the device described in this patent. Another disadvantage of the known sub according to the said patent is its unsatisfactory resource under severe conditions, in the environment of drilling fluid, salts of which and abrasive particles adversely affect the joints of the sub having gaps. Such gaps include the gap between the end of each axis of the dog and the surfaces of the holes made in the dogs 208 and flanges 206, 234 (FIG. 2B, description of patent RU 2471954 C2), as well as the gaps between the turns of the torsion spring 214, by which the dog returns to the original inoperative position. These gaps provide small angular displacements of the friction surfaces of the coil of the spring relative to each other, as well as angular displacements of the axis surface relative to the surfaces of these holes. As a result of this, gaps of particles and salts of the drilling fluid accumulate in the indicated gaps, which, as a result, removes the sub from a working state prematurely before its wear, since the dogs and springs are blocked by the drilling mud deposits.

There is also an unsatisfactory shape of each dog, due to the fact that the end working surfaces 232 and 240 (FIG. 2c of the patent specification RU 2471954 C2) unsatisfactorily interact with the inclined working surfaces of each corresponding rotor tooth 202 (FIGS. 3 and 4, patent description RU 2471954 C2). This is due to the fact that dogs with the indicated working rounded surfaces are made to facilitate entry into interaction with the corresponding rounded concave working surfaces of the rotor 202 and the inclined working surfaces of the stator 204 (Fig. 3, description of patent RU 2471954 C2). End surfaces of each dog also interact with the flat inclined sections of each tooth of the rotor. As a result, each dog in its working position under load has the ability to slide its rounded end surfaces along the inclined sections of the rotor tooth, its inclined surfaces and along the working inclined surfaces of the stator 204. In the event of slipping of the working surfaces along the working surfaces of the rotor and stator, the load is transferred to the axis of attachment dogs, and this load has a bending character and is the cause of the bend of the axis of the dog. With long-term operation of the sub, these reasons lead to the displacement of the dogs from their design position, which is the reason for the breakage of the axles, jamming of the dogs and a reduction in the life of the sub.

Another significant disadvantage of the prototype is that the sub is made integral with the turbo-drill body (stator) and its shaft (rotor), and in the event of a breakdown of the sub, it is necessary to dismantle the column, which involves removing it from the well, dismantling and replacing the sub together with the downhole motor .

The common features of the prototype and the invention presented in this description is that they relate essentially to devices for transferring torque from one part of the drill string to its other part - to locking sub, each of which contains a tubular housing with upper and lower conical joints at the ends, a shaft located in the housing on the supports and a locking mechanism connected to it, including a tubular stop, in the cavity of which there is an annular insert connected to the shaft with a radial but located by stop grooves, evenly spaced around the circumference of the annular insert, in each stop groove there is a spring-loaded stop rotary on the axis a dog, the ends of the axis of which are located in the holes of the rings located in the cavity of the tubular stop and adjacent to the ends of the annular insert from its two ends, each dog is spring loaded with torsion springs so that it can be pressed into the stop groove of the tubular stop in the “closed” position so that it is located in the thrust groove of the annular insert and one end thereof abuts either in the radial recess of the abutment or in the protrusion of the groove made in the annular insert, and each radial recess of the abutment forms a persistent groove for engagement with it sidetracking. (General features of the invention and prototype are set forth in terms of the invention presented herein).

The technical result of the invention presented in this description is to increase the resource lock stop sub.

The technical result was obtained by the first version of the locking sub, comprising a tubular housing with upper and lower conical joints at the ends, a shaft located in the housing on the supports and a locking mechanism connected thereto, including a tubular stop, in the cavity of which there is an annular insert connected to the shaft with radially arranged thrust grooves, evenly spaced around the circumference of the annular insert, in each thrust groove there is a spring-loaded locking dog turning on the axis, to The axes of which are located in the holes of the rings located in the cavity of the tubular stop and adjacent to the ends of the annular insert from its two ends, each dog is spring loaded with torsion springs with the possibility of pressing it into the stop groove of the tubular stop in the “closed” position so that it is located in the stop the groove of the annular insert and one end thereof abuts either in the radial recess of the stop or in the protrusion of the groove made in the annular insert, and each radial recess of the stop forms a stop groove for interacting with the dog’s end face, with splines made on the outer surface of the shaft, the rings connected to the tubular stop and adjacent to the ends of the annular insert on both sides, which is made with splines on its inner surface and the splines of the annular insert are mounted on the splines of the shaft, this upper conical connection of the housing is made in the form of an expanding conical socket with a thread on its inner surface, and on the outer surface of the lower conical connection of the housing is made of an external thread while the locking mechanism is located and secured between the supports, the lower surfaces of each dog of the locking mechanism are made flat with the vertex facing outward, and one lower flat surface of the dog is made short - it is shorter than its other lower flat surface, which is made long - and the working position of each dog, when it is engaged with the tubular stop and the annular insert, the dog rests its lower long surface on the groove surface of the annular insert, and in ochem position of each pawl, when it is thrust into the annular groove of the insert, the pawl rests on the bottom surface of the short surface of the groove and in this inoperative position the pawl between each of its upper surface and an annular surface of the insert is formed on the perimeter of the annular insert uninterrupted annular gap.

The angle between the lower flat working surfaces of the dog is within 110-160 °, one flat surface is shorter than the other flat surface of the dog, the axis of the dog is located in the zone of the short flat surface of the dog, in the zone of the axis there is a recess - a ledge, to which one end of the spring abuts, the other the end of which abuts against the recess of the annular insert, lateral surfaces transverse to the axis made with angular recesses parallel to the upper surface of the dog, with each angular recess located with the possibility of its stop in the adjacent ring and restricting the exit of the dog beyond the diameters of the outer surface of the adjacent ring when the dog is rotated by centrifugal force.

At each end of the axis of the dog, a torsion spring is installed, each dog having two end surfaces located across the axis of the dog, and each corner recess of the dog is made along the radius of the body of revolution and it is parallel to the outer upper surface of the dog.

The technical result was obtained by the second version of the locking sub, comprising a tubular body with upper and lower conical joints at the ends, a shaft located in the housing on the supports and a locking mechanism connected to it, including a tubular stop, in the cavity of which an annular insert connected to the shaft with radially arranged thrust grooves, evenly spaced around the circumference of the annular insert, in each thrust groove there is a spring-loaded locking dog turning on the axis, to The axes of which are located in the holes of the rings located in the plane of the annular insert and adjacent to the ends of the tubular stop from its two ends, each dog is spring-loaded with torsion springs with the possibility of pressing it into the stop groove of the ring insert to the “closed” position so that it is located in the persistent the groove of the tubular stop and one end thereof abuts either in the radial recess of the stop or in the protrusion of the groove made in the annular insert, and each radial groove of the stop forms a persistent groove for interacting with the end face of the dog, p On the outer surface of the shaft, slots are made, rings are connected to a tubular with emphasis and from both sides adjoin the ends of the annular insert, which is made with slots on its inner surface and the slots of the annular insert are mounted on the splines of the shaft, while the upper conical connection of the housing is made in the form of an expanding conical socket with thread on its inner surface, and an external thread is made of the outer surface of the lower conical connection of the housing, while the locking mechanism is located and secured between the supports, the lower surface of each dog of the locking mechanism is made and flat and in the working position of each dog, when it is engaged with the tubular stop and the annular insert, the dog rests its lower flat surface on the surface of the groove of the annular insert, and in the idle position of each dog, when it is in the groove of the tubular stop, between each its lower flat surface and the surface of the annular insert is formed around the perimeter of the annular insert a continuous annular gap, and the depth of each groove of the tubular stop is greater than the thickness of the dogs located in it.

Each dog has an angular recess under one end of the spring, the other end of which abuts against the adjacent surface of the tubular stop, and in the side view the dog has an upper flat working surface formed by the upper part of the dog, a lower flat working surface formed by the lower part of the dog, front and rear flat ends located at right angles to the lower flat working surface, left and right corner recesses.

The axis of each dog is located in the upper part of the dog so that a gap is formed between each end part of the axis and the lower part of the dog, and the surface of one end of the lower part of the dog is made flat with an upper angle rounded by the radius of the body of revolution, and the surface of the other end of the dog is made semicircular and this surface consists of two half-surfaces, one of which is a continuation of the lower part of the dog, and the other half-surface is a continuation of the upper part of the dog, and in the middle part of the dog these semi-surfaces merge into one continuous surface made along the radius of the body of revolution and this radius is equal to the radius of the body of revolution of the upper corner of the lower part of the dog.

Figure 1 shows a first embodiment of a locking sub with a locking mechanism installed in its housing.

Figure 2 - the first version of the locking mechanism.

In Fig.Z - the first version of the locking mechanism in cross section in the "open" position.

Figure 4 - the first version of the locking mechanism in cross section in the "closed" position.

Figure 5 - dog of the first embodiment of the locking mechanism, side view. Figure 6 - dog locking mechanism in a perspective view.

In Fig.7 - the first version of the locking mechanism in an enlarged view. On Fig - the first version of the locking mechanism in cross section in the "open" position in an enlarged view.

In Fig.9 - the first version of the locking mechanism in cross section in the "closed" position in an enlarged view.

Figure 10 - dog of the first embodiment of the locking mechanism, a side view in an enlarged view.

Figure 11 - dog of the first version of the locking mechanism in a perspective view in an enlarged view.

12 shows a second embodiment of a locking sub with a locking mechanism installed in its housing.

On Fig - the second version of the locking mechanism. On Fig - the second version of the locking mechanism in cross section in the "open" position.

On Fig - the second version of the locking mechanism in cross section in the closed position.

On Fig - dog of the second variant of the locking mechanism, side view. On Fig - dog of the second option in a perspective view.

On Fig - the second version of the locking mechanism in an enlarged view. On Fig - the second version of the locking mechanism in cross section in the "open" position in an enlarged view.

On Fig - the second version of the locking mechanism in cross section in the closed position in an enlarged view.

On Fig - dog of the second variant of the locking mechanism, a side view in an enlarged view.

On Fig - dog of the second option in a perspective view in enlarged view.

The first version of the locking sub (Figs. 1-11) comprises a tubular housing 1 (Fig. 1), in which a shaft 3 with splines on its outer surface is mounted on radial bearings 2. The housing 1 of the sub has an upper and lower conical connection 4 for its connection with the parts of the drill string. The upper conical connection 4 of the casing is made in the form of an outwardly expanding conical socket with a thread on its inner surface, and an external thread is made on the outer surface of the lower conical connection of the casing.

Between the supports 2, a locking mechanism 5 is located and fixed in the housing, comprising a tubular fixed stop 6 located in the housing and also an annular insert 7 located in the cavity of the stop with splines on its inner surface, mounted on the splined part of the shaft 3. In the slotted annular insert 7, there are made radially arranged stop grooves 8 (Fig. 4), arranged uniformly around the circumference of the insert, in each stop groove 8 there is a stop dog 9 with the possibility of its rotation on the axis 10 (Fig. 2) transverse to the shaft 3 the plane. The ends of the axis 10 are mounted freely in the holes of the rings 11 located in the cavity of the abutment 6, the rings 11 (Fig. 7) are rigidly attached to the ends of the spline insert 7. The ends of the axis 10 are mounted rigidly or freely in the holes of the rings 11 located in the cavity of the abutment 6, rings 11 (Fig. 7) are rigidly connected to the abutment 6 on its two sides, while the rings 11 are rigidly attached to the ends of the spline insert 7. Each axis 10 can also be pressed into the dog and made whole or in two parts. Thus, each dog 9 can be rigidly mounted on the axis 10, made in the form of a single pin, pressed into the through hole of the dog 9 or the axis 10 can be made in the form of two pieces of the pin, which are pressed into two holes of the dog, located on both sides of the dog .

At each end of the axis 10, a torsion spring 12 is installed (Fig. 7), one end 13 of which abuts against the recess 14 of the insert 7, and the other end 15 of the spring abuts against the ledge 16 of the dog 9 made from below (Fig. 10, 11). The rings 11 are adjacent to the spline insert 7 from its two opposite ends, and the torsion springs 12 are installed with the possibility of squeezing the dogs in the stop grooves 8 of the stop 6 (Fig. 3) to the closed position.

Each dog 9 is located in the abutment groove 8 of the spline insert 7 so that one end thereof abuts either in the radial recess 17 of the abutment 6 (Fig. 3) or in the protrusion of the spline annular insert 7 (Fig. 4) formed by the abutment groove 8.

Each radial recess 17 (Fig.7) extends in the radial direction of the stop 6 and along its length, with respect to the housing 1 the recess 17 forms a stop groove, allowing the dog 9 to slip when the shaft rotates right, and when the shaft rotates left, the stop groove 8 wedges the dog.

Each ring 11 (Fig.7) is adjacent to the end face of the annular insert 7 so that each spring-loaded dog has the ability to squeeze it into the stop groove 8 (Fig.4) of the annular insert to the closed position. During operation, the dog is located either in the abutment groove 8 of the annular insert and one end abuts against the radial recess 17 of the tubular stop 6, or the dog abuts against the protrusion of the abutment groove 8 (Fig. 3) made in the annular insert.

Each dog 9 in a side view has a convex upper working surface 18 (figure 10), made along the radius of the body of revolution and the lower flat working surfaces 19 and 20, located at an angle to each other.

The angle between the lower flat working surfaces 19 and 20 is selected in the range of 110-160 °, and the surface 19 is shorter than the surface 20 and the axis 10 is located in the area of the short surface. Each dog has two end surfaces 21 and 22 parallel to the axis 10 and two transverse lateral surfaces axis of the surface with angular recesses 23 parallel to the upper surface 18 of the dog.

In the axis zone, a recess is made - a step 16, forming the lower surface of the dog, to which the end of the spring 12 is adjacent. Each corner recess 23 is located with the possibility of its abutment in the adjacent ring 11 (Fig. 7) and restricting the exit of the dog outside the outer surface diameter ring 11 when turning the dog under the action of centrifugal force. Limiting the exit of the dog outside the diameter of the adjacent ring 11 excludes the possibility of contact and friction the upper surface 18 of the dog with the surface of the stop 6, which significantly reduces the wear of the dogs.

For this, in the inoperative position of the dogs (Fig. 8), when they are in the radially arranged thrust grooves 8 and in this position each dog is supported by the lower flat surface 19 on the surface of the groove 8, then between each upper surface 18 of the dog 9 and the surface of the insert 7 is formed around the perimeter of the insert 7 is a continuous annular gap 37.

The second version of the locking sub (Fig. 12-22) also, like the first version, contains a tubular housing 1 (Fig. 12), in which a shaft 3 is mounted on the radial bearing bearings 2, while the sub housing has threaded ends 4 for connecting it with parts of the drill string.

Between the supports 2 in the housing 1 there is a locking mechanism 5 containing a tubular fixed stop 6, which is mounted and fixed in the housing 1, as well as a spline insert 7 located in the cavity of the stop 6, mounted on the spline part of the shaft, while the insert 7 is made radially oriented thrust grooves 8 (Fig.20), located evenly around the circumference of the insert. In each persistent groove 8 is a part of the locking dog 9, which is installed in the grooves 24 of the stop 6 (Fig.14, 15). The dog 9 with its one end abuts against the stop of the groove 8 (Fig. 9) in one working position - when the spline insert 7 contacts through the dogs 9 with the stop 6 when the shaft 3 rotates left.

Each dog 9 is installed with the possibility of rotation on the axis 10 in the plane transverse to the shaft 3 (Fig.13, 17), the ends of the axis 10 are installed in the holes of the rings 11 located in the cavity of the abutment 6. The rings 11 are attached to the ends of the abutment 6 from both sides, with persistent grooves 24 are located in the fixed stop 6, these grooves 24 are made radially oriented and extend along the entire length of the stop 6.

It is significant that in the second embodiment, the depth of each groove 24 is greater than the thickness of the dog 9 located in it, so that when the dog 9 is completely in the groove 24, a continuous annular gap 37 is formed between its surface and the surface of the insert 7 (Fig. 19).

It is significant that in the second version of the sub, torsion springs 12 installed on each end of the axis 10 (Fig. 13), the ends 13 abut the angular recesses 31 and 32 of the dog 9 (Figs. 17, 18), and the other ends 15 of the spring abut against the internal surface 25 of the stop 6 (Fig. 18). Moreover, in any of the indicated positions of each dog 9, it is located completely or partially in the stop groove 24 of the stop 6 (Fig.13).

Each dog 9 in a side view has an upper flat working surface 26 (Fig. 17) formed by the upper part 27 of the dog, a lower flat working surface 28 formed by the lower part 29 of the dog, front and rear flat ends 30 located at right angles to the lower flat the working surface 28, the left and right corner recesses 31 and 32, in which the springs 12 are located (Fig. 18). At the same time, the upper part 27 of the dog (Fig. 17) is made shorter than the lower part 29 of the dog so that the indicated angular recesses 31 and 32 are formed between them.

The depth of each groove 24 (Fig. 15) is greater than the thickness of the dog 9 located in it (Fig. 14) by an amount that allows the dog to slip freely when the shaft rotates relative to the spline insert 7 in one of the working positions of the dog, and in the other position of each dog, when the shaft 3 rotates in the left direction, each dog 9 is in contact with the spline insert 7 and connects it to the stop 6 by jamming between them. Free slippage of the dog is achieved due to the location between the dog and the spline insert 7 of the annular gap 37.

The axis 10 of the dog is pressed into the hole of the upper part 27 of the dog so that between each end part of the axis 10 and the lower part 29 of the dog there is a gap 33 having a dimension t in FIG. The surface 34 of one end of the lower part 29 of the dog is made flat with the upper angle 35 rounded along the radius of the body of revolution. The surface 36 of the other end of the dog is semicircular and this surface consists of two half-surfaces, one of which is a continuation of the lower part 29 of the dog, and the other half-surface is a continuation top of the 27 dogs. In the middle part of the dog, these semi-surfaces merge into one continuous surface, made along the radius of the body of revolution and this radius is equal to the radius of the body of revolution of the upper angle 35 of the lower part 29 of the dog.

The first version of the sub works as follows. During the rotation of the shaft 3 at the beginning of the turbodrill operation (Fig. 1), the shaft 3 with the spline insert 7 rotates in one right direction, flushing fluid circulates between the spline insert 7 and the stop 6, while the dogs 9, pressed by the springs 12 to the “closed” position ", First slip along the recesses 17 of the stop 6. Then, when the shaft reaches 500-600 rpm, each dog due to the centrifugal force and the offset center of gravity of the dog relative to its axis of rotation 10, overcome the force of the spring 12, rotates around axis 10 and located in position when it is completely in the groove 8 with a spline insert 7 (Fig. 3). In this position, the lateral protrusions 23 on the end surfaces of the dog 9 abut against the thrust shoulder 25 of the rings 11 and do not allow the dogs to go beyond the grooves 8 of the spline insert 7. In this case, an annular gap 37 is formed between each dog and the stop 6, which eliminates the friction of the dogs against the stop 6 (Fig. 8) and their wear.

In the case of sticking the bit, when the shaft does not rotate, the housing 1 rotates with a stop 6 in the right direction, while due to the springs the dogs are pressed into the recesses 17 of the stop b and into the grooves 8 of the insert 7, as shown in Fig. 9. Dogs abut surfaces 21 and 22 against the working surfaces of the insert and stop. When this occurs, the dogs are jammed and the moment of rotation from the housing 1 is transmitted to the shaft 3. When the sub is operating, the spring 12 of the dog 9 rests on the surface 16 (Fig. 10) of the dog 9 and on the surface 14 (Fig. 7) of the groove 8 of the insert 7.

The second version of the locking mechanism works as follows.

During operation of the turbo-drill, the shaft 3 with the spline insert 7 (Fig. 14) rotates in the right direction, and washing fluid circulates between the spline insert 7 and the stop 6. Dogs 9, pressed by springs 12, slip along the grooves of the spline insert 7 and are lubricated by the flushing fluid.

Upon reaching a certain frequency of rotation of the spline insert 7 relative to the stop 6, the dogs tend to turn to the “open” position, overcoming the efforts of the springs due to the hydrodynamic force acting on each dog 9 from the side of the spline insert 7 in the cavity of the groove 8. In this position, the dogs 9 do not will be in contact with the spline insert 7 and will not wear out.

In case of sticking the bit, the shaft 3 with the spline insert 7 stops. In this case, the stop 6 begins to rotate in the right direction and the dogs under the action of the springs 12 are wrung out from their position shown in Fig. 14 and enter the grooves 8 of the spline insert 7. In this position, the locking mechanism of the sub is closed. When the shaft 3 rotates, the spline insert 7 rotates on the shaft in the right direction and the dogs 9 first slip along the grooves 8 of the spline insert 7. When the shaft reaches high revolutions, the dogs overcome the force of the springs 12 due to hydrodynamic force and each of them abuts the surface 26 against the surface the groove 24 of the stop 6 (Fig.14). This eliminates the friction of the dogs on the insert 7. When the shaft does not rotate, the case 1 rotates with the stop 6 fixed in it along with the dogs and rings 11 in the right direction. Due to the elasticity of the springs, the dogs are squeezed into the grooves 8 of the insert 7 (Fig. 15, 19), while each of them rests against the surface 34 (Fig. 21) in the groove 8 of the insert 7 and the surface 36 - in the groove 24 of the stop 6, as this shown in Fig.15, while the installation of the dogs in the working position. In this case, the torque from the housing 1 is transmitted to the shaft 3. In this embodiment, the springs 12 of each dog 9 abut against the surface 31 and 32 of the dog 9 (Fig. 18) and in the surface 25 of the groove 24 of the stop 6.

The two options for the design of the sub described above allow, when fixing the mechanism of the sub, to transmit the torque from the rotor to the bit through the shaft of the turbodrill. To prevent damage to the shafts, the locking sub provides more reliable protection by turning the locking mechanism in case of exceeding the permissible torque on the shaft of the turbodrill. To replace the sub, it is removed from the column, for this the sub body 1 is fixed, the upper part of the drill string is rotated in the direction of unscrewing it from the upper threaded end 4, then the lower part of the drill string is fixed and the lower threaded end 4 of the housing 1 of the sub is unscrewed from the upper threaded end drill string. After the worn out sub is released, a new sub in the reverse is installed in the column instead. sequence. Such autonomy of the sub allows it to be used in drill strings as an easily replaceable drill string assembly, which has a significant effect on reducing the complexity of installation and dismantling work. Since the sub at its lower end has a lower threaded end made in the form of a cone, and on top of the sub has an upper threaded end in the form of a bell, this design allows you to install the sub on top of the turbodrill, which reduces the inertial loads on the elements of the sub from the rotating masses of the drill string and into As a result, positively affect the increase in the resource of the sub. The two design options of the sub described above allow, when locking the sub mechanism, to transmit the moment of rotation from the rotor to the bit through the shaft of the turbo drill, to prevent breakage of which the stop sub is protected by turning the stop ring of the stop mechanism if the permissible torque on the turbo drill shaft is exceeded.

To replace the sub, it is removed from the column, for this the sub body 1 is fixed, the upper part of the drill string is rotated in the direction of unscrewing it from the upper threaded end 4, then the lower part of the drill string is fixed and the upper threaded end 4 of the housing 1 of the sub is unscrewed from the upper threaded end drill string. After releasing a worn out sub, a new sub is installed in the column in the reverse order instead. Such autonomy of the sub allows it to be used in drill strings as an easily replaceable drill string assembly, which has a significant effect on reducing the complexity of installation and dismantling work. Since the sub at its lower end has a lower threaded end in the form of a socket, and Since the sub has the upper threaded end in the form of a cone on top, this design allows you to install the sub on top of the turbodrill, which reduces the inertial loads on the elements of the sub from the rotating mass of the drill string and ultimately positively affects the increase in the resource of the sub.

The two design options of the locking sub presented above increase the service life of the described design by reducing the wear of the working elements of the switching mechanism of the sub, as well as by positioning the sub above the turbodrill, which reduces the load on the working elements of the sub.

Variants of the retainer sub ensure its autonomy and allow the sub to be used as a separate, easily replaceable drill string assembly; moreover, the design variants of the sub significantly increase its resource and reliability by reducing wear on the working surfaces of its elements when removing the bit from a stuck condition. Due to the fact that the sub is connected by a threaded connection to the upper threaded part of the turbodrill, the sub shaft is automatically connected to the shaft of the turbine section through a spline connection, which significantly reduces the complexity of installation and dismantling work associated with the installation of the retainer sub on the drill string if it is replaced. Since the retainer sub is installed as a separate unit on top of the turbodrill, the manufacture of turbodrills is greatly simplified and it becomes possible to install the sub on a turbodrill that does not have a retainer sub, as well as the ability to replace the retainer sub, if it breaks, directly on the rig without disassembling the turbodrill itself. The technical result is obtained by simplifying the connection of the sub with the turbodrill during the removal and installation of the sub. If necessary, such a locking sub can be connected to the turbodrill by screwing it onto the turbodrill, or disconnected from the turbodrill and replaced with another locking sub without disassembling them, which negatively affects the resource. Moreover, the autonomy of the retainer sub allows you to carry out these operations in the conditions of operation of the drill string on the rig.

Also, due to the fact that the sub is connected by a threaded connection to the upper threaded part of the turbo-drill, the sub shaft is automatically connected to the shaft of the turbine section of the turbo-drill through detachable connections, which significantly reduces the complexity of installation and dismantling work associated with installing the retainer sub on the drill string if it is replaced.

Claims

Claim

1. Lock sub, comprising a tubular housing with upper and lower conical joints at the ends, a shaft located in the housing on the supports and a locking mechanism connected thereto, including a tubular stop, in the cavity of which an annular insert connected to the shaft with radially arranged thrust bearings is located grooves evenly spaced around the circumference of the annular insert, in each thrust groove there is a spring-loaded locking dog rotatable on the axis, the ends of the axis of which are located in the holes of the rings, p located in the cavity of the tubular stop and adjacent to the ends of the annular insert from its two ends, each dog is spring loaded with torsion springs so that it can be pressed into the stop groove of the tubular stop in the “closed” position so that it is located in the persistent groove of the ring insert and one end abuts either into the radial recess of the stop, or into the protrusion of the groove made in the annular insert, and each radial recess of the stop forms a stop groove for interacting with the end face of the dog, characterized in that on the outer surface of the shaft you the slots are filled, the rings are connected to the tubular stop and are adjacent to the ends of the annular insert on both sides, which is made with slots on its inner surface and the slots of the annular insert are mounted on the splines of the shaft, while the upper conical connection of the housing is made in the form of a threaded conical expanding outward an external thread is made on its inner surface and on the outer surface of the lower conical connection of the housing, while the locking mechanism is located and secured between the supports, the lower surfaces to zhdoy dogs the locking mechanism is made flat with the apex facing outward, and one lower flat surface of the dog is made short - it is shorter than its other lower flat surface, which is made long - and in the working position of each dog, when it is engaged with the tubular stop and annular insert, the dog rests its lower long surface on the surface of the groove of the annular insert, and in the idle position of each dog, when it is in the persistent groove of the annular insert, the dog rests short bottom surface on the groove surface and the pawl between the inoperative position each of its upper surface and an annular surface of the insert is formed on the perimeter of the annular insert uninterrupted annular gap.

2. The locking sub according to claim 1, characterized in that the angle between the lower flat working surfaces of the dog is within 110-160 °, one flat surface is shorter than the other flat surface of the dog, the axis of the dog is located in the area of the short flat surface of the dog, in the axis area a depression is made - a ledge, to which one end of the spring abuts, the other end of which abuts against the recess of the annular insert, lateral surfaces transverse to the axis are made with angular recesses parallel to the upper surface of the dog, each corner The new recess is located with the possibility of its abutment in the adjacent ring and restrictions on the exit of the dog beyond the diameters of the outer surface of the adjacent ring when the dog is rotated by centrifugal force.

3. The locking sub according to claim 2, characterized in that a torsion spring is installed at each end of the dog axis, each dog having two end surfaces located across the dog axis, and each corner recess of the dog is made along the radius of the body of revolution and it is parallel to the outer upper surface of the dog.

4. A locking sub, comprising a tubular housing with upper and lower conical joints at the ends, a shaft located in the housing on the supports and a locking mechanism connected thereto, including a tubular stop, in the cavity of which an annular insert connected to the shaft with radially arranged thrust bearings is located grooves evenly spaced around the circumference of the annular insert, in each thrust groove there is a spring-loaded locking dog rotatable on the axis, the ends of the axis of which are located in the holes of the rings, p located in the plane of the annular insert and adjacent to the ends of the tubular stop from its two ends, each dog is spring loaded with torsion springs so that it can be pressed into the thrust groove of the annular insert into the “closed” position so that it is located in the thrust groove of the annular insert and one of its ends abuts or in the radial recess of the stop, or in the protrusion of the groove made in the annular insert, and each radial recess of the stop forms a stop groove for interacting with the end face of the dog, characterized in that on the outer surface of the shaft the slots are made, the rings are connected to the tubular stop and are adjacent to the ends of the annular insert on both sides, which is made with the slots on its inner surface and the slots of the annular insert are mounted on the shaft splines, while the upper conical connection of the housing is made in the form of a threaded conical expanding outward an external thread is made on its inner surface and on the outer surface of the lower conical connection of the housing, while the locking mechanism is located and secured between the supports, the lower surface l each dog locking mechanism is made flat and in the working position of each dogs, when it is engaged with the tubular stop and the annular insert, the dog rests its lower flat surface on the groove surface of the annular insert, and in the idle position of each dog, when it is in the groove of the tubular stop, between each lower flat surface and the surface of the annular the insert is formed around the perimeter of the annular insert a continuous annular gap, and the depth of each groove of the tubular stop is greater than the thickness of the dogs located in it.

5. The locking sub according to claim 4, characterized in that each dog has an angular recess under one end of the spring, the other end of which abuts against an adjacent surface of the tubular stop, and in side view the dog has an upper flat working surface formed by the upper part of the dog, lower a flat working surface formed by the lower part of the dog, front and rear flat ends located at right angles to the lower flat working surface, left and right corner recesses.

6. The locking sub according to claim 4 and 5, characterized in that the axis of each dog is located in the upper part of the dog so that a gap is formed between each end part of the axis and the lower part of the dog, and the surface of one end of the lower part of the dog is made flat with a rounded edge the radius of the body of revolution with an upper angle, and the surface of the other end of the dog is semicircular and this surface consists of two semi-surfaces, one of which is a continuation of the lower part of the dog, and the other half-surface is a continuation of the top s portion of the pawl, wherein the pawl in the middle of these polupoverhnosti merge into one continuous surface formed by the body of rotation and radius equal to the radius of rotation of the body of the upper corner radius bottom of the pawl.