DE102016223884A1 - Axial thrust bearing with distance sensor for drilling rigs - Google Patents

Abstract

A power rotary axial bearing 600 for a drilling rig with a first bearing ring 632, in particular a wave washer, a second bearing ring 634, in particular a housing plate, and a plurality of rolling elements 636, wherein the plurality of rolling elements 636 is disposed between the first bearing ring 632 and the second bearing ring 634. According to the invention, the power rotary thrust bearing 600 comprises at least one distance sensor 640 for detecting measurement parameters of the drilling operation. The distance sensor 640 is preferably an inductive proximity sensor, in particular an eddy current sensor.

Description

Field of the invention

The present invention relates to a Kraftdrehkopfiaxager with a distance sensor for a drilling rig. The distance sensor is designed to detect the distance between the bearing rings and thus the bearing load, and / or to detect the angle of rotation of the power rotary thrust bearing by means of a corresponding encoder. The distance sensor is preferably designed as an inductive proximity sensor, in particular as an eddy current sensor.

Background of the invention

The creation of wells, particularly in the oil and gas industry, requires careful handling of the drilling tool to drill along a desired path. The construction of such a drilling tool substantially comprises a drill string having a drill bit disposed at the lower end of the drill string, the drill string extending downwardly from a derrick into the earth formation or wellbore. In the derrick is usually a so-called power turret (English "Top Drive") mounted to drive the drill string via a rope in a crane hook on a crane bottle. The rope is in turn anchored with a dead rope anchor with the soil. The control of the drilling can be influenced inter alia by feeding or returning the rope. The drill bit includes a so-called downhole engine and a drill bit for actual drilling.

For the drilling process, it is important to know the forces acting on the drill bit in order to avoid damage to the drilling tool, in particular to the drill bit. The knowledge of the forces acting on the drill bit is also helpful in order to carry out the drilling process economically.

It is known that the axial load and torque acting on a drill bit (hereinafter also referred to as drill bit) during the drilling operation are important parameters that influence the direction and inclination of the borehole as well as the efficiency of the drilling work. The axial load on the drill bit is also known as weight-on-bit (WOB). A load acts on the drill bit over the drill string, which is biased on the derrick with the other surface mounted components, such as the "top drive", so that the size of the WOB can be adjusted by varying the superior hook load. WOB affects penetration rate, drill bit wear and drilling direction. Torque-on-bit (TOB) torque is also important in terms of drill bit wear and drilling direction, particularly when combined with WOB. Thus, excessive TOB is indicative of serious bit damage, such as failure of a camp under jammed skittles.

Methods and apparatus for measuring WOB and / or TOB are known over days or underground. Over-day measurements are taken by comparing the hook load weight to the "over-the-sole weight": for example, if the hook load is 100 tons with the drill string lifted and only 95 tons after lowering to the bottom of the drill hole, then the drill bit must now be five tons Load on the bottom of the hole. A drill guide can now lift the drill string from the drill floor again and adjust its control. On continuation of the boron process, he then receives the "missing" hook load as a bit load.

In order to record the hook load over days, pressure cells on the dead rope anchor or the so-called pulley in the derrick ("Crown Block") are known. Measuring sensors, such as strain gauges, are also known on the (dead) cable itself.

Underground measurements are often taken via force sensors arranged, for example, on additional cylinders or pockets in the downhole tool. However, these measurements are subject to significant inaccuracies due to the effects of borehole pressure and temperature gradients. Nor can they generally distinguish between tension caused by the weight and axial tension caused by the pressure difference. They are also adversely affected by the pressure exerted by drilling fluids.

Summary of the invention

It is the object of the invention to improve the detection of the bit load, in particular to make it more robust against measurement errors and to capture further parameters for the control of the drilling tool.

This object is achieved by a Kraftdrehkopfiaxager for a drilling rig according to claim 1. The axial swivel bearing can be used in a "top drive". The bearing comprises two bearing rings with rolling elements arranged therebetween. According to the invention, the bearing has a distance sensor, preferably an inductive proximity sensor, in particular an eddy current sensor.

The detection of the forces transmitted by the rolling elements in the form of changes in distance by the distance sensor allows the Derive stress on the bit in the borehole. The thrust bearing thrust bearing is not affected by the above-described problems of underground force measurements. Even with respect to the known over-the-day force measurements, the detection of the forces at the top-mounted power turret bearing has considerable advantages with regard to measuring errors.

In one embodiment, the distance sensor is arranged on the bearing ring that is in relation to the rotation. This has the advantage that no telemetry is required to detect the forces of the rotating drill string. In particular, no data from the borehole must be transmitted.

In one embodiment, the distance sensor is arranged on the inner circumference or on the outer circumference between the bearing rings.

In one embodiment, the distance sensor is arranged such that it detects the distance between the bearing rings. The external load on the bearing leads to elastic deflection of the rolling bearing components, such as the wave washer, housing plate and rolling elements. This elastic deflection can be detected by means of the distance sensor. The sensor detects the distance of an opposite measuring surface.

In a further embodiment, one of the bearing rings, in particular the rotatable bearing ring with respect to the rotation, a profiled measuring surface, and the at least one distance sensor is arranged on the other bearing ring, that the at least one distance sensor detects the rotation angle of the Kraftdrehkopfaxiallager means of the profiled measuring surface , In a further development, the profiled measuring surface is formed as an eccentric recess of the bearing ring. By profiling a measuring surface, such as one or two phase-shifted sinusoids or the eccentrically shaped pulse generator, the relative and / or absolute rotational angular position can be determined from the measuring signal of the sensor.

From the knowledge of the relative or the absolute angle of rotation, at a sampling frequency which is greater than twice the frequency of the torsional vibrations, these torsional vibrations can be determined. The torsional vibrations are namely all angular changes that occur at a frequency not equal to the rotational frequency of the bearing. Thus, for example, a simple evaluation by means of the Fourier transformation is possible.

In an alternative embodiment, a further encoder is arranged on one of the bearing rings, and the at least one distance sensor is arranged on the other bearing ring. The encoder and the distance sensor are aligned with each other such that in the axial direction of the rotation angle is detected and / or that the distance between the first bearing ring and the second bearing ring is detected in the radial direction, wherein for detecting the rotation angle of the encoder has a profiled measuring surface.

The detection of the change in distance between the bearing rings or for determining the angle of rotation is independent of the position of the rolling elements and of the rotational position of the two bearing rings to each other. Thus, the measuring arrangement can measure both at a stationary bearing, as well as rotating bearing. Furthermore, thus dynamic load changes can be well detected, since the measurement effect is not affected by the change in position of the rolling elements.

In one embodiment, at least three distance sensors are arranged on the circumference of the first bearing ring or of the second bearing ring. By means of the at least three distance sensors, if these are arranged correspondingly suitably distributed on a partial circle, a high measuring precision can be achieved. It is also possible to compensate for measuring errors caused, for example, by misalignment. Namely, the three distance points measured then clearly define the position of a moving plane in relation to the position of the fixed plane on which the distance sensors are mounted. The position of the two planes to each other is determined by the direction and size of the force acting on the bearing. Thus, the amount and direction of the force acting on the bearing can be determined by the described measuring arrangement.

Preferably, the three distance sensors are arranged at approximately equal angular intervals. For a high accuracy of the force signal, the sensors may preferably be positioned at approximately equal angular intervals. In the case of exactly three distance sensors so each spaced by 120 ° to each other. The measuring accuracy decreases only with a clear unequal distribution.

In a further embodiment, the at least three distance sensors form a first sensor arrangement. Furthermore, a second sensor arrangement with at least three further distance sensors is arranged on the circumference of the first bearing ring or of the second bearing ring. The distance sensors of the first sensor arrangement are each arranged offset from the distance sensors of the second sensor arrangement. This has the advantage that system security can be increased. Because the sensor arrangements can be evaluated separately and the measurement signals of both sensor arrangements compared with each other. Likewise, the entire measuring system can continue to operate with reduced reliability if one of the two subsystems, that is, a sensor arrangement, fails.

In one embodiment, the Kraftdrehkopfiaxager is designed as axial tapered roller bearings. Axial tapered roller bearings allow for very high load capacity, shock-resistant and rigid bearings with only a small axial space requirement.

Further advantages, features and details of the invention will become apparent from the embodiments described below and with reference to the figures.

list of figures

• 1 eine Überblicksdarstellung einer Bohranlage mit Bohrwerkzeug in Anwendung,
• 2 einen Ausschnitt eines Kraftdrehkopfaxiallagers mit einem Abstandssensor am Außenumfang eines Lagerrings,
• 3 einen Ausschnitt eines Kraftdrehkopfaxiallagers mit einem Abstandssensor am Innenumfang eines Lagerrings,
• 4 einen Ausschnitt eines Kraftdrehkopfaxiallagers mit einem Abstandssensor und einer exzentrischen Ausnehmung am Innenumfang von Lagerringen,
• 5 einen Ausschnitt eines Kraftdrehkopfaxiallagers mit einem Abstandssensor und einem Messgeber am Außenumfang von Lagerringen in einer ersten Ausführungsform, und
• 6 einen Ausschnitt eines Kraftdrehkopfaxiallagers mit einem Abstandssensor und einem Messgeber am Außenumfang von Lagerringen in einer zweiten Ausführungsform.

Hereinafter, embodiments of the invention will be illustrated with reference to figures. The figures show unscaled drawings. Show it:

• 1 an overview of a drilling rig with drilling tool in use,
• 2 a detail of a Kraftdrehkopfaxiallagers with a distance sensor on the outer circumference of a bearing ring,
• 3 a detail of a Kraftdrehkopfaxiallagers with a distance sensor on the inner circumference of a bearing ring,
• 4 a detail of a Kraftdrehkopfaxiallagers with a distance sensor and an eccentric recess on the inner circumference of bearing rings,
• 5 a section of a Kraftdrehkopfaxiallagers with a distance sensor and a transducer on the outer circumference of bearing rings in a first embodiment, and
• 6 a section of a Kraftdrehkopfaxiallagers with a distance sensor and a transducer on the outer circumference of bearing rings in a second embodiment.

Detailed description of the drawings

1 shows an overview of a drilling rig 100 with drilling tool in application. The drilling rig 100 includes the derrick 120 , which is arranged on the ground over days. From the derrick 120 extends a drill string 110 in the soil 105 , The drill string includes at its end a downhole motor 112 the one in a drill bit 114 ends. On the drill bit 114 the force F 116 acts during operation. Underground motor 112 , Drill bits 114 and partly the drill string 110 are underground, so in the ground 105 in a borehole. At the derrick 120 is on a crane bottle and crane hook 124 a power turret and components 122 hooked. The power turret and components 122 that the drill string 110 are driving, with the (dead) rope 126 at a dead rope anchor 128 secured. The dead rope anchor is typically firmly connected to the ground. In 1 is separated over days and underground by means of the horizontal line.

2 shows a section of a Kraftdrehkopfaxiallagers 200 with a distance sensor 240 on the outer circumference of a bearing ring 234 , The stationary bearing ring 234 may be a housing plate, the other bearing ring 232 can be a rotatable wave washer. Between the bearing rings 232 . 234 are rolling elements 236 arranged. The distance sensor 240 is therefore arranged in the above-described case on a stationary bearing part (not in 2 illustrated). This has the advantage that the distance sensor 240 No complicated telemetry is required for the transmission of its measurement data. The distance sensor 240 is adapted to the distance 216 between the two bearing rings 232 . 234 capture. The measuring surface is the opposite bearing ring 232 , Thus, no further separate encoder on the bearing ring 232 to be ordered. The distance sensor 240 So can an external load on the Kraftdrehkopfaxiallagers 200 , which for elastic deflection of the rolling bearing components, such as the bearing rings 232 . 234 and the rolling element 236 , leads, capture.

3 shows a section of a Kraftdrehkopfaxiallagers 300 with a distance sensor 340 on the inner circumference of a bearing ring 334 , The arrangement in 3 essentially reflects the arrangement in 2 again. The distance sensor 340 is in 3 however, on the inner circumference of the bearing ring 334 arranged. The distance sensor 340 also detects a distance 316 due to external loads on the bearing rings 332 . 334 and the rolling element 336 can change.

4 shows a section of a Kraftdrehkopfaxiallagers 400 with a distance sensor 440 and an eccentric recess 445 on the inner circumference of bearing rings 432 . 434 , Between the bearing rings 432 . 434 are rolling elements 436 arranged. The distance sensor 440 is on the bearing ring 434 arranged. The bearing ring 434 is preferably a stationary bearing ring, such as a housing plate, to the same advantages we 2 described to achieve. The eccentric recess 445 on the opposite bearing ring 432 , which accordingly a rotatable bearing ring, for example, the wave washer, is used to detect the relative and / or absolute angle of rotation of the Kraftdrehkopfaxiallagers 400 , Because the profiled measuring surface makes it possible to determine a clearly assignable distance value at all times, ie during rotation and even when the high-power rotary thrust bearing is stationary 400 , The arrangement in 4 can accordingly also on the outer circumference of bearing rings 432 . 434 be arranged.

5 shows a section of a Kraftdrehkopfaxiallagers 500 with a distance sensor 540 and a transmitter 545 on the outer circumference of bearing rings 532 , 534 in a first embodiment. Between the bearing rings 532 . 534 are rolling elements 536 arranged. The distance sensor 540 is C-shaped. The encoder 545 Accordingly, has a recess, so that the C-shaped distance sensor 540 and the encoder 545 can be arranged in each other, as in 5 shown. The encoder 545 has a further profiling (not in 5 illustrated). The distance sensor 540 , In particular, an eddy current sensor, the radial distance 516 between the bearing rings 532 . 534 and the axial, over the profiling changing, distance 518 to capture. Thus, over the radial distance 516 the force and over the axial distance 518 the absolute and / or relative angle of rotation of the Kraftdrehkopfaxiallagers 500 determined.

6 shows a section of a Kraftdrehkopfaxiallagers 600 with a distance sensor 640 and a transmitter 645 on the outer circumference of bearing rings 632 , 634 in a second embodiment. Between the bearing rings 632 . 634 are rolling elements 636 arranged. In contrast to the distance sensor in 5 , is the distance sensor 640 L-shaped. The encoder 645 also has a recess which has a profiling (profiling not in 6 illustrated). distance sensor 640 can the radial distance 616 between the bearing rings 632 . 634 and the axial distance 618 to capture. Thus, over the radial distance 616 the force and over the axial distance 618 the absolute and / or relative angle of rotation of the Kraftdrehkopfaxiallagers 600 determined.

LIST OF REFERENCE NUMBERS

100

drilling rig

105

soil

110

drill string

112

Downhole motor

114

drill bit

116

Force F on drill bit

120

derrick

122

Power turret and components

124

Crane hook and crane bottle

126

(Tot) rope

128

Totseilanker

200, 300

Kraftdrehkopfaxiallager

216, 316

Distance between bearing rings

232, 332

first bearing ring

234, 334

second bearing ring

236, 336

rolling elements

240, 340

distance sensor

400

Kraftdrehkopfaxiallager

432

first bearing ring

434

second bearing ring

436

rolling elements

440

distance sensor

445

eccentric recess

500, 600

Kraftdrehkopfaxiallager

516, 616

Distance between bearing rings

518, 618

Distance for angle measurement

532, 632

first bearing ring

534, 634

second bearing ring

536, 636

rolling elements

540, 640

distance sensor

545, 645

Transducers

Claims (10)

A power rotary axial bearing (200, 300, 400, 500, 600) for a drilling rig (100), comprising - a first bearing ring (232, 332, 432, 532, 632), in particular a wave washer, - a second bearing ring (234, 334, 434 , 534, 634), in particular a housing disk, and a plurality of rolling elements (236, 336, 436, 536, 636), wherein the plurality of rolling elements (236, 336, 436, 536, 636) between the first bearing ring (232 , 332, 432, 532, 632) and the second bearing ring (234, 334, 434, 534, 634), characterized in that the power rotary thrust bearing (200, 300, 400, 500, 600) further comprises at least one distance sensor (240 , 340, 440, 540, 640), preferably an inductive proximity sensor, in particular an eddy current sensor. Axial thrust bearings (200, 300, 400, 500, 600) Claim 1 wherein the at least one distance sensor (240, 340, 440, 540, 640) is disposed on the rotatable bearing ring (234, 334, 434, 534, 634). Axial thrust bearings (200, 300, 400, 500, 600) Claim 1 or 2 wherein the at least one distance sensor (240, 340, 440, 540, 640) on the inner circumference or on the outer circumference between the first bearing ring (232, 332, 432, 532, 632) and the second bearing ring (234, 334, 434, 534, 634) is arranged. Axial thrust bearings (200, 300, 400, 500, 600) according to one of the Claims 1 to 3 wherein the at least one distance sensor (240, 340, 440, 540, 640) is arranged so as to reduce the distance between the first bearing ring (232, 332, 432, 532, 632) and the second bearing ring (234, 334, 434 , 534, 634). Axial thrust bearing (400) according to one of Claims 1 to 4 wherein one of the bearing rings (432), in particular the rotatable bearing ring with respect to rotation, has a profiled measuring surface, and wherein the at least one distance sensor (440) is arranged on the other bearing ring (434) such that the at least one distance sensor (440 ) detects the angle of rotation of the thrust bearing thrust bearing by means of the profiled measuring surface. Axial thrust bearing (400) after Claim 5 , wherein the profiled measuring surface is formed as an eccentric recess (445) of the bearing ring (432). Axial thrust bearing (500, 600) according to one of the Claims 1 to 6 wherein a transducer (545, 645) is further disposed on one of the bearing rings (532, 632), wherein the at least one distance sensor (540, 640) is disposed on the other bearing ring (534, 634), and wherein the encoder (545 , 645) and the at least one distance sensor (540, 640) are aligned with one another such that the angle of rotation is detected in the axial direction and / or that in the radial direction the distance between the first bearing ring (532, 632) and the second bearing ring (534 , 634) is detected, wherein for detecting the rotation angle of the encoder (545, 645) has a profiled measuring surface. Axial thrust bearings (200, 300, 400, 500, 600) according to one of the Claims 1 to 7 wherein at least three distance sensors (240, 340, 440, 540, 640) on the circumference of the first bearing ring (232, 332, 432, 532, 632) or the second bearing ring (234, 334, 434, 534, 634), preferably in Approximately the same angular distances are arranged. Axial thrust bearings (200, 300, 400, 500, 600) Claim 8 wherein the at least three distance sensors (240, 340, 440, 540, 640) form a first sensor arrangement, further comprising a second sensor arrangement with at least three further distance sensors on the circumference of the first bearing ring (232, 332, 432, 532, 632) or second bearing ring (234, 334, 434, 534, 634) is arranged, and wherein the distance sensors (240, 340, 440, 540, 640) of the first sensor arrangement are each arranged offset from the distance sensors of the second sensor arrangement. Axial thrust bearings (200, 300, 400, 500, 600) according to one of the Claims 1 to 9 , wherein the Kraftdrehkopfaxiallager is designed as axial tapered roller bearings.

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