GB2365135A

GB2365135A - Device for monitoring and indicating rotation of machinery

Info

Publication number: GB2365135A
Application number: GB0015798A
Authority: GB
Inventors: Hector Filippus Alexand Susman; Kenneth Roderik Stewart
Original assignee: Rotech Holdings Ltd
Current assignee: Rotech Holdings Ltd
Priority date: 2000-06-29
Filing date: 2000-06-29
Publication date: 2002-02-13
Also published as: GB0015798D0

Abstract

The device 5 has an abradable body 10, a spring 15, and a housing 20, all located within a first member 25 of an apparatus. The body is spring-biassed against a second member 30 that may be rotated. During rotation, the abradable body wears at a rate relative to the number of revolutions of the second member. The removal and examination of the abradable body is used to indicate the number of revolutions of the second member, which may be drill rotor or rotary portion of a rotary swivel. The housing consists of a releasable cap 40 and a bush 35 that locates the abradable body with a sliding fit. The abradable body may be wholly or partially made of graphite, bronze, or bronze alloy. The first member 25 may be an outer housing of a drill motor or a non-rotating portion of a rotary swivel.

Description

<Desc/Clms Page number 1> Apparatus Monitoring Device and Method The present invention relates to a device for monitoring of apparatus (machinery) incorporating at least one rotational member, and in particular, though not exclusively, to apparatus such as drill motors, swivels and down-hole tools used in the exploitation of subterranean and sub-sea oil and gas deposits.

Due to the expensive nature of equipment, such as hydraulic drill motors, used in the oil and gas industry, offshore operators frequently hire equipment from specialist firms rather than buying and maintaining it themselves. The companies which hire out such equipment may base their hire charge on a number of criteria including how long a piece of equipment is in the possession of a client, or for how long the piece of equipment has actually been used.

It is often difficult to ascertain the actual use for the latter case and thus formulating a realistic hire charge can be difficult.

Additionally, equipment of the type mentioned above requires periodic maintenance and the intervals between such maintenance may be based on the actual use of the equipment. If no accurate record has been kept, then there may arise the possibilities of maintenance operations being carried out either before or after they are actually required. In the former case money is wasted on unneeded labour and spare parts, while in the latter case the tool may be susceptible to parts failure due to insufficient maintenance.

It is an object of the present invention to obviate or mitigate at least some of the aforementioned disadvantages. According to a first aspect of the present invention there is provided a device for monitoring an apparatus incorporating first and second members wherein, in use, at

least one of the first or second members rotates relative to the other, the device comprising an abradable body and means to retain the abradable body in association with the first member and against the second member.

Preferably the second member rotates relative to the first member, in use.

Preferably the abradable body is manufactured, at least in part, from a material which abrades at a predetermined rate relative to the number of revolutions of the first and/or second members.

The abradable body may be manufactured, for example, from graphite, bronze or a bronze alloy.

A contact face of the abradable member may mirror a portion of the circumference of the second member.

The retention means may comprise means for biasing the abradable body against the second member.

The biasing means may comprise at least one spring, or springlike member held in compression between the abradable body and a base member.

The retention means may be provided in the first member within a recess/aperture. The first member may, in use, be stationary relative to the second member such that any wear experienced by the abradable body results from the movement of the second member.

The first member may comprise an outer housing a drill motor or a non-rotating portion of a driven or undriven rotary swivel.

The second member may comprise, for example, a rotor of a drill motor or a rotating portion of a driven or undriven

rotary swivel. Such swivels include, eg, power swivels for table drilling and "top drives" for rotary drilling.

According to a second aspect of the present invention there is provided an apparatus incorporating first and second members wherein, in use, at least one of the first or second members rotates relative to the other, the apparatus including a device for monitoring the apparatus comprising an abradable body and means to retain the abradable body in association with the first member and against the second member.

According to a third aspect of the present invention there is provided a method of monitoring the use of an apparatus incorporating first and second members wherein, in use, at least one of the first or second members rotates relative to the other, comprising the steps of: providing the apparatus; providing a device for monitoring the apparatus, the device comprising an abradable body and means to retain the abradable"body in association with the first member and against the second member; operating the apparatus; inspecting the abradable body and deducing from a change in dimensions and/or characteristics of the abradable body information relating to the operation of the apparatus.

Preferably the change in dimensions and/or characteristics of the abradable body is related to the number of revolutions of the first and/or second members.

The relationship between the change in dimensions and/or characteristics of the abradable body and the number of revolutions of the rotatable member may take into account, among others, such factors as the force exerted by the abradable body against the second member, the surface characteristics of the second member and the material from which the abradable body is manufactured.

The characteristics of the abradable body which may change may include the body's electrical resistance.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings which show:- Fig. 1 a sectional representation of a device in accordance with a first embodiment of the present invention, Fig. 2 a perspective view of an abradable body for use in the device of Fig 1, Fig. 3 a longitudinal cross sectional view of a drill motor according to a second embodiment of the present invention, Figs. 4A-4D cross sectional views along line A-A of Fig 3. showing the rotor in four different positions, Figs. 5A-5D cross sectional views along line B-B of Fig 3. showing the rotor in four different positions, Fig. 6 a representation of a swivel and rotary table drilling arrangement employing a device according to the present invention, and Fig. 7 a representation of a powered swivel drilling arrangement employing a device according to the present invention.

Referring firstly to Figures 1 and 2 there is shown a sectional representation of a device, generally designated 5,

in accordance with an embodiment of the present invention. The device comprises an abradable body 10, a spring 15 and a spring housing 20. In the embodiment shown the spring housing 20 is provided within a first member 25 of an apparatus, adjacent to a. second member 30 thereof. The spring housing comprises a bush 35 and a cap 40, the cap 40 being releasably retained within the bush 35 by means of a thread or the like. The dimensions of the abradable body 10 and the bush 35 are such that a sliding fit is provided between the two and spring 15 is held in compression between the cap 40 and the abradable body 10.

The cap 40 may be provided with sealing means to prevent the passage of fluid across the static casing 25 via the apparatus 5. The cap 40 may further be provided with anti- tamper means to prevent the unauthorised access to the abradable body 10. The abradable body 10 may be wholly or partially manufactured from a material such as graphite, bronze or bronze alloy and is intended to be at least partially worn away by the action of relative rotation between the first and second members, 25, 30.

In use, the abradable body 10 of known dimensions and/or characteristics is inserted into the bush 35 followed by the spring 15 and the cap 40. Rotation of e.g. the second member 30 causes the abradable body 10 to abrade at a rate relative to the number of revolutions of the second member 30. The rate at which the abradable member 10 abrades is dependent on a number of factors including the biasing force exerted upon the body 10, the surface characteristics of the rotatable member 30 and the material from which the body 10 is manufactured.

Removal and examination of the body 10, provided the wear rate is known, will indicate how many rotations of the rotatable member 30 have occurred since the body 10 was first placed in contact with the second member 30. In the case of machinery such as a drill motor it will be possible to

ascertain for how long the motor has been run. Referring now to Fig 3, there is shown a drilling apparatus which is generally identified by reference numeral 110. The drilling apparatus 110 comprises a first motor 120 and a second motor 150.

The first motor 120 comprises a stator 121 and a rotor 123. A top portion 122 of the rotor 123 extends through an upper bearing assembly 124 which comprises a thrust bearing 126 and seals 125.

Motive fluid, e.g. water, drilling mud or gas under pressure, flows down through a central sub channel 112 into a central rotor channel 127, and then out through rotor flow channels 128 into action chambers 131 and 132.

Following a motor power stroke, the motive fluid flows through exhaust ports 133, and then downwardly through an annular channel circumjacent the stator 121 and flow channels 135 in a lower bearing assembly 134. A portion 136 of the rotor 123 extends through the lower bearing assembly 134 which comprises a thrust bearing 137 and seals.

The ends of the stator 121 are castellated and the castellations engage in recesses in the respective upper bearing assembly 124 and lower bearing assembly 134 respectively to inhibit rotation of the stator 121. The upper bearing assembly 124 and lower bearing assembly 134 are a tight fit in an outer tubular member 114 and are held against rotation by compression between threaded sleeves 116 and 184.

A splined union 139 joins a splined end of the rotor 123 to a splined end of the rotor 153 of the second motor 150. The second motor 150 has a stator 151.

A top portion 152 of the rotor 153 extends through an upper bearing assembly 154. Seals 155 are disposed between

the upper bearing assembly 154 and the exterior of the top portion 152 of the rotor 153. The rotor 153 moves on thrust bearings 156 with respect to the upper bearing assembly 154.

Motive fluid flows into a central rotor channel 157 from the central rotor channel 127 and then out through rotor flow channels 158 into action chambers 161 and 162. Following a motor power stroke, the motive fluid flows through exhaust ports 163 and then downwardly through an annular channel circumjacent the stator 151 and flow channels 165 in a lower bearing assembly 164. A portion 166 of the rotor 153 extends through the lower bearing assembly 164. The rotor 153 moves on thrust bearings 167 with respect to the lower bearing assembly interface. Also motive fluid which flowed through the flow channels 135 in the lower bearing assembly 134, flows downwardly through channels 179 in the upper bearing assembly 154, past stator 151 and through flow channels 165 in the lower bearing assembly 164.

The upper bearing assembly 154 and lower bearing assembly 164 are a tight fit in an outer tubular member 118 and are held against rotation by compression between threaded sleeve 184 and a lower threaded sleeve (not shown).

A lower sub is threadedly connected to the stator 151 via threads 170 and provides interconnection with a drill bit connection/bearing housing (not shown) and a typical drill bit (not shown). A solid plug or a flow restrictor 178 at the bottom of the rotor 153 may be used to restrict motive fluid flow to the drill bit and to ensure that a desired amount of motive fluid passes through the motors.

Figs 4A-4D and 5A-5D depict a typical cycle for the first and second motors 120 and 150 and show the status of the two motors with respect to each other at various times in the cycle. For example Fig. 4c shows an exhaust period for the first motor 120 while Fig. 5c, at that same moment, shows a power period for the second motor 150.

As shown in Fig. 4A, motive fluid flowing through the rotor flow channels 128 enters the action chambers 131 and 132. Due to the geometry of the chambers (as discussed below) and the resultant forces, the motive fluid moves the rotor in a clockwise direction as seen in Fig.4B. The action chamber 131 is sealed at one end by a rolling vane rod 171 which abuts an exterior surface 172 of the rotor 123 and a portion 174 of a rod recess 175.

At the other end of the action chamber 131, a seal 176 on a lobe 177 of the rotor 123 sealingly abuts an interior surface of the stator 121.

As shown in Fig. 4B, the rotor 123 has moved to a point near the end of a power period.

A shown in Fig. 4C, motive fluid starts exhausting at this point in the motor cycle through the exhausts ports 133. As shown in Fig. 4D, the rolling van rods 171 and seals 176 have sealed off the action chambers and motive fluids flowing thereinto will rotate the rotor 123 until the seals 176 again move past the exhaust ports 133.

The second motor 150 operates as does the first motor 120; but, as preferred, and as shown in Figs. 5A-5D, the two motors are out of phase by 90 sot that as one motor is exhausting motive fluid the other is providing power.

The seals 176 are, in one embodiment, made of polyethylethylketone (PEEK). The rolling vane rods 171 are also made from PEEK. The rotors (123, 125) and stators (121, 151) are preferably made from corrosion resistant materials such as stainless steel.

When a seal 176 in the first motor 120 rotates past an exhaust port 133, the motive fluid that caused the turning

exits and flows downward through the stator adaptor 184 (Fig. 3), the through the channels 179, past the exhaust ports 163, the flow channels 165, the bearing housing (not shown) and subsequently to the drill bit (not shown). A11 motive fluid that enters the top sub 111 finally exits to the drill bit.

In the disclosed embodiment, a device 5 in accordance with the present invention is installed in the outer tubular member 114 (first member) adjacent to the first rotor 123 (second member).

Referring to Figure 6 there is shown a schematic representation of a swivel and rotary table drilling arrangement. A rotary swivel 200 is shown suspended from a travelling block 205. The swivel 200 is further connected to a kelly 210 wh which in turn is connected to a stand of pipe 215. The kelly 210 passes through a kelly bush (not shown) provided in a rotary table 220. The swivel 200 is further provided with a port 225 through which drilling fluid may be pumped via a hose 230. A device 5 in accordance with the present invention may be installed in the swivel 200.

Referring finally to Figure 7 there is shown a powered swivel drilling arrangement. A powered swivel 235 is suspended from a cable and pulley arrangement 240 and restrained from lateral movement by a pair of guides 245, 245'. The swivel 235 is provided with an output shaft 250 which in turn is connected to a stand of drill pipe 260. The swivel 235 is further provided with a port 265 through which drilling fluid may be pumped via a hose 270. A device 5 in accordance with the present invention may be installed in the swivel 235.

Finally, it should be appreciated that the embodiments of the present invention hereinbefore described are given by way of example only, and are not meant to limit the scope of the invention in any way.

For example, the wear element may be housed in insulating material. The spring element may be connected to an electric resistance of the wear element can now be measured and noted. When the machine has rotated for a given period the resistance will decrease due to the shorter length of the abrading member.

Measurement of resistance can be affected whilst the machine is running thus constantly indicating the accumulated number of rotations. Suitable electronic circuitry such as a Weatstone Bridge can be devised to indicate the accumulated running time or number of revolutions. The output signal can be conveyed to an electronic comparator circuit which will set off an alarm indicating a requirement for overhaul or replacement of sacrificial wear parts in the equipment.

Claims

CLAIMS 1. A device for monitoring an apparatus incorporating first and second members wherein, in use, at least one of the first or second members rotates relative to the other, the device comprising an abradable body and means to retain the abradable body in association with the first member and against the second member.
2. A device as claimed in claim 1 wherein, in use, the second member rotates relative to the first member.
3. A device as claimed in claims 1 or 2, wherein the abradable body is manufactured, at least in part, from a material which abrades at a predetermined rate relative to the number of revolutions of the first and/or second members.
4. A device as claimed in any preceding claim, wherein the abradable body is manufactured from a material selected from the group comprising graphite, bronze and bronze alloy.
5. A device as claimed in any preceding claim, wherein a contact face of the abradable member mirrors a portion of the circumference of the second member.
6. A device as claimed in any preceding claim, wherein the retention means comprises means for biasing the abradable body against the second member.
7. A device as claimed in claim 6, wherein the biasing means comprises at least one spring member held in compression between the abradable body and a base member.

<Desc/Clms Page number 12>
8. A device as claimed in any preceding claim, wherein the retention means is provided in the first member within an aperture.
9. A device as claimed in any preceding claim, wherein, in use, the first member is stationary relative to the second member such that any wear experienced by the abradable body results from the movement of the second member.
10. A device is claimed in any preceding claim, wherein the first member comprises an outer housing of a drill motor.
11. A device as claimed in any preceding claim, wherein the second member comprises a rotor of a drill motor.
12. A device as claimed in any one of claims 1 to 9, wherein the first member comprises a non-rotating portion of a rotary swivel.
13. A device as claimed in any of claims 1 to 9 or claim 12, wherein the second member comprises a rotating portion of a rotary swivel.
14. An apparatus incorporating first and second members wherein, in use, at least one of the first or second members rotates relative to the other, the apparatus including a device for monitoring the apparatus comprising an abradable body and means to retain the abradable body in association with the first member and against the second member.

<Desc/Clms Page number 13>
15. A method of monitoring the use of an apparatus incorporating first and second members wherein, in use, at least one of the first or second members rotates relative to the other, comprising the steps of: providing the apparatus; providing a device for monitoring the apparatus, the device comprising an abradable body and means to retain the abradable body in association with the first member and against the second member; operating the apparatus; inspecting the abradable body and deducing from a change in dimensions and/or characteristics of the abradable body information relating to the operation of the apparatus.
16. A method as claimed in claim 15, wherein the abradable body is inspected to deduce a change in dimensions and/or characteristics of the abradable body related to the number of revolutions of the first and/or second members.
17. A method as claimed in claim 15 or 16, wherein the electrical resistance of the abradable body is measured.
18. A device as hereinbefore described with reference to Figures 1 and 2.
19. A drill motor as hereinbefore described with reference to Figures 2 to 5(D).
20. A swivel and rotary table drilling arrangement as hereinbefore described with reference to Figure 6.
21. A powered swivel drilling arrangement as hereinbefore described with reference to Figure 7.