CA1237952A - Method and apparatus for detecting wear of a rotatable bit - Google Patents
Method and apparatus for detecting wear of a rotatable bitInfo
- Publication number
- CA1237952A CA1237952A CA000473206A CA473206A CA1237952A CA 1237952 A CA1237952 A CA 1237952A CA 000473206 A CA000473206 A CA 000473206A CA 473206 A CA473206 A CA 473206A CA 1237952 A CA1237952 A CA 1237952A
- Authority
- CA
- Canada
- Prior art keywords
- drill bit
- ball
- drill
- recess
- sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B12/00—Accessories for drilling tools
- E21B12/02—Wear indicators
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/08—Roller bits
- E21B10/22—Roller bits characterised by bearing, lubrication or sealing details
Abstract
ABSTRACT OF THE INVENTION
A method and apparatus for detecting wear of a rotatable bit used to drill a wellbore is disclosed. In drilling operations, a drilling fluid is pumped down through a drill stem and is discharged through ports in the drill bit and into the annulus between the drill stem and the wellbore. Excessive wear of the bit at a selected location is detected by a sensor which is linked to a restrictive device capable of reducing the flow of drilling fluid through at least one port. To detect excessive wear of the bit, at least one abradable sensor is located in the bit at a selected location. As the drill bit wears at the location, the sensor will abrade until the sensor is activated.
Activation of the sensor is transmitted by a communication device such as a wire or hydraulic fluid to manipulate the restricting device. More than one sensor may be simultaneously linked to the restricting device with communication devices to detect wear of the drill bit at differing locations.
A method and apparatus for detecting wear of a rotatable bit used to drill a wellbore is disclosed. In drilling operations, a drilling fluid is pumped down through a drill stem and is discharged through ports in the drill bit and into the annulus between the drill stem and the wellbore. Excessive wear of the bit at a selected location is detected by a sensor which is linked to a restrictive device capable of reducing the flow of drilling fluid through at least one port. To detect excessive wear of the bit, at least one abradable sensor is located in the bit at a selected location. As the drill bit wears at the location, the sensor will abrade until the sensor is activated.
Activation of the sensor is transmitted by a communication device such as a wire or hydraulic fluid to manipulate the restricting device. More than one sensor may be simultaneously linked to the restricting device with communication devices to detect wear of the drill bit at differing locations.
Description
~37~352 METHOD AND APPARATUS FOR DETECTING WEAR OF A ROTATABLE BIT
A. Field of the Invention The present invention relates to a method and apparatus for detecting excessive wear of a rotatable bit used in drilling operations. In particular, the present invention relates to a method and apparatus which can detect loss of gauge of or bearing failure in a rotatable bit used to drill a Wilbur.
B. Background of the Invention In oil, gas, and geothermal drilling operations, a drill bit attached to a drill stem is rotated to drill a Wilbur through subsurface geologic formations. Roller-cone drill bits usually comprise a plurality of legs having a rotatable cone attached by a bearing to the spindle Ox each leg. Other types of drill bits such as drag-type bits do not use bearings or other moving components. As a drill bit is rotated, drilling fluid is circulated to cool the drill bit and to transport rock cuttings from the Wilbur. The drilling fluid is pumped down through the drill stem, through ports in the drill bit, and up through the annuls between the drill stem and the wallaby.
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A drill bit will wear as it is rotated to advance the depth of the Wilbur. The length of time that a drill bit can be used before it becomes excessively worn depends on a variety of factors such as the hardness and composition of the rock and the drill stem weight that the operator places on the drill bit. The drill bit should be replaced when its rate of penetration has diminished to an unacceptable level or when torque values in rotating the drill string exceed an acceptable limit. An operator can measure the rate of penetration and the - 10 torque values from the surface.
Other factors which normally require the replacement of a drill bit carrot be measured from the surface. For example a roller-cone drill bit should be replaced when the bit bearings lo are excessively worn or when the Wilbur is being drilled under gauge. As the drill bit is rotated, the load-bearing surfaces between a cone and the spindle of a leg will begin to wear. As the surfaces wear, the cone will begin to rotate eccentrically about the spindle Imtil the cone seizes, becomes excessively worn, or is separated from the spindle. In a sealed bit, the bearing will begin to fail after the seal between the cone and the spindle is damaged. If a bit bearing should fail and leave a cone in the wheelbarrows drilling operations are usually discontinued until the cone is "fished" from the Wilbur.
:
.., ..'", ~;23~352 Loss of Barlow gauge of a roller-cone bit is due to abrasion of the gauge-maintaining portion of the drill bit cones against the Wilbur wall. In a drag-type bit, loss of Barlow gauge is due to wear of the gauge maintaining cutters. Loss of gauge is undesirable because there is a greater possibility of differential pressure sticking between the drill string and the Wilbur. Ross of gauge is especially undesirable in specialized drilling operations such as in highly deviated wells because the operator may have difficulty in maintaining directional control of the Wilbur. Although loss of gauge can be reduced by hard-facing certain portions of the bit, loss of gauge remains a problem in drilling operations.
To avoid the cost of retrieving lost cones from the Wilbur, most drill bits will generally be tripped out of the Wilbur and replaced before the bit bearings fail. Because each drill bit is not used to the extent of its maximwn useful life, this practice is costly because more drill bits are required to drill the Wilbur to a particular depth. The practice of pulling drill bits "green" is particularly costly because the drill pipe and drill collars must be tripped each time that a drill bit is replaced. In deep drilling operations ; or in offshore drilling operations which may cost up to - $130,000 U.S. per day, an operator should maximize drilling time by using each drill bit to the full extent of its useful life.
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Although various techniques to detect wear of rotary drill bits have been tried, there are no commercially available techniques which can detect beaning failure or loss of Barlow gauge of a drill bit used to drill a Wilbur.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus con detecting excessive wear of a drill bit connected to a drill stem which is used to drill a Wilbur, A pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annuls between the drill stem and the Wilbur, A restricting means connected to the drill bit ; can be manipulated to reduce the flow of drilling fluid through at least one port in the drill bit. An abradable sensor means is connected to the drill bit at a selected location to detect excessive wear Ox the drill bit. A communication means is located between the sensor means and the restricting means so that activation of the sensor means is transmitted by the communication means to manipulate the restricting means to reduce the flow of drilling fluid through a port, In one embodiment of the invention, the restricting means comprises a ball means which is propelled by a spring means from a recess in the drill bit to partially or completely block a port in the drill bit. The communication means may comprise a wire or hydraulic fluid which is located between the Lo 52 sensor means and the restricting means. A single sensor means can be used to detect excessive wear of a bit at a selected location or additional sensor means may be located at other locations on the bit to simultaneously detect excessive wear of the bit at the differing locations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a sectional view of the invention in lo the body of a drill bit leg wherein an abradable sensor is located to detect bearing failure.
FIG. 2 illustrates an embodiment of the invention showing two abradable sensors located at different locations in the drill bit body.
FIG. 3 illustrates a partial sectional view of a seal within the restricting means which prevents intrusion of drilling solids into a recess located in the drill bit body.
FIG. 4 illustrates a sectional view of an alternative embodiment of the invention wherein hydraulic fluid is used as the communication means and the restricting means includes a piston means located in a recess in the drill bit body.
~25 FIG. 5 illustrates an enlarged partial sectional view of the piston means shown in FIG. 4.
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~;237~352 DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, leg 10 of a sealed journal bit is shown. In most oil and gas rotary drilling operations, three legs form a drill bit. The drill bit, which is attached to the lower end of a drill stem comprised of drill collars, drill pipe, and kelly (not Sheehan is rotated to drill a Wilbur through subsurface geologic formations. Drilling fluid is circulated down through the drill stem and is discharged through at least one port in the drill bit. The drilling fluid returns to the surface through the Wilbur annuls between the drill stem and the Wilbur.
Leg 10 is comprlfied of body 12, port 14, and spindle 16. Cone 18 is retained by bearing 20 on spindle 16.
Cone surface A contains rows of steel teeth or tungsten carbide inserts (not shown) which mechanically fracture the subsurface geological formations as the drill stem is rotated. In drilling operations, spindle 16 supports cone 18 with spindle surface B
as the weight of the drill stem rests on the drill bit. The interstice between spindle 16 and cone 18 is filled with grease .
to lubricate the bearing surfaces. Seal 22 retains the grease within the interstice.
.,, :
25~ As the drill bit is rotated to advance the depth of the Wilbur and the lubrication between spindle 16 and cone 18 degrades, spindle 16 will begin to wear along surface B. As the ::
.. .. .
wear of surface B continues, cone 18 will begin to rotate eccentrically about spindle 16. Bearing 20 may fail if wear of surface B continues to a point where bearing 20 cannot retain cone 18. In many cases, a cone will separate from the spindle S and be lost in the Wilbur. In the event of a lost cone, drilling operations are usually suspended until the cone can be removed from the Wilbur.
In addition to wear along surface B, a drill bit wears at other locations. If the outside circumferential surface of a bit has worn to a point where the diameter of the bit is less than that permitted by bit specifications, the bit is termed "under gauge." For example, a 6-7/8 inch diameter bit worn to 6-5/8 inches is unclergauge. In a roller-cone bit, the outside circumferential surface is the cone gauge maintaining surface.
Referring to FIG 1, gauge maintaining surface C of cone 18 and surface D of leg 10 may experience wear, thereby causing the bit to drill under gauge. m a drag-type bit, gauge maintaining teeth prevent the bit from drilling under gauge.
The present invention detects excessive wear of a drill bit by sensing wear of the drill bit at a particular location and by manipulating a device to at least partially reduce the flow of drilling fluid through the drill bit. Referring to FIG. 1, the invention generally comprises abradable sensor means 24, restricting means 26, and wire or other communication means 28.
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Sensor means Z4 is connected to body 12 and extends into recess 29 in cone 18 As previously described, cone 18 will begin to rotate eccentrically about spindle 16 as wear surface B is eroded When the eccentric rotation of cone 18 becomes sufficiently great due to wear of surface B, cone 18 will gradually abrade sensor means 24 until sensor means 24 is activated Restricting means 26 is illustrated as comprising ball 30, spring 32, and retaining washer 34 Ball 30 is initially located in recess 36 in bit body 12 Spring 32 is located in recess 36 behind ball 30 Washer 34 is located between ball 30 and spring 32 Initially, spring 32 is held in compression by wire 28 which is fastened to washer 34 and to sensor 24 In one embodiment, wire 28 may be silver soldered, swayed, or otherwise attached to washer 34 or sensor 24 Therefore, wire 28 is preferably installed in tension through passage 37 so that spring 32 is initially compressed Retainer cap 38 prevents drilling solids from entering recess 36 Equalization passage 40 furnishes a communication path between the inside of the drill stem and recess 36 to prevent differential pressures prom developing across restricting means when sensor 24 is activated due to abrasion from I- cone 18, the end of wire 28 which is connected to sensor 24 will e loosened end sprint I will be released from its in fat .
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g compressed state. During the activation of restricting means 26, spring 32 will propel ball 30 from recess 36 and into the drilling fluid circulating through the drill stem. The force exerted by the drilling fluid and by gravity will push ball 30 toward port 14 until ball 30 seats against the aperture of port 14. With ball 30 in its seating position, ball 30 will reduce the flow of drilling fluid through port 14. Ball I and port 14 may be configured so that ball 30 prevents any fluid from being discharged though port 14. As ball 30 reduces or prevents the flow of the drilling fluid through the port, a pressure rise in the drilling fluid will be recorded by equipment (not shown) at the surface. This pressure rise notifies the operator that sensor 24 has been activated due to excessive wear of the bit. The operator can then trip the drill stem and replace the drill bit.
In FIX I abradable sensor 42 is located at the outside circumferential surface D of leg 10 to detect loss of gauge of the drill bit. Sensor 43 detects bearing failure due to abrasion by cone 18 as previously described for sensor 24. To prevent premature abrasion of sensor 43 due to solids in the drilling fluid, sensor 43 is attached to the end Ox spindle 16 rather than at the location shown for sensor 24. Sensors 42 and 43 are connected to restricting means I by wire 44.
Wire 44 is attached to restricting means 26 and to sensors 42 and 43 in a manner so that activation of either sensor 42 or 43 will manipulate restricting means 26 as previously set forth.
~23'7~S;~
As the drill bit is rotated to advance the depth of the Wilbur, wear of the drill bit due to loss of gauge will activate sensor 42 and bearing failure will activate sensor 43.
Following the activation of either sensor, wire 44 will be released to manipulate restricting means 26. Therefore, excessive bit wear due to bearing failure or to loss of gauge may be separately or simultaneously detected.
various modifications to the preferred embodiment can be made. For example, FIG. 3 shows rubber bushing 45 located in recess 36. Bushing 45 may be used in lieu of retainer cap 38 to prevent drilling solids from entering recess 36. In addition to sensors 42 and 43, other sensors may be located in the drill bit to detect wear at points otter than those illustrated. The precise location and configuration of each sensor will determine the amount of wear at the location which is deemed excessive.
FIG. 4 illustrates another embodiment of the invention which is installed in leg 10. Abradable sensor 46 is located in bit body 12 to detect failure of bearing surface B. tradable sensor 48 is located at surface D of body 12 to detect loss ox .
gauge. In FIG 4, the communication means is shown as hydraulic fluid 50 which lo located in passages 52 through body 12. The restricting means is shown as ball 56 and compression spring 58 located in recess 60 and hydraulic piston 62 located in recess 64. Spring 58 is located behind ball 56 in recess 60 end is initially in compression. Piston 62 is initially located to .
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retain ball 56 in recess 60. Referring to FIG. 5, one embodiment of piston 62 is shown as comprising piston head 66, ring 68, and O-ring seals 70 and 72.
One side ox piston 62 is in fluid communication with hydraulic fluid SO in recess 64. Following the activation of sensor 46 or sensor 48 due to abrasion, hydraulic fluid 50 will leak prom passages 52 and recess 64 into the annuls between the drill stem and the Wilbur. The discharge of hydraulic fluid 50 is assisted by the pressure differential between the drilling fluid pressure in the drill stem and the lower pressure in the Wilbur annuls. As hydraulic fluid 50 flows from recess 64, the drilling fluid pressure acting on piston 62 will force piston 62 into recess 64 until piston 62 no longer retains ball 56 in recess 60. At such point, spring 58 will propel ball 56 from recess 60 and into the drilling fluid. The drilling fluid and gravity will urge ball 56 to seat against port 14 so that the flow of drilling fluid through port 14 is reduced as previously described.
The invention furnishes a unique method and apparatus for remotely detecting excessive wear of a drill bit. The invention does not require any Donnelly electronics or communication links between the drill bit and the surface.
moreover, the invention requires no operating adjustments or special handling. The invention canoe used in conventional rotary drilling, positive displacement motors, or turbine :
' " ' , .'. "' . '' assemblies. In addition, the invention can be adapted to sealed or nonsolid bits and to roller bearing, journal bearing, or drag type bits. The invention can be used in drilling operations using an oil base, water base, or gas as the drilling fluid. Therefore, the invention is extremely versatile and is well sited for use in drilling operations.
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SUPPL~Ml~NTARY DISCLOSURE
FIG. 6 illustrate another embodiment of the invent30n. Abradable tensor 74 if located at the outside circumferential surface D of leg 10 Jo d toot Lucy of gauge of the drill bit. Sensor 76 detects bearing failure due to Ahab by cone 18 a prove defior~bed. Restricting means 78 it compiled of ball 80 and release mechanism 82. As illustrated, release mechanism 82 is generally comprised of lever arm 84, lever pin 86, and spring 88. Lever arm 84 retains I ball 80 in a concave Russ or eta 90. Pin 92 it attached to lever arm 84. Restricting mean 78 is located in the flow stream of the drilling fluid to prevent Leeds in the drilling fluid from c10gging the operable component of restricting means 7B. The flow ox the pressurized drilling fluid prevents impurities in the trilling fluid from attach to the component of retracting means 78 without excessively abrading the component.
Sensor 74 and 76 are connected to retracting means 78 Jo by wore 94. One end of wire 94 By attacked to tensor 74, and the other end of wire 94 us threaded through passage 37, around pin 92, and back through passage 37 to be attached to sensor 76. During installation, wire 94 it tenoned to pull lever arm 84 against spring 88, thereby comparing sprung 88. Following the activation of 6en~ur 74 or sensor 76 due to wear ox the drill bit wire 94 will be released from Tennyson to manipulate restricting mean 78. prying 88 will cause lever arm By to rotate about lever pun 86, thereby releasing b Al 80 from seat 90. The drilling fluid and gravity will Roy ball 80 toward port 14 a previously described.
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of Druid thy end of aye 37 assent thy lnter~or of drill Do body 12 can be portly alto with bullying 96 Jo prevent ho lntru8~0n of drywall Lund into passage 370 As lust rated compared Snow 88 retains ~u~hl~sg go Gannett bit S body 12. Boeing 96 has 8 small aperture 9B which ~uffic~en~ly lug ten end thy Noah of we 94 there through. Sybil, to t~a~etr$c Clarence between wire I and appear 98 it latch than 0~004 rich to parent old thy dry glued Roy no pay 0 I Jll~hough FOG. 6 0 Lowe that -~,X8 94 past talc Through I rtur~ OR moron than owe preheater my by drilled thrush Boone 96 to reduce the clarion b~twe~ I 94 and portray 98. In operation, n flier caky produced by thy drilling ~ltt~d Allah thy clenrsnc~
between Weller 94 and aperture 98, thereby reptilian a prosier di~erent~l betoken the pry try ox two dry no lulled ant the prosaic on pas~ago 370 A prowar alto Noah such a pus 40 in FIGS. l 3 I not nay or they'll embotlment Buick thy nutted ox thy or ~xart~d ye pry dl~er~nts~tl ~1l6ht duo to thy snowily c~os3-~getlonai area ox we 94.
A. Field of the Invention The present invention relates to a method and apparatus for detecting excessive wear of a rotatable bit used in drilling operations. In particular, the present invention relates to a method and apparatus which can detect loss of gauge of or bearing failure in a rotatable bit used to drill a Wilbur.
B. Background of the Invention In oil, gas, and geothermal drilling operations, a drill bit attached to a drill stem is rotated to drill a Wilbur through subsurface geologic formations. Roller-cone drill bits usually comprise a plurality of legs having a rotatable cone attached by a bearing to the spindle Ox each leg. Other types of drill bits such as drag-type bits do not use bearings or other moving components. As a drill bit is rotated, drilling fluid is circulated to cool the drill bit and to transport rock cuttings from the Wilbur. The drilling fluid is pumped down through the drill stem, through ports in the drill bit, and up through the annuls between the drill stem and the wallaby.
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.
.
. .
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A drill bit will wear as it is rotated to advance the depth of the Wilbur. The length of time that a drill bit can be used before it becomes excessively worn depends on a variety of factors such as the hardness and composition of the rock and the drill stem weight that the operator places on the drill bit. The drill bit should be replaced when its rate of penetration has diminished to an unacceptable level or when torque values in rotating the drill string exceed an acceptable limit. An operator can measure the rate of penetration and the - 10 torque values from the surface.
Other factors which normally require the replacement of a drill bit carrot be measured from the surface. For example a roller-cone drill bit should be replaced when the bit bearings lo are excessively worn or when the Wilbur is being drilled under gauge. As the drill bit is rotated, the load-bearing surfaces between a cone and the spindle of a leg will begin to wear. As the surfaces wear, the cone will begin to rotate eccentrically about the spindle Imtil the cone seizes, becomes excessively worn, or is separated from the spindle. In a sealed bit, the bearing will begin to fail after the seal between the cone and the spindle is damaged. If a bit bearing should fail and leave a cone in the wheelbarrows drilling operations are usually discontinued until the cone is "fished" from the Wilbur.
:
.., ..'", ~;23~352 Loss of Barlow gauge of a roller-cone bit is due to abrasion of the gauge-maintaining portion of the drill bit cones against the Wilbur wall. In a drag-type bit, loss of Barlow gauge is due to wear of the gauge maintaining cutters. Loss of gauge is undesirable because there is a greater possibility of differential pressure sticking between the drill string and the Wilbur. Ross of gauge is especially undesirable in specialized drilling operations such as in highly deviated wells because the operator may have difficulty in maintaining directional control of the Wilbur. Although loss of gauge can be reduced by hard-facing certain portions of the bit, loss of gauge remains a problem in drilling operations.
To avoid the cost of retrieving lost cones from the Wilbur, most drill bits will generally be tripped out of the Wilbur and replaced before the bit bearings fail. Because each drill bit is not used to the extent of its maximwn useful life, this practice is costly because more drill bits are required to drill the Wilbur to a particular depth. The practice of pulling drill bits "green" is particularly costly because the drill pipe and drill collars must be tripped each time that a drill bit is replaced. In deep drilling operations ; or in offshore drilling operations which may cost up to - $130,000 U.S. per day, an operator should maximize drilling time by using each drill bit to the full extent of its useful life.
.
. ", . . .
~L23~S~
Although various techniques to detect wear of rotary drill bits have been tried, there are no commercially available techniques which can detect beaning failure or loss of Barlow gauge of a drill bit used to drill a Wilbur.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus con detecting excessive wear of a drill bit connected to a drill stem which is used to drill a Wilbur, A pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annuls between the drill stem and the Wilbur, A restricting means connected to the drill bit ; can be manipulated to reduce the flow of drilling fluid through at least one port in the drill bit. An abradable sensor means is connected to the drill bit at a selected location to detect excessive wear Ox the drill bit. A communication means is located between the sensor means and the restricting means so that activation of the sensor means is transmitted by the communication means to manipulate the restricting means to reduce the flow of drilling fluid through a port, In one embodiment of the invention, the restricting means comprises a ball means which is propelled by a spring means from a recess in the drill bit to partially or completely block a port in the drill bit. The communication means may comprise a wire or hydraulic fluid which is located between the Lo 52 sensor means and the restricting means. A single sensor means can be used to detect excessive wear of a bit at a selected location or additional sensor means may be located at other locations on the bit to simultaneously detect excessive wear of the bit at the differing locations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a sectional view of the invention in lo the body of a drill bit leg wherein an abradable sensor is located to detect bearing failure.
FIG. 2 illustrates an embodiment of the invention showing two abradable sensors located at different locations in the drill bit body.
FIG. 3 illustrates a partial sectional view of a seal within the restricting means which prevents intrusion of drilling solids into a recess located in the drill bit body.
FIG. 4 illustrates a sectional view of an alternative embodiment of the invention wherein hydraulic fluid is used as the communication means and the restricting means includes a piston means located in a recess in the drill bit body.
~25 FIG. 5 illustrates an enlarged partial sectional view of the piston means shown in FIG. 4.
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~;237~352 DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, leg 10 of a sealed journal bit is shown. In most oil and gas rotary drilling operations, three legs form a drill bit. The drill bit, which is attached to the lower end of a drill stem comprised of drill collars, drill pipe, and kelly (not Sheehan is rotated to drill a Wilbur through subsurface geologic formations. Drilling fluid is circulated down through the drill stem and is discharged through at least one port in the drill bit. The drilling fluid returns to the surface through the Wilbur annuls between the drill stem and the Wilbur.
Leg 10 is comprlfied of body 12, port 14, and spindle 16. Cone 18 is retained by bearing 20 on spindle 16.
Cone surface A contains rows of steel teeth or tungsten carbide inserts (not shown) which mechanically fracture the subsurface geological formations as the drill stem is rotated. In drilling operations, spindle 16 supports cone 18 with spindle surface B
as the weight of the drill stem rests on the drill bit. The interstice between spindle 16 and cone 18 is filled with grease .
to lubricate the bearing surfaces. Seal 22 retains the grease within the interstice.
.,, :
25~ As the drill bit is rotated to advance the depth of the Wilbur and the lubrication between spindle 16 and cone 18 degrades, spindle 16 will begin to wear along surface B. As the ::
.. .. .
wear of surface B continues, cone 18 will begin to rotate eccentrically about spindle 16. Bearing 20 may fail if wear of surface B continues to a point where bearing 20 cannot retain cone 18. In many cases, a cone will separate from the spindle S and be lost in the Wilbur. In the event of a lost cone, drilling operations are usually suspended until the cone can be removed from the Wilbur.
In addition to wear along surface B, a drill bit wears at other locations. If the outside circumferential surface of a bit has worn to a point where the diameter of the bit is less than that permitted by bit specifications, the bit is termed "under gauge." For example, a 6-7/8 inch diameter bit worn to 6-5/8 inches is unclergauge. In a roller-cone bit, the outside circumferential surface is the cone gauge maintaining surface.
Referring to FIG 1, gauge maintaining surface C of cone 18 and surface D of leg 10 may experience wear, thereby causing the bit to drill under gauge. m a drag-type bit, gauge maintaining teeth prevent the bit from drilling under gauge.
The present invention detects excessive wear of a drill bit by sensing wear of the drill bit at a particular location and by manipulating a device to at least partially reduce the flow of drilling fluid through the drill bit. Referring to FIG. 1, the invention generally comprises abradable sensor means 24, restricting means 26, and wire or other communication means 28.
.
1%3~S~
Sensor means Z4 is connected to body 12 and extends into recess 29 in cone 18 As previously described, cone 18 will begin to rotate eccentrically about spindle 16 as wear surface B is eroded When the eccentric rotation of cone 18 becomes sufficiently great due to wear of surface B, cone 18 will gradually abrade sensor means 24 until sensor means 24 is activated Restricting means 26 is illustrated as comprising ball 30, spring 32, and retaining washer 34 Ball 30 is initially located in recess 36 in bit body 12 Spring 32 is located in recess 36 behind ball 30 Washer 34 is located between ball 30 and spring 32 Initially, spring 32 is held in compression by wire 28 which is fastened to washer 34 and to sensor 24 In one embodiment, wire 28 may be silver soldered, swayed, or otherwise attached to washer 34 or sensor 24 Therefore, wire 28 is preferably installed in tension through passage 37 so that spring 32 is initially compressed Retainer cap 38 prevents drilling solids from entering recess 36 Equalization passage 40 furnishes a communication path between the inside of the drill stem and recess 36 to prevent differential pressures prom developing across restricting means when sensor 24 is activated due to abrasion from I- cone 18, the end of wire 28 which is connected to sensor 24 will e loosened end sprint I will be released from its in fat .
~Z~'7~5;~
g compressed state. During the activation of restricting means 26, spring 32 will propel ball 30 from recess 36 and into the drilling fluid circulating through the drill stem. The force exerted by the drilling fluid and by gravity will push ball 30 toward port 14 until ball 30 seats against the aperture of port 14. With ball 30 in its seating position, ball 30 will reduce the flow of drilling fluid through port 14. Ball I and port 14 may be configured so that ball 30 prevents any fluid from being discharged though port 14. As ball 30 reduces or prevents the flow of the drilling fluid through the port, a pressure rise in the drilling fluid will be recorded by equipment (not shown) at the surface. This pressure rise notifies the operator that sensor 24 has been activated due to excessive wear of the bit. The operator can then trip the drill stem and replace the drill bit.
In FIX I abradable sensor 42 is located at the outside circumferential surface D of leg 10 to detect loss of gauge of the drill bit. Sensor 43 detects bearing failure due to abrasion by cone 18 as previously described for sensor 24. To prevent premature abrasion of sensor 43 due to solids in the drilling fluid, sensor 43 is attached to the end Ox spindle 16 rather than at the location shown for sensor 24. Sensors 42 and 43 are connected to restricting means I by wire 44.
Wire 44 is attached to restricting means 26 and to sensors 42 and 43 in a manner so that activation of either sensor 42 or 43 will manipulate restricting means 26 as previously set forth.
~23'7~S;~
As the drill bit is rotated to advance the depth of the Wilbur, wear of the drill bit due to loss of gauge will activate sensor 42 and bearing failure will activate sensor 43.
Following the activation of either sensor, wire 44 will be released to manipulate restricting means 26. Therefore, excessive bit wear due to bearing failure or to loss of gauge may be separately or simultaneously detected.
various modifications to the preferred embodiment can be made. For example, FIG. 3 shows rubber bushing 45 located in recess 36. Bushing 45 may be used in lieu of retainer cap 38 to prevent drilling solids from entering recess 36. In addition to sensors 42 and 43, other sensors may be located in the drill bit to detect wear at points otter than those illustrated. The precise location and configuration of each sensor will determine the amount of wear at the location which is deemed excessive.
FIG. 4 illustrates another embodiment of the invention which is installed in leg 10. Abradable sensor 46 is located in bit body 12 to detect failure of bearing surface B. tradable sensor 48 is located at surface D of body 12 to detect loss ox .
gauge. In FIG 4, the communication means is shown as hydraulic fluid 50 which lo located in passages 52 through body 12. The restricting means is shown as ball 56 and compression spring 58 located in recess 60 and hydraulic piston 62 located in recess 64. Spring 58 is located behind ball 56 in recess 60 end is initially in compression. Piston 62 is initially located to .
' , ' ' --, I, " . ' . ' I:
retain ball 56 in recess 60. Referring to FIG. 5, one embodiment of piston 62 is shown as comprising piston head 66, ring 68, and O-ring seals 70 and 72.
One side ox piston 62 is in fluid communication with hydraulic fluid SO in recess 64. Following the activation of sensor 46 or sensor 48 due to abrasion, hydraulic fluid 50 will leak prom passages 52 and recess 64 into the annuls between the drill stem and the Wilbur. The discharge of hydraulic fluid 50 is assisted by the pressure differential between the drilling fluid pressure in the drill stem and the lower pressure in the Wilbur annuls. As hydraulic fluid 50 flows from recess 64, the drilling fluid pressure acting on piston 62 will force piston 62 into recess 64 until piston 62 no longer retains ball 56 in recess 60. At such point, spring 58 will propel ball 56 from recess 60 and into the drilling fluid. The drilling fluid and gravity will urge ball 56 to seat against port 14 so that the flow of drilling fluid through port 14 is reduced as previously described.
The invention furnishes a unique method and apparatus for remotely detecting excessive wear of a drill bit. The invention does not require any Donnelly electronics or communication links between the drill bit and the surface.
moreover, the invention requires no operating adjustments or special handling. The invention canoe used in conventional rotary drilling, positive displacement motors, or turbine :
' " ' , .'. "' . '' assemblies. In addition, the invention can be adapted to sealed or nonsolid bits and to roller bearing, journal bearing, or drag type bits. The invention can be used in drilling operations using an oil base, water base, or gas as the drilling fluid. Therefore, the invention is extremely versatile and is well sited for use in drilling operations.
Lo 2b . :
.
us :
:
, . .
.. . .
~;~3'^~3S~
SUPPL~Ml~NTARY DISCLOSURE
FIG. 6 illustrate another embodiment of the invent30n. Abradable tensor 74 if located at the outside circumferential surface D of leg 10 Jo d toot Lucy of gauge of the drill bit. Sensor 76 detects bearing failure due to Ahab by cone 18 a prove defior~bed. Restricting means 78 it compiled of ball 80 and release mechanism 82. As illustrated, release mechanism 82 is generally comprised of lever arm 84, lever pin 86, and spring 88. Lever arm 84 retains I ball 80 in a concave Russ or eta 90. Pin 92 it attached to lever arm 84. Restricting mean 78 is located in the flow stream of the drilling fluid to prevent Leeds in the drilling fluid from c10gging the operable component of restricting means 7B. The flow ox the pressurized drilling fluid prevents impurities in the trilling fluid from attach to the component of retracting means 78 without excessively abrading the component.
Sensor 74 and 76 are connected to retracting means 78 Jo by wore 94. One end of wire 94 By attacked to tensor 74, and the other end of wire 94 us threaded through passage 37, around pin 92, and back through passage 37 to be attached to sensor 76. During installation, wire 94 it tenoned to pull lever arm 84 against spring 88, thereby comparing sprung 88. Following the activation of 6en~ur 74 or sensor 76 due to wear ox the drill bit wire 94 will be released from Tennyson to manipulate restricting mean 78. prying 88 will cause lever arm By to rotate about lever pun 86, thereby releasing b Al 80 from seat 90. The drilling fluid and gravity will Roy ball 80 toward port 14 a previously described.
37~
of Druid thy end of aye 37 assent thy lnter~or of drill Do body 12 can be portly alto with bullying 96 Jo prevent ho lntru8~0n of drywall Lund into passage 370 As lust rated compared Snow 88 retains ~u~hl~sg go Gannett bit S body 12. Boeing 96 has 8 small aperture 9B which ~uffic~en~ly lug ten end thy Noah of we 94 there through. Sybil, to t~a~etr$c Clarence between wire I and appear 98 it latch than 0~004 rich to parent old thy dry glued Roy no pay 0 I Jll~hough FOG. 6 0 Lowe that -~,X8 94 past talc Through I rtur~ OR moron than owe preheater my by drilled thrush Boone 96 to reduce the clarion b~twe~ I 94 and portray 98. In operation, n flier caky produced by thy drilling ~ltt~d Allah thy clenrsnc~
between Weller 94 and aperture 98, thereby reptilian a prosier di~erent~l betoken the pry try ox two dry no lulled ant the prosaic on pas~ago 370 A prowar alto Noah such a pus 40 in FIGS. l 3 I not nay or they'll embotlment Buick thy nutted ox thy or ~xart~d ye pry dl~er~nts~tl ~1l6ht duo to thy snowily c~os3-~getlonai area ox we 94.
Claims (21)
IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An apparatus for detecting excessive wear of a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a restricting means connected to the drill bit for reducing the flow of drilling fluid through at least one port, said restricting means comprising a ball located in a recess in the drill bit and a compressed spring means located in said recess behind said ball so that when said communication means releases said spring means from compression, said ball means is propelled into a position where it reduces the flow of drilling fluid through at least one port, abradable sensor means connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and communication means located within the drill bit between said restricting means and said sensor means so that activation of said sensor means is transmitted by said communication means to manipulate said restricting means to reduce the flow of drilling fluid through said at least one port.
a restricting means connected to the drill bit for reducing the flow of drilling fluid through at least one port, said restricting means comprising a ball located in a recess in the drill bit and a compressed spring means located in said recess behind said ball so that when said communication means releases said spring means from compression, said ball means is propelled into a position where it reduces the flow of drilling fluid through at least one port, abradable sensor means connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and communication means located within the drill bit between said restricting means and said sensor means so that activation of said sensor means is transmitted by said communication means to manipulate said restricting means to reduce the flow of drilling fluid through said at least one port.
2. An apparatus as recited in Claim 1, wherein said communication means comprises a tensioned wire connected between said restricting means and said sensor for manipulating said restricting means, when said sensor means is activated by abrasion of the drill bit to release the tension in said wire, to reduce the flow of drilling fluid through said at least one port of the drill bit.
3. An apparatus as recited in Claim 1, wherein said restricting means includes piston means located in a second recess to initially retain said ball in said first recess, whereupon activation of said piston means by said sensor means permits said spring means to propel said ball from said first recess and into a position where said ball reduces the flow of drilling fluid through said at least one port.
4. An apparatus as recited in Claim 3, wherein said communication means comprises a hydraulic fluid located in a passage within the drill bit which is in fluid communication with said sensor means and with said piston means in said second recess, wherein abrasion of said sensor means releases said hydraulic fluid into the wellbore annulus so that said piston means is activated to release said ball, thereby permitting said spring means to propel said ball into a position where it reduces the flow of drilling fluid through said at least one port.
5. An apparatus as recited in Claim 1, wherein the drill bit is a drag-type drill bit.
6. An apparatus as recited in Claim 2, wherein said wire is connected between said restricting means and at least two sensors so that activation of one sensor releases the tension in said wire to manipulate said restricting means.
7. An apparatus for detecting excessive wear of a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a ball for reducing the flow of drilling fluid through a port;
release means connected to the drill bit for releasably retaining said ball in an initial position;
an abradable sensor means connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and a wire located within the drill bit connecting said release means and said sensor means so that activation of said sensor means is transmitted by said wire to manipulate said release means, thereby releasing said ball from said initial position to permit the drilling fluid to urge said ball against said port to reduce the flow of drilling fluid through said port.
a ball for reducing the flow of drilling fluid through a port;
release means connected to the drill bit for releasably retaining said ball in an initial position;
an abradable sensor means connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and a wire located within the drill bit connecting said release means and said sensor means so that activation of said sensor means is transmitted by said wire to manipulate said release means, thereby releasing said ball from said initial position to permit the drilling fluid to urge said ball against said port to reduce the flow of drilling fluid through said port.
8. An apparatus as recited in Claim 7, wherein said wire connecting said sensor and said release means is tensioned so that when said sensor has been activated by abrasion of the drill bit, the tension in said wire is released, to release said ball from the initial position.
9. An apparatus for detecting excessive wear of a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a ball, located in a recess in the drill bit body, which is capable of being urged against the aperture of a port to reduce the flow of drilling fluid through the port;
a release mechanism connected to the drill bit for initially retaining said ball in the recess;
an abradable sensor connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and a tensioned wire located in a passage within the drill bit to connect said sensor and said release mechanism so that when said sensor is activated by abrasion of the drill bit to release to the tension in said wire, said release mechanism releases said ball from the recess to permit the drilling fluid to urge said ball against a port.
a ball, located in a recess in the drill bit body, which is capable of being urged against the aperture of a port to reduce the flow of drilling fluid through the port;
a release mechanism connected to the drill bit for initially retaining said ball in the recess;
an abradable sensor connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and a tensioned wire located in a passage within the drill bit to connect said sensor and said release mechanism so that when said sensor is activated by abrasion of the drill bit to release to the tension in said wire, said release mechanism releases said ball from the recess to permit the drilling fluid to urge said ball against a port.
10. An apparatus as recited in Claim 9, wherein said release mechanism comprises a spring, held in compression by said wire, which is located in the recess between said ball and the drill bit.
11. An apparatus as recited in Claim 9, further comprising a spring located in the recess between said ball and the drill bit for propelling said ball from the recess after said release mechanism hag released said ball from the recess.
12. An apparatus for detecting excessive wear of a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein said drill bit comprises a body and at least one rotatable cone attached by a bearing to the drill bit, and a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a ball, located in a recess in the drill bit, which is capable of being urged against the aperture of a port to reduce the flow of drilling fluid through the port;
a release mechanism connected to the drill bit for initially retaining said ball in said recess;
an abradable sensor connected to the drill bit for detecting excessive wear of the drill bit hearing; and a tensioned wire connected between said sensor and said release mechanism for manipulating said release mechanism, when said sensor releases the tension in said wire, to release said ball from the recess so that the drilling fluid can urge said ball against the aperture of a port.
a ball, located in a recess in the drill bit, which is capable of being urged against the aperture of a port to reduce the flow of drilling fluid through the port;
a release mechanism connected to the drill bit for initially retaining said ball in said recess;
an abradable sensor connected to the drill bit for detecting excessive wear of the drill bit hearing; and a tensioned wire connected between said sensor and said release mechanism for manipulating said release mechanism, when said sensor releases the tension in said wire, to release said ball from the recess so that the drilling fluid can urge said ball against the aperture of a port.
13. An apparatus as recited in Claim 12, further comprising a sensor connected to the drill bit for detecting excessive wear of the outside circumferential surface of the drill bit.
14. An apparatus for detecting bearing failure in or excessive loss of gauge of a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein said drill bit comprises a body and at least one rotatable cone attached by a bearing to the drill bit body, and a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a ball, located in a recess in the drill bit, which is capable of being urged against the aperture of a port to reduce the flow of drilling fluid through the port;
a release mechanism connected to the drill bit for initially retaining said ball in said recess;
an abradable first sensor attached to the drill bit at a selected location to detect excessive wear of the drill bit bearing;
an abradable second sensor attached to the drill bit to detect wear of the outside circumferential surface of the drill bit; and a tensioned wire located in a passage within the drill bit to connect said first and second sensors to said release mechanism so that the activation of a single sensor will release the tension in said wire, thereby manipulating said release mechanism to release said ball from said recess and into the drilling fluid to reduce the flow of drilling fluid through a port.
a ball, located in a recess in the drill bit, which is capable of being urged against the aperture of a port to reduce the flow of drilling fluid through the port;
a release mechanism connected to the drill bit for initially retaining said ball in said recess;
an abradable first sensor attached to the drill bit at a selected location to detect excessive wear of the drill bit bearing;
an abradable second sensor attached to the drill bit to detect wear of the outside circumferential surface of the drill bit; and a tensioned wire located in a passage within the drill bit to connect said first and second sensors to said release mechanism so that the activation of a single sensor will release the tension in said wire, thereby manipulating said release mechanism to release said ball from said recess and into the drilling fluid to reduce the flow of drilling fluid through a port.
15. An apparatus as recited in Claim 14, wherein said release mechanism comprises a spring initially held in compression by said wire and being located in the recess between said ball and the drill bit.
16. An apparatus as recited in Claim 14, further comprising a spring located in the recess between said ball and the drill bit for propelling said ball from said recess.
17. An apparatus for detecting excessive wear of a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein said drill bit comprises a body and at least one rotatable cone attached by a bearing to the drill bit body, wherein a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a ball located in a first recess in the drill bit body, wherein said ball is capable of seating against the aperture of a port to reduce the flow of drilling fluid through the port;
a compressed spring means located behind said ball in said first recess for releasably propelling said ball from said first recess;
a piston means located in a second recess in the drill bit to initially retain said ball in said first recess;
an abradable sensor means connected to the drill bit at a selected location in a manner so that said sensor means is activated by abrasion of the drill bit at said location; and hydraulic fluid means located in a passage within the drill bit body so that said hydraulic fluid means is in fluid communication with said sensor means and said piston means, wherein abrasion of said sensor means releases said hydraulic fluid means into the wellbore annulus, thereby activating said piston means to permit said spring means to propel said ball from said first recess and into a position where said ball reduces the flow of drilling fluid through at least one port.
a ball located in a first recess in the drill bit body, wherein said ball is capable of seating against the aperture of a port to reduce the flow of drilling fluid through the port;
a compressed spring means located behind said ball in said first recess for releasably propelling said ball from said first recess;
a piston means located in a second recess in the drill bit to initially retain said ball in said first recess;
an abradable sensor means connected to the drill bit at a selected location in a manner so that said sensor means is activated by abrasion of the drill bit at said location; and hydraulic fluid means located in a passage within the drill bit body so that said hydraulic fluid means is in fluid communication with said sensor means and said piston means, wherein abrasion of said sensor means releases said hydraulic fluid means into the wellbore annulus, thereby activating said piston means to permit said spring means to propel said ball from said first recess and into a position where said ball reduces the flow of drilling fluid through at least one port.
18. An apparatus as recited in Claim 17, wherein said sensor means is located in a position to detect excessive wear of the bearing.
19. An apparatus as recited in Claim 17, wherein said sensor means is located in a position to detect wear of the outside circumferential surface of the drill bit to determine whether the drill bit is undergauge.
20. An apparatus for detecting bearing failure in or excessive loss of gauge in a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein said drill bit comprises a body and at least one rotatable cone attached by a bearing to the drill bit body, and wherein a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a ball located in a first recess in the drill bit, wherein said ball is capable of seating against the aperture of a port to reduce the flow of drilling fluid through the port;
a compressed spring means located behind said ball in said recess for releasably propelling said ball from said first recess;
a piston means located in a second recess in the drill bit to initially retain said ball in said first recess;
an abradable first sensor means attached to the drill bit at a selected location to detect excessive wear of the drill bit bearing, wherein said first sensor means can be activated by abrasion of the drill bit cone;
an abradable second sensor means attached to the outside circumferential surface of the drill bit to detect excessive loss of gauge of the drill bit, wherein said second sensor means can be activated by abrasion of the drill bit against the borehall wall; and hydraulic fluid means located in passages within the drill bit body, wherein said hydraulic fluid means is in fluid communication with said first sensor means, said second sensor means and said piston means, and wherein abrasion of either said first sensor means or said second sensor means releases said hydraulic fluid means into the wellbore annulus, thereby activating said piston means to permit said spring means to propel said ball from said first recess and into 8 position where said ball reduces the flow of drilling fluid through at least one port.
a ball located in a first recess in the drill bit, wherein said ball is capable of seating against the aperture of a port to reduce the flow of drilling fluid through the port;
a compressed spring means located behind said ball in said recess for releasably propelling said ball from said first recess;
a piston means located in a second recess in the drill bit to initially retain said ball in said first recess;
an abradable first sensor means attached to the drill bit at a selected location to detect excessive wear of the drill bit bearing, wherein said first sensor means can be activated by abrasion of the drill bit cone;
an abradable second sensor means attached to the outside circumferential surface of the drill bit to detect excessive loss of gauge of the drill bit, wherein said second sensor means can be activated by abrasion of the drill bit against the borehall wall; and hydraulic fluid means located in passages within the drill bit body, wherein said hydraulic fluid means is in fluid communication with said first sensor means, said second sensor means and said piston means, and wherein abrasion of either said first sensor means or said second sensor means releases said hydraulic fluid means into the wellbore annulus, thereby activating said piston means to permit said spring means to propel said ball from said first recess and into 8 position where said ball reduces the flow of drilling fluid through at least one port.
21. An apparatus for detecting excessive wear of a drill bit connected to a drill stem which is rotated to drill a wellbore, wherein a pressurized drilling fluid in the drill stem is discharged through at least one port in the drill bit and into the annulus between the drill stem and the wellbore, comprising:
a ball retained in a recess in the drill bit for reducing the flow of drilling fluid through at least one port after said ball has been displaced from said recess;
a compressed spring located in said recess between said ball and said drill bit;
an abradable sensor connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and a tensioned wire connected between said sensor and said spring for releasing said spring from compression, after said sensor has been activated due to abrasion of the drill bit, to displace said ball from said recess.
a ball retained in a recess in the drill bit for reducing the flow of drilling fluid through at least one port after said ball has been displaced from said recess;
a compressed spring located in said recess between said ball and said drill bit;
an abradable sensor connected to the drill bit at a selected location to detect abrasion of the drill bit at said location; and a tensioned wire connected between said sensor and said spring for releasing said spring from compression, after said sensor has been activated due to abrasion of the drill bit, to displace said ball from said recess.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US58220384A | 1984-02-21 | 1984-02-21 | |
| US582,203 | 1984-02-21 | ||
| US781,198 | 1985-09-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1237952A true CA1237952A (en) | 1988-06-14 |
Family
ID=24328227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000473206A Expired CA1237952A (en) | 1984-02-21 | 1985-01-30 | Method and apparatus for detecting wear of a rotatable bit |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS60238596A (en) |
| CA (1) | CA1237952A (en) |
| GB (1) | GB2157342B (en) |
| IE (1) | IE850412L (en) |
| IT (1) | IT1182193B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4655300A (en) * | 1984-02-21 | 1987-04-07 | Exxon Production Research Co. | Method and apparatus for detecting wear of a rotatable bit |
| US7207215B2 (en) * | 2003-12-22 | 2007-04-24 | Halliburton Energy Services, Inc. | System, method and apparatus for petrophysical and geophysical measurements at the drilling bit |
| GB2516450A (en) | 2013-07-22 | 2015-01-28 | Schlumberger Holdings | Instrumented rotary tools with attached cutters |
-
1985
- 1985-01-30 CA CA000473206A patent/CA1237952A/en not_active Expired
- 1985-02-12 IT IT47676/85A patent/IT1182193B/en active
- 1985-02-15 JP JP60028132A patent/JPS60238596A/en active Pending
- 1985-02-19 GB GB08504193A patent/GB2157342B/en not_active Expired
- 1985-02-20 IE IE850412A patent/IE850412L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60238596A (en) | 1985-11-27 |
| GB2157342A (en) | 1985-10-23 |
| IT1182193B (en) | 1987-09-30 |
| IE850412L (en) | 1985-08-21 |
| IT8547676A0 (en) | 1985-02-13 |
| GB8504193D0 (en) | 1985-03-20 |
| IT8547676A1 (en) | 1986-08-12 |
| GB2157342B (en) | 1987-05-07 |
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