System for drilling deviated boreholes
First Claim
1. A method of signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, a downhole drilling motor being positioned within said drill string, said downhole drilling motor having a power assembly operable for rotating said drill bit, said method comprising:
- rotating said drill bit with said downhole drilling motor at a bit rotation speed in revolutions per minute with respect to said borehole;
supporting at least one sensor at a location below said power assembly of said downhole drilling motor such that said at least one sensor does not rotate at said bit rotation speed; and
detecting a downhole parameter with said at least one sensor.
1 Assignment
0 Petitions
Accused Products
Abstract
Improved techniques are provided for drilling a deviated borehole through earth formations utilizing a rotary bit powered by a drill motor, and for obtaining information regarding the borehole or earth formations. A sensor permanently positioned in the drilling string between the drill bit and the drill motor detects a downhole parameter. An MWD tool may be provided within a non-magnetic portion of the drill string for receiving and transmitting a sensor representative signal to the surface. The sensor signal allows the drilling operation to be altered, and highly reliable and near-bit information thus improves the drilling operation.
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Citations
32 Claims
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1. A method of signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, a downhole drilling motor being positioned within said drill string, said downhole drilling motor having a power assembly operable for rotating said drill bit, said method comprising:
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rotating said drill bit with said downhole drilling motor at a bit rotation speed in revolutions per minute with respect to said borehole; supporting at least one sensor at a location below said power assembly of said downhole drilling motor such that said at least one sensor does not rotate at said bit rotation speed; and detecting a downhole parameter with said at least one sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. Apparatus for signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, said drill bit being powered by a downhole drilling motor within said drill string, said downhole motor including a power assembly for rotating said drill bit, said apparatus comprising:
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one or more sensors mounted below said power assembly of said downhole motor such that said one or more sensors are rotationally uncoupled with respect to said drill bit so as to be rotationally independent of said drill bit; a first downhole signal transmitter positioned below said power assembly of said downhole motor for relaying signals representative of one or more parameters detected by said one or more sensors; a second downhole signal transmitter positioned above said power assembly of said downhole motor for relaying said signals representative of said one or more parameters detected by said one or more sensors to a surface location; and at least one receiver positioned at said surface location for receiving said signals representative of said one or more parameters detected by said one or more sensors. - View Dependent Claims (10, 11, 12)
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13. A method of signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, said drill bit being powered by a downhole drilling motor within said drill string, said downhole drilling motor including a power assembly, said method comprising:
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rotating said drill bit with said downhole drilling motor at a bit rotation speed in revolutions per minute with respect to said borehole; supporting at least one signal transmitter at a location below said power assembly of said downhole drilling motor such that said at least one signal transmitter does not rotate at said bit rotation speed; detecting a downhole parameter with at least one sensor; and transmitting a signal representative of said detected downhole parameter with said at least one signal transmitter. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. Apparatus for signalling within a borehole having therein a drill string with a drill bit at a lower end thereof, said drill bit being powered by a downhole drilling motor within said drill string, said downhole motor including a power assembly for rotating said drill bit, said apparatus comprising:
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one or more sensors positioned below said power assembly of said downhole motor for detecting one or more parameters; a first downhole transmitter mounted below said power assembly of said downhole motor such that said first downhole transmitter is rotationally uncoupled with respect to said drill bit so as to be rotationally independent of said drill bit, said first downhole transmitter relaying a signal representative of said one or more parameters detected by said one or more sensors; and at least one receiver positioned at a surface location for receiving said signal representative of said one or more parameters detected by said one or more sensors. - View Dependent Claims (21, 22, 23)
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24. Apparatus for signalling within a borehole having therein a drill string, said drill bit being powered by a downhole drilling motor within said drill string, at least a portion of said drill string forming a drive shaft rotatable by said downhole drilling motor, said drive shaft being secured to a drill bit at one end thereof and being rotatable by said downhole drilling motor adjacent a second end thereof to thereby rotate said drill bit in response to rotation of said drive shaft, said apparatus comprising:
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a sensor support member mounted at a location below said second end of said drive shaft and being rotatably recoupled with respect to said drive shaft such that said sensor support member is rotatably independent of said drive shaft; one or more sensors carried by said sensor support member for detecting one or more downhole parameters; and a signal transmission system for relaying signals representative of said one or more downhole parameters to a location in said drill string uphole with respect to said drive shaft. - View Dependent Claims (25, 26, 27, 28)
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29. A method of signalling within a borehole having a drill string therein, at least a portion of said drill string forming a drive shaft with said drive shaft being rotatable by a drive unit, said drive shaft being attached to a drill bit at a first end of said drive shaft and being driven by said drive unit adjacent a second end thereof, said drill bit rotating in response to rotation of said drive shaft, said method comprising said following steps:
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rotating said drive shaft with said drive unit to thereby rotate said drill bit at a drill bit rotation speed in revolutions per minute with respect to said borehole; supporting at least one sensor at a location below said second end of said drive shaft such that said at least one sensor does not rotate at said drill bit rotation speed; supporting a downhole signal transmitter at a location below said second end of said drive shaft; and sensing at least one parameter with said at least one sensor. - View Dependent Claims (30, 31, 32)
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Specification