Exhaust Port in a Protruding Element of a Downhole Drill Bit
In one aspect of the present invention, a drill bit comprises an axis of rotation and a drill bit body that comprises a central bore and a working face, the working face comprising a plurality of fixed element cutting elements, a jack element extending from the working face and being coaxial with the axis of rotation, the jack element comprising a proximal end in mechanical communication with an oscillating hammer mechanism, the jack element also comprising a channel in fluid communication with the central bore, the channel directing a fluid flow into a formation, wherein a fluid volume defined by the hammer mechanism and the central bore is evacuated through the channel.
1 . A drill bit, comprising:
an axis of rotation and a drill bit body comprising a central bore and a working face, the working face comprising a plurality of fixed cutting elements;
a jack element extending from the working face and being coaxial with the axis of rotation;
the jack element comprising a proximal end in mechanical communication with anaxially oscillating hammer mechanism;
the jack element also comprising a channel in fluid communication with the central bore, the channel directing a fluid flow into a formation; wherein
a fluid volume defined by the hammer mechanism and the central bore is evacuated through the channel.
2 . The bit of claim 1 , wherein the channel terminates at one or more nozzles disposed proximate the distal end of the jack element.
3 . The bit of claim 2 , wherein the one or more nozzles comprise a combined cross-sectional area less than the cross-sectional area of the channel.
4 . The bit of claim 2 , wherein the one or more nozzles comprise a wear resistant material such as polycrystalline diamond or cubic boron nitride.
5 . The bit of claim 2 , wherein the one or more nozzles are threaded into the jack element.
6 . The bit of claim 2 , wherein the one or more nozzles are pressed into the jack element.
7 . The bit of claim 2 , wherein the one or more nozzles are brazed into the jack element.
8 . The bit of claim 2 , wherein the one or more nozzles comprise an adjustable trajectory.
9 . The bit of claim 1 , wherein the jack element is connected to the hammer mechanism by a shaft.
10 . The bit of claim 9 , wherein the jack element is connected to the shaft by a key and keyway, a bolted flange, a press fit, threads, or combinations thereof.
11 . The bit of claim 10 , wherein the shaft is rotated by a fluid-driven turbine or an electric motor.
12 . The bit of claim 11 , wherein a gearbox is disposed intermediate the shaft and the turbine or electric motor.
13 . The bit of claim 1 , wherein the drill bit rotates at a first angular velocity about the axis of rotation and the jack element rotates at a second angular velocity about the axis of rotation.
14 . The bit of claim 13 , wherein the second angular velocity is equal in magnitude and opposite the direction of the first angular velocity.
15 . The bit of claim 13 , wherein the second angular velocity is variable in time.
16 . The bit of claim 13 , wherein the second angular velocity varies according to a pattern that repeats with every revolution of the jack element.
17 . The bit of claim 1 , wherein the jack element comprises a hard material insert.
18 . The bit of claim 17 , wherein the hard material insert is disposed coaxial to the axis of rotation.
19 . The bit of claim 17 , wherein the hard material insert is disposed offset from the axis of rotation.
20 . The bit of claim 1 , wherein the jack element comprises an inclination instrumentation device in electrical communication with an electronic processing device disposed on the drill string.