DRILLING SYSTEM

Abstract

A bulk material drilling system is described, the drilling system arranged to allow accurate directional control of a drill bit through bulk material via non-mechanical means, while providing real-time feedback on drill bit positioning. A drilling system (22) comprising; a bulk material drill bit (10) having; a sensing portion (18), one or more ports (16) for discharging output energy, the drilling system further comprising; an input portion (30) arranged to detect input parameters from the sensing portion, a controller (32) arranged to control output energy to the port; wherein the controller is further arranged to determine one or more ports to which the output energy is provided; wherein the controller is further arranged to control the discharge of the output energy; wherein the output energy discharge is non-uniformly applied to bulk material; wherein the discharge of the output energy is used to control the drill bit direction. The invention aims to prevent mechanical wear while providing effective steering of a drill bit through bulk material.

Claims

1. A drilling system comprising; a drive mechanism; a bulk material drill string with a bulk material drill bit; the drill bit having one or more output energy discharging ports, the drilling system further comprising; a sensing portion; an input portion arranged to detect input parameters from the drill bit sensing portion and a controller arranged to control output energy to the port; wherein the controller is further arranged (i) to determine one or more ports to which the output energy is provided; (ii) to control the discharge of the output energy; whereby the output energy discharge is non-uniformly applied to bulk material and is used to control the drill bit direction.

2. A drilling system according to claim 1, wherein the system further comprises a processing portion arranged to process parameters from the input portion and provide instructions to the controller.

3. A drilling system according to claim 1, wherein the drill string is arranged to provide fluid flow to the drill bit.

4. A drilling system according to claim 3, wherein the drill bit further comprises at least one jetting portion arranged to provide fluid flow out of the drill bit.

5. A drilling system according to claim 1 wherein the drill string comprises a turbine.

6. A drilling system according to claim 1, wherein the output energy is discharged between at least two ports.

7. A drilling system according to claim 1, wherein the sensing portion comprises at least one of an accelerometer, a gyroscope, an electromagnetic sensor, a compass, a radiation sensor, a gamma ray sensor, a temperature sensor, a pressure sensor, a vibration sensor, a sonic sensor, an acoustic sensor; a position sensor; a rotation sensor; a porosity sensor; a density sensor; a resistivity sensor, a position sensor, a displacement sensor, a rotation sensor, or a frequency sensor.

8. A drilling system according to claim 1, wherein the output energy comprises at least one of electrical energy, electromagnetic energy, light energy, laser energy, radiation energy, acoustic energy, plasma energy, or vibration energy.

9. A drilling system according to claim 1, wherein the port comprises at least one of an electrode, an antenna, an optical port, or a transducer.

10. A drilling system according to claim 1, wherein the output energy source is at least one of fluid flow through or near the drill bit, or a turbine in the drill string.

11. A drilling system according to claim 1, wherein the output energy is accessible from at least one of a capacitor, a super-capacitor, or a battery.

12. A drilling system according to claim 1, further comprising an optical fiber package arranged to deliver the output energy to the port.

13. A method of drilling bulk material, wherein the method comprises the use of at least one drilling system according to claim 1.

14. A method of directing drilling of bulk material, wherein the method comprises a step of non uniform weakening of the bulk material by the use of energy discharges.

15. An optical fiber package arranged to transmit high-energy pulses as used in the method of claim 13.

16. A method of drilling bulk material according to claim 13, wherein the method further comprises the use of at least one optical fiber package according to claim 15.

Description

DETAILED DESCRIPTION

[0041] Specific embodiments will now be described by way of example only, and with reference to the accompanying drawings, in which:

[0042] FIG. 1 shows a preferred embodiment of a drill bit according to a first aspect of the present invention;

[0043] FIG. 2 shows a sectional diagram of a portion of a drilling system, including a drill string comprising a drill bit, as according to a first aspect of the present invention;

[0044] FIG. 3 shows a cutaway view of the end of the drill string proximate the drill bit in connection with the drill bit, comprising transmission lines for transmitting high energy pulses to the drill bit via energy transfer members; and

[0045] FIG. 4 shows an exploded view of the end of the drill string proximate the drill bit wherein the port of the rotating drill bit and the energy transmission line and energy transfer member of the static drill string are aligned.

[0046] Referring to FIG. 1, a preferred embodiment is shown in which drill bit 10 comprises a series of cutters 12 with teeth 14. Teeth 14 enable optimum drilling of the bulk material and in the embodiment shown in FIG. 1 are composed of silicon carbide. Other polycrystalline materials may provide optimum drilling through bulk material and may form part of the teeth 14 or another part of the drill bit 10. Alternative embodiments are available wherein the teeth 14 are not composed of silicon carbide or other polycrystalline material.

[0047] As shown in FIG. 1, located about the drill bit 10 are ports 16, from which energy discharges can occur. In the embodiment shown in FIG. 1, the ports 16 take the form of electrodes, antennae and optical ports. Optional alternative embodiments will be apparent comprising a variety of combinations of these ports 16, whereby the optional alternative embodiments may comprise one, two or all three types of the ports 16 described. That ports 16 take the form of electrodes, antennae and optical ports, means therefore that the energy discharge from these ports 16 can optionally be in the form of one selected from a range of electrical, electromagnetic, light, laser, radiation, or acoustic. In use, selection of these ports 16 is therefore optimised to suit the composition of the bulk material to be drilled. Sensing portion 18 (FIG. 2) can be used to determine properties of the drill bit 10 together with properties of an environment surrounding the drill bit 10. Properties of the drill bit 10 to be sensed preferably include the orientation of the drill bit 10; the rotational speed of the drill bit 10; the direction of drilling; the speed and/or velocity of the drill bit 10; and the spatial configuration of ports 16 on the drill bit 10. Environmental properties that can be provided in real-time by the sensing portion 18 preferably include the temperature; the pressure; vibration data; sonic data; acoustic data; radiation data. Additionally, the drill bit 10 preferably also comprises jetting portions 20, arranged to provide fluid flow to the drill bit 10. Preferably fluid flow from the jetting portions 20 is used to provide cooling and lubricating action to the drill bit 10. More preferably, fluid flow from the jetting portions 20 is used to remove drilling cuttings from the borehole 26 and therefore clear the path of the drill bit 10.

[0048] Referring to FIG. 2, a drilling system 22 comprises a drive mechanism 38, a drill string 24 and a drill bit 10, and is used to drill a borehole 26. In use drill bit 10 would rotate at a desired rotational speed, moving through the bulk material 28 to be drilled. The desired rotational speed of the drill bit 10 would be placed into effect by the drive mechanism 38. Properties obtained from the sensing portion 18, which in FIG. 2 is positioned at a downhole location on the drill string, to the input portion 30 are used to determine the orientation and direction of drilling of the drill bit 10 relative to the desired orientation and direction of drilling. A controller 32 is arranged to control the drive mechanism 38 and the provision of output energy to ports 16. Information from the sensing portion 18 is used to inform a change in the direction of the drill bit 10 in order that drill bit 10 conforms to the desired drilling direction. The controller 32 is used to determine the rate at which energy is pulsed to the ports 16 of the drill bit 10. Desired ports 16 are chosen according to the composition of the bulk material 28 to be drilled, and the corresponding form of energy to be used. Change of direction of drilling and therefore the orientation of drill bit 10 is carried out through the firing of high-energy pulses from the ports 16 at a portion 34 of the bulk material 28 to be drilled. The portion 34 of the bulk material 28 to be drilled is chosen according to the desired direction of drilling. High-energy pulses are timed as such to provide a rate of pulsing that applies repeated high-energy pulses to the same portion 34 of the bulk material 28 to be drilled. Repeated pulses are timed to occur from desired ports 16 of the drill bit 10 when the drill bit 10 reaches a desired point of rotation. That only the desired portion 34 of the bulk material 28 to be drilled is affected is a demonstration of the non-uniform application of the high-energy pulses. This non-uniform application of the high-energy pulses weakens the bulk material 28 non-uniformly in that only the desired portion 34 of the bulk material 28 is weakened. The continued drilling by the drill bit 10 is then encouraged to travel through the path of least resistance, this being the newly weakened portion 34 of the bulk material 28. The corresponding change in trajectory of the drill bit 10 therefore provides for effective steering of the drill bit 10. In this way the drilling process is directed by the weakening of the bulk material in a non-uniform way i.e. by using energy discharges.

[0049] In use, the sensing portion 18 provides information to the input portion 30, which can be used to inform the accurate pursuit of a desired region of bulk material 28. Sensing portion 18 also provides timely feedback on the properties of the drill bit 10, aiding in the early detection of problems relating to the drill bit 10 which can include properties of the drill bit 10 or the surrounding bulk material 28 to be drilled. Upon reaching proximity to a desired raw material, the composition of the bulk material 28 may change and the properties of the environment surrounding the drill bit 10 may be altered. If so, these alterations would be detected by the sensing portion 18 and used to inform an altering of the trajectory of the drill bit 10; the rate of drilling; or both. The properties detected by the sensing portion 18 can optionally include the porosity, the density, the pressure and the resistivity of the surrounding bulk material in order to inform the method or direction of drilling through the bulk material. The properties may also be used to detect the likelihood of kick. In extreme cases the likelihood of a blowout may be detected and this catastrophic event can be delayed or prevented. Embodiments will be conceivable wherein the sensing portion may be, at least in part, located on or proximate to the drill bit.

[0050] In alternative embodiments, a processing portion 36 may be used to process the information sensed by the sensing portion 18 and provided to the input portion 30. The processing portion 36 preferably then provides processed information to the controller 32. The processed information provided to the controller 32 is then preferably used to control an adjustment to the drive mechanism 38 or the manner of the provision of output energy to the ports 16. In this way, alternative embodiments may incorporate an automated response by the controller 32 to information provided by the sensing portion 18.

[0051] The input portion 30, controller 32, processing portion 36, drive mechanism 38 may be located on the surface of the bulk material to be drilled, as depicted in FIG. 2, or may be down hole and be co located with the drill string and drill bit 10.

[0052] Referring to FIG. 3 another optional embodiment is shown comprising the combination of the second and third aspects of the present invention. The end 25 of the drill string 24 proximate to the drill bit 10 is shown cut away to reveal the transmission lines 40 responsible for transmitting the high energy pulses comprising optical energy to the drill bit 10. The transmission of energy across the interface between the transmission lines 40 of the static drill string 24 and the ports 16 of the rotating drill bit 10 would require energy transfer members 42. The transmission lines 40 and the energy transfer members 42 comprise part of an optical fiber package wherein the transmission lines 40 comprise optical fibers and the energy transfer members 42 comprise optical windows. In the embodiment shown in FIG. 3 the transmission of the optical energy pulses to the desired port 16 of the drill bit 10 would require transmission across the interface between the energy transfer members 42 and the desired ports 16. Energy transmission therefore requires detection of alignment of the desired port 16 with an energy transfer member 42, wherein the detection of this rotational position of the drill bit 10 is provided by the sensing portion 18. Upon alignment of the desired port 16 with the energy transfer member 42, as shown in FIG. 4, and energy transmission across the interface and out of the port 16, the desired portion (for instance 34 as seen in FIG. 2) of the bulk material 28 is weakened. The trajectory of the drill bit 10 is thus through the portion 34 of the bulk material 28, which provides the least resistance, and therefore the direction of drilling is altered.

[0053] While the applications provided in the above embodiments primarily relate to the extraction and exploitation of raw materials, additional embodiments are conceivable wherein the application of the present invention to drilling bulk material is not related to the extraction or exploitation of raw materials. Additional applications may include the excavation of bulk material from a desired area.

[0054] The embodiment shown in FIG. 1 comprises jetting portions that are positioned equidistant from the centre of the drill bit. Embodiments of the present invention are available wherein there are no jetting portions, or where the at least one jetting portion is located anywhere on the drill bit.

[0055] It will be appreciated that the above described embodiments are given by way of example only and that various modifications thereto may be made without departing from the scope of the invention as defined in the appended claims.