AU2009100636A4 - A Modular Orientation Unit for Use in a Variety of Mining Tools - Google Patents

Description

-1 "A Modular Orientation Unit for Use in a Variety of Minir g Tools" FIELD OF THE INVENTION The invention relates to a modular orientation unit for use in a variety of mining tools. BACKGROUND TO THE INVENTION 5 The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known or part of the common general knowledge in any jurisdiction as at the priority date of the application. 10 Mining tools are expensive. At the same time, a large number Of mining tools are designed to take the same measurements in different environments. One such measurement is orientation which is the crucial measurement n determining the orientation of the core, the orientation of downhole devices and the direction of drilling of a borehole. 15 However, in situations such as determining the orientation of dow hole devices, it is preferable that the unit have a weight which allows for ease of ransport while still having sufficient mass to facilitate insertion through obstacles, such s sludge, that may be present in the borehole. In contrast, when being used for cc re orientation, it is preferable that the unit have sufficient protection to withstand the rigors of drilling. 20 Thus, in two applications requiring orientation there are two differe t requirements set by the different operational environments of the tools. It is an object of the present invention to provide a modular orient tion unit which has the capability of being used in a variety of mining tools. SUMMARY OF THE INVENTION 25 Throughout this document, unless otherwise indicated to the contrary, the terms "comprising", "consisting of", and the like, are to be construed as non-exhaustive, or in other words, as meaning "including, but not limited to". In accordance with a first aspect of the invention there is a modular -ool comprising: an orientation unit; -2 . at least one attachment unit adapted to be connected to the o ientation unit; and * a data acquisition device,. where the orientation unit is adapted to be retrieved from a borehol by way of the at least one attachment unit and an operational unit is adapted to be connected to either 5 the orientation .unit or one of the at least one attachment units to obtain at least one measurement representative of the orientation of the operational unit or an aspect thereof and communicate the at least one measurement to the data a quisition device. A further advantage of this arrangement is that if there is an elect onic failure of the orientation unit, it can be returned back to base far cheaper than the total unit. To 10 elaborate,. a full device is likely to weight in excess of 10-15 kilograms. A pair of orientation units, however, weighs approximately 0.5 kilograms. The operational unit may be a mill shoe, a core barrel or a borehole tool. Preferably, the orientation unit is able to determine the orientation of he operational unit or an aspect thereof by way of a plurality of accelerometers. Ideally, such 15 accelerometers are tri-axially arranged within the orientation unit. One of the at least one attachment units may be a casing. The casing may encapsulate, either in itself or in conjunction with other attachment u its, the orientation unit. The casing may also vary in size to facilitate connection with dr ilI strings of various sizes. 20 The data acquisition device is preferably a handheld unit with a displ y. The orientation measurements communicated to the data acquisition device from the orientation unit are displayed to a driller by way of the display. In a variation on the above processing, the measurements communicated to the data acquisition device may be the raw gravitational measurements taken by the 25 accelerometers. A processing unit inside the data acquisition device may process such raw gravitational measurements to produce a single orientation measurement. The data acquisition device may be in real-time communication with the orientation unit. This may be achieved by a wireline or wireless means. Alternate ely, the orientation unit may operate to store measurements and correlate actions taken using the data 30 acquisition device against the stored measurements on retrieval of t e modular tool.

-3 BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described, by way of example only, wit reference to the accompanying drawings, in which: Figure 1 is an isometric view of a modular tool in accordance with a first embodiment of 5 the present invention adapted for determining the direction of drilling f a borehole. Figure 2 is a schematic representation of an orientation unit used in the modular tool shown in Figure 1. Figure 3 is an isometric view of a modular tool in accordance with a second embodiment of the present invention adapted for determining core or entation. 10 PREFERRED EMBODIMENTS OF THE INVENTION In accordance with a first embodiment of the invention there is a nodular tool 10 for determining the current drilling direction of a borehole 2. The modular tool 10 comprises an orientation unit 12, a handset 14, an attachment unit 16 and a casing 18. The orientation unit 12 comprises three accelerometers 20, a pr cessing unit 22, a 15 memory 24 and a communications system 26. The accelerometers 20, processing unit 22, memory 24 and communications system 26 are all mounted on a mainboard 28. The accelerometers 20 are organised tri-axially. This allows each accelerometer to measure gravitational force along two of the x, y and z axes. This also provides for one redundant or verifying measurement for each such axes. 20 The accelerometers 20 are also in data and control communication Nith the processing unit 22 by way of the mainboard 28. This allows measurement values taken by the accelerometers 20 to be communicated to the processing unit 22. The processing unit 22 is also in data and control communication ith the memory 24 and the communications system 26. The memory 24 holds software code that controls 25 the functionality of the orientation unit 12, including code for transforming the measurement values taken by the accelerometers into an orientatio measurement. As such code would be known to the person skilled in the art, it will not be described in more detail here.

-4 The communications system 26 is, as mentioned above, operable to be controlled by the processing unit 22. The communications system 26 allows or data, including orientation measurements, to be communicated from the orientat on unit 12 to the handset 14. 5 Each element of the orientation unit 12 mentioned above is housed in a tubular housing 30. The tubular housing 30 is elongated with an enlarged head portion 32. Positioned just below the enlarged head portion 32 is a threaded portion 34. T e threaded portion 34 allows for a secure threaded connection to be made with the casi g 18. The tubular housing 30 has a glass window 36 which looks into the enlarged ead portion 32 to 10 display the components contained in the orientation unit 12. The handset 14 consists of a liquid-crystal display 38, a communica ion system 39 and a plurality of control buttons 40. The role of the control buttons 40 and the effect the pressing of such buttons 40 have on the information displayed on the liquid-crystal display 38 will be described in more detail below. 15 The attachment unit 16 is cylindrical. At one end 42 of the attachment unit is a hollow cavity 44. The hollow cavity 44 has a threaded portion (not shown which allows for a secure threaded connection to be made with the casing 18. At a second end 46 of the attachment unit 16 is a second hollow cavity 48. This hollow cavity 48 also has a threaded -portion (not shown) to facilitate a second threaded 20 connection between the attachment unit 16 and a wireline. The casing 18 has a first threaded end 50 and a second threaded end 52. The first threaded end 50 is sized and shaped to provide a secure threaded connection with the attachment unit 16. The second threaded end 52 is sized and shaped to provide a secure threaded connection with the mill shoe 19. 25 A hollow cavity 54 extends through the casing 18 from the first threaded end 50. The hollow cavity 54 also has a threaded portion (not shown). Th s threaded portion facilitates a further threaded connection between the casing 18 anc the orientation unit 12. The mill shoe 19 comprises a hollow cylindrical tube which is cu -away to provide a 30 pointed end 56. A channel 58 is provided in the side of the tube opposite the pointed end 56. Positioned within the mill shoe 19 is a recess (not shown). This recess is -5 adapted to receive a pin 60. When so received, the pin 60 extends tf rough the channel 58 at a position near its closed end 62. An end 64 of the mill shoe 19 has a hollow cavity with a threaded portion (not shown). The threaded portion allows for a secure threaded connection to be made with the 5 casing 18. The orientation unit 12, handset 14, attachment unit 16 and casing 13 will be described in more detail in the context of its use as described below. A real-time communication session is established between the orie tation unit 12 and the handset 14 by way of communication systems 26 and 39. 10 The orientation unit 12 is then threadedly connected to the cas ng 18. Once so connected, the enlarged head portion 32 extends out from the casing 18, with the remainder being received therein. In this position, it is still possible to see the internal components of the orientation unit 12 through glass window 36. The mill shoe 19 is then threadedly connected to the casing 18. -he pin 62 is then 15 inserted into its recess. A hole is then drilled in the side wall of a drill string (not shown). The hole needs to be at least equal in size to the pin 62. Preferably, the hole is such that the pin 62 is firmly received therein during drilling. With the pin 62 creating a non-rotating connection between the mod lar tool 10 and the 20 drill string, the drill string is rotated until the pin 62 points towards a known reference orientation, in this case top-dead centre. Once this position is reached, a driller then pushes a first control button 40 to indicate that the current orien tion measurement should be treated as a zero-reference measurement. The liquid-ct/stal display 38 will then operate to show the current orientation measurement as 04. 25 At the same time, an internal timer (not shown) within the handset 14 is synchronised with an internal timer (also not shown) within the orientation unit 12. The attachment unit 16 is then threadedly connected to the caing 18. Once so connected, the orientation unit 12 is completely enclosed by the threaded combination of the casing 18 and the attachment unit 16. This also terminates the real-time 30 communication session between the orientation unit 12 and the handset 14.

-6 The attachment unit 16 is then connected to a wireline (not show ) to facilitate later retrieval and reinsertion of the tool 10. The driller can then commence drilling of the borehole with the modular tool 10 connected thereto. The process of drilling will not be described ir more detail here, 5 except as is relevant to the invention, as such a process would be known to the person skilled in the art. It should be noted however, that every ten seconds following synchronisation of the two timers, the orientation unit 12 operates to determine its current orientation and stores such orientation measurements in memory 24. 10 When the driller wants to change the direction of drilling, he presses a second control button 40 on the handset 14 to take an orientation measurement of tae assembled tool. Upon pressing the second control button 40, the liquid-crystal display operates to display to the driller that they should wait a predetermined length of time before resuming drilling or otherwise altering the position of the drill string. Also, on detecting 15 the pressing of the second control button 40, the handset operates to record the current time value recorded by the handset's 14 internal timer. This valu is stored for later reference. As normal operation sees the driller only require a single measurement, following pressing of the second control button 40, it is expected that the driller will the retrieve 20 the tool 10 via the wireline. Following retrieval, the tool 10 is partially disassembled to expose t glass window 36. Once exposed, a second real-time communication session is estate lished between the orientation unit 12 and the handset 14 by way of communication sys ems 26, 39. The liquid-crystal display 38 then awaits the pressing of a furthe control button 40. 25 Once so pressed, the handset 14 makes a request of the orientation tool 12 to provide it with the orientation measurement taken at the time recorded when the second control button 40 was pressed. On receipt of this measurement, it is displ ed to the driller by way of the liquid-crystal display 38. The driller may then rotate the drill string as required until the desired direction (as an angle measurement) is reached. Drilling may 30 then recommence in the new direction.

-7 In accordance with a second embodiment of the present invention, Where like numerals reference like parts, there is a modular tool 100 for determining coie orientation. The modular tool 100 is identical to the modular tool 10 except for the structure of the attachment unit 16 and minor variations in the processing of orientat on measurements. 5 It should also be noted that the modular tool 100 is designed to be attached to a core barrel and not a mule shoe 19. In this embodiment, attachment unit 102 is cylindrical. At one end 104 of the attachment unit is a hollow cavity 106. The hollow cavity 106 has a threaded portion (not shown) which allows for a secure threaded connection to be made with the casing 10 18. A second end 108 of the attachment unit 102 has a threaded portion 110. The threaded portion 110 facilitates a second threaded connection betw en the attachment unit 102 and an overshot unit (not shown). In place of the mule shoe 19, the second threaded end 52 of the ca ing 18 is sized and 15 shaped to provide a secure threaded connection with a core barrel 112. In use, the second embodiment of the invention operates as follows. A real-time communication session is established between the orientation unit 12 and the handset 14 by way of communication systems 26 and 39. The orientation unit 12 is then threadedly connected to the casing 18. Once so 20 connected, the enlarged head portion 32 extends out from the casing 18, with the remainder being received therein. In this position, it is still possible to see the internal components of the orientation unit 12 through glass window 36. The core barrel 112 is then threadedly connected to the casing 18. The core barrel 112 is rotated a known reference orientation, in this case top-dead 25 centre, is reached. The driller then pushes a first control button 4C to indicate that the current orientation measurement should be treated as a zero-refermnce measurement. The liquid-crystal display 38 will then operate to show the current orientation measurement as 00. At the same time, an internal timer (not shown) within the handset 14 is synchronised 30 with an internal timer (also not shown) within the orientation unit 12.

-8 The attachment unit 102 is then threadedly connected to the caEing 18. Once so connected, the orientation unit 12 is completely enclosed by the threaded combination of the casing 18 and the attachment unit 16. This also terminates the real-time communication session between the orientation unit 12 and the hand set 14. 5 The attachment unit 102 is then connected to an overshot (not shown). The casing 18 is further connected to a core barrel (also not shown) The driller can then commence drilling of the borehole with the modular tool 100 connected thereto. The process of drilling will not be described ir more detail here, except as is relevant to the invention, as such a process would be known to the person 10 skilled in the art. It should be noted however, that every ten seconds following synchrOnisation of the two timers, the orientation unit 12 operates to determine its current orientation and stores such orientation measurements in memory 24. When the driller has reached the desired position for core orientation, he presses a 15 second control button on the handset 14 to take an orientation measurement. Upon pressing the second control button 40, the liquid-crystal display operates to display to the driller that they should wait a predetermined length of time befo e resuming drilling or otherwise altering the position of the drill string. Also, on detecting the pressing of the second control button 40, the handset operates to record the current time value 20 recorded by the handset's 14 internal timer. This value is stored for ter reference. As normal operation sees the driller only require a single mea urement, following pressing of the second control button 40, it is expected that the drler will the retrieve the tool 100 via the overshot as would be known to the person skilled in the art. Following retrieval, the tool 100 is partially disassembled to expose the glass window 25 36. Once exposed, a second real-time communication session is established between the orientation unit 12 and the handset 14 by way of communication systems 26, 39. The liquid-crystal display 38 then awaits the pressing of a further control button 40. Once so pressed, the handset 14 makes a request of the orientation unit 12 to provide it with the orientation measurement taken at the time recorded when the second control 30 button 40 was pressed. The handset 14 then continues a real-time measurement dialogue with the orientation unit 12. As part of this dialogue, the orientation tool 12 -9 provides the handset 14 with the orientation measurement associated with the current position of the orientation unit 12. This measurement is compared to the orientation measurement taken at the time recorded so as to determine the direction the core barrel must be rotated in order to re-orient the core barrel back to its downhole position. 5 The liquid-crystal display 38 then operates to display arrows indicative of that direction to the user until such time as re-orientation has been achieved. Once re-orientation has been achieved, the liquid-crystal display 38 operates to display a solid line around its periphery. As is evidenced by the embodiments described above, the c mbination of the 10 orientation unit 12 and the handset 14 provide a core system which can be added to with other components to meet the measurement requirements of certain mining activities. As this core includes all electronic componentry associated with the tool 10, 100, this also provides further advantages in that: * A single handset 14 and orientation unit 12 can be used in pl ce of multiple sole 15 purpose tools - hence saving on storage and transportation costs. * The additional components needed for the modular tool 10, 00 to transform its function are low-cost items - hence reducing the overall -ost of the unit in comparison to multiple sole-purpose tools. & The use of a single handset to cover the functionality of the orientation unit 12 20 regardless of its current configuration increases driller familia ity with the system and decreases learning time for the driller. It should be appreciated by the person skilled in the art that the a ve invention is not limited to the embodiment described. In particular, the following modifications and improvements may be made without departing from the scope of the present invention: 25 * The orientation unit 12 may be added to or replaced with another measuring unit designed to measure a factor other than orientation. For in tance, temperature measurement units may be used in place of the orientation ur it 12. * The casing 18 may be omitted and its connective features dapted to form an integral part of the orientation unit 12. In this manner, the additional weight of 30 the casing 18 may be foregone. Such a configuration is part cularly useful when seeking to orient a borehole tool where durability of the ool is not a prime concern.

-10 e in a configuration such as that described in the last bullet point, the orientation unit 12 is preferably constructed to facilitate direct connection to the borehole tool. Alternatively, if a casing 18 is used for the same function, it is preferable that the second threaded end 58 is adapted to facilitate direct connection to the 5 borehole tool. e The tri-axial configuration created by three accelerometers 20 as described above can be replaced by a tri-axial configuration created from two accelerometers. Of course, in doing so, the redundant or verification measurement for each axis is foregone. 10 * The casing 18 may vary in size. This allows a casing 18 to be selected to match the size of the drill string being employed. . The casing may be made of metal, plastic or such other ma erial as meets the requirements of the environmental situation in which the tool 1 , 100 will operate. * While the tool 10, 100 as described above works on a wireless non-real-time 15 communication system, it is possible to run the system using the wireline as a real-time communications conduit. Alternatively, other eal-time, wireless communication systems may be used to facilitate communic tion of orientation measurements. * As an alternative method of operation to that described above, the orientation 20 measurements need not be calculated by the orientation uni 12. In place, the raw measurement values may be recorded and, upon e ablishment of the subsequent real-time communication session, these raw va ues transferred to the handset 14. A processing unit within the handset 14 may then calculate the desired orientation measurement from these raw values. 25 * In a variation on the processing described above, the oriental ion tool 12 may be pre-configured to a reference orientation before being released to the market. This would then allow the reference orientation process described above to be omitted. * The threaded connections used to connect the various el ents of each tool 30 may be replaced by other connecting mechanisms. For instance, bayonet fittings may be used a replacements for the threaded connectors. * The liquid-crystal display 38 may display the orientation measurement in a variety of formats. For instance, if a desired direction has al eady been entered -11 into the handset, the system may provide a series of ar ows showing the direction in which the drilf string must be rotated in order to attain that direction rather than the current degree orientation measurement. It should be further appreciated by the person skilled in the art that t e above features, 5 where not mutually exclusive, can be combined to form yet further e mbodiments within the scope of the present invention.

Claims (10)

1. In accordance with a first aspect of the invention there is a module r tool comprising: an orientation unit; at least one attachment unit adapted to be connected to the or entation unit; and 5 a data acquisition device, where the orientation unit is adapted to be retrieved from a bor hole by way of the at least one attachment unit and an operational unit is adapted o be connected to either the orientation unit or one of the at least one attachmen units to obtain at least one measurement representative of the orientation of the operational unit or 10 an aspect thereof and communicate the at least one measure ment to the data acquisition device.

2. A modular tool according to claim 1, where the operational unit is a mill shoe, a core barrel or a borehole tool.

3. A modular tool according to any preceding claim, where the orientation unit is able 15 to determine the orientation of the operational unit, or an aspect t aereof, by way of a plurality of accelerometers.

4. A modular tool according to claim 3, where the accelerometers are tri-axially arranged within the orientation unit.

5. A modular tool according to any preceding claim, where one f the at least one 20 attachment units may be a casing.

6. A modular tool according to claim 5, where the casing encapsu tes, either in itself or in conjunction with other attachment units, the orientation unit.

7. A modular tool according to any preceding claim, where the data acquisition device is preferably a handheld unit with a display, the orientat on measurements 25 communicated to the data acquisition device from the orientation unit operable to be displayed to a driller by way of the display,

8. A modular tool according to any preceding claim, where he measurements communicated to the data acquisition device are the raw gravitational measurements taken by the accelerometers and a processing nit inside the data 30 acquisition device processes the raw gravitational measurements to produce a single orientation measurement. -13

9. A modular tool according to any preceding claim, where the data acquisition device is in real-time communication with the orientation unit.

10.A modular tool, according to any one of claims 1 to 9, where tie orientation unit operates to store measurements and correlate actions take using the data 5 acquisition device against the stored measurements on retrieval o the modular tool.