Downhole surveying and core sample orientation systems, devices and methods

Abstract

A method and system of validating orientation of a core obtained by drilling the core from a subsurface body of material, the method including: a) determining that vibration from drilling is below a nominated level, b) recording data relating to orientation of the core to be retrieved, the data recorded using a downhole core orientation data recording device, c) separating the core from the subsurface body, and d) obtaining from the core orientation data recording device an indication of the orientation of the core based on the recorded data obtained when the vibration from drilling was below the nominated level and before the core was separated from the subsurface body. A method of determining orientation of a core sample obtained by drilling from aboveground into a subsurface body includes recording data relating to a core sample being obtained by the drilling when vibration from drilling is below a threshold; providing an input to a user operated communication device; the communication device identifying a time of the user input to the communication device; retrieving the data gathering device and core sample; communicating between the communication device and the retrieved data gathering device; determining from indications provided by the retrieved data gathering device an orientation of the core sample.

Claims

1. A method of determining orientation of a core obtained by drilling the core from a subsurface body of material, the method comprising: a) recording data relating to orientation of the core to be retrieved, the data recorded using a downhole core orientation data recording device; b) providing a communication device at the surface having a timer and commencing timing from a specific moment; c) separating the core from the subsurface body and retrieving the core and the core orientation data recording device to the surface; d) a period of time after the specific moment, the communication device signalling to the core orientation data recording device at the surface to identify or note core orientation data recorded a period of time that has elapsed since the specific moment such that the timer of the communication device is not synchronized with timing of the recording of the data relating to the orientation of the core; and e) the core orientation data recording device providing the recorded orientation data recorded prior to and closest to the end of the period of time that the communication device has signalled to the data recorder to look back.

2. The method according to claim 1, wherein the communication device signals to the data recording device to halt surveying.

3. The method according to claim 1, further comprising the communication device referring its internal clock and transmits to the data recording device an elapsed time value when the data recording device enters a core orientation process stage.

4. The method according to claim 1, further comprising the data recording device deducting the time value from a predetermined time value of its own internal timer.

5. The method according to claim 1, further comprising the data recording device checking for a saved data event in its memory that occurred previous to time value, and retrieving a core sample roll value.

6. The method according to claim 1, wherein the core orientation data recording device comprises one or more lights or other visual indicators to give an indication of required orientation and/or direction to rotate the core for marking the core.

7. The method according to claim 1, wherein, once in orientate mode, visual indications indicate to an operator to rotate the core to find the correct rotational position for marking the orientation of the core.

8. The method according to claim 1, whereby, once in an orientation mode, visual indications indicate to an operator which direction to rotate the core to find the correct ‘down side’ of the core for marking the orientation thereof.

9. The method according to claim 1, whereby, communication to the core orientation data recording device is effected via the remote communication device and the remote communication device will then verify that the correct orientation was achieved based on the orientation data recorded.

10. The method according to claim 1, wherein the timer of the remote communication device identifies or marks a time when a user selects that a core sample is to be retrieved.

11. The method according to claim 10, wherein the core orientation data is recorded before or after the specific moment.

12. A system, for determining orientation of a core, which comprises a core orientation data recording device, a remote communication device and a core drilling assembly, wherein the core orientation data recording device is configured to record data relating to orientation of a core to be retrieved, the remote communication device, which is provided at the surface, has a timer configured to commence time from a specific moment, and after the core has been separated from a subsurface body and the core orientation data recording device and the core are retrieved to the surface, a period of time after the specific moment the communication device signals to the core orientation data recording device at the surface to identify or note core orientation data recorded a period of time that has elapsed since the specific moment, and the core orientation data recording device is configured to provide the recorded orientation data recorded prior to and closest to the end of a set period of time that the communication device has signalled to the data recorder to look back.

13. The system according to claim 12, wherein the core orientation data recording device comprises at least one visual indicator that is configured to indicate one or more of a direction to rotate the core to obtain the required orientation or a visual indication to show the required orientation.

14. The system according to claim 13, wherein the at least one visual indicator is arranged and configured to provide a flashing light indication.

15. The system according to claim 14, wherein the at least one visual indicator is arranged and configured to change a rate of flashing of the visual indication as the core orientation data recording device is rotated.

16. The system according to claim 12, wherein the remote communication device is operated to indicate or mark a time when a user selects that a core sample is to be retrieved.

17. The system according to claim 16, wherein the core orientation data recording device records the orientation data before or after the specific moment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a general arrangement of a drill assembly for obtaining core sample according to an embodiment of the present invention.

(2) FIG. 2 shows an example of a flowchart relating to a method according to an embodiment of the present invention.

(3) FIGS. 3 and 4 show features of a known core sample orientation system.

(4) FIGS. 5A, 5B and 6 show features of an arrangement of a core sample orientation system according to an embodiment of the present invention.

(5) FIG. 7 shows a core sample orientation data gathering device according to an embodiment of the present invention.

(6) FIG. 8 shows a hand held device for interrogating the core sample orientation data gathering device according to an embodiment of the present invention.

(7) FIG. 9 shows an indicator window end of a core sample orientation device according to an embodiment of the present invention wherethrough indicator lights can show when illuminated.

(8) FIGS. 10a and 10b show an alternative embodiment of a data gathering device of the present invention.

(9) FIG. 11 is a flow chart showing steps involved in obtaining usable recorded data of downhole survey equipment for determining orientation of a core sample according to an embodiment of the present invention.

(10) FIG. 12 is a flow chart of selection of useable data for use in determining core sample orientation according to an embodiment of the present invention.

(11) FIGS. 13 to 15 show the device in place ready for marking the lower face of the core after orientation, and which is still within the core tube;

(12) FIG. 16 shows a view of the device with wheels used to locate and orientate the device via gravity before marking the core end face.

(13) FIG. 17 shows a sectional view of a portion of the device with a marker within a spring loaded cartridge.

(14) FIG. 18 shows a system according to an embodiment of the present invention including a remote device communicating with the device of FIGS. 1 to 5 and used to confirm correct lower side core orientation.

(15) FIG. 19 shows a sectional view through a core marking device according to an embodiment of the present invention.

(16) FIGS. 20a to 20c show respective side, perspective and end views of an alternative embodiment of a core marking device of the present invention.

(17) FIGS. 21a to 21c show respective top, perspective and side section views of part of the alternative embodiment of a core marking device of the present invention shown in FIGS. 20-20c.

(18) FIGS. 22a to 22e are sectional views showing steps in the operation of an embodiment of the core marking device.

DESCRIPTION OF PREFERRED EMBODIMENT

(19) The present invention includes an embodiment with detection of a core for retrieval by separation or ‘breaking’ from the body of material from which it is drilled.

(20) A drill assembly 10 for drilling into a subsurface body of material 12 includes a drillstring 14 including a drill bit 16 an out tube 22 formed of linearly connected tube sections 22a,22b . . . , and an inner tube assembly 18 including an inner tube 24 for receiving the core 26 drilled from the subsurface body.

(21) One or more pressure sensors 28,30,32 can be provided to detect pressure, change in pressure and/or pressure differential. These can communicate with the core orientation data recording device and/or an operator at the surface. Once a required pressure value is detected, drilling can cease and the core orientation device can record data relating to the orientation of the core, such as gravitational field strength and direction, and/or magnetic field strength and direction.

(22) Digital and/or electro-mechanical sensors, and/or one or more pressure sensors in a core orientation data recording device 20 are used to determine the core orientation just prior to the core break, and to detect the signal of the break of the core from the body of material.

(23) Data recorded or used may optionally include ‘dip’ angle α to increase reliability of core orientation results.

(24) Dip (also referred to as inclination or declination) is the angle of the inner core tube drill assembly with respect to the horizontal plane and can be the angle above or below the horizontal plane depending on drilling direction from above ground level or from underground drilling in any direction. This provides further confirmation that the progressive drilling of a hole follows a maximum progressive dip angle which may incrementally change as drilling progresses, but not to the extent which exceeds the ‘dogleg severity’. The ‘dogleg severity’ is a normalized estimate (e.g. degrees/30 metre) of the overall curvature of an actual drill-hole path between two consecutive directional survey/orientation stations.

(25) At the surface prior to obtaining the next orientation and core sample (or first if no previous core samples have been obtained for that drilling), a remote communication device (remote communicator) is set by an operator to a start time (say, T minutes).

(26) The remote communicator communicates with the core orientation device and the core orientation device is then inserted into the drill hole.

(27) After the set period of time (say, ‘T’ minutes) has elapsed the core orientation device will begin normal operation to detect the signature of vibration indicating a core break.

(28) Alternatively, pressure changes or levels may be detected to indicate a pre-break condition or period, such as pressure of mud/water within the inner tube increasing due to the core filling or nearly filling the inner tube holding the core.

(29) The core orientation device preferably does not take any orientation measurements while vibrations (e.g. due to drilling) are present. A combination of mechanical, electromechanical and/or electronic sensors and software algorithms programmed into the core orientation device determine that the core orientation device is in motion while descending down the hole and during drilling and is therefore not yet needed to detect breaking of the core sample from the body of material.

(30) When ascending to the surface for core retrieval after core breaking ascending, the core orientation device also preferably does not take any core orientation measurements.

(31) If any measurements are taken during descending or ascending, due to sensitivity limitations of the sensors or during erratic silence segments, such measurements are discarded as they don't match the correct signature.

(32) When the drilling ends and the driller is ready to break the core, the driller instructions will be to observe a period of Y seconds silence (no rotation), (this may typically be greater than 10 s but no longer than 90 seconds). An Orientation & dip measurement will be taken during this period of silence. After breaking the core (breaking core operation should take less than, say ‘X’ seconds, which is typically X=20 s). Then the driller must wait, say ‘Z’ seconds silence (no rotation), (Z typically is greater than 90 s). The purpose of these timings is to produce the correct ‘signature’. If one of these criteria is not met then the sample can be discarded.

(33) Alternatively or in addition, pressure created within the borehole by ‘mud and/or water (which may be pumped down the borehole from the surface) may be detected. One or more forms of the present invention may include detecting that pressure reaching a certain pressure. One or more pressure sensors may be provided on the drillstring, such as on the inner and/or outer drill tube or on the drill bit or on the core orientation data recording device. Detected pressure (such as pressure within the inner tube receiving the core) or pressure differential (such as pressure differential between/across the inner and outer tubes, may be indicative of the inner tube being nearly or totally full of core. This occurs before the core is separated from the subsurface body of material (such as by breaking the core from the body by a sharp pull back on the core) and hence provides a ‘signature’ or indicator that the core is about to be broken.

(34) For at least one preferred embodiment as shown in the flowchart in FIG. 2, core orientation to be validated by the correct ‘signature’ can best be described when: a) 100: Vibration above a threshold is not detected by the core orientation device, or is detected to be below a threshold, for period Y b) 120: Core orientation measurement is taken during the ‘vibration silence’ period Y c) 130: Followed by detection of noise from breaking the core from the subsurface body during a period X d) 140: Followed by no detection of noise above a threshold, or is detected to be below a threshold, for period Z e) 150: Orientation measurement is only retained if the above are present. f) 160: The core orientation device can be configured to disregard detected signals or to not detect vibration or lack of vibration if & only if a, c, d above are present. If so, a fresh vibration silence signal 180 must then be detected before the core is broken. g) 170: Optionally, dip measurement can be obtained during the period of no drilling prior to breaking the core (period Y), preferably if dip is within the set limits.

(35) Once the required core orientation is obtained, the core orientation device may be shutdown or turned to low power standby mode 190 in preparation to be put into orientate mode 210 again.

(36) Once the core orientation device is retrieved to the surface 200, an operator can set the device to an orientate mode 210. This can be done via the remote communication device communicating with the core orientation device 220.

(37) The core orientation device can include one or more lights or other visual indicators, such as one or more display panels to give an indication of orientation direction and required orientation for marking the core.

(38) According to one or more embodiments of the present invention, once in orientate mode, visual indications, such as flashing of one or more LEDs, will indicate to the operator which direction to rotate the core to find the correct ‘down side’ for marking. The correct downside is the part of the core that was lowermost prior to separating from the subsurface body.

(39) Once correct downside is identified 230, the operator will again effect communication to the core orientation device via the remote communication device. The remote communication device will then verify 240 that the correct orientation was achieved (based on the orientation data recorded) and then preferably permit the operator to perform another orientation operation if so desired 250.

(40) Optionally dip angle can be included in determining orientation of the core. The dip angle of the drill hole may be used to determine whether or not to use the orientation data obtained. For example, a correct core orientation sample may be determined from the aforementioned ‘signature’ steps being acceptable and the dip angle of the drill hole must also be within acceptable limits.

(41) According to at least one particular embodiment of the present invention, the dip is sampled as a reference prior to the first run of a new drill hole. This is regarded as a setup function.

(42) A setup function can be selected on the remote communications device which then communicates to the core orientation device. For clarity, the core orientation device does not orientate the core, rather, it records signals indicative of the orientation of the core to be retrieved. The core orientation device is then lowered down the hole or aligned to the angle of the drill rods in the case of no hole yet to be drilled.

(43) Once the core orientation device is down to the end of the hole the user will ‘mark’ the ‘shot’, preferably via use of the remote communications device.

(44) The core orientation device is then retrieved and the remote communications device communicates to the core orientation device so that the core orientation device knows the dip (angle) of the drill hole.

(45) Alternatively, the dip of the end of the hole can be manually entered into the remote communications device and this communicated back to the core orientation device.

(46) For subsequent recordal(s) of orientation data after the first i.e. whenever a required subsequent signature occurs, and when the dip value is used, the dip is measured and if second dip value (D2) equals dip value 1 (D1)+/−E (where E typically equals 1.1), the original signature data is retained. If D2 falls outside of D1+/−E, D2 is disregarded or discarded. The core orientation device will only store in memory values relating to the first signature.

(47) For any subsequent run e.g. when the third signature occurs, if D3=D2+/−E the new signature is retained, otherwise it will be discarded if it falls outside of the required range. Only first compliant signature will be retained, etc.

(48) One or more embodiments of the present invention may utilise the final compliant signature instead of the first compliant signature. A compliant signature is obtained when one or more signals indicative of the orientation of the core is/are obtained by the core orientation device during a period of no drilling vibration prior to detecting vibration from breaking the core and that being prior to a subsequent period of no drilling vibration.

(49) In FIGS. 3 and 4, a known prior art inner tube assembly 310 replaces a standard greater with a two unit system 314,316 utilising a specialised greater unit 314 and electronics unit 316 particular to the two unit system. The electronics unit is sealed to the greater unit by o-rings, which have a tendency to fail in use and allow liquid into the electronics unit, risking loss of data and/or display failure. The electronics unit has an LCD display 318 at one end. This allows for setting up of the system prior to deployment and to indicate visually alignment of the core sample when retrieved to the surface. The greater unit is connected to a backend assembly 320 and the electronics unit 316 is connected to a sample tube 322 for receiving a core sample 324. The electronics unit is arranged to record orientation data every few seconds during core sampling. The start time is synchronised with actual time using a common stop watch. The units are then lowered into the drill string outer casing to commence core sampling. After drilling and capturing a core sample in the inner core sample tube, the operator stops the stop watch and retrieves the core sample tube back to the surface. At the surface, before removing the core sample from the inner tube, the operator views the LCD display 318, if it is still working, which steps the operator through instructions to rotate the core tube 322 until the core sample 324 lower section is at the core tube lower end 326. The core sample is then marked and stored for future analysis.

(50) Referring to FIG. 4, the known electronics unit 316 of FIG. 3 includes accelerometers 328, a memory 330, a timer 332 and the aforementioned display 318.

(51) The system 340 according to an embodiment of the present invention will hereinafter be described with reference to FIGS. 5A to 8.

(52) An outer drilling tube 334 consisting of connectable hollow steel tubes 334a-n has an extension piece 336 connected inline between two adjacent tubes in order to compensate the length of the outer drilling tube in relation to the additional length gained by the inner tube assembly 340 due to the core sample orientation data gathering device 342.

(53) The core sample orientation data gathering device 342 is a fully sealed cylindrical unit with screw threads at either end. A first end 344 connects to a standard length and size greater unit 346 and a second end 348 connects to a core sample tube 350. The greater unit connects to a standard backend assembly 320.

(54) There are no LCD display panels, indicators or switches mounted on the device. LED indicators are provided at one end 344, the greater end, that are used in determining correct orientation of the core sample once the core and the device are recovered back a the surface. FIG. 9 shows an example of the indicator end 344 of the core sample orientation data gathering device 342.

(55) In FIG. 7, the core sample orientation data gathering device 342 is shown in close up. The end 344 for connecting to the greater unit 346 includes a window (not shown in FIG. 7—see FIG. 9). One or more LED lights are provided sealed within the device 342 behind the window. A coloured light indication is given to indicate which way (clockwise or anti-clockwise) the device 342 must be rotated to obtain a desired orientation of the core sample still within the inner tube assembly that is connected to the core sample orientation data gathering device 342. For example, a red light may be given to indicate to rotate the device (and thus the core sample) anticlockwise or to the left, and a green light may be given to indicate to rotate the device clockwise or to the right. A combined red and green indication, or a white light indication, or other indication can be given, such as flashing lights, to indicate that the core sample is correctly orientated and ready for marking.

(56) FIG. 8 shows an embodiment of the hand held device 360 which receives wirelessly receives data or signals from the core sample orientation data gathering device 342. The core sample orientation data gathering device 342 includes a transmitter which can use line of sight data transfer through the window, such as by infra red data transfer, or a wireless radio transmission. The communication device 360 can store the signals or data received from the core sample orientation data gathering device 342. The communication device 360 includes a display 362 and navigation buttons 364,366, and a data accept/confirmation button 368. Also, the hand held device is protected from impact or heavy use by a shock and water resistant coating or casing 370 incorporating protective corners of a rubberised material.

(57) Setting up of the device is carried out before insertion into the drill hole. Data retrieval is carried out by infra red communication between the core sample orientation data gathering device 342 and a core orientation data receiver (see FIG. 6) or communication device 360. After recovering the core sample inner tube back at the surface, and before removing the core sample from the tube, the operator removes the ‘back end assembly, and the attached greater unit. The operator then uses the remote communication device to obtain orientation data from the core sample orientation data gathering device using an line of sight wireless infra red communication between the remote device and the core sample orientation data gathering device. However, it will be appreciated that communication of data between the core sample orientation data gathering device 342 and the communication device 360 may be by other wireless means, such as by radio transmission.

(58) The whole inner tube 350, core sample 352 and core sample orientation data gathering device 342 are rotated as necessary to determine a required orientation of the core sample. The indicators on the greater end of the core sample orientation data gathering device 342 indicate to the operator which direction, clockwise or anti-clockwise, to rotate the core sample. One colour of indicator is used to indicate clockwise rotation and another colour to indicate anti-clockwise rotation is required. This is carried out until the core sample is orientated with its lower section at the lower end of the tube. The core sample is then marked for correct orientation and then used for analysis.

(59) As shown in FIG. 9, the indicator window end 344 of the core sample orientation data gathering device 342 includes a window 372. The indicator lights can be seen through this window at least when illuminated. In this embodiment, two lights, red and green LEDs are shown. The left hand 374 (red) LED illuminates to indicate to a user to rotate the device 342 anti-clockwise. The right hand 76 (green) LED illuminates to indicate to a user to rotate the device 342 anti-clockwise. When correct core sample orientation is achieved, both LEDs might illuminate, such as steady or flashing red and green, or another illuminated indication might be given, such as a white light (steady or flashing).

(60) The visual and/or audible indicators, under certain site and/or environmental conditions, may not be sufficiently visible or audible. They may be hard to see in bright light conditions or hard to hear in loud working environments. Thus, an additional or alternative means and/or method may be utilised to ensure that the core sample has been correctly orientated. The outer casing or body or an end of the core sample data gathering device 342 may have angular degree marks. These may be scribed, etched, machined, moulded or otherwise provided, such as by printing or painting, on the device 342. For example, as shown in FIG. 9 dashes equally spaced around the outside parameter (each representing one or more angular degrees of the full circle or perimeter). Further scribing of a number every five dashes starting with the number “0” then 5, 10, 15 etc. until 355. When the core is retrieved and the orientation device communicates with the hand held communicator 360, additional information is transmitted from the orientation device to the communicator 360, such as a number between Zero and 359 (inclusive) denoting an angular degree of rotation of the core sample orientation data gathering device and the core sample. When the core is oriented during one or more embodiments of the method of the present invention, scribing on the core sample orientation data gathering device 342 number on the top side should be the same as the number transmitted to the communicator 360, which re-confirms correct orientation. Thus, if the visual or audible means for indicating core orientation are not useful or available, then the core is oriented using the angular degree arrangement (top side) to match the number transmitted, and then this would be audited using the communicator 360 as is the case now.

(61) The core sample orientation data gathering device of the present invention is hermetically sealed against ingress of water or other liquids, even at operative borehole depths and conditions. No additional or alternative sealing, such as separate o-ring seals between the greater and core sample orientation data gathering device or between the inner core tube and the core sample orientation data gathering device are required. Thus, maintenance or risk of ingress of liquid are not of concern.

(62) Additionally, only the greater needs to be separated from the core sample orientation data gathering device in order to obtain access and communicate with the device to obtain core orientation data. Likewise, setup prior to deployment is improved in terms of time and ease of use by not requiring a specialised back end assembly, rather, a standard greater and back end assembly is used. This also improves compatibility with standard systems.

(63) Obtaining core orientation is made easier by only requiring two colours lights to indicate one or other direction of rotation to establish correct core orientation prior to marking. The indicators form part of the sealed device and can be low power consumption LED lights. Alternatively, flashing lights may be used. For example, a certain frequency or number of flashes for one direction and another frequency or number of flashes for the other direction of rotation. A steady light could be given when correct orientation is achieved.

(64) Confirmed correct core alignment is registered in the remote communication device 360. This provides for an audit trail, and the data can be readily transferred to computer for analysis and manipulation. This also provides reassurance of accuracy of sampling and orientation to operators, geologists and exploration/mining/construction companies.

(65) In use, the core inner tube 350, data gathering device 342 and greater 46 are connected together in that order and lowered into a core sampling outer tube having an annular diamond drill bit at the furthest end. Once a core sample is obtained, the inner tube assembly with the data gathering device and greater are recovered back to the surface, the back end assembly 320 and greater are removed. Using an infra red link or other wireless link, the data gathering device is put into orientation indicating mode by the remote communication device 360. The core sample and data gathering device are then rotated either clockwise or anti clockwise to establish a required orientation position. The remote communication device is then used to communicate with the data gathering device to obtain core sample orientation data from the data gathering device. No LCD or other display is needed on the data gathering device that might otherwise risk leakage in use and ingress of liquid or failure of the display due to display power demands on the limited battery life or display failure due to the harsh environment downhole. The required orientation of the core sample is then marked and the core sample can be stored and used for future analysis. The received data can be transferred to a computer for analysis.

(66) According to an alternative embodiment of the present invention shown in FIGS. 10a and 10b, a data gathering device 380 houses the light emitters 374,376. Light from these emitters (e.g. LEDs) passes through the window 372 (shown in FIG. 9). Reference arrow A refers to the drill bit end direction, and reference arrow B refers to the backend assembly direction. An optical adapter 382 is provided at the end 342 of the device and which adapter extends into the greater unit 346 when connected thereto. The optical adapter has a reflective material. The greater unit 346 has apertures 384 that allow light therethrough. Light from the emitters is directed onto at least one reflector 386 of the adapter. The emitted and reflected light can be observed through the apertures 384 in the greaser. It will be appreciated that the adapter need not extend into a greaser. A tube section or other component having at least one aperture to observe the light through is sufficient. The red-green indications (or whatever selected colour combination of light is used) can be observed through the aperture(s) when rotating the device to obtain core sample orientation. Thus, advantageously, when the data gathering device and core sample are recovered from down the hole, the data gathering device need not be separated from the greater in order to determine a required orientation of the core sample. Wireless communication to a remote device, such as a hand held device, to transfer data between the data gathering device and the remote device, can also be effected by transmitting through the at least one aperture.

(67) Embodiments of the present invention provide the advantage of a fully operating downhole tool/device without having to disconnect or disassemble any part of the tool/device from the inner tube and/or from the backend assembly or any other part of the drilling assembly that the tool/device would need to be assembled within for its normal operation. Disconnecting or disassembling the tool/device from the backend and/or inner tube risks failure of seals at those connections and/or risks cross threading of the joining thread. Also, because those sections are threaded together with high force, it takes substantial manual force and large equipment to separate the sections. High surrounding pressure in the drill hole means that the connecting seals between sections must function perfectly otherwise water and dirt may ingress into and damage the device. Having a tool/device that does not need to be separated from the inner tube and/or backend sections in order to determine core sample orientation and/or to gather data recorded by the device/tool means that there is less risk of equipment failure and drilling downtime, as well as reduced equipment handling time through not having to separate the sections in order to otherwise obtain core sample orientation. Known systems require end on interrogation of the device/tool. By providing a sealed device/tool and the facility to determine orientation of the core sample, by observing the orientation indications through one or more apertures in the side of the greater or other section, reliability and efficiency of core sample collection and orientating is improved. Consequently operational personnel risk injury, as well as additional downtime of the drilling operation. Without having to separate the tool/device from the inner tube and/or backend, the orientation of the core sample can be determined and the gathered information retrieved with less drilling delay and risk of equipment damage/failure.

(68) One or more forms of the present invention relate to asynchronous time operation for core sampling. The data recording events taken by the downhole data gathering device are not synchronized in time with the communication device. That is, the communication device and the data gathering device do not commence timing from a reference time, and the data gathering device does not take samples (shots) a specific predetermined time intervals. For example the data gathering device does not take a three second sample every one minute with that one minute interval synchronized to the remote which would therefore know when each sample is about to take place. The communication device of the present invention is not synchronized to the data gathering device (the downhole survey or core orientation unit) i.e. asynchronous operation, and therefore the communication device does not know if or when a sample is being taken. Thus, obtaining an indication of core sample orientation is simplified over known arrangements.

(69) A method and system according to one or more embodiments of the present invention will hereinafter be described with reference to the Figures, particularly FIGS. 11 and 12.

(70) A communication device 360 can signal to the data gathering device 342,380 to activate or come out of a standby mode. However, if preferred, the data gathering device may already be activated i.e. it is not necessary to have the data gathering device switch on from a deactivated (‘turned off’) state.

(71) The communication device 360 and the data gathering device 342,380 do not require to send or exchange time information from one to the other.

(72) The communication device 360 does not mark start time and the actual start time is not recorded by or in the communication device 360.

(73) The communication device 360 does not start a timer, its clock (preferably a ‘real time’ clock) is permanently running.

(74) The data gathering device 342,380 does not record a start time as an initial reference time. Thus, it is not necessary to make a data gathering event (shot) in a specific period of time beyond this reference time. The data gathering device does not start a timer, its own internal clock is always running.

(75) No initial roll indication at the surface prior to deploying the device is required. Thus, no initial reference point is required before the device is deployed downhole of the data gathering device 342,380 is taken before lowering downhole as a reference “orientation point”.

(76) Importantly, the data gathering device only records data (takes ‘shots’) when it detects drilling is not occurring. That is, the data gathering device does not obtain or generate downhole data during drilling.

(77) For the purposes of this invention, the phrase ‘during drilling’ means whilst drilling (i.e. rotation of the drill bit and drill string) is actually occurring rather than the general drilling operation as a whole. Data recording events (‘shots’) are not constantly taken on a set time period.

(78) The data gathering device 342,380 of the present invention includes at least one vibration sensor, and preferably at least one of a gravity sensor, magnetic field sensor, accelerometer, inclinometer, and preferably a combination two or more of these devices. These ‘sensors’ are packaged into the data gathering device which is compatible for connection with downhole tubing, greasers and other instrumentation devices. The data gathering device is powered by an onboard battery, and preferably the data gathering device is hermetically sealed to prevent ingress of water and contaminants at pressure when ‘downhole’. The data gathering device forms part of a system in conjunction with the communication device 60, and preferably any other equipment as needed.

(79) The communication device may be incorporated in a remote controller. For example, a remote controller may be used to control or affect operation of the data gathering device. The remote controller may include an internal timer which operates without synchronization with an internal timer of the data gathering device.

(80) One form of the present invention provides the following method, whereby: 1. When the data gathering device 342,380 initially detects vibration 900 it wakes 902 from a standby mode. The device determines that such vibration is because drilling is occurring. While awake at this stage the device also checks 904 whether there is a valid communication from the communication device. The device then goes back into a standby mode until vibration is not detected above a threshold, which is preferably set to be zero detected vibration. This has a valuable benefit of saving battery power. Known prior art devices, such as in WO 2006/024111 and related cases, continuously draw or on a frequent periodic basis draw on battery power, thereby vastly decreasing battery life and reducing the amount of time a device can spend in operation before the battery needs recharging or replacing. Extending battery life is a major benefit to drilling operations which occur in remote locations. Less capital investment is needed in equipment to maintain a charged standby device, and less time is lost in changing over equipment if battery life is extended. 2. Once no vibration has been detected for a desired period (e.g. 6 seconds) 906, the data gathering device determines that drilling has stopped, the device activates (‘wakes up’ from its standby or ‘sleep’ mode) 908 and records first data (‘takes a 1.sup.st roll shot’) 910. The device will self check 907 whether there is no vibration for the desired period of time. 3. A desired period of time later (e.g. 4 seconds) 912, the data gathering device records second data (‘takes a 2.sup.nd roll shot’) 914. If the second data recording event (roll) is close to the immediately previous first data recording event (1.sup.st roll shot) 910 and found to be acceptable 916, then the second data recording event 914 is saved to a memory and time stamped 918.

(81) The data gathering device then stops recording data and reverts to its standby or ‘sleep’ mode and either: a) waits at step 5 below) 920, or b) continues to step 4) below 922. 4. If the second data recording event (2.sup.nd roll shot) is not similar 922 to the first data recording event, then a third data recording event is carried out (‘3.sup.rd roll shot’). This 3.sup.rd shot's roll is compared to the 2.sup.nd shot's roll. If the third data recording event is close to the second data recording event, then the third data recording event is stored in memory and time stamped, and the data gathering device reverts to standby (‘sleep’) mode. Thus, the device compares the most recent data recording event to the immediately previous data recording event. This process continues until: a. one data recording event (roll) is accepted and time stamped 918; or b. a limit or preset maximum number of recording events is reached (e.g. five ‘shots’) 924 then the data gathering device will revert to standby or ‘sleep’ mode (shut down) and wait for the next vibration to occur 900. 5. When the next vibration 900 event is detected, the data gathering device comes out of standby mode (‘wakes up’) 904. This allows the data gathering device to determine that vibration is occurring and then it reverts to standby mode (‘goes to sleep again’) in preparation to be re-activated at the next ‘No vibration’ event 906. This occurs without the need to take or record any downhole data (rolls) in memory. If none of the roll shots are acceptable, the device is set to wake on the next vibration and then go to sleep again 926. 6. Steps 1) to 5) are repeated until the data gathering device receive a signal to enter an ‘orientation process’. The signal is preferably provided by the communication device.

(82) Remote controller (communication device)

(83) A user inputs 950 to the communication device one or more of the following: 1. the last time when drilling has stopped 2. immediately prior to breaking off the core sample off; 3. immediately after breaking off the core sample.

(84) The communication device identifies (‘marks’) a time 952, using its own real time clock, when a user selects that the core sample is to be retrieved.

(85) Importantly, the present invention does not need or rely on an indication indicative of when during the drilling process the core sample was detached from the body of material.

(86) Once the core sample has been broken off, and the time is marked by the communication device before, during or after that core breaking off event, the core assembly is retrieved to the surface.

(87) Once the data gathering device is retrieved to the surface 954, the communication device communicates 956 to the device, and the device confirms communication received 958. The communication device signals to the data gathering device to halt surveying 960 and the communication device obtains from the data gathering device recoded data prior to a defined time elapsed period 960. At this point in time the communication device refers to its own internal clock and subtracts from this the time that the user indicated that the core was being retrieved 962. This time difference is transmitted to the data gathering device as a time value, which device enters a core orientation process stage 964.

(88) Core Orientation Process

(89) The data gathering device receives the time value (days, hours, minutes and seconds) (e.g. from the communication device) and enters an orientation process stage 964, as mentioned above.

(90) The data gathering device deducts this time value from a predetermined time value in its own internal timer. The data gathering device checks for a saved data event ‘roll’ that occurred previous to this time in its memory, and retrieves that roll value. No time measurement is measured, and the data gathering device does not provide a time value indicative of when the core sample was broken off. Such a value is not required to determine orientation of the core sample.

(91) The data gathering device then provides visual indications of which direction to rotate the core sample to indicate the ‘downside’ of the core. As discussed earlier in this specification, light indicators, such as the flashing coloured LEDs, and the described method of use, can be employed to indicate to the user which direction to rotate the barrel to the required ‘downside’. For such use, a user rotates the barrel until the flashing stops and a solid ON LED indicates that the barrel is in the ‘downside’ position.

(92) User inputs to the communication device to indicate that the core barrel, and therefore the core sample, is in the correct orientation. The communication device communicates to the data gathering device and verifies that this has occurred. This ‘orientation’ or ‘roll’ value is not transferred from the data gathering device to the communication device.

(93) One or more further embodiments of the present invention will hereinafter be described with reference to the accompanying FIGS. 13 to 19.

(94) The present invention involves a system 460 utilising a core sample (core) orientation identification device 410 and a marker device 490. These components may be provided separately as discrete items or may be connected together, such as by an adjustment means.

(95) Typically the extracted inner core tube 412 is placed on a support 480 for ease of work. After the inner core tube 412 containing the core sample 414 has been orientated to the up/down position (corresponding to its orientation underground before being drilled out), the pen/pencil marker 416 associated with the device 410 is adjusted to a pre-set height corresponding to the diameter size of the core tube used. The device is then activated by pulling the opposed handles 420,422 apart to a ‘latched’ position of the device ready to be released when signaled to do so.

(96) The unit is placed on the core tube by opening the jaws assembly 424 sufficiently wide to allow the opposed jaws to be placed about the external diameter of the tube 412. This embodiment includes three jaws 426,428,430. The first 426 and third 428 jaws oppose the second jaw 430 with the second jaw operating between the first and third jaws. It will be appreciated that two opposed jaws can be sufficient. One or both of the opposed jaws can have a bifurcated end with rollers thereon rather than the three jaws with rollers.

(97) The device is positioned such that the marking pen/pencil faces the exposed core face ‘A’.

(98) By closing the opposed jaws together, the rollers 432 on the jaws contact the external surface of the core inner tube 412, which allows the device to find its correct position via gravity so that the marker is pointing to the lower portion of the core face A. The device hangs or suspends from the tube.

(99) The device contains a self-feeding and extruding wax nib which will always be extended ready to mark the core face A. This can be position adjusted via the adjustment means 418.

(100) Electronics within the housing 434 of the device include one or more central processors, accelerometer(s), infrared communication components, other supporting components and a battery power supply 442.

(101) There is also an electromechanical releasing device 440 to allow the marking pencil to stamp the core face when required. This may be in the form of a solenoid which when activated, releases the compressed spring 444 previously latched when the handles 420,422 were pulled in opposite directions to set the latch 446 against a latch plate 448. As is shown, the handle 420 has sliders 450,452 which slide in bushes 454.

(102) In preferred embodiments the electronics can operate to confirm the up/down position of the device using its accelerometer(s) and other components.

(103) One or more light emitting diodes (LEDs) 456 can be provided behind a window 458 on the device. The window may be an IR window for communication between the device and the remote controller. The LED(s) can be set to illuminate or extinguish when not centered. In a preferred embodiment, the LED(s) flash when the device is not centred and are steady when it is centred (see infrared window 56 pointed to by the hand-held controller 460 in FIG. 18).

(104) When self-alignment is completed by the device, the hand-held controller 60 signals the device via infrared communication to release the marking pen/pencil. The embedded electronics confirms that the unit is properly aligned before allowing activation to release the marking pen/pencil towards the exposed core face and thereby mark its lower end to indicate correct orientation.

(105) FIG. 17 shows a sectional view of the pencil holder 416. A wax pencil core 462 is held within the tubular body 464. The pencil core is spring 466 biased to protrude from the open end 468 of the holder. A removable screw cap 470 allows replacement of the pencil core.

(106) Height adjustment for the marker is achieved by releasing the adjustment mechanism 418, raising or lowering the pencil holder 416 relative to the support 472 attached to handle 420 (seen in FIG. 13, not shown in FIG. 17).

(107) In FIGS. 20a to 20c, an embodiment of a self aligning system 560 (aligning with respect to the core 512), including core sample orientation device 510 and a marker device 590

(108) Typically the extracted inner core tube 512 is placed on a support 580 for ease of work. After the inner core tube 512 containing the core sample 514 has been orientated to the up/down position (corresponding to its orientation underground before being drilled out), the pen/pencil marker 516 associated with the device 510 is adjusted to a pre-set height corresponding to the diameter size of the core tube used. The device is then activated by extending the pencil assembly to a ‘latched’ position “L” of the device ready to be released when signaled to do so.

(109) The unit is placed on the core tube by opening the jaws assembly 520,522 sufficiently wide to allow the opposed jaws to be placed about the external diameter of the tube 512. This embodiment includes three jaws 520a,522,520b. The first 520a and third 520b jaws oppose the second jaw 522 with the second jaw operating between the first and third jaws. It will be appreciated that two opposed jaws can be sufficient. As a component saving measure and to provide a simplified device, no rollers are provided on the ends of the arms/jaws 520a,520b,522. Gravity causes the device to rotate to a stable orientated position ready for operation.

(110) The device is positioned such that the marking pen/pencil faces the exposed core face ‘A’.

(111) FIGS. 21a to 21c show an embodiment of the core sample orientation device 510 portion of the system.

(112) There is also an electromechanical releasing device to allow the marking pencil to stamp the core face when required. FIG. 21c shows the internal release mechanism. A rotary cam 550 is driven by motor when triggered. The cam acts on the lever arm 552 to retract the spring loaded detent 554. When operated, the retracted detent disengages from a latch 557 allows a spring 560 loaded slide arm 558 (shown in dotted phantom) to release. This causes the marker (e.g. wax pencil) to release and mark the end of the core. A damper spring 556 cushions the end of travel. Resetting is by pulling the latch back.

(113) FIGS. 22a to 22e show steps in operation of the electro-mechanical mechanism to release the marker to mark the core. As the cam 550 rotates, the pivoting lever arm 552 is depressed. This retracts the spring loaded detent 554 and releases that detent from engagement with the latch 557. The spring 560 pulls the latch which causes the marker (not shown) to contact the end of the core and mark it.