CA2813039A1 - Device and method for data communication through metal - Google Patents

Abstract

A method, device and system to pass signals through a metal substrate includes transmission of at least one ultrasonic signal from a transmitter (20) through a metal substrate (16) from a transmission means (30) attached directly or indirectly to a surface of a first side of the metal substrate, and receiving the signals at a receiver (20) releasably connected to a surface at a second surface or side of the metal substrate. The metal substrate can be part of a metal enclosure (12), such as of a data communication module (10) arranged to be put down a borehole. The device may clamp using jaws (36a,36b) and may include a visual display (36). A remote communicator (39) may communicate with the device, such as via an infra red sensor (38). The device, system and method can be used to communicate data through the metal wall of a downhole information tool, such as a survey or core orientation instrument package.

Description

2 PCT/AU2011/001282 DEVICE AND METHOD FOR DATA COMMUNICATION
THROUGH METAL
TECHNICAL FIELD
The present invention relates to data communication through solid metal of apparatus used in harsh environmental conditions, such as in below ground surveying, exploration and testing in relation to the mining, oil and gas, and construction industries.
BACKGROUND
During sub-surface exploration underground drilling is carried out to obtain core samples, such as when in search of mineral deposits, oil or gas reserves, or in soil/ground analysis for construction projects. These core samples are extracted and analysed to eventually produce a three dimensional map of sub surface material content. Such activity involves not only extracting numerous physical rock or soil core samples, but also accurate data collection to pin point azimuth, depth and orientation of the samples to be able to produce accurate mapping. Survey instruments/probes are used to take multiple measurements of such data required for analysis. Such instruments/probes need to be 'started' or `set' above ground before being inserted into the exploration drill hole. This activates the instruments/probes to commence making data readings while in the drill hole. Once the data is gathered, the instruments/probes need to be extracted from the drill hole and the data retrieved from the instrument/probe package.
There has been a variety of means developed for setting the probe before use and extracting the measured data after data collection. The methods described below are, or have been, used by different instrument/probe suppliers:
a) Mechanical compass in a metallic housing - A small mechanical compass on a gimbal is installed in a cylindrical probe which has a camera pointed at it. This probe may also have to be seated within a brass pressure barrel.
- A timer is set (before use) to initiate the mechanical camera to take a photograph of the compass after a certain time delay.

- The metallic cylindrical probe enclosure is re-sealed (within a pressure barrel) with waterproofing '0' rings and lubricant to prevent leakage and to guard against pressure build up in the harsh environment below the surface.
- After taking the photograph(s) and retrieving the probe to the surface, the protective pressure casing is unscrewed and the camera with film is removed.
- The film is developed to see the compass position so that measurement data (azimuth) can be manually documented.
b) Cable connection for data communication - An electronic probe may have an exposed plug or socket at one end or on the length of its body.
- A cable is connected between the probe and an external device to set up the probe before use.
- After initiating set up, the probe is inserted into a pressure barrel which has '0' rings and is lubricant sealed to prevent leakage and pressure build up.
- The probe is then lowered into the drill hole for measurements.
- After measurements and retrieval back to the surface, the probe is removed from the pressure barrel.
- The cable and external data reader is again connected to the probe to read the instrument data.
c) Mechanical switches and LCD (Liquid Crystal Display) screen mounted on a probe body - Some probes have a number of switches and display mounted on the cylindrical probe casing itself.
- The probe is set up using the switches and display, - Again the probe is installed into a water and pressure sealed brass barrel before inserting into the drill hole, - After retrieval, the probe is removed from the pressure barrel and data retrieved using the mechanical switches and LCD.

3 d) RF (Radio Frequency) communication - The probe has an RF transmitter/receiver (transceiver) built into it which can be set up to start by a hand controller also fitted with an RF
transceiver.
- For RF transmission to work from the probe, a section of the probe body will need to be non-metallic to allow radio waves to be transmitted and received from the probe.
- When ready for use, the probe is inserted into a water/pressure sealed brass barrel before inserting into the drill hole.
- After retrieval, the probe is removed from the pressure barrel and data retrieved using the RF transceiver unit.
e) IR (Infra-Red) communication - The probe body has a section of see-through or infra-red material window which allows IR communication to take place.
- A hand held unit with similar IR interface circuitry is 'pointed' at the probe IR window where setup data instructions can be transmitted.
- After set up the probe is inserted into a water/pressure sealed brass barrel before inserting into the drill hole.
- After retrieval, the probe is removed from the pressure barrel and data retrieved using an IR hand-held communicator.
f) IR communication from a probe built into its own pressure barrel - One of newer models of survey probes is built into its own pressure barrel to save time installing into a separate pressure barrel before use.
- This unit has its IR communication window built into one end of its brass probe body.
- Set up occurs by pointing the equivalent IR enabled hand-held unit into the end of the probe.
- To prevent water/pressure leakage, the exposed end will still have to have a pressure/water sealed screw-on cap with its own '0' rings and lubricant installed before inserting into the drill hole.

4 - After retrieval, the pressure sealed screw cap would have to be removed before data extraction using the IR hand-controller.
With the exception of the version described at point "f" above, all of the rest of the above arrangements of data communication an external pressure barrel which requires significant amount of time to install, remove, retrieve the data, and re-install in the pressure barrel for subsequent surveys.
The arrangement at point "f" still requires removal and re-sealing of one end of its built-in pressure barrel.
All the above arrangements require the use of '0'-ring seals which need to be maintained and lubricated to ensure no water or pressure leakage occurs in the harsh environment below ground.
The industries that use sub-surface survey instruments usually operate in harsh "in-field" conditions, operating under tight schedules associated with 'metres drilled per day' and efficiency of instrument use without breakdowns to meet budgeted costs.
Environmental conditions are sometimes extreme with wide temperature and/or pressure variations, muddy/ wet, dirty, dusty and/or freezing or snowy conditions.
Careful installation, removal and re-installation of probes from pressure barrels or sealed covers containing lubricated '0' rings are not always vigilantly adhered to in the field and can result in leakage of the pressure barrel.
Permanent damage often occurs to the sensitive electronics in a survey instrument. The damage may not be apparent until the instrument or probe is delivered down hole, or even worse, after the instrument or probe has been down hole and then recovered to the surface where the expected data has not been collected or is incomplete due to damage or corruption of the instrument components or operation. This can occur due to water or other liquids present in drill hole and/or dirt/rock from the drill hole being able to ingress into the pressure barrel past the damaged or defective o-rings. Apart from cost incurred from damaged instruments, a higher cost of the operation in man-hours and drilling operation downtime is incurred in not being able to take survey measurements at

5 the drill rig.
In the light of such problems associated with known arrangements, it is desirable of the present invention to provide improved means and method of retrieving data from an instrument or probe that does not require opening of the sealed instrument/probe package.
SUMMARY OF THE INVENTION
With the aforementioned in mind, an aspect of the present invention provides a method of obtaining signals through a metal substrate, the method including:
transmitting at least one ultrasonic signal from a transmitter through a metal substrate from a transmission means attached to a surface of a first side of the metal substrate;
receiving said at least one signal at a receiver releasably connected to a surface at a second side of the metal substrate.
The first surface of the metal substrate may be a surface of an internal face of a data transmission module. The second surface may be a surface of an exterior face of the data transmission module. The data transmission module may be connected to or form part of an instrument package, such as for use in drill holes.
The method may further provide for two-way transmission/reception of signals. For example, the present invention may include transmitting through the metal substrate at least one ultrasonic signal from a transmitter attached to the first surface within a cavity of the module, and receiving said signal(s) at a receiver attached to the second surface on an exterior of the module, and transmitting back through the metal substrate a further at least one ultrasonic signal from a second transmitter attached to the second surface at the exterior of the module to a receiver attached to the first surface within a cavity of the module.

6 A coupling medium may be disposed between the transmitter and the metal substrate and/or between the metal substrate and the receiver, when connected to the substrate, to match respective signal transmission/reception characteristics of the transmitter/receiver with the metal substrate.
The method may include temporarily attaching a reading device to the metal substrate, and the reading device may include or be connected to the receiver.
The transmitter may be incorporated into a sealed module, such as a hermetically sealed transmitter device, which may be permanently electrically connected to instruments for obtaining the signals, preferably within a single hermetically sealed module.
The releasable receiver may include a manual device incorporating a data reading and/or storage means, and preferably also a data transfer means, such as a transmitter or outlet port for connection to a remote computer.
The releasable receiver may be incorporated into or be connected to a manually actuated or power actuated reading device, such as a clamp device.
The reading device may receive the signals via the receiver and display and/or store and/or transmit those signals, or a modified form of the signals.
Alternatively, other forms of attachable device may be used, such as an interference or friction fit, screw clamp, suction or magnetic attachment. As an example, a clamp may be used to clasp around the metal substrate, the clamp incorporating the signal receiver. Resilient biasing of the clamp to clasp the metal substrate may provide sufficient contact for effective data reception.
Alternatively, one or more contact members of the clamp for contacting the substrate may include the coupling medium permanently or temporarily on a contact surface of the respective contact member(s).
The manual device may be battery powered or may be supplied with power via a hard wire connection. In the case of a battery powered device, the battery may be rechargeable or replaceable, or both.
The metal substrate is preferably part of or connected to an instrument package for a drilling operation. The metal substrate may be formed as part of a hermetically sealed enclosure incorporating instrument components for obtaining

7 or deriving the signals from physical parameters to be measured by the instrument package.
The method may include the step of:
1) Connecting, preferably attaching, the receiver to the second substrate surface to receive the signals.
The method may further include or more of the following steps:
2) Transmitting set up/start data to the probe or instruments through the metal substrate.
3) Retrieving the instrument package/probe from the drill hole, attach the hand clamp reader to the metal surface, and extract the survey data while the probe is still attached to the wire line.
The present invention may be used with automated drill rigs where non-human operated systems are able to setup & read back data from a down-hole instrument. In this case, the reader (clamp') would be on a wired system attached to the rig computer system.
Embodiments of the present invention provide for data communication without the need to open a sealed enclosure or risk failure of important water tight seals at a later date.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a data transmission module according to an embodiment of the present invention.
Figure 2 shows a cross section through a data transmission module with transmitter/receiver mounted in position within a cavity of the module according to an embodiment of the present invention.
Figure 3 shows a releasable receiver clamped in position around a data transmission module according to an embodiment of the present invention.
Figure 4 shows a portable receiver with data display, remote communication facility with a hand held controller, and data storage facility, according to an embodiment of the present invention.

8 DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiments of the present invention provide apparatus and method of data communication through metal (such as brass or steel) for utilisation particularly with, though not limited to, down hole survey instruments/probes.
Ultrasonic signalling can be used as the mode of transmitting digital data across the metal barrier. In particular, data can be transmitted from the inside surface of a hermetically sealed (totally watertight) and pressure sealed enclosure, to the outside surface, and preferably transmitted from the outside surface to the inside, without having to physically penetrate the enclosure surface or open the sealed enclosure.
There are distinct advantages using this form of data communication compared to other forms of communication, such as:
Wire communication ¨ Requires holes through the enclosure in order to pass wires.
Radio Frequency (RF) transmission ¨ Cannot be used due the shielding effect of the metal (brass or steel) barrier. A hole would have to be provided through the metal enclosure and a non-shielding material would have to be used to cover the hole.
Infra-Red (IR) communication ¨ as with RF above, will not transmit through the metal barrier and the enclosure would have to be penetrated to have an IR
compatible material window to allow data transmission.
All three of the above methods of communication require part of the metal enclosure material to be replaced to have effective data communication.
Further advantages and benefits achieved by embodiments of the present invention for data communication through the metallic enclosure are:
- The electronic circuitry for the instruments can be permanently fitted within the pressure barrel. This pressure barrel does not have to be separated from the instrument.

9 - The instrument housing (within its own pressure barrel) need not be disassembled and re-assembled in the field by drill rig operators, hence saving time between drilling and multiple survey operations.
- Because the pressure barrel or any part of the instrument/probe does not require disassembly or re-assembly, there is no need for maintaining '0' rings or lubricants or ensuring that water, dirt, grime etc. do not affect the integrity of a watertight and/or secure pressure seal after taking data readings from the instrument.
- An overall saving of survey setup/retrieval time, no maintenance requirements by the user and minimal operational procedures for the drill rig operator (ease of use).
Method of taking survey readings using instruments and using data communication through the metal enclosure:
1) Attach a 'surface contact reader' spring loaded hand clamp to the probe body surface.
2) Set up/start data is transmitted to the probe.
3) Remove the clamp and insert the probe into the drill hole.
4) After retrieval from the drill hole, attach the hand clamp reader to the probe body surface to extract the survey data while the probe is still attached to the wire line.
5) The GTC probe is now ready for its next survey.
Embodiments of the present invention can also be used in automated drill rigs where non-human operated systems are able to setup & read back data from a down-hole instrument. In such cases, the 'clamp' could be on a wired system attached to the rig computer system.
Figure 1 shows two alternative sizes of data communication module 10 according to an embodiment of the present invention. Differences vary only in the dimensions of the module. The module has a metal enclosure 12 with a cavity 14. The cavity is arranged to receive one or more ultrasonic transmitters and/or receivers therein. The enclosure has a flat exterior face 16 for contact with a data communication device, such as a hand held receiver/transmitter shown in figure 3.
Figure 2 shows a cross section through a module according to figure 1.
5 The cavity 14 of the metal enclosure 12 has a flat faced surface 18 with at least one ultrasonic transmitter/receiver 20 mounted thereto.
The transmitter(s)/receiver(s) are wired to instruments within an instrument package or probe (not shown). In use, the module is itself hermetically sealed against ingress of water and dirt as well as being so sealed to the instrument package or

10 probe. The module and instrument package/probe can form an integral, fully sealed, unit.
Figure 3 shows a data communication device 30 in the form of a manual clamp 32 clamped around the module 10 of figure 1. The device has a pair of handles 34a, 34b for opening the respective jaws 36a, 36b about a pivot axis 44.
Resilient biasing, such as by a spring, can assist in clamping the jaws around the module once hand opening pressure is released.
The data communication device can be battery powered. In addition, a visual display 36 may be provided to display to a user required or preferred information, such as that data has been or is being transferred, a status of the instrument package/probe, that instrument set-up is in progress or has been completed, that data has been stored successfully, battery power, status of the device etc.
An infra red sensor 38 may be provided for transmitting and/or receiving information to/from a remote communicator 39. This enables remote data transfer to from the data communication device without needing to connect a cable to the device.
As shown in figure 4, the data communication device may have means to enable storage of data, such as a port 41 for connecting a removable storage device 42. One or more of the contact faces 40 of the jaws may provide a surface for transmitting/receiving the at least one signal to/from the ultrasonic receiver/transmitter within the cavity of the data transmission device.

Claims (15)

1. A method of obtaining signals through a metal substrate, the method including:
transmitting at least one ultrasonic signal from a transmitter through a metal substrate from a transmission means attached to a surface of a first side of the metal substrate;
receiving said at least one signal at a receiver releasably connected to a surface at a second side of the metal substrate.

2. A method as claimed in claim 1, wherein the first surface of the metal substrate is a surface of an internal face of a data transmission module and the second surface is a surface of an exterior face of the data transmission module.

3. A method as claimed in claim 2, wherein the data transmission module is connected to, or forms part of, an instrument package.

4. A method s claimed in any one of the preceding claims, further providing two-way transmission/reception of signals through the metal substrate.

5. A method as claimed in claim 4, further including transmitting through the metal substrate at least one ultrasonic signal from a transmitter attached to the first surface within a cavity of the module, and receiving said signal(s) at a receiver attached to the second surface on an exterior of the module, and transmitting back through the metal substrate a further at least one ultrasonic signal from a second transmitter attached to the second surface at the exterior of the module to a receiver attached to the first surface within a cavity of the module.

6. A method as claimed in any one of the preceding claims, including providing a coupling medium between the transmitter and the metal substrate and/or between the metal substrate and the receiver, when connected to the substrate, to match respective signal transmission/reception characteristics of the transmitter/receiver with the metal substrate.

7. A method as claimed in any one of the preceding claims, including temporarily externally attaching a reading device to the metal substrate, .

8. A method as claimed in any one of the preceding claims, including incorporating the first transmitter into a hermetically sealed transmitter device.

9. A data transmission module including a metal enclosure having at least one signal transmitter mounted to a face of an internal cavity, and an exterior surface arranged to receive a releasable receiver for signals transmitted from the at least one signal transmitter.

10. A module as claimed in claim 9, the releasable receiver including a manual device having a data reading and/or storage means.

11. A module as claimed in claim 10, the releasable receiver including a data transfer means.

12. A module as claimed in claim 11, the data transfer means including one or more of a transmitter or outlet port for connection to a remote computer, or infra red transmitter to communicate with a remote device.

13. A module as claimed in claim 12, the releasable receiver incorporated into or be connected to a manually actuated or power actuated reading device.

14. A module as claimed in claim 13, wherein the releasable receiver includes a clamp device.

15. A module as claimed in claim 14, the clamp including resilient biasing means to retain the clamp to the metal enclosure of the module.