The Patent
8 The claimed priority date of the Patent is 15 August 2011.
9 The inventors are Gordon Stewart and Michael Klass, both current directors of Globaltech.
10 The first section of the Patent is headed "Field of the invention" and comprises just one paragraph as follows:
FIELD OF THE INVENTION
[0001] The present invention relates to devices enabling data to be transmitted to and from downhole equipment, such as core orientation units and borehole telemetry probes.
11 The above paragraph refers to "borehole telemetry probes". The word "telemetry" is relevant to a number of the construction issues to be discussed later in these reasons. At this stage, it may be helpful to note that, according to a dictionary definition, the word "telemetry" refers to the science and technology of the automatic transmission and measurement of data conveyed by wire, radio or other means, from remote sources (Macquarie Dictionary, 6th ed, 2013, p 1510). However, as discussed later in these reasons, the primary judge held that, in the context of the Patent, the word "telemetry" refers to sensing (or measuring) data while equipment is down a hole without immediate transmission of the data to the surface (Reasons, [324]).
12 The "Background to the invention" was explained at [0002]-[0020]:
[0002] Core orientation is the process of obtaining and marking the orientation of a core sample from a drilling operation.
[0003] The orientation of the sample is determined with regard to its original position in a body of material, such as rock or ore deposits underground.
[0004] Core orientation is recorded during drilling, and analysis is undertaken during core logging. The core logging process requires the use of systems to measure the angles of the geological features, such as an integrated core logging system.
[0005] Whilst depth and azimuth are used as important indicators of core position, they are generally inadequate on their own to determine the original position and attitude of subsurface geological features. Core orientation i.e. which side of the core was facing the bottom (or top) of a borehole and rotational orientation compared to surrounding material, enables such details to be determined.
[0006] Through core orientation, it is possible to understand the geology of a subsurface region and from that make strategic decisions on future mining or drilling operations, such as economic feasibility, predicted ore body volume, and layout planning.
[0007] In the construction industry, core orientation can reveal geological features that may affect siting or structural foundations for buildings. Core samples are cylindrical in shape, typically around 3 metres long, and are obtained by drilling with an annular hollow core drill into subsurface material, such as sediment and rock, and recovering the core sample.
[0008] A diamond tipped drill bit is used at the end of the hollow drill string. As the drill progresses deeper, more sections of hollow steel drill tube are added to extend the drill string. An inner tube assembly captures the core sample. This inner tube assembly remains stationary while the outer tubes rotate with the drill bit. Thus, the core sample is pushed into the inner tube.
[0009] A 'back end' assembly connects to a greaser. This greaser lubricates the back end assembly which rotates with the outer casing while the greaser remains stationary with the inner tubing.
[0010] Once a core sample is cut, the inner tube assembly is recovered by winching to the surface. After removal of the back end assembly from the inner tube assembly, the core sample is recovered and catalogued for analysis.
[0011] Various core orientation systems have previously been used or proposed. Traditional systems use a spear and clay impression arrangement where a spear is thrown down the drill string and makes an impression in clay material at an upper end of the core sample. This impression can be used to vindicate the orientation of the core at the time and position the spear impacted the clay.
[0012] A more recent system of determining core orientation is proposed in Australian patent number 2006100113 (also as US patent number 7,584,055). This patent document describes a core orientation device for a core drill. The device provides signals associated with a physical orientation of a core orientation device for a particular moment in time. The device includes a memory for storing and providing the orientation data when required.
[0013] The system described in AU 2006100113 provides a two unit replacement for the greaser described above. A first orientation system unit houses electronics and a battery used to record orientation data, and the second greaser unit is an extended greaser accommodating a physical screw on connector for the first unit as well as serving as the greaser. This combination forms part of the inner tube assembly with the core tube, orientation system 'first' unit and the connector/greaser 'second' unit.
[0014] However, as a result of the now extended length of the combined orientation system and greaser units compared with a standard greaser only unit, the outer drill string casing now requires a matching extension piece to extend the outer casing an equal amount. The core orientation system has a display on one face which is used when setting up the unit prior to deployment, and to indicate core sample alignment when the core sample is recovered. At the surface before removing the core sample from the inner tube assembly, the operator views the display fitted on the system. The display indicates for the operator to rotate the unit and the sample within the tube until the whole core tube and sample is oriented with the lower section of the core sample at the lower end of the tube. The core sample is marked (usually by pencil) before being removed from the core for future analysis.
[0015] However, the device described in AU 2006100113 has been found to have certain limitations. The orientation unit is connected to the greaser by a screw thread and o-ring seal arrangement. In the harsh down hole environment within the drill string, it has been realised that the o-ring seals are not always effective and can let fluid into the space between the orientation unit and the greaser. The display unit allows fluid into the electronics of the orientation, resulting in a risk of fault or failure of the device. Furthermore, the orientation unit must be disassembled from the greaser unit before the display and orientation unit can be viewed, rotated and the required core orientation displayed. Thus, the device of AU 2006100113 requires manual manipulation before any reading can be viewed on the display, if the display and the electronics have survived any ingress of fluid past the o-ring seal.
[0016] Similar issues arise with downhole probes that are used to obtain borehole telemetry data to determine drilling progress, such as depth and direction of the borehole and change in surrounding magnetic field.
[0017] Typically the downhole equipment is brought to the surface once sufficient data is gathered or task completed, such as obtaining a core sample. It is common practice to manually have to separate the backend assembly from an electronics package used for gathering downhole data. This task involves unscrewing the backend assembly from the electronics package, which takes time and risks thread damage as well as resulting in risk of ingress of dirt and water into the thread. Also, o-ring seals protecting the electronics unit may be compromised through separation and refitting of the backend assembly and electronics unit. Similar issues exist with separating the electronics unit of a downhole probe from its backend assembly.
[0018] It has been found desirable to provide means of obtaining signals/data from or providing signals/data to downhole equipment electronics units, such as used in core sample orientation units or downhole probes.
[0019] One improved system is described in the applicant's international patent application PCT/AU2011/000954, the contents of which are incorporated herein in its entirety. At least one embodiment described in PCT/AU2011/000954 utilises an optical device extending from an end of a data gathering device, such as an electronics unit, into an end of a greaser unit. Light from LEDs in the data gathering device is reflected out of apertures in the greaser unit behind the optical device. The present invention improves on such a system.
[0020] With this in mind, it has been found desirable to provide improved means for obtaining signals/data from or providing signals/data to an electronics unit of downhole equipment.
(Emphasis added.)
13 It is convenient to note at this stage that, at [0015], the specification identifies certain limitations of existing core orientation equipment. In particular, the equipment needed to be disassembled before the data could be obtained. In that context, [0016] states that "[s]imilar issues arise with downhole probes that are used to obtain borehole telemetry data to determine drilling progress". The primary judge reasoned that the "[s]imilar issues" were those identified in [0015]; those issues all concerned the problems associated with manual manipulation of the device at the surface to obtain data; this indicated that, by "borehole telemetry data to determine drilling progress", the Patent did not mean data that is communicated from down the hole to the surface while the equipment is down the hole (Reasons, [324]).
14 The "Summary of the invention" comprises [0021]-[0045] and includes:
[0021] With the aforementioned in mind, in one aspect the present invention provides a device that transfers at least one electromagnetic signal to or from an electronics unit of downhole equipment, the device including a body and an electromagnetic signal direction altering means, the body having a light path arranged to allow the electromagnetic signal from an electromagnetic wave source associated with the electronics unit to pass to the electromagnetic signal direction altering means, the electromagnetic signal direction altering means causing the electromagnetic signal to change direction of travel, the device, in use, configured to transmit or receive the electromagnetic signal through at least one aperture through a side wall of a component of downhole equipment.
…
[0025] The optical signal direction altering means may act on optical signals incoming to the electronics unit and/or outgoing from the electronics unit.
[0026] The optical signal direction means may include a boundary of or within the body of the optical device. For example, refraction may occur at a surface edge of the optical device. The boundary and/or the nature of the material (refractive index) may be used to change the path of the light in order to transfer the light signal via the device.
[0027] Alternatively, refraction may occur at a change of material or material density within the body of the optical device. Such refraction may cause the transmitted optical signal to emit sideways/transversely with respect to a longitudinal extent of the optical device.
…
[0032] Preferably the transmitted signal emits to the side of the device, which is beneficial in aiding signal detection through at least one overlying aperture formed or provided in the downhole equipment. Such at least one aperture may be the water supply hole(s) through a greaser unit or at least one aperture provided in part of a downhole probe assembly.
…
[0036] The electronics unit (and hence the optical device) may be connected to other equipment, such as a portion of a downhole probe.
[0037] An advantage of the present invention is that the greaser or other equipment to which the electronics unit attaches does not need to be separated from the electronics unit in order to obtain access and communicate with the device to obtain data. This avoids needing to unscrew components of the downhole equipment and risk ingress of dirt/water or damaged threads, as well as reduces time taken to obtain data.
[0038] In addition, the electronics unit can be started or stopped remotely and at the most opportune time. For example, in known devices an operator usually delays turning on the electronics unit until the last minute in order to conserve the unit's onboard battery power. The operator then starts the electronics unit and assembles the unit to the other equipment, such as a greaser or probe assembly.
[0039] The present invention avoids the need for such urgent activity by allowing an operator to switch the unit on or off by sending an optical signal from a hand held device to the optical device through an overlying aperture, the device then transmitting the optical signal to the electronics unit to activate/deactivate the unit. Data to/from the unit can also be sent/received utilising the same optical device.
…
[0042] A further aspect of the present invention provides downhole equipment having an electronics unit configured to obtain data relating to a borehole into which the electronics unit is inserted or to obtain data relating to equipment used within the borehole system, and an optical device associated with the electronics unit, and an optical device according to any one of the preceding claims configured to enable optical signals to be transmitted to or received from the electronics unit whilst the electronics unit is connected to the downhole equipment.
15 The summary at [0021] is in similar language to claim 1. The summary also includes the following paragraph that is similarly worded to claim 21:
[0044] A still further aspect of the present invention provides a downhole data gathering system, including a communication device arranged to communicate wirelessly with an electronics unit of downhole equipment, the downhole equipment including an electronics unit configured to obtain data relating to a borehole into which the electronics unit is inserted or to obtain data relating to equipment used within the borehole system, and a device that transfers electromagnetic signals to or from the electronics unit of the downhole equipment, the device including a body and an electromagnetic signal direction altering means, the body having a light path arranged to allow the electromagnetic signals from an electromagnetic wave source associated with the electronics unit to pass to the electromagnetic signal direction altering means, the electromagnetic signal direction altering means causing the electromagnetic signal to change direction of travel and wherein the device is configured to enable the electromagnetic signals to be transmitted to or received from the electronics unit whilst the electronics unit is connected to the downhole equipment, the device enabling transmission of the electromagnetic signals from the electronics unit to the wireless communication device, or from the wireless communication device to the electronics unit, through at least one aperture in a side wall of the downhole equipment.
16 The Patent includes a number of figures that are described in sections headed "Brief description of the drawings" and "Description of preferred embodiment".
17 Figure 1 (set out below) shows an end on view of a core sample orientation device or downhole probe having an indicator window whereby indicator lights provide optical signals to an optical device according to an embodiment of the present invention: [0047].
18 As explained at [0051] of the Patent, figure 1 depicts the indicator window end 12 of an electronics unit of a core sample orientation data gathering device 10 and includes a window 14. Indicator lights 16, 18 can be seen through this window, at least when illuminated. The window end is sealed by a retaining plate 20. Two lights, eg red and green LEDs, are shown, though there may be more or less lights. The left hand 16 (red) LED illuminates to indicate to a user to rotate the unit 10 anti-clockwise. The right hand 18 (green) LED illuminates to indicate to a user to rotate the unit 10 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).
19 Figures 2a and 2b (set out below) show an arrangement of a data-gathering device incorporating an optical device: [0048].
20 The description of figures 2a and 2b is as follows:
[0058] As shown in figures 2a and 2b, an electronics unit 30 for gathering data downhole houses the light emitters 16,18. Light from these emitters (e.g. LEDs) passes through the window 14 (shown in figure 1).
[0059] Reference arrow A refers to the drill bit end direction, and reference arrow B refers to the backend assembly direction.
[0060] An optical device 32 according to an embodiment of the present invention is provided at the end 34 of the electronics unit 30 and which device extends into the greaser unit 36 of the backend assembly when connected thereto.
[0061] The optical device has a body 38 and a light path altering means 40. The body also defines a light path therethrough (see figure 3) arranged to allow the optical signal from a light source(s) 16,18 associated with the electronics unit to pass to the light path altering means.
[0062] The light path altering means 40 can be arranged to cause the optical signal from/to the electronics unit to change direction of travel and emit out of the body/into the body of the optical device.
[0063] The greaser unit 36 has apertures 42 that allow light therethrough. Light from the emitters is directed onto at least one light path altering means of the device.
[0064] The emitted light can be observed through the apertures 42 in the greaser.
21 The description includes:
[0066] The red-green indications (or whatever selected colour combination of light is used) can be observed through the aperture(s) when a remote device (such as a handheld device) reads the optical data signal. Also, a handheld device can transmit data via an optical signal or use a transmitted optical signal to operate the electronics unit or store data in the unit. Thus, advantageously, when the unit is recovered from down the hole, the unit need not be separated from the rest of the downhole equipment in order to determine required information or control the electronics unit. Thus, wireless communication to/from a remote device, such as a hand held device, to transfer data between the electronics unit and the remote device, can also be effected by transmitting through … at least one aperture.
[0067] Embodiments of the present invention provide the advantage of a fully operating downhole electronics unit without having to disconnect or disassemble the unit from the inner tube and/or from the backend assembly or any other part of the drilling assembly that the unit would need to be assembled within for its normal operation.
[0068] Disconnecting or disassembling the unit 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.
[0069] 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.
[0070] Having an electronics unit 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 unit 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 unit. By providing a sealed unit 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 greaser 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 unit 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.
22 Figure 3 (set out below) shows an optical device according to an embodiment of the present invention arranged to be at least partially received into a housing or casing of an electronics unit of downhole equipment: [0049].
23 The description of figures 3 is as follows:
[0071] Figure 3 shows a particular embodiment of an optical device 32 for use with a downhole electronics unit. The optical device is shown in side, profile view. In practice, the device is cylindrical in cross section A-A.
[0072] The optical device has a body 44 of a transparent machined plastics material, such as polycarbonate, acrylic, nylon etc. Glass may also be used, though a plastic material is preferred.
[0073] The body has annular grooves 46 therearound to receive o-rings for sealing the device within a housing or casing of a downhole unit, such as an electronics unit. In this embodiment, the transparent material of the body allows light to pass therethrough. Thus, the body forms a light path of the light to travel through. Other materials can also be suitable, depending on the type of light or other electromagnetic wave used. Preferably the body allows infra red light to pass therethrough. UV (ultra-violet light) may also be transmitted, or alternatively light in the visible spectrum.
[0074] At least a portion of the body is shaped to fit within a housing or casing of a component of downhole equipment, such as an electronics unit or a greaser unit or extension piece etc.
[0075] A first end 48 of the body is shaped so that an end surface 50, in use, faces the light emitters 16,18 or other light emitters depending on the equipment used and required application.
[0076] Light from one or more such emitters is transmitted by the light path through the body to impinge on a light path altering means 52. In this embodiment, the light path altering means includes a reflector 54.
[0077] The reflector reflects some or a majority of the light impinging upon it, and said reflected light is re-directed sideways (S) with respect to a longitudinal direction (L) of the device. The light path altering means may be provided, as in this embodiment, by forming a recess in its second end 56. The recess may form a conical surface 58 to which a reflective material is applied, such as a silvery coating.
24 Figure 4 (set out below) shows an alternative embodiment of an optical device according to the present invention: [0050].
25 The description of figure 4 is as follows:
[0078] Figure 4 shows an alternative embodiment of the present invention which works in the same manner as that of figure 3.
[0079] This alternative form of optical device 60 is provided as an insert for use with a downhole probe. Again, this device as the one above in figure 3, is shown in side view but is a cylinder with a circular cross section B-B. Light 62 entering the device 60 passes through the body 64 material and reflects off of a protrusion 66 into the envelope of the cylinder.
[0080] The protrusion is a machined surface coated from the exterior with a reflective material. A conical surface 68 assists in diffracting light sideways (S).
26 The description of the preferred embodiment includes:
[0082] It will be appreciated that the optical device can be inserted into a downhole component and removed from replacement or access to an end of the electronics unit as required. Otherwise, the optical device can be left in situ to transmit light from/to the electronics unit. This can avoid the need to disassemble the electronics unit from the backend assembly, greaser unit or probe etc to which it is connected.
[0083] The electronics unit can be switched on or off by sending a controlling optical signal to the electronics unit through the optical device.
[0084] It will be appreciated that the optical device may be formed of one or multiple parts. For example, the optical device may be machined as a monolithic component or may be formed of multiple sub-components brought together, which may be bonded together or simply abutting in use.
[0085] It will be appreciated that light impinging on the light path altering means can be emitted sideways omni-directionally. Thus, and of great benefit to an operator, the optical device needs no alignment with … at least one aperture of the downhole assembly through which the light is to be transmitted.
27 Claim 1 in the Patent is as follows:
1. A device that transfers at least one electromagnetic signal to or from an electronics unit of downhole equipment, the optical device including a body and an electromagnetic signal direction altering means, the body having a light path arranged to allow the electromagnetic signal from an electromagnetic wave source associated with the electronics unit to pass to the electromagnetic signal direction altering means, the electromagnetic signal direction altering means causing the electromagnetic signal to change direction of travel, the device, in use, configured to transmit or receive the electromagnetic signal through at least one aperture through a side wall of a component of downhole equipment.
28 Claims 5, 7, 8, 9, 10, 12 and 17, which are also in issue, are dependent on claim 1.
29 Claim 21 is as follows:
21. A downhole data gathering system, including a communication device arranged to communicate wirelessly with an electronics unit of downhole equipment, the downhole equipment including an electronics unit configured to obtain data relating to a borehole into which the electronics unit is inserted or to obtain data relating to equipment used within the borehole system, and device-that transfers electromagnetic signals to or from the electronics unit of the downhole equipment, the device including a body and an electromagnetic signal direction altering means, the body having a light path arranged to allow the electromagnetic signals from an electromagnetic wave source associated with the electronics unit to pass to the electromagnetic signal direction altering means, the electromagnetic signal direction altering means causing the electromagnetic signal to change direction of travel and wherein the device is configured to enable the electromagnetic signals to be transmitted to or received from the electronics unit whilst the electronics unit is connected to the downhole equipment, the device enabling transmission of the electromagnetic signals from the electronics unit to the wireless communication device, or from the wireless communication device to the electronics unit, through at least one aperture in a side wall of the downhole equipment.
30 Claims 22, 24, 25, 26, 27 and 29, which are also in issue, are dependent on claim 21.