WO2001040625A1

WO2001040625A1 - Exploration apparatus with video camera

Info

Publication number: WO2001040625A1
Application number: PCT/ZA2000/000239
Authority: WO
Inventors: Pieter Cornelius Christiaan Redelinghuys
Original assignee: Iscor Limited
Priority date: 1999-11-30
Filing date: 2000-11-30
Publication date: 2001-06-07
Also published as: AU2979001A

Abstract

An exploration unit (24) comprises a three-dimensional compass (61) and a video camera (58) mounted on the unit, in use, to capture video images of a face of the compass. Data communication means (56, 20, 68, 74) connected to the camera serve to transmit data relating to the images to a remote computer (78) which processes the data, to display the images in real time on a monitor (82). Data derived from displayed images at various depths in a hole and data relating to corresponding depths are utilized to compute and plot a profile of the hole.

Description

EXPLORATION APPARATUS WITH VIDEO CAMERA

TECHNICAL FIELD

THIS invention relates to borehole exploration apparatus.

BACKGROUND ART

Exploration drilling is conducted to obtain information regarding

minerals present in a sub-surface region of the earth, water levels,

magnetic zones, rock formations etc. The bore holes drilled, often

slant away from an intended straight line, due to obstructions

presented in use by rocks, boulders or the like to the operative drilling

element. Hence, to relate the aforementioned data to depth of the

hole, the gradient or profile of the hole needs to be determined.

Certain apparatus for determining the profile of the hole is known.

These apparatus suffer from various disadvantages.

OBJECT OF THE INVENTION

Accordingly it is an object of the present invention to provide an

exploration unit, apparatus and a method of determining the profile of

a hole with which the applicant believes the aforementioned

disadvantages may at least be alleviated. SUMMARY OF THE INVENTION

According to the invention, an exploration unit for a hole, such as a

borehole comprises a compass, and video image capturing means

mounted on the unit for capturing a video image of a face of the

compass and for generating an image signal relating to the captured

image.

The compass may be a three-dimensional compass and the video

image capturing means may comprise a video camera.

The unit may further comprise illumination means for illuminating the

face of the compass.

The illumination means may comprise at least one light emitting

device, such as a light emitting diode (LED) .

The unit may further comprise a signal amplifier connected to an

output of the camera for amplifying the image signal.

The unit may further comprise a tubular housing wherein the compass,

illumination means, video camera and signal amplifier are housed. The housing may comprise an aluminum tube having a first and a second

end.

A shock absorber in the form of a PVC tube having a first end and a

second end may be connected in end to end relationship to the second

end of the aluminum tube. A ballast or weight member may be

provided towards the second end of the PVC tube.

The unit may form part of exploration apparatus also comprising a

cable connected to the unit and extending to a drum arrangement from

which and onto which the cable may be wound to displace the unit in

the hole. The cable may comprise power supply conductors and a

signal conductor.

The apparatus may still further comprise a stand for a pulley over

which the cable extends in use, to suspend the unit into a hole.

The apparatus may comprise means for automatically determining

distance data relating to a distance between the unit and a reference.

The said distance data determining means may comprise a tachometer

associated with the pulley. The apparatus may further comprise means for displaying the distance

data.

The drum arrangement may comprise a power supply for providing the

unit with electrical power via the power supply conductors. It may

further comprise a second signal amplifier for further amplifying the

image signal received via the signal conductor and a transceiver for

transmitting the signal to a remote monitoring station.

The monitory station may comprise a receiver for receiving the signal

and a monitor for displaying the video image. The monitoring station

may also comprise computing means for capturing and storing data

derived from images captured at various levels in the hole. The

computing means may comprise software for processing the captured

data and the distance data to compute data relating to a profile of the

hole.

Also included within the scope of the invention is a method of

determining a profile of a hole, the method comprising the steps of:

- locating a compass in the hole;

capturing a video image of a face of the compass; transmitting a signal relating to the image to a monitor station;

and

reproducing the image at the monitoring station and interpreting

the reproduced image to determine a gradient of a section of the

hole.

The image is preferably interpreted in real time.

In a preferred form of the method the gradient is determined at a

plurality of levels in the hole and data relating to the gradient and

distance data associated with each level are utilized to determine the

profile of the hole.

BRIEF DESCRIPTION OF THE ACCOMPANYING DIAGRAMS

The invention will now further be described, by way of example only,

with reference to the accompanying diagrams, wherein:

figure 1 is a diagrammatic perspective view of the exploration

apparatus according to the invention;

figure 2 is a transverse section through a cable extending from an

exploration unit, both of which form part of the apparatus

in figure 1 ;

figure 3 is a longitudinal sectional view of the exploration unit; figure 4 is a block diagram of electronic circuitry forming part of

the apparatus;

figure 5 is a copy of a video image of a face of a compass forming

part of the unit and apparatus; and

figure 6 is a representation of a profile of a borehole as

determined with the apparatus and according to the

method of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Exploration apparatus according to the invention for determining the

profile of a hole (normally a borehole 1 2) in the ground 1 4, is generally

designated by the reference numeral 10 in figure 1 .

The apparatus 1 0 comprises a tri-legged stand 1 6. A pulley 1 8 is

suspended from an apex of the stand. A cable 20 is wound onto and

extends from a drum 22 over the pulley 1 8 to an exploration unit 24

to which it is connected. The drum is supported for rotation relative to

a stand 26. In use, the cable 20 is paid out from the drum to lower the

unit 24 into the hole 1 2. Conversely, the unit may be withdrawn from

or raised in the hole by paying the cable in and onto the drum. Means

(not shown) for determining the cable length extending into the hole,

alternatively a distance d between the unit 24 and a reference level R is associated with the pulley 1 8 and/or the drum 22. The means may

include a tachometer 1 9 mounted on pulley 1 8 and may be connected

by a conductor 21 to a display 23 which may be located at any

suitable location.

Referring to figure 2, the cable 20 is flexible, at least 500m, but

preferably 1 000m in length and comprises an outer insulating sleeve

28, three insulated multi-strand cables 30, 32 and 34 and a

strengthening core 36. Cables 30 and 32 are power cables for

providing the unit 24 with electrical power and cable 34 is a signal

cable for conveying electrical signals to and from the unit 24.

The exploration unit 24 is shown in more detail figure 3. The unit

comprises an aluminum tube 38 of about 0.5m in length, a PVC tube

40 of about 3m connected to a distal end of the aluminum tube 38

and a conical point member 42 of copper connected to the distal end

of the PVC tube 40. The PVC tube 40 serves as a shock absorber

and stabilizer. The cable 20 extends into a first or proximate end 44 of

the aluminum tube 38 via adapters 46 and 48 and is wound around an

element 50, before it terminates in connector 52. Connector 52 is

connected to a printed circuit board 54 supporting a first signal

amplifier 56, shown in figure 4. The first signal amplifier 56 serves to -o-

amplify a signal generated by a video camera 58 mounted in region 60

of the unit, as best shown in figure 4.

Video camera 58 is focussed on a face 61 .1 of a conventional three-

dimensional compass 61 . The face of the compass is illuminated by

illumination means including a plurality of infra red light emitting

diodes (LED's) 62. The signal amplifier 56, video camera 58 and LED's

62 derive electrical power from battery 64 via multi-strand cables 30

and 32 of cable 20.

Battery 64, a second signal amplifier 66 and an RF signal transmitter

68 are mounted on the inside of drum 22. Second signal amplifier 66

serves to amplify the signal received via cable 34 from the first signal

amplifier 56 forming part of unit 24. The signal amplifier 66 is

connected to the RF transmitter 68. Transmitter 68 transmits amplified

signals received from the unit 24 via antenna 70 to an antenna 72

connected to an RF receiver 74 of a remote receiving station 80.

Receiver 74 derives power from a battery 76. The receiver 74 is

connected via cable 77 to a video capture card 79 installed in

computer 78. The battery 76, receiver 74, antenna 72, computer 78

and display 23 may all form part of the receiving station 80. -y-

ln use, the gradient of the hole 1 2 is determined by lowering the unit

24 into the hole 1 2. Data relating to cable length d from reference

level R is captured via the tachometer and recorded. The camera 58 is

caused to record a video image of the face of the 3D- compass which

is illuminated by LED's 62. An electronic signal relating to the video

image is amplified by first amplifier 56 and caused to propagate in

cable 34 to second amplifier 66 where it is amplified again. The signal

is then transmitted by transmitter 68 to remote receiver 74 where it is

further processed by the video capture card 79 and computer 78, to

enable the image to be displayed in real time on a monitor 82 of

computer 78.

An example of the image is shown in figure 5 designated 90. The

operator (not shown) interprets the image displayed of the compass

face in well known manner and determines the gradient of the hole at

the level of the unit. Thereafter the unit is displaced in the hole and

the procedure repeated for various levels.

Referring to figure 6, for each level 92.1 to 92.8, respective data

relating to the gradient and the length d is recorded in computer 78.

The computer utilizes this data and an application program to compute, and if necessary, to plot a profile of the hole. An example

of such a profile is shown at 94 in figure 6.

Data relating to magnetic zones and changes thereof including the

depths thereof may also be obtained form an interpretation of the

video image.

It will be appreciated that there are many variations in detail on the

unit, apparatus and method according to the invention without

departing from the scope and spirit of the appended claims.

Claims

CLAIMS:

1 . An exploration unit for a hole, comprising a compass; and video

image capturing means mounted on the unit for capturing a

video image of a face of the compass and for generating an

image signal relating to the captured image.

2. An exploration unit as claimed in claim 1 wherein the compass

is a three-dimensional compass and the video image capturing

means comprises a video camera.

3. An exploration unit as claimed in claim 1 or claim 2 comprising

means for illuminating the face of the compass.

4. An exploration unit as claimed in claim 3 wherein the means for

illuminating the face of the compass comprises at least one light

emitting diode.

5. An exploration unit as claimed in any of the preceding claims

comprising a tubular housing having a first end and a second

end.

6. An exploration unit as claimed in claim 5 wherein the housing is

of a metal and wherein the housing at the second end

comprises a shock absorber.

7. An exploration unit as claimed in claim 6 wherein the shock

absorber comprises an elongate element of a plastics material

connected in end to end relationship to the housing.

8. An exploration unit as claimed in claim 6 or claim 7 wherein the

shock absorber comprises a ballast element.

9. An exploration unit as claimed in claim 7 or claim 8 wherein the

housing is at least 0.5m in length and the shock absorber is at

least 3m in length.

1 0. An exploration apparatus comprising an exploration unit as

claimed in any one of claims 5 to 9 wherein an electrical cable

for transmitting the image signal is connected to the unit and

extends from the first end thereof.

1 1 . Apparatus as claimed in claim 1 0 wherein the cable is

collectable on a rotatable drum.

1 2. Apparatus as claimed in claim 1 1 comprising a stand erectable

in the region of a hole and for guiding the unit suspended by the

cable into the hole.

1 3. Apparatus as claimed in claim 1 3 comprising means for

automatically determining distance data relating to a distance

between the unit and a reference.

14. Apparatus as claimed in claim 1 3 comprising means for

displaying the distance data.

1 5. Apparatus as claimed in claim in any one of claims 1 1 to 14

comprising signal transceiving means at the drum for receiving

the image signal on the cable and for transmitting the image

signal to a remote monitoring station.

1 6. Apparatus as claimed in claim 1 5 wherein the remote monitoring

station comprises a receiver for receiving the image signal and a computer connected to the receiver to process the image signal

and to display the captured image in real time.

7. Apparatus as claimed in claim 1 6 wherein the transceiving

means and the receiving means comprise a radio frequency

transmitter and an associated radio frequency receiver

respectively.

8. Apparatus as claimed in claim 1 6 or claim 1 7 wherein the

computer comprises software for processing data relating to the

image and the distance data to compute data relating to a

profile of the hole.

9. A method of determining a profile of a hole, the method

comprising the steps of:

locating a compass in the hole;

capturing a video image of a face of the compass;

transmitting a signal relating to the image to a monitor

station; and

- reproducing the image at the monitoring station and

interpreting the reproduced image to determine a gradient

of a section of the hole.

20. A method as claimed in claim 1 9 wherein the image is

interpreted in real time.

21 . A method as claimed in claim 1 9 or claim 20 wherein the

gradient is determined at a plurality of levels in the hole and

wherein data relating to the gradient and distance data

associated with each level are utilized to determine the profile of

the hole.

22. An exploration unit substantially as herein described with

reference to the accompanying diagrams.

23. An exploration apparatus substantially as herein described with

reference to the accompanying diagrams.

24. A method of determining a profile of the hole substantially as

herein described with reference to the accompanying diagrams.