Note: Descriptions are shown in the official language in which they were submitted.
CA 02321546 2000-08-28
WO 99/44367 PCT/US99/04357
1
SINGLE CAMERA VIDEO INSPECTION SYSTEM FOR
WATER WELLS AND BORE HOLES
TECHNTCAL FIELD OF THE INVENTION
This invention relates generally to inspection tools
and more particularly to a video inspection system for
passages such as water wells and bore holes.
'BACKGRO ND OF THE INVENTT_ON
It is often necessary to inspect passages such as
water wells, bore holes, pipes, pipelines, tanks or
underground cavities. This might be done in order to
pinpoint damaged casings, obstruction, or other conditions
that can be repaired. A down hole inspection might also be
used to located lost or damaged pumps or tools. By
capturing the inspection of a borehole or water well on a
video tape, a record of the well's condition can be
captured and saved.
In a typical down hole surveying system, the down hole
tool has a single camera which allows for downward viewing
only. This eliminates the possibility of examining the
sides of a wall or a bore hole.
One solution to this problem has been to use mirrors
in conjunction with a downward camera to capture images of
the side of the bore hole. This solution is inadequate
because it produces poor image quality, produces an image
of reduced size and provides a reversed image.
Another solution proposed to address this problem is
a two camera system. One such system is disclosed in U.S.
CA 02321546 2000-08-28
WO 99/44367 PCT/US99I04357
2
Patent No. 5,652,617, entitled "Side Scan Down Hole Tool
Having Two Cameras" and issued to Barbour on May 31, 1996.
This system includes one camera pointed straight down
the bore hole and operable to view down the hole and a
second camera mounted to provide a close up of the side of
the borehole. One drawback of this system is that an added
camera involves added expense, additional complexity and
takes-up additional space.
Accordingly, it may be appreciated that a need has
arisen for a single camera video inspection tool for water
wells, bore holes or other passages. In accordance with
the teaching of the present invention, a single camera
video inspection tool is provided that substantially
eliminates or reduces the disadvantages of previous
inspection tools.
In one embodiment, a system for video inspection of a
bore hole is provided. The system includes a carrying case
having a deep housing and a removable cover with a spool of
coaxial cable stored inside the carrying case. The coaxial
cable exits the carrying case at an opening. A cable arm
attached to the carrying case and supported by an
adjustable leg has the coaxial cable pass over it.
Attached to the end of the coaxial cable is a camera
assembly. The camera assembly includes a single camera
operable to capture an image in a first direction along a
long axis and a second direction, ninety degrees off set
from the first direction.
In another embodiment, a down hole tool for video
inspection is provided. The camera includes a first image
sensor operable to acquire an image in a first direction
along a first axis and a second image sensor operable to
acquire an image in a second direction essentially
perpendicular to the first direction. Also included is a
CA 02321546 2000-08-28
WO 99/M1367 PCT/US99/04357
3
camera board and processor coupled to the first image
sensor and second image sensor operable to receive an image
from either the first image sensor or second image sensor
and prepare the image for display.
In another embodiment, a down hole tool for video
inspection is provided. The tool includes an image sensor
in a housing operable to capture an image in a first
direction parallel to a first axis. The image sensor is
further able to capture an image in a second direction.
The second direction is approximately perpendicular to the
first direction. Also included is a camera board and
processor coupled to the image sensor and operable to
process the image and prepare it for display.
The present invention provides various technical
advantages over current methods. For example, a single
camera can be used to view downward images and side images,
reducing the size and bulk of the camera assembly. Also,
an inspection tool is provided that can be easily
transported. Other technical advantages may be readily
apparent to one skilled in the art from the following
figures, descriptions and claims.
DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present
invention and advantages thereof, reference is now made to
the following descriptions taken in conjunction with the
accompanying drawings, in which like numbers represent like
parts, in which:
FIGURE 1 illustrates a system for inspecting bore
holes and water wells:
FIGURE 2 illustrates a carry case in accordance with
the teachings of the present invention;
FIGURE 3 illustrates a control system and monitor in
accordance with the teachings of the present invention;
CA 02321546 2000-08-28
WO 99/44367 PC"T/US99/04357
4
FIGURE 4 illustrates a cable winder in accordance with
the teachings of the present invention
FIGURE 5 illustrates a cable arm encoder in accordance
with the teachings of the present invention;
FIGURE 6 illustrates a single camera assembly in
accordance with the teachings of the present invention;
FIGURE 7 illustrates a two camera system in accordance
with the teachings of the present invention;
FIGURES 8A, 8B, and 8C illustrate a one camera system
in accordance with the teachings of the present invention;
FIGURE 9 illustrates a close-up view of the lower
section of the one camera system in accordance with the
teachings of the present invention; and,
FIGURE 10 illustrates a single camera system having
multiple image sensors in accordance with the teachings of
the present invention.
DETATT.ED DESCRIPTION O~THE INVENTION
Embodiments of the present invention and its
advantages are best understood by referring to FIGURES 1
through 10 of the drawings, like numerals being used for
like and corresponding parts of the various drawings.
FIGURE 1 illustrates a system for using a video
inspection system in accordance with the teachings of the
present invention. System 10 includes a carrying case 1
which includes a deep housing 12 and a removable cover 14.
Carrying case 1 also includes a spool 16 of coaxial cable
18. Coaxial cable 18 is fed through carrying case 1 and
over a cable arm 20 which is supported by an adjustable leg
22. The end of coaxial cable 18 is attached to down hole
camera assembly 24, which will be discussed in detail in
conjunction with FIGURES 6 through 10. Coaxial cable 18
can be equipped with a quick disconnect 26. One half of
the quick disconnect is mounted to coaxial cable 18 and the
other half near the top of camera assembly 29. This
CA 02321546 2000-08-28
WO 99/44367 PCT/US99/04357
allows for quick disconnection of camera assembly 29 from
coaxial cable 18, so that other cameras or analytical
instruments can be attached to coaxial cable 18 and the
remainder of the system without disrupting the seal
5 integrity of camera assembly 24. The system is designed
for easy transportation and can be run off a generator or
battery. Components in carrying case 1 are designed for
easy removal and replacement. Camera assembly 24, in one
embodiment, is constructed of stainless steel which is
water sealed to at least a depth of 2300 feet at an
approximate pressure of 1000 pounds per square inch.
In operation, down hole camera assembly 24 is lowered
into a well or bore hole 2 that needs inspecting. Bore
hole 2 can be a well water hole, a natural gas or oil well,
a hole produced at a construction site, a hole produced
when taking a core sample or any other hole in the ground
that needs to be investigated. Coaxial cable 18 is fed
from through housing 12 and over cable arm 20 as camera
system 24 is lowered. Depth information and video from
camera assembly 24 are displayed on a monitor 5 located in
housing 12. Further details on the operation of system 10
are provided in FIGURES 2-10.
The complete system is made up of five subassemblies.
The carrying case, which is illustrated in FIGURE 2, the
control system and monitor, which is illustrated in FIGURE
3, the cable winder, illustrated in FIGURE 4, the cable arm
encoder illustrated in FIGURE 5 and variations of the
cameras illustrated in FIGURES 6-10.
FIGURE 2 illustrates the carrying case 1 in accordance
with the teaching of the present invention. Illustrated is
a deep housing 12 which contains a spool 16 of coaxial
cable 18 as well as electronic equipment that will be
discussed in conjunction with FIGURE 3. Attached to deep
housing 12 is a removable cover 14 which can close to
provide a water-tight seal. Also illustrated is opening 13
CA 02321546 2000-08-28
WO 99/44367 PCT/US99/04357
6
which allows coaxial cable 18 to pass from spool 16 to
outside carrying case 1. Carry case 1 can be mounted to a
pickup truck or van. Alternatively, carrying case 1 can be
transported to a site by manual labor.
FIGURE 3 illustrates a control system 9 and monitor
5 in accordance with the teaching of the present invention.
Control system 9 includes a monitor 5. Also pictured are
a depth gauge 11 which can display the depth of camera
assembly 24. Also included are electronics 7 which
provides for control of the camera, control of the power
supply, control of monitor 5 and control of or regulation
of any other electronic system'. Monitor control
electronics, power supply electronics and camera control
electronics are well known to those skilled in the art.
The entire unit is mounted on a rail 3 for easy removal.
Monitor 5 is operable to display the output of camera
assembly 24. It also is operable to display the depth of
camera assembly 29. Additionally, monitor 5 can include an
integrated video tape recorder or can attach to an external
video tape recorder or similar storage device for recording
what is displayed on monitor 5. Monitor 5 can also be
attached to a video printer, not pictured, which can
provide pictures of the display.
FIGURE 4 illustrates a cable winder in accordance with
the teaching of the present invention. Cable winder 13
includes spool 16 of coaxial cable 18. Spool 16 is
controlled by a motor 17 which is linked to spool 16 via a
chain or belt. As cable is wound or unwound by motor 17
(which is a reversible motor), it passes over level
mechanism 19, which maintains an even distribution of
coaxial cable 18 over spool 16. Motor 17 controls are
mounted on control system 9 and can be lowered and raised
by an operator.
FIGURE 5 illustrates a cable arm encoder in accordance
with the teaching of the present invention. Illustrated is
CA 02321546 2000-08-28
WO 99/44367 PCTNS99I04357
7
cable arm 20 which can be supported by adjustable leg 22.
Also included is an encoder pulley 23 which is attached to
electronic encoder shaft 25. As coaxial cable 18 moves
along encoder pulley 23, encoder shaft 25 turns. The
number of turns can then be used to determine the amount of
cable sent in terms of linear feet or linear meters as is
well known to those of skill in the art. The result can be
displayed directly onto monitor 5. Also included on cable
arm 20 is support pulley 29, which is used to support the
cable and camera assembly 24 as it is conveyed along the
passage. Encoder shaft 25 could be mounted on to support
pulley 29.
FIGURE 6 illustrate a single camera in accordance with
the teachings of the present invention. Single camera 30
includes one or more image sensors 32 coupled to a single
camera board and processor 34. A single camera may have
multiple image sensors 32 but only one camera board and
processor. Image sensors can be charged coupled devices
(CCD~ sensors, such as the Sony ICX086AK, or can be other
types of sensors such as CMOS sensors. In embodiments
where single camera 30 includes multiple image sensors 32,
a switch is provided to allow switching between image
sensors 32. Switch 36 can be any type of electronic switch
and can be fiber optic switches as well. Associated with
each image sensor 32 are optics 38 which are used to focus
the image on image sensor 32. Optics 38 can be of fixed
focal length, typically providing a wide angle view, or can
be of variable focal length in order to provide a zoom
feature. A zoom feature can also be provided
electronically, by manipulation of the image captured by
image sensor 32.
FIGURE 7 illustrates a double camera embodiment of the
present invention. Illustrated in FIGURE 7 is a coaxial
cable 18 attached to an upper housing of camera assembly
24. Upper housing 40 of camera assembly 24 includes two
CA 02321546 2000-08-28
WO 99/44367 PCTNS99/04357
8
camera control boards 42 and 44, along with interface
control 46. The interface control 46 ties camera assembly
24 to control system 9 as illustrated in FIGURE 3, through
coaxial cable 18. Control boards 42 and 44 and interface
control 46 are well known, readily available, off-the-shelf
devices as are well known by those of skill in the art.
Lower housing 41 of camera assembly 29 includes a down view
camera 54 and a side view camera 52. Side view camera 52
is mounted approximately 90 degrees from down view camera
59. Down view camera 54 is operable to view down a long
axis of a bore hole or water well while side view camera
52, views along a plane approximately perpendicular to the
long axis of the bore hole. Illumination for the cameras
is provided by high intensity lights 50 with two located on
the side and three located on the lower face of the housing
and associated with down camera 54. The lower housing is
mounted in such a way that side view camera 52 can be
rotated while downward view camera 54 stays fixed. Side
view camera 52 is rotated by means of a stepper motor 48.
Camera assembly 24 is lowered~into a well or bore hole
by means of coaxial cable 18 stored on a motor driven spool
16 bolted into housing. As coaxial cable 18 is unwound or
wound, it threads a level wind mechanism 19 which maintains
an even distribution of the cable 18 over the spool 16.
Once camera assembly 24 is lowered into a passage such
as a well or bore hole, pipe, tank, pipeline, pit or any
other fluid containment system, the video is displayed on
the monitor 5 and viewed by the operator at the surface.
Typically a user would switch between down view camera 54
and side view camera 52 depending on what view was needed.
Side view camera 52 can also be rotated 360 degrees for
enhanced viewing. In one embodiment the display of monitor
5 can be split into two or more windows. Part of the
display could show the view of down view camera 54 while
another part could display the view of side camera 52. One
CA 02321546 2000-08-28
WO 99/44367 PCT/US99/04357
9
advantage of this arrangement is that when a split screen
is used, the down view camera 54 image is fixed while the
side view camera 52 can provide a moving image of the
condition of the sides of a bore hole or similar structure.
An operator can then see down hole problems, make note of
the depth or provide a voice-over narration on the tape
using a microphone input (not shown) which can be provided
as part of the video tape recorder.
FIGURES 8A, 8B, and 8C illustrate a single-camera
system with a single image sensor. Camera assembly 24
consists of an upper section 56a and a lower section 56b.
Upper section 56a comprises camera control board 34 along
with an electronic interface control 61 which ties the
camera system to the master control panel as illustrated in
FIGURE 3, through the coaxial cable 18. The housing 58, 60
of upper section 56a, in one embodiment is constructed of
stainless steel which is water sealed to at least a depth
of 2300 feet at an approximate pressure of 1000 pounds per
square inch.
Lower section 56b of camera assembly 24, is comprised
of two parts, an upper part 66 coupled to a lower part 68.
Upper part 66 and lower part 68 are coupled by a pair of
pivot arms 74 and 76, which are rigidly mounted to upper
part 66 and lower part 68 by pivot shafts. This connection
allows lower part 68 to be suspended and able to rotate 90
degrees from a vertical to a horizontal position.
Upper part 66 is coupled to upper section 56a by a
hollow shaft 64 which may be rotated by a stepper motor 62
located in upper section 56a. Coaxial cable 18 and other
cables are routed from upper section 56a to lower section
56b via hollow shaft 64.
FIGURES 8B and 8C illustrate lower section 56b of
camera 60. As illustrated in FIGURE 8B, lower section 56b
contains a high torque do motor 78 which is connected to a
chain and sprocket system 80 as illustrated in FIGURE 8C.
CA 02321546 2000-08-28
WO 99/44367 PCTNS99/04357
Chain and sprocket system 80 are mounted within one of the
pivot arms 79. Chain and sprocket system 80 are therefore
connecting upper part 66 with lower part 68. Second pivot
arm 76 provides a path for routing coaxial cable 56 and
5 other electronic cables from hollow shaft 64 through upper
part 66 of lower section 51b to lower part 68 of lower
section 51b in order to provide power to a video camera 70,
a plurality of lights 72, and pivot switches (not pictured)
contained in lower part 68.
10 Lower part 68 comprises the camera enclosure which
contains a single image sensor 70 with a wide-angle lens.
Image sensor 70 typically includes a CCD-type image sensor.
Lower part 68 also includes three high intensity lights 72,
which can be adjusted to provide for a variety of
brightness levels. When image sensor 70 is pointed down,
lights 72 may be set for a variety of voltages to display
a variety of brightness levels. Down position is achieved
when the image sensor is pointing down the bore hole or
passage along an axis parallel to the long axis of the bore
hole. This is a first position. The second position is
ninety degrees off-set from the first position and is the
side-view position. When image sensor 70 is rotated to a
side-view position, the voltage supplied to lights 72 are
automatically switched to a lower setting in order to
reduce the brightness caused by reflection off of the wall
of the passage, particularly when camera system 60 is used
in white PVC casing. When image sensor 70 is in side-view
mode, lower part 68 is operable to rotate a full 360
degrees around the first axis to view the side wall of the
bore hole or well casing. The rotation is controlled at
the control panel as illustrated in earlier figures and
allows for image sensor 70 to be started, stopped and
reversed to a complete 360 degrees while in a side-view
mode. Image sensor 70 can capture an image at any angle
between the down position and the side-view position.
CA 02321546 2000-08-28
WO 99/4436'7 PCT/US99/0435'I
11
FIGURE 9 illustrates a close-up view of lower section
56b of camera system 60. Illustrated in upper section 66
coupled to lower section 68 by pivot arms 74 and 76. Also,
illustrated is chain and sprocket system. 80 as housed
inside pivot arm 74. As mentioned before, chain and
sprocket system allows lower section 68 to be moved from a
horizontal to a vertical position to allow both down hole
view and side viewing.
In operation camera assembly 24 is lowered into a
passage such as a well, pipe, pipeline, bore hole, tank,
pit or any other fluid containment system. As previously
described in conjunction with FIGURE 5, as the cable 18 is
lowered, electronic devices 25 measures the linear feed of
cable deployed which is recorded in order to indicate depth
of camera assembly 24 on the video tape. This allows the
depth reading to be shown on a monitor for continuous
viewing. The operator of camera assembly 24 can control
the positioning of lower section 68 if the operator wishes
to only view straight down the bore hole or other opening,
lower section 68 can be set to stay in the down position.
However, when the operator wants to view a side view of the
bore hole or other opening, a signal can be sent from the
operator to lower section 56b and lower part 68 can be
rotated 90 degrees to a side view position via a pivoting
means 80. Pivoting means 80 may include a chain and
sprocket assembly, a belt driven assembly, a direct gear
assembly or similar means to pivot lower part 68. Then,
the entire lower section 56b may be rotated 360 degrees for
viewing all of the side of a bore hole or other opening by
use of stepper motor 62 and 69. The 360 degree rotation
can be started, stopped, or reversed in any order that the
operator needs. The advantage of this system is that only
one camera is used and there is no need to switch between
a down view camera and a side-view camera.
CA 02321546 2000-08-28
WO 99/44367 PCTNS99/04357
12
FIGURE 10 illustrates a single camera with a multiple
image sensor down-hole camera in accordance with the
teachings of the present invention. Camera assembly 24 has
at least one down image sensor 82 operable to capture a
view downward along a first axis and one side image sensor
84 operable to capture an image along a plane essentially
ninety degrees from down camera 82. Down image sensor 82
and side image sensor 84 are coupled to a single camera
board 34, forming a single camera with multiple image
sensors. Side image sensor 84 can be mounted in such a way
that it can rotate 360 degrees around camera assembly 24.
Alternatively, all or part of camera assembly 24 can be
made to rotate in such a way that side image sensors 84 can
capture an image in a complete 360 degree circle around the
inside of a bore hole or well.
Alternatively, a number of side image sensors 84 can
be placed around camera assembly 24 in such a way that the
entire side of a bore hole can be viewed by simply
switching side view image sensors 84 to view the
appropriate sections. Alternatively, camera board and
processor 34 can display all of the outputs from side view
image sensors 89 together on a display, thus giving an
instantaneous three hundred and sixty degree view without
rotating camera assembly 24.
While the embodiments discussed in conjunction with
FIGURES 1-10 discuss the use of the present invention in
bore holes and the like, the present invention can also be
used in pipelines and the like that have substantial
horizontal runs. In this case, down view would be along a
long axis of the pipeline.
Although the present invention has been described in
detail, it should be understood that various changes,
substitutions and alterations can be made thereto without
departing from the spirit and scope of the invention as
defined by the appended claims.
