Note: Descriptions are shown in the official language in which they were submitted.
326021-3
PIPELINE INSPECTION SYSTEMS AND METHODS
BACKGROUND
[0001] Inspection of a pipeline can sometimes be performed using a
system,
commonly referred to as a pipeline inspection gauge or "PIG," which travels
inside the
pipeline. As an example, a PIG can include one or more sensor modules having
sensors
arranged for measuring or detecting wall thickness or defects in the wall of
the pipeline.
[0002] In some instances, the sensors (e.g., ultrasonic sensors, magnetic
sensors, etc.)
can be mounted on sensor holders of the sensor module(s). The sensor holders
can be
configured to position the sensors adjacent to the pipe wall at a set
inclination angle
when, for example, the sensor module(s) carries out an inspection run through
a pipeline.
These sensor holders can include skids formed of flexible material (e.g., an
elastomer).
The skids can often be arranged left and right of the sensors, front and back
of the sensors,
or both. A skid can be configured to run immediately adjacent to or in contact
with an
inner surface of the pipe, with the sensors arranged at a standoff distance
from the outer
surface of the skid, in order to protect the sensors against wear or other
damage from
contact with the pipe and set a given standoff distance. Further, the
flexibility of the skid
can allow a sensor holder to travel through bends and other pipeline features.
SUMMARY
[0003] Pipeline inspection systems are provided. In some instances, the
pipeline
inspection modules including a sensor module do not provide clear or accurate
data. For
instance, when passing the sensor module(s) through the pipeline, frictional
drag between
the skids and the interior surface of the pipeline can cause the sensor
holders (and the
sensors) to pull away from the wall of the pipeline, moving the sensors out of
a desired
sensing position, thereby reducing the quality of acquired sensory data.
Moreover, over
time, wear and deterioration of the skids can be observed. Even minimal
abrasion of the
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skids can adversely affect the accuracy of the sensor measurements, and can
prevent the
sensor modules from successfully passing through portions the pipeline (e.g.,
sections of
the pipeline in which the inside diameter of the pipeline changes). For
example, an
uneven abrasion of the skids can reduce the standoff distance from the sensors
to the pipe
wall, and consequently, the desired set inclination angle of the sensors.
Alternatively, or
additionally, the flexibility of the skid material can result in uncontrolled
deformations of
the shape of the skid, which in turn can cause skid liftoff from the interior
surface of the
pipe wall and deviations in the set inclination angle of the sensors.
[0004] In one exemplary embodiment, a pipeline inspection system can
include at
least one sensor module having a module body extending from a first module end
to a
second module end, and a plurality of sensor holders mounted to the module
body. Each
sensor holder can include a holder body with a first body end, a second body
end, and a
plurality of sensors positioned therebetween, and a plurality of rotational
guides in which
each sensor holder can be at least partially pivotable about a longitudinal
axis of the
holder body extending between the first body end and the second body end. The
plurality
of sensors can be configured to sense a parameter of a wall of a pipeline
having a
longitudinal axis extending therethrough. The plurality of rotational guides
can be
coupled to the holder body and configured to be biased towards an interior
surface of the
pipeline wall so as to define a standoff distance between each sensor and the
interior
surface of the pipeline wall.
[0005] In another embodiment, the pipeline inspection system can include
a drawbar
coupled to an axle extending through the first and second rotational guides
and coupled to
the first body end to allow the holder body to at least partially pivot about
the
longitudinal axis of the holder body.
[0006] In some embodiments, the plurality of rotational guides can
include a first
rotational guide and a second rotational guide coupled to the first body end,
and a third
rotational guide and a fourth rotational guide coupled to the second body end.
In one
embodiment, the first and third rotational guides can be longitudinally
aligned relative to
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each other such that the third rotational guide follows substantially the same
path as the
first rotational guide when the at least one sensor module translates through
the pipeline.
In another embodiment, the second and fourth rotational guides can be
longitudinally
aligned relative to each other such that the fourth rotational guide follows
substantially
the same path as the second rotational guide when the at least one sensor
module
translates through the pipeline.
[0007] In another embodiment, the plurality of sensors can be positioned
in a
predetermined pattern such that when at least one of the plurality of
rotational guides
contacts a feature on the interior surface of a pipeline, a first sensor of
the plurality of
sensors tilts relative to the longitudinal axis of the pipeline from an
initial position to a
deviated position while at least one of the other plurality of sensors is in
the initial
position when sensing the parameter of the pipeline wall.
[0008] In another embodiment, each sensor holder can include at least one
suspension arm mounted between the module body and the sensor holder that is
configured to bias at least one of the plurality of rotational guides into
contact with the
pipeline wall.
[0009] In another embodiment, the at least one sensor holder of the
plurality of
sensor holders can include at least one protection member that can be
configured to
prevent damage to the plurality of sensors as the at least one sensor module
translates
though the pipeline.
[0010] In another embodiment, the at least one sensor module can have a
module
longitudinal axis extending between the first and second module ends, and the
at least one
sensor module can include a supporting member that is configured to
substantially align
and overlap the module longitudinal axis with the longitudinal axis of the
pipeline when
the at least one sensor module is translated through the pipeline.
[0011] In another embodiment, the at least one sensor module can have a
module
longitudinal axis extending between the first and second module ends, and the
plurality of
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sensor holders can be spaced circumferentially from one another about the
longitudinal
axis of the at least one sensor module.
[0012] In another embodiment, the at least one sensor module can include
first and
second sensor modules that can be axially offset from one another with respect
to the
longitudinal axis of the pipeline wall.
[0013] In another embodiment, the at least one sensor module can include
first and
second sensor modules, and the plurality of sensor holders of the first sensor
module can
be out of phase with the plurality of sensors holders of the second sensor
module such
that the system has about 360 degrees of inspection coverage of the pipeline
wall when
the first and second sensor modules translate through the pipeline.
[0014] In another embodiment, the at least one sensor module can include
first and
second sensor modules in which the plurality of sensors of the first sensor
module can be
angled in a first direction and the plurality of sensors of the second sensor
module can be
angled in a second direction opposite the first direction.
[0015] Methods for inspecting a pipeline is also provided. In one
exemplary
embodiment, the method can include advancing at least one sensor module in a
downstream direction through a pipeline having a longitudinal axis extending
therethrough. The at least one sensor module can have a plurality of sensor
holders in
which each sensor holder can include a holder body with a plurality of
sensors. Each
holder body can include a plurality of rotational guides that are biased
toward a wall of
the pipeline so as to define a standoff distance between each sensor and an
interior
surface of the pipeline wall. Each holder body can be pivoting about a
longitudinal axis
thereof such that at least one of the plurality of rotational guides remains
in contact with
the interior surface of the pipeline wall as the at least one sensor module
translates
through the pipeline. The method can also include sensing, by the plurality of
sensors, a
parameter of the pipeline wall as the at least one sensor module translates
through the
pipeline.
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[0016] In another embodiment, when at least one of the plurality of
rotational guides
contacts a feature on the interior surface of the pipeline, a first sensor of
the plurality of
sensors can tilt relative to the longitudinal axis of the pipeline from an
initial position to a
deviated position while at least one of the other plurality of sensors is in
the initial
position when sensing the parameter of the pipeline wall.
[0017] In another embodiment, the parameter can be at least one of a
thickness of a
portion of the pipeline, one or more cracks in the pipeline, and a size of the
one or more
cracks in the pipeline.
[0018] In another embodiment, the method can also include substantially
maintaining the standoff distance between each sensor and the interior surface
of the
pipeline wall as the at least one sensor module translates through the
pipeline.
[0019] In another embodiment, the method can include maintaining a
predetermined
inclination angle between each sensor and the interior surface of the pipeline
wall as the
at least one sensor module translates through the pipeline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] These and other features will be more readily understood from the
following
detailed description taken in conjunction with the accompanying drawings, in
which:
[0021] FIG. 1 is a side perspective view of a portion of a pipeline
inspection system
including four in-line sensor modules within a portion of a pipeline;
[0022] FIG. 2 is a magnified side perspective view of one of the sensor
modules
having five sensor holders and disposed within the portion of the pipeline
shown in FIG.
1;
[0023] FIG. 3 is a front perspective view of the sensor module shown in
FIG. 2
without being disposed in the portion of the pipeline;
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[0024] FIG. 4 is a back perspective view of the sensor module shown in
FIG. 3;
[0025] FIG. 5 is a top perspective top view of one of the sensor holders
coupled to
the sensor module shown in FIGS. 2-4;
[0026] FIG. 6 is a side perspective side view of the one sensor holder
coupled to the
sensor module shown in FIG. 5;
[0027] FIG. 7A is a schematic illustrating a cross-sectional view of the
pipeline
shown in FIG. 1 without the sensor modules, and a first portion of a
predetermined
inclination angle with respect to a crack extending in a first direction;
[0028] FIG. 7B is a schematic illustrating the pipeline in FIG. 1 without
the sensor
modules, and a second portion of a predetermined inclination angle with
respect to a
crack extending in a second direction;
[0029] FIG. 8 is a schematic illustrating a cross-sectional view of the
sensor module
shown in FIGS. 2-4 at a first position within a pipeline;
[0030] FIG. 9 is another cross-sectional view of the sensor module shown
in FIG. 8;
[0031] FIG. 10 is a schematic illustrating the sensor module in a
downstream
position relative to the first position shown in FIG. 8 in which front wheels
of the sensor
holder contact a girth weld; and
[0032] FIG. 11 is a schematic illustrating the sensor module in a further
downstream
position relative to the downstream position shown in FIG. 10 in which the
front wheels
of the sensor holder are no longer in contact with the girth weld.
[0033] It is noted that the drawings are not necessarily to scale. The
drawings are
intended to depict only typical aspects of the subject matter disclosed
herein, and
therefore should not be considered as limiting the scope of the disclosure.
Those skilled
in the art will understand that the systems, devices, and methods specifically
described
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herein and illustrated in the accompanying drawings are non-limiting exemplary
embodiments and that the scope of the present invention is defined solely by
the claims.
DETAILED DESCRIPTION
[0034] Inspection of a pipeline for transporting fluids, such as natural
gas, oil, water,
etc., can be periodically performed to detect cracks, corrosion, and/or other
defects in a
wall of the pipeline. An inspection system, known as a PIG, may be passed
through a
section of pipeline. These systems can include sensor modules, which can
include at
least one sensor holder that can be equipped with at least one sensor disposed
within at
least one skid. The skids can come in contact with an interior wall of the
pipeline as the
sensor module moves through the pipeline, and therefore set a standoff
distance between
the sensors and the interior wall of the pipeline. However, as the sensor
module passes
through the pipeline, the skids can deteriorate (e.g., can wear down) and this
deterioration
can cause the sensor holders to separate from the pipeline wall, change the
set inclination
angle of the sensors, and/or change the standoff distance. Any of these
changes can
introduce error into measurements acquired by the sensors, which can cause
data to be
inaccurate and for defect features to be incorrectly identified and/or
measured.
[0035] Sensor measurements can be improved if the set standoff distances
and set
inclination angles of the sensors can be substantially maintained while the
sensor module
translates through the pipeline. Additionally, reducing the number of sensors
that are
affected (e.g., tilted) when the sensor module comes into contact with a
feature of the
pipeline wall (e.g., a protrusion from or a recess in the pipeline wall) can
also improve
sensor measurements. Accordingly, sensor modules are provided that can include
sensor
holders each having features that facilitate maintaining set standoff
distances and set
inclination angles of the sensors with respect to the interior wall of the
pipeline during
inspection.
[0036] In certain embodiments, a sensor module can include a plurality of
sensor
holders. Each sensor holder can include a holder body with sensors in which
the holder
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body pivots in its long direction (e.g., about a longitudinal axis of the
holder body). The
sensor holders can also include rotational guides coupled to the holder body
and biased
toward the interior pipeline wall to define the distance between the sensors
and the
pipeline wall. The ability of the holder body to pivot can increase stability
of its
respective sensor holder, by keeping the rotational guides in contact with the
pipeline
wall. So configured, the predetermined inclination angle of the sensors can be
substantially maintained as the sensor module translates through the pipeline.
Increased
stability provided to the sensor holders can facilitate accurate sensor
positioning, and
consequently, improve the accuracy of sensor measurements.
[0037] FIG. 1 illustrates a portion of a pipeline inspection system. The
system 100
can include at least one sensor module, such as a series of four sensor
modules 102a,
102b, 102c, 102d that are coupled for movement along a pipeline 103 (e.g., an
interior
surface 103a of a pipeline wall 103b).
[0038] As shown, sensor module 102a is the leading or downstream sensor
module,
with sensor modules 102b, 102c, 102d subsequently arranged in sequence and
sensor
module 102d as the trailing or upstream sensor module. As such, the sensor
module 102a
is downstream of sensor modules 102b, 102c, 102d, and sensor module 102d is
upstream
of sensor modules 102a, 102b, 102c. As discussed in more detail below, each
sensor
module shown in FIG. 1 includes a plurality of sensor holders 104 each having
a holder
body 112 with a plurality of sensors 114, a plurality of rotational guides
118, and a
drawbar 119.
[0039] As shown in FIG. 1, respective sensors of sensor modules 102a and
102b,
collectively referred to herein as a downstream sensor module group 105a, are
oriented at
a first oblique angle relative to a surface normal aligned with a
predetermined axis (e.g., a
surface normal to the pipeline wall 103b) of the pipeline wall 103b. Further,
respective
sensors of sensor modules 102c and 102d, collectively referred to herein as an
upstream
sensor module group 105b, are oriented at a second oblique angle relative to
the surface
normal aligned with the predetermined axis (e.g., the surface normal to the
pipeline wall
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103b) in which the second oblique angle is opposite the first oblique angle.
It should be
noted that a downstream direction can refer to a direction of translation of
system 100
(e.g., through the pipeline 103). Thus, in FIG.1, the sensor modules 102a,
102b, 102c,
102d, are shown to be translating through the pipeline 103 in a downstream
direction. As
such, in FIG. 1, the sensor module group 105a is downstream relative to the
sensor
module group 105b.
[0040] Further, as shown, for example, in FIG. 1, for each sensor module
the sensor
holders 104 are spaced radially around the sensor module and therefore each
sensor
module has a zone of non-coverage with respect to the internal surface 103a of
the
pipeline wall 103b along which the sensor modules travels. As such, in FIG. 1,
for each
sensor module group to provide about 360 degrees of inspection coverage of the
pipeline
wall 103b, the sensor holders 104 of each module within each sensor module
group are
positioned out of phase. That is, with respect to the downstream sensor module
group
105a, the sensor holders 104 of the first module 102a are out of phase with
the sensor
holders 104 of the second module 102b. Likewise, with respect to the upstream
sensor
module group 105b, the sensor holders 104 of the third module 102c are out of
phase
with the sensor holders 104 of the fourth module 102d. It is also contemplated
herein that
the pipeline inspection system 100 can also include one or more additional
modules, such
as a tow (or battery module) and a circuitry module that are connected
together and the
circuitry module being coupled to a sensor module, such as sensor module 102a.
[0041] FIGS. 2-4 show the first sensor module 102a positioned within the
pipeline
103 and decoupled from the pipeline inspection system 100. The sensor module
102a has
a module body 106 having a first module end 106a and a second module end 106b
with a
module longitudinal axis (LM) extended therebetween. While the module body 106
can
have a variety of configurations, in some embodiments, as shown in FIGS. 2-4,
the
module body 106 includes an elongated tubular member 108 that extends between
the
first module end 106a and the second module end 106b with cables 110 disposed
therethrough.
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[0042] As shown, the sensor module 102a includes a sealing/supporting
member 111
that can create a seal between the sensor module 102a and the interior surface
103a of the
pipeline wall 103b. The sealing/supporting member 111 can also be configured
to
provide support for, and center, the sensor module 102a within the pipeline
103 as the
sensor module 102a translates therethrough. That is, the supporting member 111
can
align and overlap the module longitudinal axis (Lm) with the pipeline
longitudinal axis
(Lp). This overlapping alignment can help to prevent the sensor module 102a
from
sagging, which can cause inaccurate sensor measurements of pipeline
properties. While
the supporting member 111 can have a variety of configurations, as shown in
FIGS. 2-4,
the supporting member 111 is a disc-shaped, annular structure that is coupled
to the
sensor module 102a at the first module end 106a.
[0043] The sensor module 102a can also include a plurality of sensor
holders 104.
The sensor module 102a can include any suitable number of sensor holders, and
therefore
is not limited to the number of sensors holders illustrated herein. It can be
appreciated
that the number of sensor holders can be based at least in part on a desired
size and shape
of the sensor module. For example, in some embodiments, the plurality of
sensors
holders 104 can include about 2 to 50 sensor holders. In other embodiments,
the plurality
of sensors holders 104 can include about 2 to 15 sensor holders or about 8 to
50 sensor
holders.
[0044] In some embodiments, as shown in FIGS. 2-4, the plurality of sensor
holders
104 includes five sensor holders that are radially arranged about the module
longitudinal
axis (Lm) of the sensor module 102a. The five holders can be spaced a distance
apart
from each other, such as distance (D) shown in FIGS. 2-4. In some
configurations, as
shown in FIGS. 2-4, each sensor holder 104 is equally spaced from one another.
It is
therefore contemplated herein that the distance between sensor holders can
vary. Further,
it can be appreciated that the distance between adjacent sensor holders can be
based at
least in part on the desired size and shape of the sensor module. In some
embodiments,
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adjacent sensor holders are spaced apart from one another at a distance from
the range of
about 150 mm to 1 mm.
[0045] While five sensor holders are illustrated in FIGS. 2-4, for clarity
of the
following discussion, reference is made to aspects of a single sensor holder
104a. It can
be understood that the following discussion is applicable to the other sensor
holders of
the sensor module 102a. The sensor holder 104a includes a holder body 112 that
has a
first body end 112a, a second body end 112b, and a longitudinal axis (LB)
extending
therebetween. While the holder body 112 can have a variety of shapes, in some
embodiments, as shown in FIGS. 2-4, the holder body 112 has a generally
arcuate
configuration which extends in a circumferential direction with respect to the
longitudinal
axis (LB) of the holder body 112. The sensor holder 104a is shown in more
detail in
FIGS. 5-6, with some components of the sensor module 102a removed for
simplicity.
[0046] The holder body 112 can be formed of any suitable material that is
substantially rigid with respect to the pipeline wall 103b. For example, in
some
embodiments, the holder body 112 can be formed of a material having an elastic
modulus
from the range of about 60 GPa to 500 GPa or from the range of about 3 GPa to
220 GPa.
In one embodiment, the holder body 112 is formed of aluminum. In other
embodiments,
the holder body 112 can be formed of steel, titanium, magnesium, ceramics,
plastic or
reinforced plastic. The rigidity of the holder body 112 can help prevent the
inclination
angles of the sensor facing surfaces 113 of the sensors 114 from changing with
respect to
the predetermined inclination angle as the sensor module 102a translates
through the
pipeline 103. As a result, the accuracy of the sensor measurements can be
improved as
compared to the sensor measurements of conventional sensor modules (e.g.,
sensor
modules that include one or more skids). As shown in FIGS. 1-4, the sensor
facing
surface 113 of each sensor 114 is oriented at an angle relative to the normal
vector to the
internal surface 103a of the pipeline wall 103b. As discussed in more detail
below, this
angle can be a predetermined inclination angle or a companion angle depending
on crack
orientation.
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[0047] As shown, the holder body 112 includes a plurality of sensors 114.
It will be
appreciated that the number of sensors is based at least in part on the size
and shape of
the holder body. Non-limiting examples of suitable sensors can include various
types of
ultrasonic sensors, electromagnetic acoustic transducers (EMATs), magnetic
flux sensors,
etc. In some embodiments, the plurality of sensors 114 can include a group of
ultrasonic
sensors 114a. In such embodiments, the holder body can include from about 5 to
100
ultrasonic sensors. While sensor holders with ultrasonic sensors are shown and
described
below, it can be appreciated that the sensor holders disclosed herein can be
used with
other types of sensors without limit.
[0048] While the plurality of sensors 114 can have a variety of
configurations, in
some embodiments, as shown in FIGS. 2-6, each sensor 114 is generally
cylindrically
shaped. The plurality of sensors 114 can be used to detect the presence of
cracks,
corrosion, or other features, measure wall-thickness, or otherwise determine
the condition
of the pipeline. For example, the plurality of sensors 114 can include
ultrasonic sensors
114a that can emit an ultrasonic signal into the pipeline wall 103b and
receive reflected
ultrasonic signals from the pipeline wall 103b. Echoes in the reflected
ultrasonic signals
may be indicative of a crack, deformity, or other features in the pipeline
wall 103b.
Additionally, the plurality of sensors 114 can include a sensor 114b that can
be
configured to the measure wall thickness of the pipeline wall 103b.
[0049] The predetermined inclination angle can define the incident angle
at which
the emitted ultrasonic signal interacts with the interior surface 103a of the
pipeline wall
103b. As such, the accuracy of the sensory measurements can be improved when
the
predetermined inclination angle can be substantially maintained as the sensor
module
102a translates through the pipeline 103. The predetermined inclination angle
can be any
angle that defines a desirable inclination angle such that each ultrasonic
sensor 114a can
accurately detect and measure features of the pipeline wall 103b (e.g., one or
more
cracks, wall thickness, etc). In some embodiments, the predetermined
inclination angle
can range from about 0.1 degrees to 20 degrees or from about 10 to 35 degrees
relative to
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the normal vector to the internal surface 103a of the pipeline wall 103b. It
can also be
understood that in some embodiments, the predetermined inclination angle can
be zero.
[0050] FIGS. 7A-7B illustrate two cross-sectional views of the pipeline
without
having the sensor module 102a disposed therein. FIG. 7A illustrates a first
portion of a
predetermined inclination angle when a crack is oriented in a first direction,
and FIG. 7B
illustrates a second portion of a predetermined inclination angle when a crack
is oriented
in a second direction that is different than the first direction. As such, the
predetermined
inclination angle is based at least in part on the crack orientation. In one
embodiment, a
first portion of a predetermined inclination angle (Ii A if the sensors are
tilted clockwise
and I2A if the sensors are tilted counterclockwise in the y-z plane) can be
defined as
shown in FIG. 7A. In another embodiment, a second portion of a predetermined
inclination angle (Im if the sensors are tilted downstream and I2B if the
sensors are tilted
upstream in the x-z plane) can be defined as shown in FIG. 7B. It can be
appreciated that
that a first portion of a predetermined inclination angle and a second portion
of a
predetermined inclination angle can each have additional components in the
respective
other planes. That is, a first portion of the predetermined inclination angle
in the y-z
plane can have an additional component in the x-z plane, and a second portion
of the
predetermined inclination angle in the x-z plane can have an additional
component in the
y-z plane. These components in the respective other planes can also have a
value of 0.
Thus, the predetermined inclination angle is defined with respect to a normal
vector
coincident to the z-axis, as shown in FIGS. 7A-7B.
[0051] The plurality of sensors 114 can be positioned in a predetermined
pattern.
For example, as shown in FIGS. 2-6, the plurality of ultrasonic sensors 114a
are divided
into four arrays 116A, 116B, 116C, 116D in which each array extends along a
corresponding predefined longitudinal axis, such as predefined longitudinal
axis A, B, C,
and D, respectively. The predetermined pattern is shown in more detail in
FIGS. 5-6.
Within each array, the sensors 114 are axially offset from each other with
respect to their
corresponding predefined longitudinal axis. The predetermined pattern can help
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minimize the number of ultrasonic sensors 114a that tilt, and thus deviate
from the
predetermined inclination angle, for example, in instances where rotational
guides 118 at
the first body end 112a contact either a protrusion extending from the surface
of the
pipeline or a recess extending beneath the surface of the pipeline wall 103b,
e.g., a girth
weld, as shown in FIGS. 8-11. Further, the predetermined pattern shown in
FIGS. 2-6
can employ a greater number of sensors as compared to conventional sensor
modules. As
such, the sensor module 102a can have higher circumferential measurement
resolution
and thus improved pipeline defect detection capability.
[0052] A plurality of rotational guides 118 can be attached to the sensor
holder 104a
and can be designed to contact the interior surface 103a of the pipeline wall
103b. The
rotational guides 118 can be formed of any suitable material that is
substantially resistant
to abrasion as the rotational guides 118 travel along the interior surface
103a of the
pipeline wall 103b. For example, in some embodiments, the rotational guides
118 are
formed of hardened steel. Other non-limiting examples of suitable material for
the
rotational guides 118 include ceramic, titanium, aluminum, brass, plastic, and
reinforced
plastic. In some embodiments, the rotational guides 118 can be narrow in width
to
minimize contact with the interior surface 103a of the pipeline wall 103b. For
example,
the rotational guides 118 can have a width of about 2 mm to 15 mm. Further,
employing
narrow rotational guides 118 can reduce the orientation positions in which the
rotational
guides 118 travel along a longitudinal seam of the pipeline 103, as discussed
in more
detail below.
[0053] While the plurality of rotational guides 118 may be any rotational
structure
such as rollers, balls, or wheels, the following discussion will refer to the
rotational
guides 118 as wheels for simplicity. It can be appreciated that the rotational
guides 118
can be replaced with posts or other components that are configured to slide
against the
interior surface of the pipeline wall.
[0054] As shown in FIGS. 2-6, four wheels are coupled to the holder body
112,
where two wheels are positioned in front of the plurality of sensors 114
(e.g., at the first
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body end 112a), and two wheels are positioned in back of the plurality of
sensors 114
(e.g., at the second body end 112b). As such, the four wheels are outside of
the sensor
area, and therefore define the standoff distance (Ds) between the plurality of
sensors 114
and the interior surface 103a of the pipeline wall 103b. Additionally, the
rigidity of the
four wheels can also enhance the wheels ability to function as standoff
elements. It can
be appreciated that "front" and "back" are used herein with reference to the
longitudinal
travel direction of the sensor holder with respect to the pipeline.
[0055] As shown, the first and second wheels 118a, 118b, collectively
referred to
herein as the front wheels, are coupled to the first body end 112a of the
holder body 112,
and third and fourth wheels 118c, 118d, collectively referred to herein as the
back wheels,
are coupled to the second body end 112b of the holder body 112. As discussed
above,
this wheel positioning allows the four wheels to define the standoff distance
of the
plurality of sensors 114 relative to the pipeline wall 103b. This wheel
positioning relative
to the plurality of sensors 114, as shown in FIGS. 2-6 can also help reduce
the number of
sensors 114 that tilt, and therefore deviate from the predetermined
inclination angle, for
example, in instances when the front wheels 118a, 118b contact a girth weld
(FIGS. 8-
11), as discussed in more detail below. Further, when considering a rotation
of the sensor
module 102a, and thus the sensor holder 104a, in the pipeline while the sensor
module
102a translates therethrough, this wheel positioning can allow detection of
cracks at a
longitudinal seam weld before the sensors 114 are tilted out of position from
a wheel
finally running on the longitudinal seam weld.
[0056] As further shown in FIGS. 2-6, the front wheels 118a, 118b and the
back
wheels 118c, 118d are longitudinally aligned relative to each other so that
the back
wheels 118c, 118d follow substantially the same path as the front wheels 118a,
118b
when the sensor module 102a translates though the pipeline 103. This wheel
alignment
can also improve sensor detection of cracks at the longitudinal seam weld by
minimizing
the amount of times a wheel comes into contact with and runs on the
longitudinal seam
weld. As such, this wheel alignment and, as discussed above, using narrower
wheels can
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minimize the tilting of sensors. It should be noted that when the system 100
is traveling
through the pipeline 103 and a wheel of sensor module 102a is running on a
longitudinal
seam weld, the area next to the longitudinal seam weld in the pipeline wall
103 can be
inspected by sensors of a sensor holder of the sensor module 102c or 102d.
[0057] The four wheels can be biased into contact with the interior
surface 103a of
the pipeline wall. For example, the four wheels can be biased in a radial or
outward
direction relative to the module longitudinal axis (Lm). As shown in FIGS. 2-
6,
suspension mechanisms are used to bias the four wheels. It can be appreciated
that the
mechanism(s) used to bias the four wheels are not limited to the illustrated
mechanisms,
and therefore other suspension mechanisms can be employed with the sensor
holder 104a
without limit.
[0058] As shown in FIGS. 2-6, the first and second wheels 118a, 118b are
coupled to
a first suspension mechanism that includes a spring-loaded suspension arm 120
that is
coupled between the module body 106 of the sensor module 102a and the first
body end
112a of the holder body 112. The spring-loaded suspension arm 120 includes two
opposing spacer arms 122a, 122b with a spring 124 disposed therebetween. Non-
limiting
examples of suitable materials forming the spring 124 can include steels. A
first end
124a of the spring 124 is coupled to the module body 106 and the second end
124b of the
spring 124 is coupled to the two opposing spacer arms 122a, 122b. The two
opposing
spacer arms 122a, 122b are coupled between the holder body 112 and the module
body
106. As such, the spring-loaded suspension arm 120 is configured to pivot
relative to the
module longitudinal axis (Lm). That is, in use, the spring-loaded suspension
arm 120 can
allow the sensor holder 104a to adjust to changes in the inner diameter of the
pipeline.
For example, the spring-loaded suspension arm 120 can move the sensor holder
104a
radially inward or outward, toward or away from the module longitudinal axis
(LM),
while still biasing the first and second wheels 118a, 118b in contact with the
interior
surface 103a of the pipeline wall 103b.
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[0059] As further shown in FIGS. 2-6, the third and fourth wheels 118c,
118d are
coupled to a second suspension mechanism and a third suspension mechanism,
respectively. More specifically, as illustrated, the third wheel 118c is
coupled to a first
interconnected spring 126, such as torsion springs and the like, that is
coupled between
the module body 106 and the second body end 112b of the holder body 112, and
the
fourth wheel 118d is coupled to a second interconnected spring 128, such as
torsion
springs and the like, that is coupled between the module body 106 and the
second body
end 112b of the holder body 112. As such, the two interconnected springs 126,
128 can
allow the sensor holder 104a to adjust to changes in the inner diameter of the
pipeline 103
while still biasing the third and fourth wheels 118c, 118d in contact with the
interior
surface 103a of the pipeline wall 103b.
[0060] As discussed above, the pattern of sensors can reduce the number of
sensors
affected as the sensor module travels along a girth weld. This can be achieved
by spacing
sensors within an array apart from each other at a distance ("bump length")
that is greater
than the width of the girth weld. The bump length is longer than the distance
of the
wheel rolling across the girth weld width. This is because the bump length is
also
dependent on the travelling speed of the sensor module. Thus, sensors within
an array
can be positioned at least one bump length apart from each other to increase
the number
of sensors that can detect the same crack without being displaced due to
tilting caused by
the wheels of the sensor holder contacting a girth weld.
[0061] For example, FIGS. 8-11 illustrate sensor module 102a translating
through a
section of a pipeline 203 in a downstream direction and the effect wheel
positioning and
the pattern of sensors has on sensor tilting, and thus sensor measurements, as
the sensor
module 102a passes over a girth weld 230. As shown in FIGS. 8-9, and by way of
example, the sensor module 102a translates through the section of the pipeline
203 in
which the first sensor 116A1 in the first array 116A emits an ultrasonic
signal toward the
interior surface 203a of the pipeline wall 203b at a suitable first portion of
a
predetermined inclination angle 4, e.g., an angle with respect to the normal
to the interior
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surface 203a of the pipeline wall 203b in the y-z plane shown in FIG. 9, and a
suitable
companion angle 41 e.g., an angle with respect to the normal to the interior
surface 203a
of the pipeline wall 203b in the x-z plane shown in FIG. 8, and therefore
accurately
detects a crack 232 in the pipeline wall 203b. The sensor module 102a
continues to
translate through the pipeline 203, as shown in FIG. 10, and the first and
second wheels
118a, 118b come into contact with and travel along a first portion 230a of the
girth weld
230 until the wheels 118a, 118b reach the highest point 230b of the girth weld
230. This
causes the second sensor 116A2 in the first array 116A to tilt out of position
causing the
second sensor 116A2 to deviate from the suitable companion angle 41. As a
result, this
tilt causes the second sensor 116A2 to emit an ultrasonic signal that contacts
the interior
surface 203a of the pipeline wall 203b at a deviated predetermined inclination
angle (not
shown in FIG. 10) due to the unsuitable companion angle 42, and thus
erroneously
detects the crack 232 in the pipeline wall 203b. However, as shown in FIG. 11,
the
subsequent sensors in the first array 116A are not affected by the girth weld
230 or the
tilting of the second sensor 116A2, and thus, as the sensor module 102a
continues to
translate through the pipeline 203, subsequent sensors, such as the third
sensor 116A3,
remain in position. That is, the third sensor 116A3 emits an ultrasonic signal
toward the
interior surface 203a of the pipeline wall 203b at a first portion of a
predetermined
inclination angle 4 and suitable companion angle 41, and therefore accurately
detects the
crack 232 in the pipeline wall 203b.
[0062] As discussed above, and as shown in FIGS. 2-6, the sensor module
102a also
includes a drawbar 119 that is coupled to the axle extending through the first
and second
wheels 118a, 118b and coupled to the first body end 112a of the holder body
112. While
the drawbar 119 can have any suitable configuration, in some embodiments, as
shown in
FIGS. 2-6, the drawbar 119 can be generally u-shaped. For example, the drawbar
119
can include a base 119a and two opposing members 119b, 119c extending
therefrom and
in an outward direction. As shown, the base 119a is directly coupled to the
first body end
112a. The two opposing members 119b, 119c can be directly coupled to the axle
that
extends through the first and second wheels 118a, 118b. The drawbar 119 can be
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configured to allow the holder body 112 to at least partially pivot about the
longitudinal
axis of the holder body (LB). The pivoting of the holder body 112 can cause
the four
wheels 118a, 118b, 118c, 118d to function as three wheels. As such, this can
result in a
substantially stable position for the sensor holder 104a relative to the
pipeline wall 103b
as the sensor module 102a translates through the pipeline 103.
[0063] By way of example, in instances where the sensor module 102a
encounters a
change in pipeline geometry (e.g., bends in a pipeline or non-circular
portions of a
pipeline, such as an oval), the drawbar 119 can allow the holder body 112 to
pivot such
that all four wheels 118a, 118b, 118c, 118d can remain in contact with the
pipeline wall.
For example, as the sensor module 102a travels through a non-circular portion
of a
pipeline, the interior surface of the pipeline wall can be uneven. Thus, to
maintain
stability of the holder body 112 on this uneven surface, the drawbar 119 can
allow the
holder body 112 to pivot such that the holder body 112 does not rock from side
to side.
That is, the pivoting of the holder body 112 prevents the back wheels 118c,
118d from
lifting off the uneven surface and shifting the holder body 112 into an
unstable state. As
such, having all four wheels 118a, 118b, 188c, 118d in contact with the
interior surface of
the pipeline wall independent of pipeline geometry, undesirable tilting of the
sensors can
be minimized. Further, the increase in stiffness of the sensor holder, for
example, due to
the holder body material and the number of sensors employed, can be at least
partially
offset by the drawbar 119, and thus by the pivoting ability of the holder body
112.
[0064] Additionally or alternatively, the use of the drawbar 119 can
compensate for
misalignment of the module longitudinal axis and the pipeline longitudinal
axis due to
sagging of the sensor module as a result of gravity while the sensor module
102a
translates through the pipeline 103. Misalignment occurs when the module
longitudinal
axis does not overlap with the pipeline longitudinal axis. That is, when
misalignment
occurs, the module longitudinal axis may still run parallel to, but not
overlap with, the
pipeline longitudinal axis. However, the ability for the holder body 112 to
pivot about its
longitudinal axis LB, due to the use of the drawbar 119, provides an
additional biasing
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force to the back wheels 118c, 118d so that the back wheels 118c, 118d can
remain in
contact with the interior surface 103a of pipeline wall 103b.
[0065] As further shown in FIGS. 2-6, the sensor holder 104a can include
at least
one protection member that is configured to prevent damage to the plurality of
sensors
114 as the sensor module 102a translates through the pipeline 103. For
example, the at
least one protection member can address at least one of offtake rims, offtake
bars, clapper
valves, and gate valve voids. As shown, the at least one protection member
includes a
deflector roll 134. The deflector roll 134 is tubular shaped and positioned
between the
first and second wheels 118a, 118b. The same axle that extends through the
first and
second wheels 118a, 118b also extends though the deflector roll 134. Thus, the
deflector
roll 134 is configured to rotate about the axle if the deflector roll 134
comes into contact
with an obstacle in the pipeline 103 that can potentially damage the plurality
of sensors
114. Further, as shown in FIGS, 2-6, the at least one protection member also
includes a
deflector block 136 that is coupled to the second body end 112a of the holder
body 112.
As shown, the deflector block 136 is generally rectangular in shape that
extends between
the third and fourth wheels 118c, 118d.
[0066] Alternatively or additionally, the at least one protection member
can include
protector pins 138, guard plates 140a, 140b, and/or protector fins 144. As
shown, for
example, the protector pins 138 are generally cylindrically shaped and extend
outward
from the sensor holder body 112. The guard plates 140a, 140b are laterally
displaced
relative to the longitudinal axis of the holder body (LB) and each run along a
portion of a
surface 142 of the sensor holder body 112. The protector fins 144 each extend
outwardly
from the surface 142 of the sensor holder body 112 at an angle relative to the
longitudinal
axis of the holder body (LB). It can be appreciated that the protection
members are not
limited to the structural configurations as illustrated.
[0067] The sensor modules can be used to inspect a pipeline using any
suitable
method. For example in some embodiments, at least one sensor module can be
advanced
in a downstream direction through a pipeline. The sensor module can have a
plurality of
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sensor holders. Each sensor holder can include a holder body with a plurality
of sensors,
a plurality of rotational guides that can be biased toward the pipeline wall
so as to define
a standoff distance between each sensor and an interior surface of the
pipeline wall. Each
holder body can pivot about a longitudinal axis thereof such that at least one
of the
plurality of rotational guides remains in contact with the interior surface of
the pipeline
wall as the at least one sensor module translates through the pipeline. The
method can
also include sensing, by the plurality of sensors, a parameter of the pipeline
wall as the at
least one sensor module translates through the pipeline. In some embodiments,
the
parameter can be at least one of a thickness of a portion of the pipeline, one
or more
cracks in the pipeline, and a size of the one or more cracks in the pipeline.
In some
embodiments, the method can also include substantially maintaining the
standoff distance
between each sensor and the interior surface of the pipeline wall as the at
least one sensor
module translates through the pipeline. In some embodiments, the method can
also
include substantially maintaining a predetermined inclination angle between
each sensor
and the interior surface of the pipeline wall as the at least one sensor
module translates
through the pipeline.
[0068] In some embodiments, when at least one of the plurality of
rotational guides
contacts a feature on the interior surface of the pipeline, a first sensor of
the plurality of
sensors tilts relative to the longitudinal axis of the pipeline from an
initial position to a
deviated position while at least one of the other plurality of sensors is in
the initial position
when sensing the parameter of the pipeline wall.
[0069] Exemplary technical effects of the methods, systems, and devices
described
herein include, by way of non-limiting example, the ability to increase
circumferential
measurement resolution, the prevention of sensor tilting during crack
detection through
wheel positioning and alignment, maintaining a desired standoff distance
between the
sensors and the pipeline or maintaining set inclination angles of the sensors
through
employing guides, such as wheels, that are substantially resistant to abrasion
from traveling
along the pipeline wall, increased position accuracy of the sensors while
sensing close to
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and at girth welds, minimal sensor tilting when traveling along a longitudinal
seam weld
and prevent tilted sensors from running next to or at longitudinal seams, and
increase the
long term capability of the sensor modules to adapt to different inner
diameters of pipeline
though steel spring loaded suspension.
[0070] Approximating language, as used herein throughout the
specification and
claims, may be applied to modify any quantitative representation that could
permissibly
vary without resulting in a change in the basic function to which it is
related.
Accordingly, a value modified by a term or terms, such as "about,"
"approximately," and
"substantially," are not to be limited to the precise value specified. In at
least some
instances, the approximating language may correspond to the precision of an
instrument
for measuring the value. Here and throughout the specification and claims,
range
limitations may be combined and/or interchanged, such ranges are identified
and include
all the sub-ranges contained therein unless context or language indicates
otherwise.
[0071] Certain exemplary embodiments are described to provide an overview
of the
principles of the structure, function, manufacture, and use of the systems,
devices, and
methods disclosed herein. One or more examples of these embodiments are
illustrated in
the accompanying drawings. The features illustrated or described in connection
with one
exemplary embodiment can be combined with the features of other embodiments.
Such
modifications and variations are intended to be included within the scope of
the present
invention. Further, in the present disclosure, like-named components of the
embodiments
generally have similar features, and thus within a particular embodiment each
feature of
each like-named component is not necessarily fully elaborated upon.
[0072] One skilled in the art will appreciate further features and
advantages of the
invention based on the above-described embodiments. Accordingly, the present
application is not to be limited by what has been particularly shown and
described, except
as indicated by the appended claims. All publications and references cited
herein are
expressly incorporated by reference in their entirety.
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