Note: Descriptions are shown in the official language in which they were submitted.
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HAZARD AVOIDANCE DURING WELL RE-ENTRY
BACKGROUND
[0001] Once a wellbore has been drilled, it may be required to re-enter
the wellbore to conduct various operations, such as logging, completing,
intervention, etc. In many cases, this re-entry occurs long after the wellbore
has been drilled and completed. During that time, wellbore conditions may have
changed. For instance, the inner diameter of the wellbore may no longer be the
same as it was when it was originally drilled and/or completed. In other
cases,
there may be a buildup of material deposits (paraffin, scales, etc.) on the
walls
of the wellbore or casing that lines the wellbore. In yet other cases, the
casing
may have been damaged, or the wellbore may contain various trapped objects
(tools) that have inadvertently fallen into the well.
[0002] Due to these various obstructions in the wellbore, downhole
conveyances, such as a string of jointed pipe or coiled tubing, may become
stuck
or damaged when re-entering and traversing the wellbore. This often creates a
large amount of non-productive time trying to get the conveyance unstuck, and
can cause damage to the conveyances and to any tools attached to the
conveyances, loss of the tools, or even loss of use of the well. Even when the
conveyances are not stuck, the speed at which the conveyance is lowered into
or
pulled out of the well is often slow due to being cautious of unknown hazards
or
obstacles. Being able to run in and out of a well at optimal speed would
greatly
decrease well operation costs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The following figures are included to illustrate certain aspects of
the present disclosure, and should not be viewed as exclusive embodiments.
The subject matter disclosed is capable of considerable modifications,
alterations, combinations, and equivalents in form and function, without
departing from the scope of this disclosure.
[0004] FIG. 1 illustrates a well system that may embody or otherwise
employ one or more principles of the present disclosure.
[0005] FIG. 2A illustrates an enlarged perspective view of a distal end
of the downhole tool in FIG. 1 depicting a configuration of the plurality of
sensing
devices.
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[0006] FIG. 2B illustrates another enlarged perspective view of the
distal end of the downhole tool in FIG. 1 depicting another configuration of
the
plurality of sensing devices.
DETAILED DESCRIPTION
[0007] The present disclosure is related to a system that detects
obstacles and hazards in the wellbore ahead of the string and communicates
that information in real time so that the speed/force with which the string is
forced into the well can be controlled to mitigate this problem.
[0008] Presently, downhole tools having video cameras are lowered into
=
wellbores on a conveyance and used to detect any hazards (or obstructions)
that
may be present in the wellbore. However, in order for the video cameras of the
downhole tool to image the wellbore hazards that may be present ahead of the
downhole tool, it is required that clear fluids be present in the wellbore.
Acoustic
tools are sometimes used instead to detect potential hazards present in the
wellbore. However, existing acoustic tools only image the wellbore in the
radial
direction and, therefore, have to be moved past a point in the wellbore in
order
to detect any hazard present at that point. Accordingly, existing acoustic
tools
are not configured to "look" ahead of the downhole tool in the wellbore.
[0009] Embodiments disclosed herein help to better identify wellbore
hazards present in the wellbore and make better decisions about how to remove
or clean out the wellbore hazards. This reduces non-productive time during
wellbore operations due to downhole tools or conveyances being stuck in the
wellbore due to unknown hazards or obstacles, reduces the cost of poor
quality,
and the costs incurred due to lost tools. Embodiments disclosed herein also
allow for optimal speed of travel into and out of the wellbore without the
fear of
hitting the wellbore hazards present in the wellbore.
[0010] Referring to FIG. 1, illustrated is a well system 100 that may
embody or otherwise employ one or more principles of the present disclosure,
according to one or more embodiments. As illustrated, the well system 100 may
include a service rig 102 that is positioned on the earth's surface 104 and
extends over and around a wellbore 106 that penetrates a subterranean
formation 108. The service rig 102 may be a drilling rig, a completion rig, a
workover rig, or the like. In some embodiments, the service rig 102 may be
omitted and replaced with a standard surface wellhead completion or
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installation, without departing from the scope of the disclosure. Moreover,
while
the well system 100 is depicted as a land-based operation, it will be
appreciated
that the principles of the present disclosure could equally be applied in any
sea-
based or sub-sea application where the service rig 102 may be a floating
platform, a semi-submersible platform, or a sub-surface wellhead installation
as
generally known in the art.
[0011] The wellbore 106 may be drilled into the subterranean formation
108 using any suitable drilling technique and may extend in a substantially
vertical direction away from the earth's surface 104 over a vertical wellbore
portion 110. At some point in the wellbore 106, the vertical wellbore portion
110 may deviate from vertical relative to the earth's surface 104 and
transition
into a substantially horizontal wellbore portion 112. In some embodiments, the
wellbore 106 may be completed by cementing a casing string 114 within the
wellbore 106 along all or a portion thereof. In other embodiments, however,
the
casing string 114 may be omitted from all or a portion of the wellbore 106 and
the principles of the present disclosure may equally apply to an "open-hole"
environment.
[0012] The system 100 may further include a downhole tool 116 that
may be conveyed into the wellbore 106 on a conveyance 118 that extends from
the service rig 102. In some embodiments, the conveyance 118 may comprise a
cable having one or more electric lines and/or fiber optic waveguides. In at
least
one embodiment, the cable and the conveyance 118 may comprise the same
structure. In other embodiments, however, the conveyance 118 and the cable
may not be the same and the cable may instead be coupled to the conveyance
118 and otherwise strung along therewith, but not used to lower the downhole
tool 116 into the wellbore 106. Suitable conveyances 118 in this case can
include drill pipe, coiled tubing, production tubing, a downhole tractor, and
the
like.
[0013] In some embodiments, the conveyance 118 (and/or the cable)
may be in communication at the surface with a data processing unit 124 and
may provide real time bidirectional communication between the downhole tool
116 and the data processing unit 124. The data processing unit 124 may
include a signal processor 126 communicably coupled to a computer-readable
storage medium 128 storing a program code executed by the processor 126.
The results of the processing may be displayed on a display 130. Examples of a
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computer-readable storage medium include non-transitory medium such as
random access memory (RAM) devices, read only memory (ROM) devices,
optical devices (e.g., CDs or DVDs), and disk drives.
[0014] According to the present disclosure, the downhole tool 116 may
comprise an array of sensing devices 117 located at a distal end thereof. As
used herein, the term "distal" refers to the portion of the component that is
furthest from the wellhead. Each sensing device 117 may emit a wave energy
121 into the wellbore 106 to detect one or more wellbore hazards 122 present
in
the wellbore 106. For the purpose of discussion herein, the wellbore hazards
122 may include any obstacle that may impede advancement of the downhole
tool 117 or the conveyance 118 within the wellbore 106. Example wellbore
hazards 122 include, but are not limited to, a tool lost in the wellbore 106,
damaged casing 114, buildup of a substance (e.g., paraffin, scale, etc.) in
the
wellbore 106, or any combination thereof.
[0015] It will be appreciated by those skilled in the art that even though
FIG. 1 depicts the downhole tool 116 as being arranged and operating in the
horizontal portion 112 of the wellbore 106, the embodiments described herein
are equally applicable for use in portions of the wellbore 106 that are
vertical,
deviated, or otherwise slanted.
[0016] FIG. 2A illustrates an enlarged perspective view of a distal end
119 of the downhole tool 116 of FIG. 1. As illustrated, the sensing devices
117
may be arranged in a desired configuration on a leading face 115 of the
downhole tool 116 at the distal end 119. In at least one embodiment, as
illustrated, the sensing devices 117 may be angularly offset from each other
on
the leading face 115 by equidistant spacing. In other embodiments, however,
the sensing devices 117 may be angularly offset from each other on the leading
face 115 by random spacing, without departing from the scope of the
disclosure.
[0017] The sensing devices 117 may be arranged such that the wave
energy 121 from each of the sensing devices 117 is emitted in a generally
axial
direction within the wellbore 106 (or the casing 114, FIG. 1). As used herein,
axial direction refers to the direction that is substantially parallel to the
longitudinal axis A of the wellbore 106 and/or the downhole tool 116. However,
the wave energy 121 emitted can have a range of axial angles cp, such as
anything less than 90 with respect to the longitudinal axis A. As illustrated
in
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FIG. 2A, the axial angle cp is defined between the direction of travel of the
wave
energy 121 and the longitudinal axis of the wellbore 106 and/or the casing
114.
[0018] In one example, the wave energy 121 emitted by the sensing
devices 117 may include acoustic wave energy and the sensing devices 117 may
comprise acoustic sensing devices, each of which may include an acoustic wave
generator and an acoustic sensor. The acoustic wave generator emits acoustic
waves through fluid present in the wellbore 106. The acoustic waves may be
reflected back to the sensing devices 117 by the wellbore hazards 122.
[0019] In another example, the wave energy 121 may comprise
pressure pulses and the sensing devices 117 may alternatively comprise
pressure sensing devices, each of which includes a pressure pulse generator
and
a pressure sensor. The pressure pulse generator transmits a pressure pulse
through the fluid in the wellbore 106, at least a portion of which may be
reflected by the wellbore hazards 122. The reflected pressure pulse may then
be received by the pressure sensing devices.
[0020] In yet another example, the wave energy 121 may include
radiant energy, such as visible light, gamma rays, radio waves, ultraviolet
light,
infrared radiation, and the sensing devices 117 may include suitable devices
for
sensing the radiant energy. For instance, if the wave energy 121 incudes
visible
light, then the sensing devices 117 may include optical sensing devices, each
of
which may include a light pulse generator and an optical sensor. The light
pulse
generator emits light pulses through the fluid and any light pulse reflected
by
one or more wellbore hazards 122 in the wellbore 106 is received by the
optical
sensor.
[0021] In still other examples, the wave energy 121 may include
electromagnetic (EM) waves and the sensing devices may include EM
transceivers, each including an EM source that emits EM waves and an EM
receiver that receives EM waves reflected from the wellbore hazards 122.
[0022] It should be noted that wave energy 121 are not limited to the
examples noted herein, and may include other kinds of wave energy, without
departing from the scope of the disclosure. It should also be noted that it is
not
necessary for all of the sensing devices 117 to sense the same parameter. For
example, one sensing device 117 could sense pressure waves, while another
sensing device 117 on the same downhole tool 116 could sense radiant energy
waves.
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[0023] The distance that the wave energy 121 propagates into the
wellbore 106 may define a field of view 120 of the downhole tool 116. As the
downhole tool 116 is conveyed downhole, the wellbore hazards 122 that lie
within the field of view 120 may be detected. The sensing devices 117 may be
arranged such that the wave energy exhibits the field of view 120 having a pre-
determined shape and extending a pre-determined axial distance L (e.g., about
5-10 feet) from the distal end 119 of the downhole tool 116. For instance, as
illustrated in FIG. 2A, the field of view 120 is generally conical or
frustoconical in
shape.
[0024] In an embodiment, the sensing devices 117 may transmit wave
energies 121 having different frequencies. Since different frequencies are
absorbed or reflected differently by different materials, by choosing
frequencies
with different absorption/reflection rates, the size, shape and the material
of the
wellbore hazards 122 can be determined. For instance, a relatively harder
material may reflect a relatively larger amount of frequencies as compared to
a
relatively softer material. As a result, the hardness of the material of the
wellbore hazards 122 can be determined and would permit distinguishing
between "hard" and "soft" wellbore hazards 122 (like steels and paraffins).
The
frequencies that are received by the sensing devices 117 are communicated to
the data processing unit 124 that may process the received frequencies to
produce an image of the wellbore hazards 122 that is displayed on the display
130.
[0025] In another embodiment, based on the time difference between
the time the wave energy 121 was transmitted by the sensing device 117 and
the time the reflected wave energy 121 was received by the sensing device 117,
the data processing unit 124 (FIG. 1) may determine a distance to the one or
more wellbore hazards 122. Once the size, shape, and/or material of the
wellbore hazards 122, and a distance to the wellbore hazards 122 are
determined, an operator may undertake appropriate remedial actions to remove
or repair the hazard 122. The operator can control the sensing devices 117 via
the data processing unit 124 to vary the emitted frequencies to obtain a
better
image of the wellbore hazards 122. This may provide a better understanding of
the size and shape of the wellbore hazards 122, and/or better identify the
material of the wellbore hazards 122. The remedial actions can then be
modified
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to more efficiently remove the hazard 122 or aim a cleanout tool (or verify
the
quality of the clean out).
[0026] FIG. 2B illustrates another enlarged perspective view of the
distal end 119 of the downhole tool 116 of FIG. 1. FIG. 2B may be similar in
some respects to FIG. 2A, and therefore may be best understood with reference
thereto where like numerals designate like components not described again in
detail. In the illustrated embodiment in FIG. 2B, the sensing devices 117 may
be arranged about the outer periphery of the downhole tool 106 at the distal
end
119 thereof. Again, the sensing devices 117 may be arranged such that the
wave energy 121 from each of the sensing devices 117 is emitted in a generally
axial direction. It should be noted that the configuration (or the placement)
of
the sensing devices 117 on the downhole tool 116 in FIGS. 2A and 2B is merely
an example and that any configuration of the sensing devices 117 that results
in
the wave energy 121 being emitted in the axial direction is within the scope
of
this disclosure.
[0027] Embodiments disclosed herein include:
[0028] A. A system that includes a downhole tool conveyable into a
wellbore on a conveyance, a plurality of sensing devices positioned at a
distal
end of the downhole tool to emit wave energy in an axial direction within the
wellbore, at least a portion of the wave energy being reflected by one or more
wellbore hazards and received by the plurality of sensing devices, and a data
acquisition system communicatively coupled to the downhole tool to receive and
process reflected wave energy and thereby identify the one or more wellbore
hazards.
[0029] B. A method that includes conveying a downhole tool into a
wellbore on a conveyance, emitting wave energy in an axial direction within
the
wellbore using a plurality of sensing devices positioned at a distal end of
the
downhole tool, at least a portion of the wave energy being reflected by one or
more wellbore hazards, receiving reflected wave energy using the plurality of
sensing devices, receiving and processing the reflected wave energy with a
data
acquisition system communicatively coupled to the downhole tool, and
identifying the one or more wellbore hazards with the data acquisition system
based on the reflected wave energy.
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[0030] Each of embodiments A and B may have one or more of the
following additional elements in any combination: Element 1: wherein the
plurality of sensing devices are located on a leading face of the downhole
tool.
[0031] Element 2: wherein the plurality of sensing devices are located
about an outer periphery of the downhole tool at the distal end. Element 3:
wherein the wave energy emitted by the plurality of sensing devices exhibits a
field of view having a pre-determined shape and extends a pre-determined
distance from the distal end of the downhole tool. Element 4: wherein the data
acquisition system processes the reflected wave energy to determine at least
one of a size, shape, and a material of the one or more wellbore hazards.
Element 5: wherein the data acquisition system processes the reflected wave
energy to determine a hardness of the material of the one or more wellbore
hazards, and distinguishes two or more wellbore hazards from each other based
on the hardness of the material of the two or more wellbore hazards. Element
6: wherein the wave energy includes at least one of acoustic waves, pressure
pulses, electromagnetic waves, and radiant energy. Element 7: wherein the
data acquisition system determines a distance of the one or more wellbore
hazards from the downhole tool. Element 8: wherein the data acquisition
system processes the reflected wave energy to display an image of the one or
more wellbore hazards.
[0032] Element 9: wherein emitting the wave energy comprises
generating a field of view having a pre-determined shape and extending a pre-
determined distance from the downhole tool. Element 10: further comprising
processing the reflected wave energy using the data acquisition system to
determine at least one of a size, shape, and a material of the one or more
wellbore hazards. Element 11: processing the reflected wave energy using the
data acquisition system to determine a hardness of the material of the one or
more wellbore hazards, and distinguishing two or more wellbore hazards from
each other based on the hardness of the material of the two or more wellbore
hazards. Element 12: wherein emitting the wave energy includes emitting at
least one of acoustic waves, pressure pulses, electromagnetic waves, and
radiant energy. Element 13: further comprising processing the reflected wave
energy using the data acquisition system to determine a distance of the one or
more wellbore hazards from the distal end of the downhole tool. Element 14:
further comprising processing the reflected wave energy to display an image of
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the one or more wellbore hazards. Element 15: further comprising varying a
frequency of the wave energy emitted by one or more sensing devices of the
plurality of sensing devices to vary the image of the one or more wellbore
hazards. Element 16: further comprising emitting the wave energy using the
plurality of sensing devices located on a leading face of the downhole tool at
a
distal end thereof. Element 17: further comprising emitting the wave energy
using the plurality of sensing devices located about the periphery of the
downhole tool at a distal end thereof.
[0033] By way of non-limiting example, exemplary combinations
applicable to A and B include: Element 4 with Element 5; Element 10 with
Element 11; and Element 14 with Element 15.
[0034] Therefore, the disclosed systems and methods are well adapted
to attain the ends and advantages mentioned as well as those that are inherent
therein. The particular embodiments disclosed above are illustrative only, as
the
teachings of the present disclosure may be modified and practiced in different
but equivalent manners apparent to those skilled in the art having the benefit
of
the teachings herein. Furthermore, no limitations are intended to the details
of
construction or design herein shown, other than as described in the claims
below. It is therefore evident that the particular illustrative embodiments
disclosed above may be altered, combined, or modified and all such variations
are considered within the scope of the present disclosure. The systems and
methods illustratively disclosed herein may suitably be practiced in the
absence
of any element that is not specifically disclosed herein and/or any optional
element disclosed herein. While compositions and methods are described in
terms of "comprising," "containing," or "including" various components or
steps,
the compositions and methods can also "consist essentially of" or "consist of"
the
various components and steps. All numbers and ranges disclosed above may
vary by some amount. Whenever a numerical range with a lower limit and an
upper limit is disclosed, any number and any included range falling within the
range is specifically disclosed. In particular, every range of values (of the
form,
"from about a to about b," or, equivalently, "from approximately a to b," or,
equivalently, "from approximately a-b") disclosed herein is to be understood
to
set forth every number and range encompassed within the broader range of
values. Also, the terms in the claims have their plain, ordinary meaning
unless
otherwise explicitly and clearly defined by the patentee. Moreover, the
indefinite
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articles "a" or "an," as used in the claims, are defined herein to mean one or
more than one of the elements that it introduces. If there is any conflict in
the
usages of a word or term in this specification and one or more patent or other
documents that may be incorporated herein by reference, the definitions that
are
consistent with this specification should be adopted.
[0035] As used herein, the phrase "at least one of" preceding a series of
items, with the terms "and" or "or" to separate any of the items, modifies the
list
as a whole, rather than each member of the list (i.e., each item). The phrase
"at least one of" allows a meaning that includes at least one of any one of
the
items, and/or at least one of any combination of the items, and/or at least
one
of each of the items. By way of example, the phrases 'at least one of A, B,
and
C" or "at least one of A, B, or C" each refer to only A, only B, or only C;
any
combination of A, B, and C; and/or at least one of each of A, B, and C.
[0036] The use of directional terms such as above, below, upper, lower,
upward, downward, left, right, uphole, downhole and the like are used in
relation
to the illustrative embodiments as they are depicted in the figures, the
upward
direction being toward the top of the corresponding figure and the downward
direction being toward the bottom of the corresponding figure, the uphole
direction being toward the surface of the well and the downhole direction
being
toward the toe of the well.
