U.S. patent application number 16/928701 was filed with the patent office on 2022-01-20 for casing annulus leakage repair method and system.
The applicant listed for this patent is Saudi Arabian Oil Company. Invention is credited to Brett Bouldin, Robert John Turner.
Application Number | 20220018201 16/928701 |
Document ID | / |
Family ID | 1000004987728 |
Filed Date | 2022-01-20 |
United States Patent
Application |
20220018201 |
Kind Code |
A1 |
Bouldin; Brett ; et
al. |
January 20, 2022 |
CASING ANNULUS LEAKAGE REPAIR METHOD AND SYSTEM
Abstract
A method for repairing a leak in a cement sheath of a casing of
a well. A portion of the inner casing and the cement sheath is
removed to create an opening that extends through the inner casing
and the cement sheath. A tool is inserted within the inner casing
to a location adjacent to the opening and one or more segments of a
heat-deforming material that are part of the tool is heated to
cause melting of the heat-deforming material. The tool is
configured to direct the melted heat-deforming material radially
outward into the opening. Once cooled, the heat-deforming material
plugs the opening, thereby repairing the leak within the cement
sheath.
Inventors: |
Bouldin; Brett; (Spring,
TX) ; Turner; Robert John; (Dhahran, SA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Saudi Arabian Oil Company |
Dhahran |
|
SA |
|
|
Family ID: |
1000004987728 |
Appl. No.: |
16/928701 |
Filed: |
July 14, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 37/00 20130101;
E21B 36/04 20130101; E21B 29/002 20130101; E21B 33/12 20130101;
E21B 29/10 20130101; E21B 36/008 20130101; E21B 47/107
20200501 |
International
Class: |
E21B 29/10 20060101
E21B029/10; E21B 29/00 20060101 E21B029/00; E21B 33/12 20060101
E21B033/12; E21B 36/00 20060101 E21B036/00; E21B 36/04 20060101
E21B036/04; E21B 47/107 20060101 E21B047/107; E21B 37/00 20060101
E21B037/00 |
Claims
1. A method for repairing a leak in a casing of a well, wherein the
casing comprises an inner casing and an outer casing with a first
space formed therebetween, the method comprising: removing a
portion of the inner casing to create an opening in the inner
casing so that the first space is accessible; inserting a tubular
and an annular packer tool attached to the tubular to a location
adjacent to the opening, wherein the annular packer tool surrounds
the tubular and comprises one or more segments of heat-deforming
material on an outer surface of the annular packer tool; inserting
a heater into the well and positioning the heater at a location
that is internally within the tubular and is adjacent to the
annular packer tool; activating the heater to a temperature above
an activation temperature of the one or more segments of
heat-deforming material, thereby causing the heat-deforming
material to melt, and wherein the melted heat-deforming material
flows into the opening; and reducing the temperature of the
location adjacent to the annular packer tool to below the
activation temperature of the heat-deforming material to cause the
melted heat-deforming material to solidify within the opening and
within the first space.
2. The method of claim 1, wherein the step of removing the portion
of the inner casing comprises using a underreamer device to create
the opening in the inner casing and to make the first space
accessible.
3. The method of claim 1, wherein the opening comprises an
annular-shaped opening that is formed through the inner casing and
through the first space so as to reveal an inner surface of the
outer casing.
4. The method of claim 1, wherein the heater comprises an electric
heater, an inductive heater, or a chemical heater.
5. The method of claim 1, further comprising: locating the leak in
the casing by identifying inflow and outflow positions of the leak
in the casing.
6. The method of claim 5, wherein the step of identifying the
inflow and outflow positions is performed by an acoustic logging
tool.
7. The method of claim 1, further comprising: cleaning the opening
to remove debris and excess cement that comes from a cement sheath
that is disposed within the first space.
8. The method of claim 1, wherein the inner casing and the outer
casing are separated by a cement sheath, wherein the step removing
a portion of the inner casing further comprises removing an
adjacent portion of the cement sheath via underreaming such that
the opening includes an area from which the portions of inner
casing and cement sheath are removed.
9. The method of claim 1, further comprising: tying the scab liner
to a production liner or a wellhead of the well to secure the scab
liner.
10. The method of claim 1, wherein the heat-deforming material is a
low melting point alloy.
11. The method of claim 10, wherein the low melting point alloy is
an alloy that comprises bismuth (Bi) and tin (Sn).
12. The method of claim 1, wherein the step of inserting the heater
into the well comprises: lowering the heater into the well on an
electricline, and positioning the heater at a predetermined
location that is adjacent to the annular packer tool; and wherein
the method further comprises: deactivating and subsequently
removing the heater from the location adjacent to the annular
packer tool.
13. The method of claim 1, wherein the annular packer tool further
comprises metal portions having a higher melting point than the
activation temperature of the heat-deforming material segments, and
wherein the heater heats the location adjacent to the annular
packer tool to a temperature above the activation temperature of
the one or more segments of heat-deforming material but below a
melting point of the metal portions.
14. The method of claim 13, wherein heat from the heater passes
through the scab liner to heat the heat-deforming material segments
that are located radially outward of both the heater and the scab
liner.
15. The method of claim 13, wherein the heater heats the location
adjacent to the annular packer tool to a temperature approximately
50.degree. C. above a highest expected service temperature of the
well.
16. A method for repairing a leak in a cement sheath of a casing of
a well, wherein the casing comprises an inner casing and an outer
casing with the cement sheath formed therebetween, the method
comprising: removing a portion of the inner casing and the cement
sheath at a location above the leak to create an opening that
extends through the inner casing and extends at least partially
within the cement sheath, respectively; inserting a tool within the
inner casing to a location adjacent to the opening, the tool being
positioned radially inward of the inner casing, cement sheath and
outer casing, the tool including one or more segments of
heat-deforming material disposed along an outer surface of the
tool; heating the one or more segments of the heat-deforming
material to cause the one or more segments of the heat-deforming
material to melt and wherein the tool is configured to direct the
melted heat-deforming material radially outward into the opening;
and cooling the melted heat-deforming material while the
heat-deforming material remains in place within the opening to
cause the heat-deforming material to solidify and plug the opening,
thereby repairing the leak within the cement sheath.
17. The method of claim 16, wherein the tool comprises an annular
packer tool that surrounds and is coupled to a scab liner, wherein
the annular packer tool is located adjacent the opening and wherein
the step of heating the one or more segments comprises: inserting a
heater within the scab liner and activating the heater to cause
heat to radiate through the scab liner to the one or more segments
of the heat-deforming material to cause melting thereof, and
wherein the step of cooling the melted heat-deforming material
results in the heat-deforming material solidifying between the scab
liner and the outer casing within the opening, thereby bonding the
scab liner to the outer casing.
18. A system for repairing a leak in a casing of a well, wherein
the casing comprises an inner casing and an outer casing, the
system comprising: an underreamer configured to remove a portion of
the inner casing at the location of the leak to create an
annular-shaped opening in the inner casing; a tubular and an
annular packer tool attached to the tubular, wherein the tubular is
positioned a location adjacent to the annular-shaped opening, and
wherein the annular packer tool comprises one or more segments of
heat-deforming material on its outer surface; and a heater
configured to heat the well at the location adjacent to the annular
packer tool, to a temperature above an activation temperature of
the one or more segments of heat-deforming material.
19. The system of claim 18, further comprising: an acoustic logging
tool is configured to identify inflow and outflow positions of the
leak behind the inner casing to determine the location of the
leak.
20. The system of claim 18, wherein the inner casing and the outer
casing are separated by a cement sheath, wherein the underreamer is
further configured to remove a portion of the cement sheath.
21. The system of claim 18, further comprising: a production liner
attached to the inner casing of the well; and at least one tie
configured to fix the scab liner to the production liner.
22. The system of claim 18, wherein the heat-deforming material of
the annular packer tool is a low melting point alloy.
23. The system of claim 22, wherein the low melting point alloy is
an alloy that comprises bismuth (Bi) and tin (Sn).
24. The system of claim 18, further comprising: an electricline
wherein the heater is configured to be attached to the electricline
and the electricline is configured to be selectively lowered into
the well on the electricline and stopped at a predetermined
location that is adjacent to the annular packer tool.
25. The system of claim 18, wherein the annular packer tool further
comprises: metal portions having a melting point that is higher
than the activation temperature of the segments of heat-deforming
material, and wherein the heater is configured to heat the location
adjacent to the annular packer tool to a temperature above the
activation temperature of the segments of heat-deforming material
but below the melting point of the metal portions.
26. The system of claim 23, wherein the heater is configured to
heat the location adjacent to the annular packer tool to a
temperature approximately 50.degree. C. above a highest expected
service temperature of the well.
Description
TECHNICAL FIELD
[0001] The present disclosure is generally related to systems and
processes for repairing a leak in a well and more particularly
related to systems and processes for repairing a leak in a casing
of a well.
BACKGROUND OF THE DISCLOSURE
[0002] Sufficient pressure isolation between casing strings has
been an oil industry problem since its inception. Cement is used to
seal the annulus between concentric casing strings, but cement
fundamentally shrinks as it cures, resulting in micro channels and
micro-annuli in the cement. The micro channels and micro-annuli can
permit gas to flow between the casing strings. Sometimes the gas
can flow for thousands of feet between the tubulars and can be
measured at the surface wellhead. Further, downhole media can flow
from one zone of the well to another via the micro channels
(casing-to-casing leak path). Such problems occur more frequently
in gas wells because of higher pressures and lower media viscosity.
Moreover, casing-to-casing annular (CCA) pressure at the surface
can be an indicator of much more serious conditions, such as a
downhole circulation or a blowout in the most serious
instances.
[0003] In recent years, new cements have been created with the aim
of having less shrinkage during curing. These newer cement
chemistries are generally composites with other materials such that
the net behavior of the cement actually expands slightly during
curing. These improvements in cement chemistries have resulted in
better performance for sealing between casing strings (CCA
sealing), but they have not solved the problem entirely. In
particular, micro channels can still develop in the casing after
the curing of the cement, which results in CCA leaks that are not
detected until long after the casing is cemented. Currently,
retrofit methods for repair of these CCA leaks in gas wells have
been difficult to implement and are largely ineffective.
[0004] The present application addresses these and other challenges
related to repairing leaks in the casing of a well.
SUMMARY OF THE DISCLOSURE
[0005] In one embodiment, the present disclosure is directed to a
method for repairing a leak in a cement sheath of a casing of a
well, the casing including an inner casing and an outer casing with
the cement sheath formed therebetween. The method includes the
steps of:
[0006] removing a portion of the inner casing and the cement sheath
at a location above the leak to create an opening that extends
through the inner casing and extends at least partially within the
cement sheath, respectively;
[0007] inserting a tool within the inner casing to a location
adjacent to the opening, the tool being positioned radially inward
of the inner casing, cement sheath and outer casing, the tool
including one or more segments of heat-deforming material disposed
along an outer surface of the tool;
[0008] heating the one or more segments of the heat-deforming
material to cause the one or more segments of the heat-deforming
material to melt and wherein the tool is configured to direct the
melted heat-deforming material radially outward into the opening;
and
[0009] cooling the melted heat-deforming material while the
heat-deforming material remains in place within the opening to
cause the heat-deforming material to solidify and plug the opening,
thereby repairing the leak within the cement sheath.
[0010] In at least one embodiment, the casing can include an inner
casing and an outer casing with a first space formed therebetween,
and the method can include the steps of:
[0011] removing a portion of the inner casing to create an opening
in the inner casing so that the first space is accessible;
[0012] inserting a tubular and an annular packer tool attached to
the tubular to a location adjacent to the opening, wherein the
annular packer tool surrounds the tubular and comprises one or more
segments of heat-deforming material on an outer surface of the
annular packer tool;
[0013] inserting a heater into the well and positioning the heater
at a location that is internally within the tubular and is adjacent
to the annular packer tool;
[0014] activating the heater to a temperature above an activation
temperature of the one or more segments of heat-deforming material,
thereby causing the heat-deforming material to melt, and wherein
the melted heat-deforming material flows into the opening; and
[0015] reducing the temperature of the location adjacent to the
annular packer tool to below the activation temperature of the
heat-deforming material to cause the melted heat-deforming material
to solidify within the opening and within the first space.
[0016] In at least one embodiment, the present disclosure is
directed to a system for repairing a leak in a casing of a well,
where the casing comprises an inner casing and an outer casing. The
system includes:
[0017] an underreamer configured to remove a portion of the inner
casing at the location of the leak to create an annular-shaped
opening in the inner casing;
[0018] a tubular and an annular packer tool attached to the
tubular, wherein the tubular is positioned a location adjacent to
the annular-shaped opening, and wherein the annular packer tool
comprises one or more segments of heat-deforming material on its
outer surface; and
[0019] a heater configured to heat the well at the location
adjacent to the annular packer tool, to a temperature above an
activation temperature of the one or more segments of
heat-deforming material.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0020] FIG. 1 displays a cross-section of a portion of a well that
has a leak in its casing in accordance with one or more
embodiments; and
[0021] FIG. 2A displays a cross-section of a portion of a well
during repair of the leak and a system for repairing the leak in
accordance with one or more embodiments;
[0022] FIG. 2B displays a cross-section of a portion of the casing
after repair of the leak in accordance with one or more
embodiments; and
[0023] FIG. 3 displays a diagram of an exemplary annular packer
tool of the system for repairing the leak in accordance with one or
more embodiments.
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS IN ACCORDANCE WITH THE
DISCLOSURE
[0024] By way of overview and introduction, the present application
discloses methods and systems for repairing a leak in a casing of a
well. In one or more embodiments, the system can include an
underreamer, a cleaning tool (e.g., hydrojet), a tubular (e.g.,
scab liner), an annular packer tool, and a heater. In accordance
with one or more embodiments of the method, a leak such as a
casing-to-casing annular (CCA) leak is located in a casing of the
well. The casing can include an inner casing string ("inner
casing") and an outer casing string ("outer casing") with cement
separating the inner and outer casings.
[0025] After the location of the leak is determined, an underreamer
is used to remove a portion of the inner casing and sometimes the
cement at the location of the leak, thereby creating an
annular-shaped opening in the inner casing. This annular-shaped
opening is then cleaned to remove any debris. It will be
appreciated that the formed opening can be a concentric annular,
partially eccentric annular, or fully eccentric annular in shape,
for example.
[0026] A tubular, such as a scab liner, is inserted into the well
and an annular packer tool is attached to the scab liner. The
annular packer tool includes one or more segments of heat-deforming
material (e.g., eutectic metal) on its outer surface. The scab
liner and the annular packer tool are inserted into the well at a
location adjacent to the created annular-shaped opening. A heater
(e.g., thermite heater) is inserted into the well at a location
adjacent to the annular packer tool, and then initiated. Initiation
of the heater heats the location adjacent to the annular packer
tool such that the segments of heat-deforming material of the
annular packer tool melt. The melted heat-deforming material then
flows into the annular-shaped opening and solidifies after cooling.
Solidification of the heat-deforming material in the annular-shaped
opening plugs the annular-shaped opening, thereby repairing
(sealing) the previously identified leak in the casing.
[0027] These and other aspects of the present systems and methods
are described in further detail below with reference to the
accompanied drawing figures, in which one or more illustrated
embodiments and/or arrangements of the systems and methods are
shown. The systems and methods of the present application are not
limited in any way to the illustrated embodiment and/or
arrangement. It should be understood that the systems and methods
as shown in the accompanying figures are merely exemplary of the
systems and methods of the present application, which can be
embodied in various forms as appreciated by one skilled in the art.
Therefore, it is to be understood that any structural and
functional details disclosed herein are not to be interpreted as
limiting the present systems and methods, but rather are provided
as a representative embodiment and/or arrangement for teaching one
skilled in the art one or more ways to implement the present
systems and methods.
[0028] FIG. 1 is a cross-section of a portion of a well 100 that
has a leak in a casing 102 after the casing is cemented in
accordance with one or more embodiments. The casing 102 comprises
an inner casing 104 and an outer casing 106, which surrounds the
inner casing 104. The inner casing 104 and outer casing 106 are
separated by a cement sheath 108. In one or more embodiments, the
outer casing 106 can be a 13 and 3/8ths inch (133/8'') outer
diameter (OD) casing and the inner casing can be a 9 and 5/8ths
inch (95/8'') OD casing. However, it should be understood that the
sizes of the inner casing 104 and the outer casing can vary, and
thus are not limited to the above embodiment.
[0029] Leaks can develop between the inner casing 104 and the outer
casing 106 over time. The root cause of these leaks is often a lack
of sufficient sealing of the cement between the inner casing 104
and outer casing 106. This lack of sufficient sealing between the
casing strings can occur for one or more of the following reasons:
1) cement shrinkage during curing; 2) poor casing centralization
that yields non-uniform cement sealing stress; 3) cement leakage,
particularly in horizontal wells as an annulus develops in the
upper part of the casing seal; 4) development of micro-cracks due
to excessive mechanical or thermal stresses that can cause the
cement to fail (crack) and develop a leak; 5) mud channeling,
particularly in deviated wells with poor centralization, which to
leave a mud channel on a thin side of the casing which is not
displaced with cement, resulting in future leakage; 6) gas
channeling; and (7) micro-annuli. Gas channeling can occur as a
result of cement slurry hardening as it goes through the gelation
state, and the resulting shrinkage of the cement causes reduction
in hydrostatic pressure. This shrinkage and reduction in
hydrostatic pressure allows an influx of gas from permeable
formations to form channels for gas to migrate between formation
zones or between a zone and the surface of the well. Micro-annuli
are concentric gaps created between tubular and cement due to high
pressures such as fracturing causing the casing to elastically
deform, excessive compression of the cement, then opening of an
annulus as the pressure is reduced.
[0030] Gas wells are especially susceptible to leaks in the casing
102 (e.g., casing-to-casing annular [CCA] leaks) and are equally
difficult to repair once they occur. The present systems and
methods allow for the effective repair of casing leaks,
particularly in a well that has already been cemented using
conventional techniques.
[0031] FIGS. 2A-2B a cross-section of a portion of a well during
and after repair of the leak via the systems and methods of the
present application in accordance with one or more embodiments. As
shown in FIG. 2A, a CCA leak 109 can develop in the cement sheath
108 of the casing 102. In other words, a CCA leak 109 develops in
the cement sheath 108 because the cement is not sealing between the
inner casing 104 and the outer casing 106. In one or more
embodiments, the method for repairing the leak begins by
determining the location of the leak. There are several ways to
determine the location of the CCA leak 109 in the casing 102. For
example, in one or more embodiments, the CCA leak 109 can be
detected by identifying the inflow and outflow positions of the
leak using one or more acoustic logging tools. The acoustic logging
tools can be used in the well while the well is shut-in, for
example. In one or more embodiments, the acoustic logging tools are
used to listen for fluid and glass flows behind the casing. It will
be appreciated that any number of suitable detection techniques can
be used.
[0032] Once the location of the CCA leak 109 is determined, one or
more portions of the inner casing 104 near the location of the leak
109 is removed so as to expose the leak. In one or more
embodiments, at least one portion of the inner casing 104 that is
removed is above the location of the leak 109 (i.e., above the
inflow point).
[0033] In one or more embodiments, the one or more portions the
inner casing 104 is removed using an underreamer to remove the
selected portion of the inner casing 104. In one or more
embodiments, in addition to removing the portion of the inner
casing 104, an adjacent portion of the cement sheath 108 is also
removed. For instance, the cement sheath 112 adjacent to the
removed inner casing portion can also be removed, thereby revealing
the outer casing 106 (see FIG. 2A). The removal of each portion of
the inner casing 104 and, in some embodiments, an adjacent portion
of the cement sheath 112, results in an annular-shaped opening 110
or "donut" being formed. In one or more embodiments of the present
method, the step of removing the at least one portion of the inner
casing 104 includes determining a length of the inner casing 104 to
remove based on the locations of inflow and outflow positions of
the leak in the casing. For example, in an embodiment in which
there is a 133/8'' outer casing and a 95/8'' inner casing, the
annular-shaped opening 110 can be approximately 3 feet in length.
However, the size of the one or more formed annular-shaped openings
110 can vary depending on the distance between the inflow and
outflow positions of the leak, as well as the size of inner and
outer casings.
[0034] After the at least one annular-shaped opening 110 in the
inner casing 104 is created (e.g., via underreaming), the at least
one annular-shaped opening 110 is cleaned. In one or more
embodiments, the annular-shaped opening 110 can be cleaned via a
cleaning tool, such as a hydro-jetting tool ("hydrojet"). In one or
more embodiments, the cleaning tool can be a laser tool, a
sonic/acoustic tool, or a vibration tool, for example. Cleaning of
the annular-shaped opening 110 cleans the debris and any remnants
of the cement sheaths (excess cement) from the annular-shaped
opening 110.
[0035] After the annular-shaped opening 110 is cleaned, a tubular
112 (e.g., scab liner) is inserted to a location adjacent to the
annular-shaped opening 110. As shown and described in exemplary
embodiments discussed below, the tubular 112 can be a scab liner.
However, it should be understood that, in one or more embodiments,
the tubular can be another type of tubular or liner and is not
limited to a scab liner. In one or more embodiments, the scab liner
is a 7'' scab liner. However, in other embodiments, the diameter of
the scab liner can vary depending on the size of the well and the
size casing. The scab liner 112 is inserted along with an annular
packer tool 114 that is attached to the scab liner along the outer
surface of the scab liner 112. In other words, the annular packer
tool 114 is disposed such that it surrounds the scab liner 112 and
the annular packer tool 114 is disposed between the scab liner 112
and the inner casing 104. Since the scab liner 112 has a smaller
inner diameter than the inner casing 104, the location of the scab
liner 112 represents a local constricted area.
[0036] In one or more embodiments, the annular packer tool 114 can
be a modified version of the TDAP tool as produced by BiSN Tec Ltd,
except that that the annular packer tool 114 of the present
application does not include springs, annular seals, or axial hole
for cementing as provided in TDAP tool of BiSN Tec Ltd. A diagram
of an exemplary annular packer tool 114 attached to the scab liner
112 is shown at FIG. 3. The annular packer tool 114 is cylindrical
in shape and is sized to run on the outside of the scab liner 112,
which is also cylindrical. The annular packer tool 114 thus
surrounds the scab liner 112 and can be positioned at the desired
select position of the scab liner 112 for placement in the desired
repair location relative to the leak which is located radially
outward from the annular packer tool 114.
[0037] The annular packer tool 114 has previously been utilized in
methods as a proactive measure for preventing leaking during the
construction phase of the well. For example, in previous methods,
the annular packer tool is run with a casing string during the well
construction phase. The annular packer tool 114 is used in a
completely different manner and matter in the systems and methods
of the present application as compared to its prior uses, and
particularly for repairing existing leak in the casing of a
well.
[0038] Specifically, in one of more embodiments of the present
application as shown in FIG. 3, the annular packer tool 114
comprises one or more segments 116 (cylinders) of heat-deforming
material on its outer surface. In one or more embodiments, the
heat-deforming material 116 comprises a low-melting point metal,
such as a eutectic metal. For example, the eutectic metal can
comprise bismuth (Bi) and tin (Sn) (e.g., a bismuth-tin alloy).
While the exemplary embodiments discussed herein often refer to the
heat-deforming material 116 as eutectic metal segments, in other
embodiments, the heat-deforming material 116 can comprise one or
more other low-melting point materials or metals that are not
considered eutectic metals.
[0039] In at least one embodiment, the annular packer tool 114 can
also include other portions of one or more metals that have a
higher melting point than the activation temperature of the
heat-deforming material (e.g., eutectic metal) segments 116. For
example, in one or more embodiments, the annular packer tool 114
can comprise centralizers 117 (e.g., carbon steel guides) that have
the same or larger diameter as the eutectic metal segments 116 are
configured to fix the ends of the annular packer tool 114 to the
scab liner 112 such that the annular packer tool 114 remains on the
scab liner 112. The annular packer 114 is inserted on the scab
liner 112 to a location that is adjacent to the annular-shaped
opening 110.
[0040] As the scab liner 112 and the annular packer tool 114 are
inserted in the well at a location adjacent to the annular-shaped
opening 110, the scab liner 112 is secured to a portion of the
inner casing 104. In at least one embodiment, the well can include
a production liner 124 (e.g., 7'' production liner) and the scab
liner 112 can be tied back to the production liner 124 (e.g., via a
tie or other fixture). In one or more embodiments, to attach the
scab liner 112 and the production liner 124, an upper part of the
production liner 124 can have a polished bore receptacle (PBR) and
the bottom of the scab liner 112 can have a seal assembly. As the
scab liner 112 is lowered, the seal assembly enters and seals in
the PBR. In at least one embodiment, the scab liner can
alternatively be tied back to a wellhead of the well. In one or
more embodiments, the scab liner can be held at a location adjacent
to the annular-shaped opening 110 with a running tool.
[0041] Once the scab liner 112 with the attached annular packer
tool 114 is located adjacent to the annular-shaped opening 110, a
heater 120 is inserted into the well 100 inside the scab liner 112
and thus can be positioned inside the annular packer tool 114. The
heater 120 is lowered in the well 100 to a predetermined location
adjacent to the annular packer tool 114. The heater 120 can be, for
example, an electric heater, an inductive heater, or a chemical
heater (e.g., thermite heater).
[0042] In one or more embodiments, the heater 120 is lowered into
the well 100 via an electricline 121. In such an embodiment, the
heater 120 is attached to the electricline 121 and both are then
selectively lowered into the well to a predetermined location
adjacent to the annular packer tool 114 with the scab liner 112
being between the heater 120 and the annular packer tool 114. Once
the heater 120 has been lowered to the location adjacent to the
annular packer tool 114, the heater 120 is initiated, thereby
heating the location adjacent to the annular packer tool 114. The
heat from the heater 120 thus passes through the scab liner 112 to
the annular packer tool 114 that surrounds the scab liner 112.
[0043] The initiated heater 120 is configured to heat the location
adjacent to the annular packer tool 114 to a temperature above an
activation temperature of the one or more segments of
heat-deforming material 116 (without adversely impacting the scab
liner 112). As such, the increased temperature causes the
heat-deforming material segments 116 to melt. In embodiments in
which the annular packer tool 114 also includes portions of metal
with a higher melting point than the activation temperature of the
heat-deforming material (e.g., eutectic metal) segments 116, the
heater 120 is configured to heat the location adjacent to the
annular packer tool 114 to a temperature above the activation
temperature of the heat-deforming material segments 116 but below
the melting point of the other metal portions. As the
heat-deforming material melts, the melted heat-deforming material
flows into the at least one adjacent annular-shaped opening 110. In
at least one embodiment, the preferred activation temperature of
the heat-deforming material (e.g., eutectic metal) when the
heat-deforming material is a Bi--Sn alloy is approximately
50.degree. C. greater than the highest expected temperature
experienced during service in the well. In one or more embodiments,
the activation temperature can be in the range of 90.degree. C. to
500.degree. C. However, it should be understood that higher or
lower temperatures for the activation temperature of the
heat-deforming material can be selected in other embodiments.
[0044] In one or more embodiments in which the scab liner is held
in place by the running tool, the heater 120 can be run through the
running tool and into the scab liner 112 adjacent to the
heat-deforming material segments 116 (e.g., eutectic metal). In
such an embodiment, the heater can then be initiated to melt the
heat-deforming material.
[0045] As mentioned earlier, the annular packer tool 114 is
constructed such that when the heat-deforming material segments 116
melt, the melted metal flows into the opening 110. The centralizers
117 that border the ends of the metal segments 116 limit where the
melted heat-deforming material can flow until the melted
heat-deforming material can solidify within the opening 110.
[0046] After the heat-deforming material segments 116 of the
annular packer tool 114 has melted, the heater 120 is turned off or
deactivated such that the reaction that causes the increase in
temperature in the heater 120 is neutralized and the temperature
around the heater 120 is lowered below the activation temperature
of the heat-deforming material. As such, due to the decrease in
temperature, the melted heat-deforming material solidifies within
the at least one annular-shaped opening 110. Once the heater 120
has cooled, the heater 120 is removed from the location adjacent to
the annular packer tool 114. In one or more embodiments, the heater
120 is removed from the location adjacent to the annular packer
tool 114 via the electricline 121.
[0047] As shown in FIG. 2B, as the heat-deforming material (e.g.,
eutectic metal) solidifies in the annular-shaped opening 110, the
heat-deforming material expands volumetrically in the
annular-shaped opening 110. This volumetric expansion exerts radial
stress on the portion of the inner casing 104 and outer casing 106
that surrounds the annular-shaped opening 110. Once the
heat-deforming material solidifies in the annular-shaped opening
110, it forms a seal 126. This seal 126 forms a metal-to-metal seal
with the metal of the inner casing 104 and the metal of the outer
casing 106 that surrounds the annular-shaped opening 110, thereby
providing a gas-tight seal at the location of the CCA leak.
[0048] In one or more embodiments, the scab liner 112 remains in
the well after the leak has been repaired/sealed, and thus
permanently or semi-permanently constricts the area of the well in
which the leak was repaired. For example, in one or more
embodiments in which the scab liner 112 is held in place by the
running tool, once the heater is deactivated and the heat-deforming
material solidifies within the opening 110, the heater is removed,
and the running tool is retrieved, but the scab liner can remain in
the well.
[0049] Moreover, since the packer tool 114 is located between the
scab liner 112 and the outer casing 106 within the opening 110, the
heat-deforming material (e.g., eutectic metal) that flows and then
cools and hardens is bonded to both the scab liner 112 and the
outer casing 106. The cooled, hardened heat-deforming material that
is formed thus in effect plugs the opening 110 and also causes the
scab liner 112 to be bonded to the outer casing 106. The packer
tool 114 is thus left in place and can be at least partially
embedded within the hardened heat-deforming material. The annular
packer tool 114 is thus sacrificed and left in place along with the
scab liner 112.
[0050] As such, the present system and methods for repairing an
existing leak in a casing effectively sections off one or more
portions of the casing around the leak. This is accomplished by
removing the inner casing 104 and cement sheath at these portions
of the casing (e.g., via underreaming) and filling the created void
in the casing (annular-shaped opening 110) with heat-deforming
material from the annular packer tool 114 to form a gas-tight,
metal-to-metal seal. Via the gas-tight, metal-to-metal seal, the
present systems and methods provide an effective and durable repair
of the casing compared to prior solutions.
[0051] As also mentioned, one or more production liners 125 can be
provided and can be secured within the inner casing 104. The
production liner 125 and the scab liner 112 preferably having the
same inner diameter.
[0052] The present method and system thus provides a solution to
remedying leaks that occur in the already formed cement sheath 108
of the well that is located between the two sheaths 104, 106. The
tool (i.e., the packer tool 114) that repairs (e.g., plugs) the
leak is delivered to a location radially inward of the inner casing
104 but is carried radially outward of the scab liner 112. After
positioning the tool at the desired location that corresponds to an
opening that is formed through the inner casing 104 and the cement
sheath 108 so as to expose the inner surface of the outer casing
106. The melted heat-deforming material flows radially outward into
such opening resulting in repair of the cement sheath, thereby
forming a seal between the scab liner 112 and the outer casing
106.
[0053] Although much of the foregoing description has been directed
to systems and methods for repairing a leak in a casing of a well,
the system and methods disclosed herein can be similarly deployed
and/or implemented in scenarios, situations, and settings far
beyond the referenced scenarios. It should be further understood
that any such implementation and/or deployment is within the scope
of the system and methods described herein.
[0054] It is to be further understood that like numerals in the
drawings represent like elements through the several figures, and
that not all components and/or steps described and illustrated with
reference to the figures are required for all embodiments or
arrangements. Further, the terminology used herein is for the
purpose of describing particular embodiments only and is not
intended to be limiting of the invention. As used herein, the
singular forms "a", "an" and "the" are intended to include the
plural forms as well, unless the context clearly indicates
otherwise. It will be further understood that the terms
"including," "comprising," or "having," "containing," "involving,"
and variations thereof herein, when used in this specification,
specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0055] It should be noted that use of ordinal terms such as
"first," "second," "third," etc., in the claims to modify a claim
element does not by itself connote any priority, precedence, or
order of one claim element over another or the temporal order in
which acts of a method are performed, but are used merely as labels
to distinguish one claim element having a certain name from another
element having a same name (but for use of the ordinal term) to
distinguish the claim elements.
[0056] Notably, the figures and examples above are not meant to
limit the scope of the present disclosure to a single
implementation, as other implementations are possible by way of
interchange of some or all of the described or illustrated
elements. Moreover, where certain elements of the present
disclosure can be partially or fully implemented using known
components, only those portions of such known components that are
necessary for an understanding of the present disclosure are
described, and detailed descriptions of other portions of such
known components are omitted so as not to obscure the disclosure.
In the present specification, an implementation showing a singular
component should not necessarily be limited to other
implementations including a plurality of the same component, and
vice-versa, unless explicitly stated otherwise herein. Moreover,
applicants do not intend for any term in the specification or
claims to be ascribed an uncommon or special meaning unless
explicitly set forth as such. Further, the present disclosure
encompasses present and future known equivalents to the known
components referred to herein by way of illustration.
[0057] The foregoing description of the specific implementations
will so fully reveal the general nature of the disclosure that
others can, by applying knowledge within the skill of the relevant
art(s) (including the contents of the documents cited and
incorporated by reference herein), readily modify and/or adapt for
various applications such specific implementations, without undue
experimentation, without departing from the general concept of the
present disclosure. Such adaptations and modifications are
therefore intended to be within the meaning and range of
equivalents of the disclosed implementations, based on the teaching
and guidance presented herein. It is to be understood that the
phraseology or terminology herein is for the purpose of description
and not of limitation, such that the terminology or phraseology of
the present specification is to be interpreted by the skilled
artisan in light of the teachings and guidance presented herein, in
combination with the knowledge of one skilled in the relevant
art(s). It is to be understood that dimensions discussed or shown
are drawings are shown accordingly to one example and other
dimensions can be used without departing from the disclosure.
[0058] The subject matter described above is provided by way of
illustration only and should not be construed as limiting. Various
modifications and changes can be made to the subject matter
described herein without following the example embodiments and
applications illustrated and described, and without departing from
the true spirit and scope of the invention encompassed by the
present disclosure, which is defined by the set of recitations in
the following claims and by structures and functions or steps which
are equivalent to these recitations.
* * * * *