Note: Descriptions are shown in the official language in which they were submitted.
"Method for Well Remediation and Repair"
FIELD
[0001] Embodiments herein relate generally to completion, maintenance,
and
remediation of oil and gas wells. In particular, embodiments herein relate to
an
improved method and system for wellbore cementing operations and mitigating
undesirable communication between subterranean formations.
BACKGROUND
[0002] Oil and gas wells are drilled into subterranean hydrocarbon-
bearing
formations for extraction of hydrocarbons therefrom. Wellbores are drilled
through or
into the hydrocarbon formation and often lined or "cased" with a tubular steel
casing
for at least a portion of the length of the wellbore. Wellbores are typically
38.1mm
(1.5") larger in diameter than the outside diameter of the casing, defining an
annular
space therebetween. When the well is completed, this annular space, or casing
annulus, is often filled with cement, which seals the casing annulus to
prevent
hydrocarbon communication to the surface therethrough. While operators seek to
ensure that the cement seal is complete and uniform, the integrity and/or
durability of
the seal can be affected by variances in the characteristics of the geological
formations through which the wellbore passes.
[0003] Over time, the cement and the surrounding geology
characteristics of
the wellbore change as hydrocarbons are produced from the reservoir. The
cement
shrinks, creating micro-annular spaces between the outside diameter of the
steel
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casing and the inside diameter of the cement sheath. Thus, the cement seal may
have been incomplete for the reasons discussed above. This can allow
communication between the production zone and the surface, and/or between
different zones in the reservoir. Both conditions are undesirable. This
problem is
exacerbated by the repeated elastic expansion and contraction of the casing by
production practices.
[0004] Traditionally, oil and gas well operators have used a method of
perforating the steel casing and injecting additional cement or some other
sealant
into the annular space to "fill" the problematic micro-annular leak paths.
This is
commonly referred to as a "cement squeeze". This method only successfully
remediates the problem less than 50% of the time.
[0005] When a cement squeeze operation is performed, the operator has
no
way of determining from surface where the cement will flow once it has passed
through the perforations formed in the casing. Being fluid, the cement slurry
will
follow the path of least resistance, which is not always the annular leak
pathway to
be repaired. For example, in the event of a gas leak along the annular leak
path, gas
is much less viscous than liquid, and will pass through void spaces that will
not allow
the passage of cement slurry. To increase the chances of the cement reaching
the
annular leak path, operators turn to increasing the pressure and volumes of
cement
pumped downhole and through larger perforation areas. In some cases, the steel
well casing is milled entirely away to gain access to the entirety of the
casing
annulus.
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[0006] Performing cement squeezes near hydrocarbon producing zone(s)
may also result in cement entering the producing zone(s), thus impairing
production
and negatively affecting the commercial value of the well.
[0007] More recently, wells have been completed with an "external
casing
packer" which is designed to enhance the seal between the casing and wellbore
using a mechanical means or plug that serves to further block flow via the
micro-
annular leak path formed between. Such external casing packers must be
installed
along the casing string in advance prior to the running in and setting of the
casing in
the wellbore. As it is typically not feasible to determine where leak paths
will form in
advance, external casing packers must be installed at one or more intervals
along
the casing in advance with placement selected in the areas in which the cement
leakage or poor cement seal is likely to occur. This increases well completion
costs.
[0008] In older wellbores, cement was not always placed to the surface
in the
casing annulus if there were no hydrocarbon bearing formations impacted by
drilling.
More recently, concern has grown regarding the contamination of ground water
aquifers near wellbores that are not protected by a cement seal. In such
cases, the
operator may be required to place cement in the theretofore non-cemented
portion
of the casing annulus to protect areas above the existing cement sheath.
Typically,
such remedial cementing is done by perforating the casing uphole of the
existing
cement sheath and pumping cement into and up the casing annulus to the surface
to
fill the annulus with cement. As in cement squeeze operations, control of the
cement
flow is problematic and cement may not necessarily flow along the desired flow
path,
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necessitating additional cement volume and flow pressure to increase the
chances
of the cementing operation being successful.
[0009] Wellbore remediation may also be necessary when there is inter-
zonal
communication between the hydrocarbon producing zone(s) of interest and
another
zone containing water or natural gas, as such inter-zonal communication may
interfere with the production of hydrocarbons. For example, deficient
cementing of
the casing annulus, or deterioration of the cement sheath, can lead to
communication between hydrocarbon producing and other zones. Water inflow to
the production stream increases production costs. The conventional method of
remediating inter-zonal communication is perforating the casing and performing
cement squeeze operations therethrough, which are expensive and unreliable for
the reasons discussed above.
[0010] There remains a need for a method of remediating an oil and gas
well
and cementing the wellbore annulus while reducing the amount of cement
expended
and preventing the flow of cement to hydrocarbon producing zones near the area
to
be cemented. There is also a need for a reliable and cost-effective method of
mitigating unwanted communication between various zones of a wellbore.
SUMMARY
[0011] Methods for more reliably cementing and remediating oil and gas
wells
are disclosed herein, comprising controlling fluid flow in the micro-annular
leak paths
formed in the casing annulus between the cement sheath and casing by
plastically
expanding the diameter of the wellbore casing at select locations along the
wellbore.
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Such methods do not require pre-placement of casing packers or prediction of
potential leak points of the casing annulus.
[0012] In cementing operations, casing expansion can be performed at
strategic locations along the wellbore to reduce the porosity and permeability
of the
cement sheath thereabout, eliminating annular leak paths that permit
detrimental
flow, and direct the flow of cement to the desired portions of the wellbore.
Further,
the casing expansions can be used to prevent the flow of cement to oil
producing
formations. Casing expansion can also be performed at locations along the
wellbore
with no cement sheath to restrict or prevent flow through the casing annulus.
[0013] In instances of inter-zonal communication between subterranean
formations, casing expansion can be performed at one or more locations
intermediate the formations to mitigate or prevent communication therebetween
via
annular leak paths formed between the casing and cement sheath, or between the
casing and wellbore.
[0014] In a broad aspect, a method of cementing a wellbore having a
wellbore
casing extending therethrough, the casing having a casing bore, comprises:
conveying a casing expanding tool downhole to at least one expansion location
along the casing; actuating the casing expanding tool to plastically deform
the casing
radially outward at the at least one expansion location; conveying a cementing
string
downhole through the casing bore to position one or more cement outlets of the
cementing string proximate a target interval having one or more perforations
formed
through the casing; and introducing cement from surface downhole through the
cementing string and to the outside of the casing via the one or more
perforations.
Date Recue/Date Received 2021-05-31
[0015] In an embodiment, the method further comprises forming the one
or
more perforations through the casing at the target interval for establishing
communication between the casing bore and an outside of the casing.
[0016] In an embodiment, the at least one expansion location is
located
downhole of the target interval.
[0017] In an embodiment, the at least one expansion location is
located
uphole of the target interval.
[0018] In an embodiment, the at least one expansion location comprises
at
least one uphole expansion location uphole of the cementing zone, and at least
one
downhole expansion location downhole of the cementing zone.
[0019] In an embodiment, the step of actuating the casing expanding
tool
further comprises actuating an expansion element of the casing expanding tool
radially outwards and radially contracting the expansion element after the
casing has
been plastically deformed.
[0020] In an embodiment, the step of actuating the expansion element
comprises axially compressing the expansion element to expand the expansion
element radially outwards, and the step of radially contracting the expansion
element
comprises axially releasing the expansion element.
[0021] In an embodiment, the step of axially compressing the expansion
element comprises actuating an axial actuator of the casing expanding tool to
drive a
second stop of the casing expanding tool toward a first stop of the casing
expanding
tool, and the step of axially releasing the expansion element comprises
actuating the
axial actuator to move the second stop away from the first stop.
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[0022] In an embodiment, the step of actuating the axial actuator
comprises
operating an electric motor of the casing expanding tool to drive a hydraulic
pump of
the casing expanding tool.
[0023] In an embodiment, the step of driving the hydraulic pump
comprising
hydraulically driving one or more pistons relative to an outer sleeve of the
axial
actuator, the one or more pistons operatively connected to the second stop and
the
outer sleeve operatively to the first stop.
[0024] In an embodiment, one or more of the at least one expansion
location
is located at a portion of the casing having a cement sheath thereabout, such
that
plastically deforming the casing radially outward further comprises
compressing the
cement sheath to compact the cement.
[0025] In an embodiment, the target interval is selected to include
one or
more leak paths formed between a casing annulus defined between the casing and
the cement sheath.
[0026] In an embodiment, the target interval is selected to include an
uncemented length of the casing.
[0027] In another broad aspect, a method of mitigating communication
between a first subterranean formation and a second subterranean formation of
a
wellbore comprises: conveying a casing expanding tool downhole on a conveyance
string to at least one expansion location along the casing located
intermediate the
first and second subterranean formations; and actuating the casing expanding
tool to
plastically deform the casing radially outward at the at least one expansion
location.
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[0028] In an embodiment, the step of actuating the casing expanding
tool
further comprises actuating an expansion element of the casing expanding tool
radially outwards and radially contracting the expansion element after the
casing has
been plastically deformed.
[0029] In an embodiment, the step of actuating the expansion element
comprises axially compressing the expansion element to expand the expansion
element radially outwards, and the step of radially contracting the expansion
element
comprises axially releasing the expansion element.
[0030] In an embodiment, the step of axially compressing the expansion
element comprises actuating an axial actuator of the casing expanding tool to
drive a
second stop of the casing expanding tool toward a first stop of the casing
expanding
tool, and the step of axially releasing the expansion element comprises
actuating the
axial actuator to move the second stop away from the first stop.
[0031] In an embodiment, the step of actuating the axial actuator
comprises
operating an electric motor of the casing expanding tool to drive a hydraulic
pump of
the casing expanding tool.
[0032] The method of claim 18, wherein the step of driving the
hydraulic pump
comprising hydraulically driving one or more pistons relative to an outer
sleeve of the
axial actuator, the one or more pistons operatively connected to the second
stop and
the outer sleeve operatively to the first stop.
[0033] In an embodiment, one or more of the at least one expansion
location
is located at a portion of the casing having a cement sheath thereabout, such
that
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plastically deforming the casing radially outward further comprises
compressing the
cement sheath to compact the cement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figures 1A to 1D are diagrammatic representations of a wellbore
cement squeeze operation utilizing casing expansion;
[0035] Figure 1A depicts a perforation tool creating perforations in
the
wellbore casing at a target interval of the wellbore;
[0036] Figure 1B depicts a casing expansion tool expanding the
wellbore
casing at locations downhole of the target interval;
[0037] Figure 1C depicts the casing expansion tool of Figure 1B
expanding
the wellbore casing at locations uphole of the target interval;
[0038] Figure 1D depicts a cement string introducing cement into the
target
interval via the casing perforations;
[0039] Figures 2A to 2D are diagrammatic representations of a remedial
cementing operation utilizing casing expansion;
[0040] Figure 2A depicts a perforation tool creating perforations in
the
wellbore casing at a target interval comprising an uncased length of the
wellbore;
[0041] Figure 2B depicts a casing expansion tool expanding the
wellbore
casing at locations downhole of the target interval;
[0042] Figure 2C depicts a cement string introducing cement into the
target
interval via the casing perforations;
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[0043] Figure 2D depicts a cement string introducing cement into a
different
target interval via casing perforations, the casing being expanded at a
section of
casing having no cement sheath thereabout;
[0044] Figures 3A to 3C are diagrammatic representations of an inter-
zonal
communication mitigation operation utilizing casing expansion;
[0045] Figure 3A depicts a wellbore extending through a gas formation,
oil
formation, and water formation, wherein gas and water are able to flow to the
oil
formation via annular leak paths between the wellbore casing and wellbore;
[0046] Figure 3B depicts a casing expansion tool expanding the
wellbore
casing at locations intermediate the oil formation and water formation;
[0047] Figure 3C depicts a casing expansion tool expanding the
wellbore
casing at locations intermediate the oil formation and gas formation;
[0048] Figure 4 is an expanded cross-sectional view of a wireline
setting tool
and expansion element according to one embodiment;
[0049] Figure 5A is a side view of a single use, pleated ring
expansion
element installed about a mandrel;
[0050] Figure 5B is a schematic representation of a cross-section of a
single
use, pleated ring expansion element deployed in casing;
[0051] Figure 5C is a cross-section of the single use, pleated ring
expansion
element of Fig. 5B after actuation;
[0052] Figure 6 is a drawing representation of a photograph of a
partial
section of 5.5" casing expanded by a single use expansion element according to
Example 1;
Date Recue/Date Received 2021-05-31
[0053] Figure 7A is a cross-section of a multi-use, resettable
elastomeric
expansion element deployed in casing;
[0054] Figure 7B is a cross-section of the a multi-use, resettable
elastomeric
expansion element of Fig. 7A after actuation;
[0055] Figures 8A and 8B are drawing representations of a photograph
of a
partial section of 5.5" casing and a multi-use expansion element respectively,
the
casing having been plastically expanded by the multi-use expansion element of
Fig.
13B;
[0056] Figure 9 is a schematic cross-sectional representation of a
setting tool
having a plurality of piston elements coupled to multi-use expansion element,
such
as that shown in Figs. 8A,8B;
[0057] Figures 10A, 10B and 10C are schematic cross-sections of the
setting
tool and expansion element of Fig. 8A, actuated in a first joint of casing,
moved
uphole and actuated in a second successive joint of casing, and moved uphole
and
actuated in a third successive joint of casing;
[0058] Figure 11 is a side perspective view of three joints of casing,
each joint
having a weld seam at a different circumferential location, each joint having
had a
target location expanded using a multi-use expansion element;
[0059] Figure 12 is a cross-sectional view of the casing of Fig. 11
before
expansion; and
[0060] Figures 13A, 13B and 13C are cross-sectional views taken at the
specific location of expansion for each of the three joints of casing of Fig.
11, each
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illustrating a stiff weld effect at a different circumferential location about
the cement
sheath.
[0061] Figure 14A is a cross-sectional view of the mandrel and
shifting
housing of the wireline setting tool of Fig. 4;
[0062] Figure 14B is a perspective view of the mandrel and a J-slot
profile for
compression and release of the expansion element;
[0063] Figure 15 is a cross-sectional view of several of the piston
assemblies
of the setting tool of Fig. 4;
[0064] Figure 16 is a cross-sectional view of a top sub of the setting
tool
having a piston and hydraulic piston distribution passages;
[0065] Figure 17 is a cross-sectional view of the power sub having a
motor
and pump for an electrical wireline embodiment; and
[0066] Figures 18A through 18E are sequential steps of the operation
of the
setting tool and a single use expansion element, namely running in hole to a
target
location, actuating the expansion element, releasing the settling tool from
the
mandrel, withdrawal of the setting tool from the mandrel and pulling the
setting tool
out of hole, respectively.
DESCRIPTION
[0067] With reference to Figs. 1A-3C, embodiments of methods for
remediating oil and gas wells are described herein utilizing the permanent
plastic
deformation of casing to increase the casing diameter at select locations
along the
wellbore. Such selective casing deformation has only recently been enabled by
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Date Recue/Date Received 2021-05-31
technological advances, such as the device disclosed in Applicant's PCT Patent
Application No. PCT/CA2018/050661 or the device closed in Applicant's US
Patent
Application No. 16/099/942, incorporated herein in their entirety.
[0068] In the context of cement squeeze operations, with reference to
Figs.
1A-1D, it is desired to introduce remedial cement to a target interval 8 of
the
wellbore where micro-annular leak paths have formed in the casing annulus
between the casing 12 and cement sheath 14 thereabout. To reduce the amount of
cement needed for the cement squeeze operation, the target interval 8 can be
limited to the length of the wellbore that encompasses the zone experiencing
problematic leakage.
[0069] Turning to Fig. 1A, in preparation for cement squeeze
operations,
perforations 15 can be formed in the casing 12 at the target interval 8 using
a
suitable wireline or tubing-conveyed casing perforation tool 6 to establish
communication between the casing bore and the outside of the casing. In other
embodiments, perforations 15 may already be present in the casing 12 at the
target
interval 8 and the step of perforating the casing 12 is not needed. Referring
to Fig.
1B, after the perforations 15 are formed, a casing expanding / setting tool 20
capable of permanently plastically deforming the casing 12 can be run therein
and
positioned at a downhole expansion location 13d downhole of the target
interval 8.
Once located at the downhole expansion location 13d, the tool 20 is actuated
to
plastically deform the casing 12 and expand its diameter to radially compress
and
compact the surrounding cement sheath 14. Such deformation of the casing 12
and
compression of the sheath 14 is permanent, and acts to reduce or block fluid
flow
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Date Recue/Date Received 2021-05-31
through annular leak paths of the sheath 14. In embodiments, the tool 20 can
be
used to expand the casing 12 multiple axial locations 13d downhole of the
target
interval 8 in the same manner.
[0070] With reference to Fig. 1C, the casing expanding tool 20 can then
be
repositioned to an uphole expansion location 13u uphole of the target interval
8, and
actuated to expand the diameter of the casing 12 in the manner described above
so
as to block fluid flow through the annular leak paths thereat. As above, in
embodiments, the tool 20 can be used to expand the casing 12 at multiple axial
locations 13u uphole of the target interval 8.
[0071] Turning to Fig. 1D, once the casing 12 has been expanded at the
desired expansion locations, the casing expanding tool 20 can be retrieved to
surface, and a cement string 40 can be run into the casing bore such that one
or
more cement outlets 42 thereof are positioned at or proximate the target
interval 8.
The casing bore can then be sealed off such that cement exiting the cement
outlets
42 must flow out through the casing perforations 15 of the target interval 8.
For
example, as shown in Fig. 1D, a bridge plug 50 can be set below the cement
outlets
42 prior to running in of the cementing string 40 to fluidly seal the casing
bore
downhole of the cement outlets 42. Further, packers 44 located above the
cement
outlets 42 of the cementing string 40 can be set so as to prevent fluid flow
thereby in
the annulus 48 formed between the cementing string 40 and inner wall of the
casing
12, and fluidly seal the casing bore uphole of the cement outlets 42.
[0072] After flow in the casing bore uphole and downhole of the cement
outlets 42 is blocked, cement can be introduced into the target interval 8 by
pumping
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cement from surface downhole through the cementing string 40. Cement then
flows
out of the cementing string 40 through the cement outlets 42, and through the
perforations 15 to the outside of the casing 12 within the target interval 8.
The
expanded portions of the casing 12 at the expansion locations 13 mitigate or
prevent
cement flow through annular leak paths formed between the casing 12 and cement
sheath 14 or in the sheath 14 itself. In other words, the expanded portions
act as
barriers to cement flow out of the target interval 8. Such control of cement
flow using
casing expansions reduces the volume of cement lost via flow to undesired
regions
via annular leak paths, and thus the volume of cement required for the cement
squeeze operation is reduced. Additionally, the casing expansions can be used
to
prevent cement flow to oil producing formations near the target interval 8.
[0073] While instances of casing expansion described above involve
expanding casing 12 to compress and compact the cement sheath 14 thereabout,
Applicant has found that expansion of portions of casing 12 not surrounded by
a
cement sheath 14 is still effective in restricting fluid flow along the casing
annulus
between the casing 12 and wellbore. In such cases, the casing expansions can
extend partially into the casing annulus, or contact the wellbore to compress
and
compact the wellbore thereabout, to restrict or block annular leak paths
thereabout.
[0074] In remedial cementing operations, with reference to Figs. 2A-2C,
it is
desired to introduce cement to a target interval 8 comprising a length of the
wellbore
lacking a cement sheath 14. To reduce the volume of cement required for such
operations, the casing 12 can be permanently plastically expanded at one or
more
expansion locations 13 downhole of the target interval 8. As shown in Fig. 2A,
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Date Recue/Date Received 2021-05-31
remedial cementing operations to protect a water zone at an uncemented portion
of
the casing 12, perforations 15 can be formed at target interval 8 comprising
the
uncemented portion, if not already present. Referring to Fig. 2B, the casing
12 is
then expanded with the casing expanding tool 20 at one or more casing
expansion
locations downhole of the target interval 8, such as at a first casing
expansion
location 13c located at a portion of the wellbore having a cement sheath 14
and at a
second expansion location 13d located at a portion of the wellbore not having
a
cement sheath 14. In other embodiments, the cementing operation can comprise
more or fewer casing expansion locations 13 as needed, said casing expansion
locations 13 located at areas having a cementing sheath 14 thereabout, not
having a
cement sheath 14, or a combination thereof. For example, Fig. 2D depicts an
embodiment where the casing expansion locations 13 are selected to be at
portions
of the casing 12 having no sheath 14 thereabout, the casing 12 being radially
plastically expanded to contact the wellbore. As above, with reference to Fig.
2C,
once the casing 12 has been expanded at the expansion locations 13, a
cementing
string 40 can then be run into the casing bore and the flow through the casing
bore
blocked off above and below the cement outlets 42 of the cementing string 40,
such
as with bridge plug 50 and packers 44. Cement can then be pumped from surface
downhole through the cementing string 40 to the outside of the casing 12
within the
target interval 8. The casing expansions at the expansion locations 13 act as
barriers to prevent cement from flowing downhole therepast, thus directing
cement
to the target interval 8 and away from other portions of the wellbore. By this
manner
of directing cement flow, the volume of cement required to remedial cementing
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operation is reduced and cement flow to undesirable areas, such as oil
producing
formations, is mitigated or prevented. While Figs. 2A-2D depict a remedial
cementing operation to protect a water zone in the target interval, the method
of
performing remedial cementing using casing expansions can be used in any
situation wherein it is desirable to introduce cement to a previously uncement
portion
of the casing 12. Further, while Figs. 2A-2D depict the casing expansion
locations 13
as being downhole of the target interval 8, in some embodiments, the casing
expansion locations 13 can be located uphole of the target interval 8, or both
uphole
and downhole of the target interval 8.
[0075]
Turning to Figs. 3A-3C, in instances where there is undesirable
communication between various subterranean zones of the wellbore, such as an
incursion of gas from a gas formation and water from a water formation into an
oil
producing formation via annular leak paths between the casing 12 and cement
sheath 14, casing expansion may be utilized to mitigate or prevent such
communication. As shown in Figs. 3B and 3C, the setting tool 20 can be run
into the
wellbore to expand the casing 12 at one or more expansion locations 13 axially
intermediate the oil producing, gas, and water formations to prevent
communication
therebetween via annular leak paths. As above, said expansion locations 13 can
be
located at portions of the casing 12 either having a cement sheath 14
thereabout or
not having a cement sheath 14. While Figs. 3A-3C depict casing expansions
formed
between gas, water, and water formations to prevent unwanted communication
therebetween, casing expansion can be used to prevent communication between
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any two or more subterranean zones via microannular leak paths in the casing
annulus.
[0076] An example of a suitable setting or casing expanding tool 20 for
the
operations above is described herebelow.
Setting Tool / Casing Expanding Tool
[0077] With reference to Fig. 4, in an embodiment of a suitable casing
expanding tool 20, a casing expansion element 10 is provided for localized and
permanent expansion of well casing 12 at a target location 13.
[0078] The setting tool 20 is provided for running the expansion
element 10
downhole to the target location 13 and actuation thereof for plastically
expanding the
casing 12. The casing 12 is expanded into the cement sheath 14 surrounding the
casing 12. The cement sheath 14 is compressed at the point of expansion.
Permanent deformation of the casing 12 maintains contact of the expanded
casing
12 with the compressed, volume-reduced cement sheath 14.
[0079] Applicant notes that others have determined that, surprisingly,
integrity
issues of the cement sheath 14, including micro-annular channeling and
fractures,
do heal after having experienced significant compression. Once one has
determined
a casing expansion location 13 of the well casing 12, such as a location of
the
casing 12 experiencing an annular leak, the casing is expanded permanently,
and
with a diametral magnitude to remediate leaking thereby. As set forth in
IADC/SPE
SPE-168056-MS, entitled "Experimental Assessment of Casing Expansion as a
Solution to Microannular Gas Migration, it was determined that expanding
casing
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through a swaging technique, applied generally along a casing, compresses the
cement, and though the cements consistency changes it does regain its solid
structure and compressive strength.
[0080] In the embodiment disclosed herein, the expansion element 10 is
a
material or metamaterial which accepts an axially compressive actuation force
resulting in radial expansion. More commonly known as Poisson's Ratio as
applied
to homogeneous materials, it is also a convenient term for the behavior of
composite
or manufactured materials. Sometimes such manufactured materials are referred
to
as meta-materials, usually on a small material properties scale, but also
applied here
in the context of an assembly of materials that are intractable in a
homogenous form,
e.g. a block of steel, but are more pliable in less dense manufactured forms.
[0081] The expansion element is conveyed down the well casing 12 by
the
setting tool 20, on tubing or wireline 22 (as shown) to the specified location
13 for
remediation. The setting tool 20 imparts significant axial actuating forces to
the
expansion element for a generating a corresponding radial expansion. The force
of
the radial expansion causes plastic deformation of the casing 12 at the
specified
expansion location(s) 13.
[0082] The setting tool 20 comprises an actuating sub 24, one or more
piston
modules 26,26 ..., a top adapter sub 28, and a power unit 30.
[0083] The setting tool 20 has an uphole end 32 for connection with
the
wireline 22 typically incorporated with the power unit. The expansion element
10 is
operatively connected at one end or the other of the setting tool. In an
embodiment,
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the expansion element 10 is supported at a downhole end 34, at the actuating
sub
24, and thereby separates a conveyance end from the expansion element end.
[0084] When the setting tool is equipped with an expansion element 10
for
single use, such as the stack of pleated rings described below, is configured
with the
expansion element 10 at the downhole end 34, permitting release and
abandonment
of the expansion element downhole and subsequent recovery of the setting tool
20
by pulling-out-of-hole thereabove. An expansion element 10 capable of multi-
use
could be located at either end, but is practically located again at the
downhole end
34 as illustrated for separation again of conveyance and expansion functions,
or for
emergency release of the more risky expansion element.
Pleated Expander
[0085] With reference to Figs. 5A, 5B, 5C and 6, in one embodiment, the
expandable element 10 is a metamaterial assembly of metal components, some of
which are folded, which have a high compressibility as the metal is forced to
unfold
and rigid metal components to control the axial and radial behavior of the
folded
metal. Actuation of the pleated ring¨form of expandable element 10 results in
irreversible deformation thereof and is intended for single use.
[0086] This embodiment of the expandable element 10 is a stack 40 of
pleated rings 42 slidably mounted on a mandrel 44. Each ring 42 is separated
and
spaced axially apart from an adjacent ring 42 by a flat, annular washer 46.
The
behavior of pleated rings 42 for sealing a wellbore within the well casing 12
is also
Date Recue/Date Received 2021-05-31
described in Applicant's international application PCT/CA2016/051429 filed
Monday,
Dec. 5, 2106 and claiming priority of CA 2,913,933 filed Dec. 4, 2015.
[0087] As shown in Fig. 5A, the material of the annular pleated rings
42 is
formed to undulate axially about the circumference of the ring like a wave
disk
spring. The pleated ring 42 can be axially compressed against a stop and as
the
pleat of the ring 42 flattens the added material in the flattened plane
results in an
increase in the ring's diameter. Like the ubiquitous Belleville spring
washers, pleated
rings 42 can be stacked in parallel for increase spring resistance or in
series for
increased deflection. Pleated rings 42 also have a greater capability for both
axial
and deflection and radial expansions than do the Belleville washers. Two or
more
pleated rings 42,42 ... can be aligned axially in parallel, with the peaks and
valleys
aligned to increase the axial resistance to compression or misaligned
angularly and
separated by the washers 46 for serial stacking to minimize axial resistance
and
thus minimize actuation force. The stack 40 of pleated rings 42,42 .. forms
the
expandable element 10.
[0088] With reference to Figs. 5B and 5C, a top and bottom of the
expandable
element 10 is supported axially by first and second stops 52,54 being actuable
towards the other stop for compressing the stack 40. In this illustrated
embodiment
the bottom of the stack 40 is guided axially by the mandrel 44. When actuated,
the
pleated stack 40 is compressed axially between the first and second stops, so
as to
cause the pleated rings 42 to flatten between each washer 46.
[0089] As shown in Figs. 5C and 6, when flattened axially, each ring 42
expands radially, the expanding rings 42 engaging the inside diameter of the
casing
21
Date Recue/Date Received 2021-05-31
12. As the rings 42 are axially restrained while compressed, dimensional
change is
directed into a radial engagement with the casing 12, the magnitude of which
results
in a plastic displacement thereof.
[0090] The overall axial height of the stack of pleated rings is
limited to
concentrate the radial force and hoop stress into the short height of the
casing 12.
The radial force displaces the casing beyond its elastic limit and imparts
plastic
deformation over a concentrated, affected casing length for a given axial
force. The
magnitude of the plastic expansion can be controlled by the magnitude of the
axial
force
[0091] As shown in Fig. 6, a 5" tall stack of pleated rings 42, having
a pleated
outer diameter of about 4.887", can be deployed in 5.5", 141b/ft casing
(5.012"
internal diameter ID ¨ nominal 5.5" OD). Depending upon the magnitude of the
axial
compression, the outside diameter of the casing is readily expanded in the
order of
0.875. If evenly distributed circumferentially about the casing 12, this
results in a
reduction of almost 1/2 of the radial dimension of the cement sheath 14.
Applicant
has determined that an expansion of 0.375" on the casing diameter has been
effective to shut off surface flow along the cement sheath 14.
[0092] In a first example, Example 1, a test expansion element 10 was
prepared and comprised a stack of five double-pleated rings 42 separated and
isolated by six flat spacer washers 46 for a stack height of about 4.6" to
5.1". The
stack height controls the amount of diametrical expansion. The greater the
pleat
height, the greater the casing expansion. Each ring 42 was a 0.042" thick,
fully
hardened stainless steel. Between each pleated ring 42 was a strong 0.1875"
thick
22
Date Recue/Date Received 2021-05-31
washer 46 of QT1 steel having a 4.887 OD and a 3.017 ID. A 3" diameter test
mandrel 44 was provided.
[0093]
In testing, compression of the stack reduced the stack height by about
1.0" to 1.5" for the 3/16" thru 7/8" expansion respectively. For 5.5", 14
lb./ft J55
casing, having 5.012 ID, a nominal 5.5" OD and a 4.887 drift size. The initial
dimensions are 4.887 OD with a 3.017" ID. The flattened ID and OD width varies
with the initial pleat height.
[0094]
At 90 tons (180,000 lbs force) of axial load to flatten the pleats, the OD
of a pleated ring 42, having an initial 0.280" pleat height, expanded in
diameter from
4.887" OD to 5.280" OD and the ID expanded from 3.017" to 3.410" ID. This
resulted in about a 3/16" casing expansion.
[0095]
For a ring having a 0.380" pleat height, when flattened, expanded in
diameter from 4.887" OD to 5.655" OD and the ID expanded from 3.017" to -
3.785
ID. This resulted in a 7/8" casing expansion.
Applicant believes that the
measurements scale proportionately up and down from 4" to 9 3/8" casing.
[0096]
In other embodiments Applicant may use a semi-solid viscous fluid
embedded in the assembled stack 40 to add greater homogeneity thereto. When
flattened, the individual pleats impose a plurality of point hoop loads on the
casing.
Applicant determined that a more distributed load can result with the addition
of the
viscous fluid or sealant 56 located in the interstices of the stack 40.
[0097]
A suitable sealant 56 is a hot molten asphaltic sealant that becomes
semi-solid when cooled. The stack of pleated rings 42 can be dipped in hot
sealant
and cooled for transport downhole embedded in the stack between the rings 42
and
23
Date Recue/Date Received 2021-05-31
the washers 46 and within the valleys of the pleated rings 42 themselves.
Plastomers are used to improve the high temperature properties of modified
asphaltic materials. Low density polyethylene (LDPE) and ethylene vinyl
acetate
(EVA) are examples of plastomers used in asphalt modification. The sealant can
be
a molten thermo¨settable asphaltic liquid, typically heated to a temperature
of about
200 C. Such as sealant is a polymer¨modified asphalt available from Husky
EnergyTM under the designation PG70-28. The described sealant melts at about
60 C and solidifies at about 35 C.
[0098] The semi-solid sealant 56 in the stack of pleated rings, when
actuated
to the compressed position, seals or fluid exit is at least restricted from
between
adjacent washers, the mandrel, the adjacent pleated rings and the casing, for
further
applying fluid pressure to the wall of the casing 12.
[0099] Expansion elements 10 assembled from metal tend to be
irreversible;
once expanded they remain expanded, and as a result tend to become integrated
with the casing 12 and thus cannot be reused.
[0100] Applicant is aware of wells that have multiple sources of
leakage along
the casing annulus, and it is advantageous to be able to expand the casing 12
at
multiple locations 13,13 without having to trip out of the well casing 12 to
install a
new expandable element 10.
Elastomeric Expander
[0101] Accordingly, and with reference to Figs. 7A, 7B, 8A and 8B, in
another
embodiment, a multiple-use casing expansion element 10 is conveyed downhole
24
Date Recue/Date Received 2021-05-31
and actuated at the target location 13 to expand the casing 12, released, and
then
moved to a successive location. The magnitude of expansion is related to axial
actuation force.
[0102] An elastomeric cylindrical bushing 60 has a central bore 62
along its
axis and is mounted on the mandrel 44 passing therethrough. A suitable
elastomeric
material is a nitrile rubber, 75 durometer. A bottom of the bushing 60 is
supported
axially by a downhole stop 54 at a bottom the mandrel 44. A support washer 46,
similar to the washers 46 used in the stack 40 of pleated rings.
[0103] The actuator sub 26 is fit with an uphole stop 52. When
actuated, the
bushing 60 is compressed relative to the bottom stop 52, so as to cause the
bushing
to expand radially related to its Poisson's ratio, engaging the casing 12. As
the
bushing is axially restrained and compressed, dimensional change is directed
into a
radial engagement with, and a plastic displacement, of the casing. Again,
total axial
height of the bushing is limited to concentrate force and maximize hoop stress
in the
casing 12 for a given axial force.
[0104] Generally, the diameter of the mandrel 44 is sized to about 50%
to
75% of the outside diameter of the bushing 60. The inside diameter of the
bushing
60 is closely size to that of the mandrel 44. For example, for 5.5" 14 lb/ft
casing, the
bushing height is 5" tall, the OD is 4.887" and the mandrel OD and bushing ID
can
be 2.125". Rather than changing out the mandrel for different sized elements
10,
one can sleeve the mandrel for larger elements. Not shown, the mandrel 44 can
also be fit with sleeve for varying the OD to fit the ID of larger bushings.
For 9-5/8"
Date Recue/Date Received 2021-05-31
40 lb/ft casing, having a bushing OD of 8.765", a 2.125" mandrel provided with
a
setting tool for 5.5" casing, can be sleeved to about 4" OD for the larger
busing 60.
[0105] The elastomeric expansion element 10 has been tested with both
5.5"
and 7" casing configurations. In both instances the element 10 has been about
5" tall
which creates a bulge or plastic deformation along the wall of the casing 12
of about
3", consistent with the 5" tall pleated ring system.
[0106] In both sizes, the lighter weight casing 7", 17 lb/ft J55 and
5.5", 14 lb/ft
J55 having wall thicknesses of about 0.25") expands to the point of permanent
deformation between 80 ¨ 90 tons of axial force.
[0107] The clearance, or drift, between the outer diameter of the
expansion
element 10 and the ID of the casing 12 is typically about 1/4", or a 1/8" gap
on the
radius. In the case of an elastomeric element, capable of multi-use, partial
extrusion
of the elastomer is inevitable, but discouraged. Beveling of the uphole and
downhole stops 52,54, or intermediate washers 46,46, minimizes cutting of the
elastomer.
[0108] Use of a sleeve on the mandrel, or changing out the mandrel for
a
larger size keeps the thickness of the annular portion of the element
generally
constant. As stated, in the 5.5 and 7 inch casing the permanent diameter
expansion
is typically 5/8" to 7/8".
[0109] The casing expansion behaves predictably with increasing axial
force
and increasing diameter once the steel of the casing begins to yield.
Applicant has
determined that it is possible to expand casing diameter by up to 1.6" which
would
26
Date Recue/Date Received 2021-05-31
completely fill the cement sheath's annular space between most casing and
formation completions.
[0110] As discussed, the expansion element 10 plastically deforms the
casing
so that the diametral compression of the cement sheath 14 is maintained after
actuation and further, in the case of a multi-use element, after removal of
the
expansion element 10 for re-positioning to a new location. While the magnitude
of
the plastic deformation can be larger than that required to shut off the
simplest
SCVF, it is however a conservative approach to ensure that all of the cement
defects
are resolved, including, micro-annular leak paths, radial cracks, "worm holes"
and
poor bonds between cement and geological formation. The minimum expansion
provided is that which creates a permanent bulge or deformation in the casing
that
does not relax when the force is removed.
[0111] In testing, Applicant has successfully multi-cycled the
elastomeric
elements for a dozen or more compression cycles. Applicant also notes that the
elastomeric appears to translate the axial force to radial force slightly more
efficiently
than the pleated ring and viscous fluid system.
[0112] In scale up, it is expected that a 220 ton (440,000 lb)/ft
setting tool will
actuate the expansion elements for plastic deformation on thicker and more
robust
casing, such as the API 5CT L80 and P110 in about 26/ft casing weights (-0.50"
wall
thickness). Applicant has successfully tested P110 casing with axial loads of
170
tons and the expansion performance is similar to the same way that the tests
for
lighter casing.
27
Date Recue/Date Received 2021-05-31
Multi-use Expansion
[0113] With reference to Figs. 9 through 13, the materials
characteristics of
casing manufactured with welded seams, such as by electrical resistance
welding,
vary at the weld area. The welded seams are typically stiffer than the parent
casing
wall material and thus are variable in their resistance to expansion.
Accordingly the
resulting periphery of the expanded casing 12 can be asymmetrical, potentially
resulting in less robust leak path remediation in the cement sheath at about
the
seam.
[0114] Accordingly, and with reference to Fig. 11, as a matter of
chance, the
seam of each connected joint of casing 12 is typically angularly offset from
the
preceding and subsequent joint. Thus in one embodiment, the setting tool 20
and
expansion element 10 are operated at two or more locations spaced along the
string
of well casing 12. The joints of casing are typically 20-40 ft (6-12m) lengths
and
movement between successive joints 12 can be easily accommodated by the
wireline or tubing conveyed setting tool 20. It is unlikely that any two
separate joints
of casing, and it is even less likely that three separate joints of casing
have the weld
seams aligned. Thus, by performing two or three expansions, the cement sheath
is
remediated about a full circumferential and annular coverage.
[0115] In the event that three, spaced expansions are not sufficient to
shut off
the SCVF, as evidence by surface testing, one can repeat as necessary without
having to replace the elastomeric element.
[0116] Turning to Fig. 9 and Figs. 10A through 10C, the setting tool 20
is
illustrated with a plurality of piston modules 26. In an embodiment, the power
28
Date Recue/Date Received 2021-05-31
module and piston modules provide about 17,000 pounds per module; for example,
nine modules generate about 80 tons and 13 modules generate110 tons.
[0117] As shown in Fig. 9 the setting tool 20 and an expansion element
is
conveyed downhole on a conveyance string or wireline 22 to a specified
location 13
along the casing 12. At Fig. 10A, the setting tool 20 is shown broken in the
middle
and pistons not illustrated for display purposes. The element 10 is actuated
radially
outwards to plastically expand the casing 12 at the specified location 13.
[0118] At Fig. 10B, the setting tool 20 is actuated to release the
expansion
element 10. The element contracts radially inward from the casing 12 to its
original
run-in dimensions. Thereafter the setting tool 20 and expansion element 10 can
be
moved along the casing, typically uphole to a successive specified location 13
and
repeating the actuating and element-releasing steps for expanding the casing
12
again. With reference to Fig. 10C, the expansion element is conveyed along the
casing to a successive specified location and repeating the actuating and
element-
releasing steps.
Setting Tool
[0119] As introduced above, the setting tool 20 provides axial forces
for
actuating the expansion element 10 axially for a corresponding radial
expansion.
[0120] With a reminder back to Fig. 4, the setting tool 2 comprises the
actuating sub supporting the first uphole stop 52, the mandrel 44 and the
second
29
Date Recue/Date Received 2021-05-31
downhole stop 54, the piston modules 26, the top adapter sub 28, and the power
unit 30.
[0121] Turning to Figs. 14A through 17, the setting tool further
comprises a
modular tubular body having a contiguous bore 102 and a modular outer sleeve
104.
The outer sleeve comprises a series of housings of at least the actuator sub
24, the
piston modules 26 and the top adapter sub 26. The downhole end 34 of the outer
sleeve forms a first uphole stop 52. The bore 102 of the actuator sub 24 is
slidably
fit with the 44 mandrel, and the mandrel is fit with the second downhole stop
54.
Whichever expansion element 10 is selected is sandwiched between the first
uphole
and second downhole stops 52,54. Above the actuator sub 24, the outer sleeve
104
comprises the piston modules 26, each module having a piston housing or
cylinder
108 fit with a hydraulic piston 106 sealably slidable therein for driving the
mandrel 44
and connected downhole stop 54 towards the uphole stop 52, compressing the
expansion element 10 therebetween.
[0122] Two or more of the pistons 106,106 ... are coupled axially to
each
other and to the mandrel 44, such as through threaded connections. As the
pistons
106, mandrel 44 and downhole stop 54 are hydraulically driven uphole, the
outer
sleeve 104 and uphole stop 52 are correspondingly and reactively driven
downhole.
Reactive, and downhole, movement of the outer sleeve 104 drives the uphole
stop
52 towards the downhole stop 54.
[0123] Each piston 106 and cylinder 108 is stepped, providing a first
uphole
upset portion 116 and a second smaller downhole portion 118. The pistons
uphole
and downhole portions are sealed slidably in the cylinder 108. Hydraulic fluid
F
Date Recue/Date Received 2021-05-31
under pressure is provided to a chamber 120, situate between the uphole and
downhole portions 116,118, which results in a net uphole piston area for an
uphole
force on the piston 106 and an equivalent downhole force on the outer sleeve
104.
[0124] As shown in Figs. 15 and 16, a plurality of the piston modules
26 are
provided which can be assembled in series for multiplying the actuating force.
Each
module 26 comprises the stepped cylinder 108 and a stepped-piston 106 therein.
As shown in Fig. 16 fluid supply passages 126 extend from the top adapter sub
28
through each piston 106 to the next piston 106. A transverse fluid passage 124
across the piston 106 is in fluid communication between the supply passage 126
and the chamber 120.
[0125] With reference to Fig. 17, the power sub 30 provides the
actuating
hydraulics for the piston modules 26. A motor 130, such as an electrical
motor, is
carried within the power sub and connected through the wireline 22 to a source
of
electric power at the well surface, the motor 130 having an output shaft 132.
A
hydraulic pump 134 is also carried within the power sub 30, having a fluid
intake 136
and fluid output 138. The pump 134 is coupled to the output shaft 132 of the
motor
130 and driven thereby. A hydraulic reservoir 135 can be fit into power sub,
or a
separate tank sub (not shown), having sufficient volume corresponding to the
number and stroke of the piston modules 26. The fluid output 138 is in fluid
communication with the ganged and stepped pistons 106,106 ... and supplies
pressurized hydraulic fluid F to the chambers 120 between the pistons 106 and
the
cylinders 108 of the sleeve 104.
31
Date Recue/Date Received 2021-05-31
[0126] The actuator sub 24 includes the mandrel 44 and a piston
connector
122 between the pistons 106 and the mandrel 44. If the expansion element 10 is
a
single use element, then the mandrel 44 is releasably coupled to the balance
of the
setting tool 20. The mandrel 44 can be fixed to the piston connector 122 or
releasable therefrom. For a multi-use element, the mandrel 44 is not
necessarily
releasably coupled, the mandrel being required during each of multiple
expansions
along the casing 12. Regardless, as if conventional for downhole, multi-
component
tools, for emergency release the mandrel 44 can be coupled with s shear screw
or
other overload safety.
[0127] For the instance of a single use expansion element, such as the
stack
40 of pleated rings 42, the mandrel 44 is releasably coupled to the adapter
sub 24.
The adapter sub 24 and mandrel 44 further include a J-mechanism 140 having a J-
slot housing 142 and a J-slot profile 144 formed in the mandrel 44. The J-slot
housing and J-slot profile are coupled using pins 146. The J-slot housing 142
is
connected to the piston connector 122 for axial movement within the adapter
sub's
outer shell 104 as delimited by the J-slot profile 144. The J-slot housing,
pin 146
and J-slot profile connect the piston connector 122 to the mandrel 44. For
managing
large axial loads, the J-slot profile 144 can have multiple redundant pin 146
and slot
144 pairs for distributing the forces.
[0128] With reference to Figs. 14A and 14B, each J-slot profile 144 has
an
uphole J-stop 152 for enabling axial force on the mandrel 44 and therefore the
downhole stop 154 to compress the expansion element 10 against the uphole stop
52. Upon completion of the expansion step, the hydraulic force on the pistons
106,
32
Date Recue/Date Received 2021-05-31
106 is released and the J-slot housing 142, and pins 146 move along the J-slot
profile 146 to an axial release slot 154. The J-slot housing 142 can be biased
to a
downhole position using a return spring 160 to release compression on the
element
10. A suitable return spring rate can be about 185 lbs/in. When the spring 160
is
compressed 2.50" results in a 462.5 lb force. The pins 146 align with the
axial
release slot 154 and the adapter sub 24 and setting tool 20 generally can be
pulled
free of and off of the mandrel 44. For stepped pistons having a large end OD
of
3.187" and a small end of OD 2.127, an assembly of 10 pistons 106 will
provided
over 110 tons of force.
[0129] In the case of a multi-use expansion element, such as the
elastomeric
element 10, the mandrel 44 remains connected to the piston connector 122 for
repeated compression and release of the element ad different specified
location 13.
If either single use or multi-use expansion elements are to be used with the
same
setting tool, the J-mechanism 140 for release of the mandrel maybe enabled or
disabled. A disabled J-mechanism 140 may include a locking pin or J-slot
blanks fit
to the J-profile to prevent J-slot operations.
Operation
[0130] As described in more detail above, and with reference again to
Figs. 9
to 10C for multi-use operations, the setting tool 20 and an expansion element
10 are
conveyed downhole to a specified location 13 along the casing 12. The element
10
is actuated radially outwards to plastically expand the casing 12 at the
specified
location 13. The setting tool 20 is actuated to release the expansion element
10.
33
Date Recue/Date Received 2021-05-31
The hydraulic fluid can be directed back the reservoir 135. The element 10
contracts radially inward from the casing 12 to its original run-in
dimensions.
Thereafter the setting tool 20 and expansion element 10 are moved along the
casing
12, typically uphole, to a successive specified location 13 for repeating the
actuating
and element-releasing steps for expanding the casing 12 again. The expansion
element moved from location to location along the casing for repeating the
actuating
and element-releasing steps.
[0131]
With reference to Fig. 11, three joints of casing 72,74,76 are illustrated,
each having a seam 82,84,86 respectively. Note a fanciful, but typical
rotational
misalignment of the seams 82,84,86. Figs. 13A, 13B and 13C correspond with
cross
sections of the expanded locations 13 for each joint of casing 72,74,76
respectively.
In Fig. 13A, a less than uniform expansion of the casing 12 illustrated at the
weld 82
with less compression and possibly less remediation of the cement sheath at
that
angular position. However, through a subsequent expansion for the successive
joint
74,the similar expansion defect at the weld 84 is rotated relative to the weld
82
below, any axial path of gas up the cement sheath past weld 82 being captured
by
the successful remediation for the successive joint 74 above. Similarly, with
reference to Fig .13C, the third joint has a potential stiff weld expansion
defect at
weld 86, but it is unlikely to be axially in line with either of the lower
welds 82,84,
again sealing the cement sheath against imperfect remediation therebelow. It
is
expected that with the large plastic expansions now possible, even the areas
of the
casing have a weld seam will be sufficiently expanded to heal the cement
sheath
thereat.
34
Date Recue/Date Received 2021-05-31
[0132] Turning to the single use element of Figs. 5A, 5B and 5C, and
with
reference also to Figs. 18A through 18E, the method of operation includes
running
the setting tool 20 downhole, setting the element 10, releasing the element,
abandoning the element and tripping out the setting tool.
[0133] In Fig. 18A, the setting tool 20 and element 10 are run into the
well
casing 12 to a specific location 13. The power sub 30 provides fluid F to the
pistons
106. The pistons 106 shift uphole, driving the downhole stop 54 uphole,
compressing the element 10 against the uphole stop 52. In Fig. 18B, one can
see a
piston chamber 120 filled with fluid F and piston connector 122 uphole, and
correspondingly the pins 146 of the J-slot housing 144 having pulled the
mandrel
and downhole stop 54 uphole to compress the element 10. As a result,
sufficient
load is applied to the expansion element 10 to expand the element radially
into the
casing 12 and plastically deform the casing 12 and impinge on the cement
sheath at
the location 13.
[0134] Turning to Fig. 18C, the hydraulic fluid pressure is released
and return
spring 160 drives J-slot housing 142 downhole. The housing pins 146 follow the
J-
slot profile 144 from the uphole stops 152 to the axial release slot 154. The
single
use expansion element 10 remains engaged with the casing 12 and the mandrel 44
may or may not move axially through the element 10.
[0135] With reference to Fig. 18D, as the pins 146 are axially aligned
with the
axial release slot 154 of the J-slot profile 144, setting tool 20 can be
pulled uphole
and the pins 146 move unrestricted along the slot 154 to leave the mandrel 44
behind in the casing 12. In Fig. 18E, the setting tool 20 continues uphole to
surface.
Date Recue/Date Received 2021-05-31
[0136] The applicant's tool 20 enables axial actuation, at a specific
location,
for plastic expansion of tubulars of various configurations including liner
hangers and
casing patches. With axial setting forces now available in the hundreds of
thousands
of pounds, and an effective axial actuation to radial displacement, casing
with wall
thicknesses of up to 1/2" or more can be permanently plastically expanded.
Such
heretofore unavailable targeted expansion of casing 12 enables the control of
flow of
cement and other fluids along micro-annular leak paths formed between the
casing
12 and surrounding cement sheath 14, and the improved wellbore cementing
procedures, and mitigation of inter-zonal communication discussed above.
[0137] While certain embodiments of a setting tool / casing expanding
tool 20
are described above, other devices capable of permanently plastically
expanding the
diameter of the casing 12 may be used to effect the casing expansions at the
desired target locations 13.
36
Date Recue/Date Received 2021-05-31
