U.S. patent application number 14/710721 was filed with the patent office on 2016-06-09 for degradable anchor device with retained granular material.
The applicant listed for this patent is Baker Hughes Incorporated. Invention is credited to Jason M. Harper, Barbara Pratt, Yingqing Xu.
Application Number | 20160160593 14/710721 |
Document ID | / |
Family ID | 56093852 |
Filed Date | 2016-06-09 |
United States Patent
Application |
20160160593 |
Kind Code |
A1 |
Xu; Yingqing ; et
al. |
June 9, 2016 |
DEGRADABLE ANCHOR DEVICE WITH RETAINED GRANULAR MATERIAL
Abstract
Therefore in one aspect, an anchoring device is disclosed,
including: a degradable substrate with a first hardness wherein an
outer extent of the degradable surface includes at least one
retaining feature; and a granular gripping material associated with
the outer extent of the degradable substrate and the at least one
retaining feature, wherein the at least one retaining feature
retains the granular gripping material and the granular gripping
material has a second hardness greater than the first hardness. In
certain embodiments, the at least one retaining feature is at least
one bump ring. In certain embodiments, the at least one bump ring
is at least one segmented bump ring. In certain embodiments, the at
least one retaining feature is at least one helical feature. In
certain embodiments, the at least one retaining feature is at least
one knurled region. In certain embodiments, the degradable
substrate includes a leading protrusion.
Inventors: |
Xu; Yingqing; (Tomball,
TX) ; Harper; Jason M.; (Cypress, TX) ; Pratt;
Barbara; (Pearland, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Incorporated |
Houston |
TX |
US |
|
|
Family ID: |
56093852 |
Appl. No.: |
14/710721 |
Filed: |
May 13, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14561523 |
Dec 5, 2014 |
|
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14710721 |
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Current U.S.
Class: |
166/382 ;
166/206 |
Current CPC
Class: |
E21B 33/1208 20130101;
E21B 33/124 20130101; E21B 23/01 20130101; E21B 33/129 20130101;
E21B 29/02 20130101 |
International
Class: |
E21B 23/01 20060101
E21B023/01 |
Claims
1. An anchoring device, comprising: a degradable substrate with a
first hardness, wherein an outer extent of the degradable surface
includes at least one retaining feature; a granular gripping
material associated with the outer extent of the degradable
substrate and the at least one retaining feature, wherein the at
least one retaining feature retains the granular gripping material
and the granular gripping material has a second hardness greater
than the first hardness.
2. The anchoring device of claim 1, wherein the at least one
retaining feature is at least one bump ring.
3. The anchoring device of claim 2, wherein the at least one bump
ring is at least one segmented bump ring.
4. The anchoring device of claim 1, wherein the at least one
retaining feature is at least one helical feature.
5. The anchoring device of claim 1, wherein the at least one
retaining feature is at least one knurled region.
6. The anchoring device of claim 1, wherein the degradable
substrate includes a leading protrusion.
7. The anchoring device of claim 6, wherein the leading protrusion
limits an engagement depth of the anchoring device.
8. The anchoring device of claim 6, wherein the leading protrusion
retains the granular gripping material.
9. A method to anchor a downhole device, comprising: providing a
degradable substrate with a first hardness, wherein an outer extent
of the degradable surface includes at least one retaining feature;
applying a granular gripping material to the outer extent of the
degradable substrate and the at least one retaining feature,
wherein the granular gripping material has a second hardness
greater than the first hardness; and retaining the granular
gripping material via the at least one retaining feature.
10. The method of claim 9, wherein the at least one retaining
feature is at least one bump ring.
11. The method of claim 10, wherein the at least one bump ring is
at least one segmented bump ring.
12. The method of claim 9, wherein the at least one retaining
feature is at least one helical feature.
13. The method of claim 9, wherein the at least one retaining
feature is at least one knurled region.
14. The method of claim 9, wherein the degradable substrate
includes a leading protrusion.
15. A down hole system, comprising: a casing string; and an
anchoring device associated with the casing string, comprising: a
degradable substrate with a first hardness, wherein an outer extent
of the degradable surface includes at least one retaining feature;
and a granular gripping material associated with the outer extent
of the degradable substrate and the at least one retaining feature,
wherein the at least one retaining feature retains the granular
gripping material and the granular gripping material has a second
hardness greater than the first hardness.
16. The downhole system of claim 15, wherein the at least one
retaining feature is at least one bump ring.
17. The downhole system of claim 16, wherein the at least one bump
ring is at least one segmented bump ring.
18. The downhole system of claim 15, wherein the at least one
retaining feature is at least one helical feature.
19. The downhole system of claim 15, wherein the at least one
retaining feature is at least one knurled region.
20. The downhole system of claim 15, wherein the degradable
substrate includes a leading protrusion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a Continuation-In-Part
Application of U.S. Non-Provisional patent application Ser. No.
14/561,523, filed Dec. 5, 2014 which is incorporated herein by
reference in its entirety.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] This disclosure relates generally to degradable slip rings
and systems that utilize same for downhole applications.
[0004] 2. Background of the Art
[0005] Wellbores are drilled in subsurface formations for the
production of hydrocarbons (oil and gas). Hydrocarbons are trapped
in various traps or zones in the subsurface formations at different
depths. In many operations, such as fracturing, it is required to
anchor devices (such as packers, bridge plugs, etc.) in a downhole
location to facilitate production of oil and gas. After such
operations, anchoring devices must be removed or destroyed before
following operations can begin. Such removal operations may be
costly and/or time consuming. It is desired to provide an anchoring
device that can provide sufficient anchoring performance while
providing desired and predictable degradation characteristics.
[0006] The disclosure herein provides controlled degradable slip
rings and systems using the same for downhole applications.
SUMMARY
[0007] In one aspect, an anchoring device is disclosed, including:
a degradable substrate with a first hardness wherein an outer
extent of the degradable surface includes at least one retaining
feature; and a granular gripping material associated with the outer
extent of the degradable substrate and the at least one retaining
feature, wherein the at least one retaining feature retains the
granular gripping material and the granular gripping material has a
second hardness greater than the first hardness.
[0008] In another aspect, a method to anchor a downhole device is
disclosed, including: providing a degradable substrate with a first
hardness, wherein an outer extent of the degradable surface
includes at least one retaining feature; applying a granular
gripping material to the outer extent of the degradable substrate
and the at least one retaining feature, wherein the granular
gripping material has a second hardness greater than the first
hardness; and retaining the granular gripping material via the at
least one retaining feature.
[0009] In another aspect, a downhole system is disclosed,
including: a casing string; and an anchoring device associated with
the casing string, including: a degradable substrate with a first
hardness, wherein an outer extent of the degradable surface
includes at least one retaining feature; and a granular gripping
material associated with the outer extent of the degradable
substrate and the at least one retaining feature, wherein the at
least one retaining feature retains the granular gripping material
and the granular gripping material has a second hardness greater
than the first hardness.
[0010] Examples of certain features of the apparatus and method
disclosed herein are summarized rather broadly in order that the
detailed description thereof that follows may be better understood.
There are, of course, additional features of the apparatus and
method disclosed hereinafter that will form the subject of the
claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The disclosure herein is best understood with reference to
the accompanying figures, wherein like numerals have generally been
assigned to like elements and in which:
[0012] FIG. 1 is a schematic diagram of an exemplary drilling
system that includes downhole elements according to embodiments of
the disclosure;
[0013] FIG. 2 is a schematic diagram of an exemplary downhole
device for use in a downhole system, such as the one shown in FIG.
1, according to one embodiment of the disclosure;
[0014] FIG. 3A shows a partial view of the substrate of an
exemplary anchoring device for use with a downhole device, such as
the downhole device shown in FIG. 2 for use with a downhole system,
according to one embodiment of the disclosure;
[0015] FIG. 3B shows a partial cross sectional view of the
anchoring device shown in FIG. 3A;
[0016] FIG. 3C shows a partial cross sectional view of the
anchoring device shown in FIG. 3A with a granular gripping
material;
[0017] FIG. 4A shows a partial view of the substrate of another
exemplary anchoring device for use with a downhole device, such as
the downhole device shown in FIG. 2 for use with a downhole system,
according to one embodiment of the disclosure;
[0018] FIG. 4B shows a partial view of the substrate of another
exemplary anchoring device for use with a downhole device, such as
the downhole device shown in FIG. 2 for use with a downhole system,
according to one embodiment of the disclosure;
[0019] FIG. 4C shows a partial view of the substrate of another
exemplary anchoring device for use with a downhole device, such as
the downhole device shown in FIG. 2 for use with a downhole system,
according to one embodiment of the disclosure; and
[0020] FIG. 4D shows a partial view of the substrate of another
exemplary anchoring device for use with a downhole device, such as
the downhole device shown in FIG. 2 for use with a downhole system,
according to one embodiment of the disclosure.
DESCRIPTION OF THE EMBODIMENTS
[0021] FIG. 1 shows an exemplary embodiment of a downhole system to
facilitate the production of oil and gas. In certain embodiments,
system 100 allows for fracturing operations to facilitate
production of oil and gas. System 100 includes a wellbore 106
formed in formation 104 with casing 108 disposed therein.
[0022] In an exemplary embodiment, a wellbore 106 is drilled from a
surface 102 to a downhole location 110. Casing 108 may be disposed
within wellbore 106 to facilitate production. In an exemplary
embodiment, casing 108 is disposed through multiple zones of
production Z1 . . . Zn in a downhole location 110. Wellbore 106 may
be a vertical wellbore, a horizontal wellbore, a deviated wellbore
or any other suitable type of wellbore or any combination
thereof.
[0023] To facilitate downhole operations, such as fracturing
operations, bridge plugs 116a, packers 116b, or other suitable
downhole devices are utilized within casing string 108. In certain
embodiments, such downhole devices 116a,b are anchored to casing
string 108 via an anchor assembly 118. In certain embodiments,
bridge plugs 116a utilize an anchor assembly 118 and frac balls 120
to isolate zones Z1 . . . Zn for fracturing operations. In certain
embodiments, frac balls 120 are disposed at a downhole location 110
to obstruct and seal fluid flow in local zone 112 to facilitate
flow to perforations 114 in conjunction with bridge plugs 116a. In
certain embodiments, packers 116b are utilized in conjunction with
anchor assembly 118 to isolate zones Z1 . . . Zn for fracturing
operations.
[0024] In certain embodiments, frac fluid 124 is pumped from a frac
fluid source 122 to a downhole location 110 to flow through
perforations 114 in a zone 112 isolated by downhole device 116a,b.
Advantageously, fracturing operations allow for more oil and gas
available for production.
[0025] After desired operations (such as fracturing operations) and
before following operations, anchoring devices 118 are often
removed or otherwise destroyed to allow the flow of oil and gas
through casing 108. In an exemplary embodiment, anchoring devices
118 are configured to anchor against casing 108 of local zone 112
until a predetermined time at which anchoring devices 118 dissolve
or degrade to facilitate the production of oil and gas.
Advantageously, in an exemplary embodiment, the anchoring devices
118 herein are formed of multiple materials to have predictable and
adjustable degradation characteristics while allowing for suitable
anchoring characteristics.
[0026] FIG. 2 shows a downhole device 216, such as a bridge plug,
packer, or any other suitable downhole device, for use downhole
systems such as the system 100 shown in FIG. 1. In an exemplary
embodiment, downhole system 200 includes downhole device 216
interfacing with casing 208 via anchor assembly 218 to anchor a
downhole device 216. In certain embodiments, a frac ball 220 is
used with downhole device 216 to isolate frac fluid flow within the
wellbore.
[0027] In an exemplary embodiment, anchor assembly 218 includes a
wedge 224 and a slip ring 228. In certain embodiments, wedge 224 is
forced downhole to force slip ring 228 outward against casing 208
to anchor against casing 208. In certain embodiments, slip ring 228
can crack or otherwise separate as it is driven against casing 208.
In certain embodiments, wedge 224 is forced via a setting tool,
explosives, or any other suitable means. In certain embodiments,
downhole device 216 further utilizes a sealing member 226 to seal
downhole device 216 against casing 208 and further resist movement.
Sealing member 226 may similarly be driven toward casing 208 via
wedge 224.
[0028] In an exemplary embodiment, a substrate of a slip ring 228
is formed of a degradable material to allow slip ring 228 to
dissolve or degrade after a desired anchoring function is
performed. In certain embodiments, a secondary material is used in
conjunction with the substrate of the slip ring 228 to anchor the
slip ring 228 against casing 208. Typically, a secondary material
is harder than casing 208 to allow slip ring 228 to partially embed
in casing 208. In certain embodiments, the downhole temperature
exposure to downhole device 216 and slip ring 228 varies from 100
to 350 degrees Fahrenheit at a particular downhole location for a
given area. Advantageously, slip ring 228 as described herein may
allow for degradation after a desired time in certain downhole
environments, while allowing suitable anchoring performance. In
certain embodiments, portions of slip ring 228 can degrade or
otherwise not prevent further downhole operations or restrict flow
within a wellbore.
[0029] FIGS. 3A, 3B and 3C show an exemplary embodiment of slip
ring 328. In an exemplary embodiment, slip ring 328 includes a
substrate 331 and a granular gripping material 330. In certain
embodiments, slip ring 328 is used with downhole devices as shown
in FIG. 2 to anchor the downhole devices against a casing.
Advantageously, slip ring 328 is a degradable device, allowing slip
ring 328 to degrade without any secondary removal or destruction
operations.
[0030] In an exemplary embodiment, substrate 331 is a degradable
material. Advantageously, by forming substrate 331 of slip ring 328
from a degradable material, a downhole device may be anchored by
slip ring 328 for the desired period of time, and then the slip
ring 328 may be disintegrated to allow further operations without
any obstructions. In certain embodiments, substrate 331 is formed
from a corrodible metal such as a controlled electrolytic metallic,
including but not limited to Intallic. Substrate 331 materials may
include: a magnesium alloy, a magnesium silicon alloy, a magnesium
aluminum alloy, a magnesium zinc alloy, a magnesium manganese
alloy, a magnesium aluminum zinc alloy, a magnesium aluminum
manganese alloy, a magnesium zinc zirconium alloy, and a magnesium
rare earth element alloy. Rare earth elements may include, but is
not limited to scandium, yttrium, lanthanum, cerium, praseodymium,
neodymium, and erbium. In certain embodiments, substrate materials
331 are further coated with aluminum, nickel, iron, tungsten,
copper, cobalt. In certain embodiments, substrate 331 materials are
consolidated and forged. In certain embodiments, the elements can
be formed into a powder and a substrate can be formed from pressed
powder. In an exemplary embodiment, the material of substrate 331
is selected based on desired degradation characteristics of slip
ring 328.
[0031] In an exemplary embodiment, substrate 331 forms a generally
cylindrical shape with an inner extent 336 and an outer extent 334.
In certain embodiments, inner extent 336 has a reducing or reduced
radius portion to allow a downhole device to be retained within the
slip ring 328. In an exemplary embodiment, the material of
substrate 331 is chosen with respect to the relative hardness of
the downhole device to prevent damage to the downhole device. In an
exemplary embodiment, outer extent 334 of slip ring 328 is
configured to interface with a casing. In an exemplary embodiment,
outer extent 334 includes granular gripping material 330 designed
to interface with casing.
[0032] In an exemplary embodiment, slip ring 328 can be configured
to break in to several sections when expanded. In certain
embodiments, slip ring 328 can be expanded by a wedge as previously
shown in FIG. 2. In order to facilitate fracturing of slip ring 328
certain embodiments of slip ring 328 include crack initiation
points 332 disposed on outer extent 334. Crack initiation points
332 include, but are not limited to cuts, grooves, slits,
perforations, etc. Crack initiation points 332 may serve as a
stress concentration point to initiate cracking, fracturing, or
separation along the longitudinal axis of slip ring 328 as slip
ring 328 is expanded. In certain embodiments, crack initiation
points 332 are formed via electrical discharge machining substrate
331.
[0033] In an exemplary embodiment, outer extent 334 includes
granular gripping material 330 configured to interface with a
casing or other suitable anchor medium. In an exemplary embodiment,
the material of granular gripping material 330 is selected to be
harder than the interfacing casing. In other embodiments, the
material of the granular gripping material 330 is the same hardness
or softer than the interfacing casing. Casing may have a hardness
of approximately 120 ksi. Casing grades may range from L80 to Q125.
Advantageously, a relatively harder anchor granular gripping
material 330 allows for granular gripping material 330 to firmly
anchor the downhole device to casing or other suitable anchor
medium. In other embodiments, granular gripping material 330
utilizes friction and casing irregularities to interface with a
casing or other suitable anchor medium. In certain embodiments,
anchor granular gripping material 330 is formed of a harder
material than substrate 331. Advantageously, materials,
particularly degradable materials, may not have a suitable hardness
to adequately anchor to a casing or other suitable anchor material,
requiring the use of a harder anchor granular gripping material 330
as described herein. Materials selected for substrate 331 and
granular gripping material 330 may be carefully selected to ensure
gripping material 330 embeds further into a casing or anchor medium
compared to substrate 331.
[0034] In an exemplary embodiment, granular gripping materials 330
are on the outer extent 334 of slip ring 328. In certain
embodiments, granular gripping materials 330 are disposed in
undercut portion 338. Advantageously, a large portion of slip ring
328 may be covered with granular gripping materials 330 to allow
for greater anchoring performance. In certain embodiments, by
covering a large portion of slip ring 328 the substrate 331 of slip
ring 328 can avoid or mitigate damage. Advantageously, by utilizing
granular gripping materials 330, a substrate 331 can be formed with
a lower strength material to allow for greater ductility of slip
ring 328. In an exemplary embodiment, granular gripping materials
330 can be generally granular form of similar sizes and of regular
or irregular shapes. In certain embodiments, granular gripping
materials 330a can be relatively larger. In other embodiments,
granular gripping materials 330b can be relatively smaller compared
to other granular gripping materials 330a. As shown in FIG. 3C the
grain size of granular material 330a,330b may vary based on
application. In certain embodiments, granular material 330a,330b is
applied to slip ring 328 in multiple layers. Advantageously, the
use of multiple layers of granular material 330a,330b can prevent
damage to substrate 331 by distributing anchor forces and allowing
harder materials (or larger granular materials) 330a to interface
with casing or anchor medium, while softer granular materials (or
smaller granular materials) 330b interface with substrate 331. In
certain embodiments, materials 330a interfacing with casing or
anchor medium have a granule size of 0.5 to 10 mm. In an embodiment
materials 330a interfacing with casing or anchor medium have a
granule size of 1 to 5 mm. In certain embodiments, materials 330b
interfacing with substrate 331 have a granule size of 1 micron to 2
mm. In an embodiment, materials 330b interfacing with substrate 331
have a granule size of 50 micron to 1 mm. In certain embodiments,
the combined thickness of layers 330a,330b ranges from 0.5 to 10
mm. In an embodiment, the combined thickness of layers 330a,330b
ranges from 2 to 5 mm. Further, the characteristics and performance
of slip ring 328 can be adjusted and designed by altering the
layers 330a,b in relation to substrate 331 and casing or anchor
medium. Advantageously, granular gripping materials 330 may be
configured to be sized and shaped to allow passage through intended
flow paths and to allow operations to continue after a substrate
331 has dissolved.
[0035] In an exemplary embodiment, granular gripping materials 330
are formed from disintegrable materials that disintegrate into
small particulates. Granular gripping materials 330 can be formed
of any suitable material, including, but not limited to oxides,
carbides, and nitrides. In certain embodiments, granular gripping
materials 330 are formed from aluminum oxide, silicon carbide,
tungsten carbide, zirconium dioxide, and silicon nitride. In
certain embodiments, granular gripping materials 330 can contain
ceramic type proppants or other high hardness materials.
[0036] In an exemplary embodiment, granular gripping materials 330
are disposed in an undercut portion 338 formed in substrate 331. In
certain embodiments, undercut portion 338 has a smaller outside
diameter than the remainder of outer extent 334 to allow the
inclusion of granular gripping materials 330 while maintaining the
same or similar outside diameter as the remainder of outer extent
334. Advantageously, undercut portion 338 may ease the application
of granular gripping material 330 and binder 339.
[0037] Granular gripping materials 330 may be attached to substrate
331 via a binder 339 or any other suitable adhesive. In certain
embodiments, the binder utilizes is degradable. Binders include,
but are not limited to toughened acrylics, epoxy, low metal point
metals (such as aluminum, magnesium, zinc, and their alloys), etc.
In other embodiments, undercut portion 338 can retain granular
gripping materials 330 without any additional components. In
certain embodiments, various sizes of granular material 330a,b are
bound by various binders 339a,b. In certain embodiments, various
binders 339a,b can vary based on size of granular material 330a,b
as well as relative location within slip ring 328.
[0038] FIGS. 4A-4D show alternative embodiments of slip ring 428.
In an exemplary embodiment, slip ring 428 includes a retaining
feature 440 formed in substrate 431. In an exemplary embodiment,
retaining feature 440 can be utilized to retain granular gripping
material when slip ring 428 is engaged against casing or other
suitable surfaces. In certain embodiments, slip ring 428 is used
with downhole devices as shown in FIG. 2 to anchor against a
casing.
[0039] In an exemplary embodiment, outer extent 434 of slip ring
428 includes at least one retaining feature 440 formed in substrate
431. Retaining feature 440 can be formed to retain a granular
gripping material to prevent the unwanted migration of the
material, particularly in high pressure and high temperature
environments. In certain embodiments, retaining feature 440 can
retain granular gripping material when the granular gripping
material is subjected to shear forces and other forces during
engagement. Advantageously, retaining feature 440 provides
additional surface area for a binder associated with the granular
gripping material as well as features to resist sliding of the
granular gripping material. Retaining features 440 can include, but
are not limited to protrusions, grooves, surface irregularities,
finishes, surface scratches, threading, holes, angled portions,
etc. Retaining features 440 can be continuous, discontinuous,
patterned, random, etc.
[0040] Referring to FIG. 4A, in an exemplary embodiment, retaining
feature 440 is at least one bump ring to prevent the sliding of
granular gripping material. Bump rings can be raised protrusions or
grooves circumferentially disposed along the outer extent 434 of
slip ring 428. In certain embodiments, bump rings can be of any
suitable height, number, pattern, etc. In certain embodiments, bump
rings can be disposed at any suitable location.
[0041] Referring to FIG. 4B, in an exemplary embodiment, retaining
feature 440 is at least one segmented bump ring to prevent the
sliding of granular gripping material. Segmented bump rings can be
raised protrusions or grooves circumferentially disposed along the
outer extent 434 of slip ring 428. In certain embodiments,
segmented bump rings can be of any suitable height, number,
pattern, etc. In certain embodiments, segmented bump rings can be
disposed at any suitable location. In certain embodiments, segments
of bump rings can be randomly disposed.
[0042] Referring to FIG. 4C, in an exemplary embodiment, retaining
feature 440 is helical feature to prevent the sliding of granular
gripping material. Helical feature can be raised protrusions or
grooves circumferentially disposed along the outer extent 434 of
slip ring 428. In certain embodiments, helical bump feature can be
of any suitable height, number, pattern, etc. In certain
embodiments, helical features can a continuous helical shape or a
segmented helical shape be disposed at any suitable location along
outer extent 434 of slip ring 428. In certain embodiments, segments
of helical features can be randomly disposed.
[0043] Referring to FIG. 4D, in other embodiments, retaining
feature 440 is a knurled or rough surface portion disposed along
outer extent 434 of slip ring 428. In certain embodiments, a
knurled, rough, or other treatment portion can be formed in
substrate 431 and disposed circumferentially, axially, etc. In
certain embodiments, surface treatments can be of any suitable
width, depth, pattern, roughness, etc. In certain embodiments,
retaining feature 440 can include either bump rings or surface
treatments in multiple locations, a combination of retaining
features 440, or any other suitable retaining feature 440 to retain
the granular gripping material.
[0044] In an exemplary embodiment, retaining feature 440 can be
integrally formed in substrate 431. Retaining feature 440 can be
formed via casting, machining, or any other suitable forming
technique. In certain embodiments, retaining feature 440 can be
formed after other portions of slip ring 428 are formed.
[0045] In certain embodiments, slip ring 428 includes a leading
protrusion 442 formed in substrate 431. Leading protrusion 442 may
be disposed on the outer extent 434 of a downhole edge of slip ring
428. During operation, a cone or other suitable device can impart a
force upon inner extent 436 to expand slip ring 428 along crack
initiation points 432. Advantageously, leading protrusion 442 can
limit expansion and travel of slip ring 428 during use by
contacting the inner walls of the casing before other portions of
slip ring 428. The expansion and travel of slip ring 428 can be
modified by adjusting the radius, width, and other parameters of
leading protrusion 442. In certain embodiments, leading protrusion
442 can further be utilized to retain granular gripping material
either alone, or in conjunction with retaining feature 440.
[0046] Therefore in one aspect, an anchoring device is disclosed,
including: a degradable substrate with a first hardness wherein an
outer extent of the degradable surface includes at least one
retaining feature; and a granular gripping material associated with
the outer extent of the degradable substrate and the at least one
retaining feature, wherein the at least one retaining feature
retains the granular gripping material and the granular gripping
material has a second hardness greater than the first hardness. In
certain embodiments, the at least one retaining feature is at least
one bump ring. In certain embodiments, the at least one bump ring
is at least one segmented bump ring. In certain embodiments, the at
least one retaining feature is at least one helical feature. In
certain embodiments, the at least one retaining feature is at least
one knurled region. In certain embodiments, the degradable
substrate includes a leading protrusion. In certain embodiments,
the leading protrusion limits an engagement depth of the anchoring
device. In certain embodiments, the leading protrusion retains the
granular gripping material.
[0047] In another aspect, a method to anchor a downhole device is
disclosed, including: providing a degradable substrate with a first
hardness, wherein an outer extent of the degradable surface
includes at least one retaining feature; applying a granular
gripping material to the outer extent of the degradable substrate
and the at least one retaining feature, wherein the granular
gripping material has a second hardness greater than the first
hardness; and retaining the granular gripping material via the at
least one retaining feature. In certain embodiments, the at least
one retaining feature is at least one bump ring. In certain
embodiments, the at least one bump ring is at least one segmented
bump ring. In certain embodiments, the at least one retaining
feature is at least one helical feature. In certain embodiments,
the at least one retaining feature is at least one knurled region.
In certain embodiments, the degradable substrate includes a leading
protrusion.
[0048] In another aspect, a downhole system is disclosed,
including: a casing string; and an anchoring device associated with
the casing string, including: a degradable substrate with a first
hardness, wherein an outer extent of the degradable surface
includes at least one retaining feature; and a granular gripping
material associated with the outer extent of the degradable
substrate and the at least one retaining feature, wherein the at
least one retaining feature retains the granular gripping material
and the granular gripping material has a second hardness greater
than the first hardness. In certain embodiments, the at least one
retaining feature is at least one bump ring. In certain
embodiments, the at least one bump ring is at least one segmented
bump ring. In certain embodiments, the at least one retaining
feature is at least one helical feature. In certain embodiments,
the at least one retaining feature is at least one knurled region.
In certain embodiments, the degradable substrate includes a leading
protrusion.
[0049] The foregoing disclosure is directed to certain specific
embodiments for ease of explanation. Various changes and
modifications to such embodiments, however, will be apparent to
those skilled in the art. It is intended that all such changes and
modifications within the scope and spirit of the appended claims be
embraced by the disclosure herein.
* * * * *