U.S. patent application number 15/484322 was filed with the patent office on 2018-10-11 for downhole plug assembly.
The applicant listed for this patent is SCHLUMBERGER TECHNOLOY CORPORATION. Invention is credited to Gregoire Jacob, Kyle Tse, Huilin Tu, John R. Whitsitt.
Application Number | 20180291700 15/484322 |
Document ID | / |
Family ID | 63711090 |
Filed Date | 2018-10-11 |
United States Patent
Application |
20180291700 |
Kind Code |
A1 |
Tu; Huilin ; et al. |
October 11, 2018 |
DOWNHOLE PLUG ASSEMBLY
Abstract
An apparatus includes a body member and a ring member. The body
member has a through passageway, and the body member includes an
outer engagement surface. The ring member has a contracted state
and an expanded state, and the ring member includes an inner
engagement surface and an outer surface. The seal member is adapted
to axially move with respect to the body member in response to the
application of an axial force such that the outer engagement
surface of the body member physically engages the inner engagement
surface of the ring member to radially expand the ring member to
transition the ring member to the expanded state and cause the
outer surface of the ring member to contact an inner wall of a
tubing string. The physical engagement of the inner engagement
surface of the ring member with the outer engagement surface of the
body member forms a seal between the ring member and the body
member. The contact of the outer surface of the ring member with
the tubing string forms a seal between the ring member and the
tubing string and secures the ring member to the tubing string. The
inner engagement surface and the outer engagement surface are
adapted to physically interact to retain the ring member in the
expanded state when the axial force is removed.
Inventors: |
Tu; Huilin; (Sugar Land,
TX) ; Tse; Kyle; (Houston, TX) ; Whitsitt;
John R.; (Houston, TX) ; Jacob; Gregoire;
(Rosharon, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOY CORPORATION |
Sugar Land |
TX |
US |
|
|
Family ID: |
63711090 |
Appl. No.: |
15/484322 |
Filed: |
April 11, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 33/128 20130101;
E21B 33/1212 20130101 |
International
Class: |
E21B 33/128 20060101
E21B033/128; E21B 33/12 20060101 E21B033/12 |
Claims
1. A method comprising: running a plug assembly inside a tubing
string of a well; and setting the plug assembly, wherein setting
the plug assembly comprises: axially, moving a seal member of the
plug assembly with respect to a body member of the plug assembly to
cause an outer engagement surface of the body member to physically
engage an inner engagement surface of a ring member of the plug
assembly to radially expand the ring member to transition the ring
member to an expanded state and cause an outer surface of the ring
member to contact an inner wall of the tubing string; using the
physical engagement of the inner engagement surface of the ring
member with the outer engagement surface of the body member to form
a seal between the ring member and the body member; using contact
of the outer surface of the ring member with the tubing string to
form a seal between the ring member and the tubing string and
secure the ring member to the tubing string; and using a physical
interaction between the inner engagement surface and the outer
engagement surface to retain the ring member in the expanded state
when the axial force is removed.
2. The method of claim 1, wherein using the physical engagement of
the inner engagement surface of the ring member with the outer
engagement surface of the body member to form the seal comprises
forming the seal between tapered surfaces.
3. The method of claim 1, wherein using the inner engagement
surface and the outer engagement surface to retain the ring member
in the expanded state comprises using the physical interaction of
tapered surfaces.
4. The method of claim 1, wherein using the physical interaction of
the inner engagement surface and the outer engagement surface to
retain the ring member in the expanded state comprises engaging
ratchet teeth of the ring member and the body member.
5. A system usable with a well comprising: a tubing string; and an
untethered object; and a plug assembly, comprising: a body member
having a through passageway, the body member comprising an outer
engagement surface and a seat adapted to catch the untethered
object to form a fluid barrier in the tubing string; and a ring
member having a contracted state and an expanded state, the ring
member comprising an inner engagement surface and an outer surface,
wherein: the seal member is adapted to axially move with respect to
the body member in response to the application of an axial force
such that the outer engagement surface of the body member
physically engages the inner engagement surface of the ring member
to radially expand the ring member to transition the ring member to
the expanded state and cause the outer surface of the ring member
to contact an inner wall of the tubing string; the physical
engagement of the inner engagement surface of the ring member with
the outer engagement surface of the body member forms a seal
between the ring member and the body member; the contact of the
outer surface of the ring member with the tubing string forms a
seal between the ring member and the tubing string and secures the
ring member to the tubing string; and the inner engagement surface
and the outer engagement surface are adapted to physically interact
to retain the ring member in the expanded state when the axial
force is removed.
6. The system of claim 5, wherein the inner engagement surface of
the ring member comprises a tapered surface, the ring circumscribes
a longitudinal axis, and the tapered surface is inclined with
respect to the axis by an angle between 5 and 10 degrees.
7. The system of claim 5, wherein the inner engagement surface of
the ring member comprises a ratchet profile.
8. The system of claim 5, wherein: the inner engagement surface of
the ring member comprises a first tapered surface; the outer
engagement surface of the body member comprises a second tapered
surface; and the first and second tapered surfaces are adapted to
form the seal between the ring member and the body member.
9. The system of claim 5, wherein: the inner engagement surface of
the ring member comprises a first tapered surface; the outer
engagement surface of the body member comprises a second tapered
surface; and the first and second tapered surfaces are adapted to
produce a friction force to retain the ring member in the expanded
state when the axial force is removed.
10. The system of claim 5, wherein: the inner engagement surface of
the ring member comprises a first tapered surface and first ratchet
teeth; the outer engagement surface of the body member comprises a
second tapered surface and second ratchet teeth; the first and
second tapered surfaces are adapted to form the seal between the
ring member and the body member; and the first and second ratchet
teeth are adapted to lock an axial position of the seal member
relative to the body member to retain the ring member in the
expanded state when the axial force is removed.
11. An apparatus comprising: a body member having a through
passageway, the body member comprising an outer engagement surface;
and a ring member having a contracted state and an expanded state,
the ring member comprising an inner engagement surface and an outer
surface, wherein: the seal member is adapted to axially move with
respect to the body member in response to the application of an
axial force such that the outer engagement surface of the body
member physically engages the inner engagement surface of the ring
member to radially expand the ring member to transition the ring
member to the expanded state and cause the outer surface of the
ring member to contact an inner wall of a tubing string; the
physical engagement of the inner engagement surface of the ring
member with the outer engagement surface of the body member forms a
seal between the ring member and the body member; the contact of
the outer surface of the ring member with the tubing string forms a
seal between the ring member and the tubing string and secures the
ring member to the tubing string; and the inner engagement surface
and the outer engagement surface are adapted to physically interact
to retain the ring member in the expanded state when the axial
force is removed.
12. The apparatus of claim 11, wherein the body member comprises a
slotted metal ring.
13. The apparatus of claim 11, wherein the inner engagement surface
of the ring member comprises a tapered surface.
14. The apparatus of claim 13, wherein the ring member
circumscribes a longitudinal axis and the tapered surface is
inclined with respect to the axis by an angle between 5 and 10
degrees.
15. The apparatus of claim 11, wherein the inner engagement surface
of the ring member comprises a ratchet profile.
16. The apparatus of claim 11, wherein: the inner engagement
surface of the ring member comprises a first tapered surface; the
outer engagement surface of the body member comprises a second
tapered surface; and the first and second tapered surfaces are
adapted to form the seal between the ring member and the body
member.
17. The apparatus of claim 11, wherein: the inner engagement
surface of the ring member comprises a first tapered surface; the
outer engagement surface of the body member comprises a second
tapered surface; and the first and second tapered surfaces are
adapted to produce a friction force to retain the ring member in
the expanded state when the axial force is removed.
18. The apparatus of claim 11, wherein: the inner engagement
surface of the ring member comprises a first tapered surface and
first ratchet teeth; the outer engagement surface of the body
member comprises a second tapered surface and second ratchet teeth;
the first and second tapered surfaces are adapted to form the seal
between the ring member and the body member; and the first and
second ratchet teeth are adapted to lock an axial position of the
seal member relative to the body member to retain the ring member
in the expanded state when the axial force is removed.
19. The apparatus of claim 18, wherein: the first ratchet teeth of
the inner engagement surface of the ring member is associated with
a first range of inner diameters of the ring member; the first
tapered surface of the inner engagement surface of the ring member
is associated with a second range of inner diameters of the ring
member; and the diameters of the first range of inner diameters are
larger than the diameters of the second range of inner
diameters.
20. The apparatus of claim 11, wherein the body member comprises a
seat to circumscribe the through passageway, and the seat is
adapted to catch an object to form a fluid barrier in the well.
21. The apparatus of claim 11, wherein the at least one of the seal
members or the body member comprises a degradable material
constructed to degrade in a time interval less than one month in a
downhole environment of the well.
Description
BACKGROUND
[0001] For purposes of preparing a well for the production of oil
or gas, at least one perforating gun may be deployed into the well
via a conveyance mechanism, such as a wireline, slickline or a
coiled tubing string. The shaped charges of the perforating gun(s)
are fired when the gun(s) are appropriately positioned to perforate
a casing of the well and form perforating tunnels into the
surrounding formation. Additional operations may be performed in
the well to increase the well's permeability, such as well
stimulation operations and operations that involve hydraulic
fracturing. The above-described perforating and stimulation
operations may be performed in multiple stages of the well.
[0002] The above-described operations may be performed by actuating
one or more downhole tools (perforating guns, sleeve valves, and so
forth) and by forming one or more fluid-diverting fluid barriers
downhole in the well.
SUMMARY
[0003] The summary is provided to introduce a selection of concepts
that are further described below in the detailed description. This
summary is not intended to identify key or essential features of
the claimed subject matter, nor is it intended to be used as an aid
in limiting the scope of the claimed subject matter.
[0004] In accordance with an example implementation, a technique
includes running a plug assembly inside a tubing string of a well;
and setting the plug assembly. Setting the plug assembly includes
axially, moving a seal member of the plug assembly with respect to
a body member of the plug assembly to cause an outer engagement
surface of the body member to physically engage an inner engagement
surface of a ring member of the plug assembly to radially expand
the ring member to transition the ring member to an expanded state
and cause an outer surface of the ring member to contact an inner
wall of the tubing string; using the physical engagement of the
inner engagement surface of the ring member with the outer
engagement surface of the body member to form a seal between the
ring member and the body member; using contact of the outer surface
of the ring member with the tubing string to form a seal between
the ring member and the tubing string and secure the ring member to
the tubing string; and using a physical interaction between the
inner engagement surface and the outer engagement surface to retain
the ring member in the expanded state when the axial force is
removed.
[0005] In accordance with another example implementation, a system
that is usable with a well includes a tubing string, an untethered
object and a plug assembly. The plug assembly includes a body
member and a ring member. The body member has a through passageway,
and the body member includes an outer engagement surface and a seat
that is adapted to catch the untethered object to form a fluid
barrier in the tubing string. The ring member has a contracted
state and an expanded state; and the ring member includes an inner
engagement surface and an outer surface. The seal member is adapted
to axially move with respect to the body member in response to the
application of an axial force such that the outer engagement
surface of the body member physically engages the inner engagement
surface of the ring member to radially expand the ring member to
transition the ring member to the expanded state and cause the
outer surface of the ring member to contact an inner wall of the
tubing string. The physical engagement of the inner engagement
surface of the ring member with the outer engagement surface of the
body member forms a seal between the ring member and the body
member. The contact of the outer surface of the ring member with
the tubing string forms a seal between the ring member and the
tubing string and secures the ring member to the tubing string. The
inner engagement surface and the outer engagement surface are
adapted to physically interact to retain the ring member in the
expanded state when the axial force is removed.
[0006] In accordance with yet another example implementation, an
apparatus includes a body member and a ring member. The body member
has a through passageway, and the body member includes an outer
engagement surface. The ring member has a contracted state and an
expanded state, and the ring member includes an inner engagement
surface and an outer surface. The seal member is adapted to axially
move with respect to the body member in response to the application
of an axial force such that the outer engagement surface of the
body member physically engages the inner engagement surface of the
ring member to radially expand the ring member to transition the
ring member to the expanded state and cause the outer surface of
the ring member to contact an inner wall of a tubing string. The
physical engagement of the inner engagement surface of the ring
member with the outer engagement surface of the body member forms a
seal between the ring member and the body member. The contact of
the outer surface of the ring member with the tubing string forms a
seal between the ring member and the tubing string and secures the
ring member to the tubing string. The inner engagement surface and
the outer engagement surface are adapted to physically interact to
retain the ring member in the expanded state when the axial force
is removed.
[0007] Advantages and other features will become apparent from the
following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIGS. 1A and 1B are schematic diagrams of a well
illustrating the use of a plug assembly in connection with a well
stimulation operation according to an example implementation.
[0009] FIGS. 2 and 5 are perspective views of plug assemblies
according to example implementations.
[0010] FIG. 3A is a cross-sectional view of a portion of a well
illustrating the running of the plug assembly of FIG. 2 into a
tubing string according to an example implementation.
[0011] FIG. 3B is a cross-sectional view of the portion of the well
illustrating the setting of the plug assembly in the tubing string
according to an example implementation.
[0012] FIG. 3C is a cross-sectional view of the portion of the well
illustrating a fluid barrier formed in the tubing string using the
plug assembly according to an example implementation.
[0013] FIG. 4 is an illustration of physical interaction of ratchet
teeth of a seal member with ratchet teeth of a plug assembly of a
body member of the plug assembly according to an example
implementation.
[0014] FIG. 6A is a cross-sectional view of a portion of the well
illustrating the running of the plug assembly of FIG. 5 into a
tubing string according to an example implementation.
[0015] FIG. 6B is a cross-sectional view of the portion of the well
illustrating the setting of the plug assembly in the tubing string
according to an example implementation.
[0016] FIG. 6C is a cross-sectional view of the portion of the well
illustrating a fluid barrier formed from the plug assembly of FIG.
5 according to an example implementation.
[0017] FIG. 7 is an illustration of physical interaction of an
engagement surface of a seal member of a plug assembly with an
engagement surface of a body member of the plug assembly according
to an example implementation.
[0018] FIG. 8 is a flow diagram illustrating a technique to form a
fluid barrier in a tubing string according to an example
implementation.
DETAILED DESCRIPTION
[0019] In the following description, numerous specific details are
set forth but implementations may be practiced without these
specific details. Well-known circuits, structures and techniques
have not been shown in detail to avoid obscuring an understanding
of this description. "An implementation," "example implementation,"
"various implementations" and the like indicate implementation(s)
so described may include particular features, structures, or
characteristics, but not every implementation necessarily includes
the particular features, structures, or characteristics. Some
implementations may have some, all, or none of the features
described for other implementations. "First", "second", "third" and
the like describe a common object and indicate different instances
of like objects are being referred to. Such adjectives do not imply
objects so described must be in a given sequence, either
temporally, spatially, in ranking, or in any other manner.
"Coupled", "connected", and their derivatives are not synonyms.
"Connected" may indicate elements are in direct physical or
electrical contact with each other and "coupled" may indicate
elements co-operate or interact with each other, but they may or
may not be in direct physical or electrical contact. Also, while
similar or same numbers may be used to designate same or similar
parts in different figures, doing so does not mean all figures
including similar or same numbers constitute a single or same
implementation. Although terms of directional or orientation, such
as "up," "down," "upper," "lower," "uphole," "downhole," and the
like, may be used herein for purposes of simplifying the discussion
of certain implementations, it is understood that these
orientations and directions may not be used in accordance with
further example implementations.
[0020] In accordance with example implementations, a plug assembly
may be run into a tubing string (a casing string, for example) of a
well for purposes of forming a fluid barrier at a target downhole
location. For example, the plug assembly may be run downhole inside
the tubing string on a conveyance mechanism (a coiled tubing string
or a wireline, as examples), and when the plug assembly is at the
target location, a setting tool may be actuated for purposes for
causing the plug assembly to radially expand to engage the wall of
the tubing string to anchor the plug assembly in place. Moreover,
in the setting of the plug assembly, a fluid seal may be formed
between the plug assembly and the tubing string wall. The plug
assembly may have a through passageway that may be blocked to form
a fluid obstruction, or barrier, by deploying an untethered object
(an activation ball, for example) inside the tubing string
passageway such that the untethered object travels down through the
tubing string passageway to land in an internal seat of the plug
assembly.
[0021] The fluid barrier may be used in connection with a well
stimulation operation. For example, in accordance with some
implementations, the fluid barrier may be used to divert fluid to
the surrounding formation in a hydraulic fracturing operation.
[0022] In accordance with example implementations, the plug
assembly includes a sealing member, or ring, which is radially
expanded downhole inside the tubing string for purposes of
securing, or anchoring, the plug assembly to the tubing string wall
and forming a seal for the plug assembly between the sealing ring
and the tubing string wall. In accordance with example
implementations, the sealing ring has both an inner profile and an
outer profile, which do not significantly change (other than having
increased corresponding diameters) when the sealing ring is
transitioned from its radially contracted state to its radially
expanded state. The preservation of these profiles allows an inner
engagement surface of the sealing member to be used to both anchor
and seal against a body member of the plug assembly.
[0023] More specifically, in accordance with example
implementations, the plug assembly has a tapered inner engagement
surface that is constructed to physically engage an outer
engagement surface of the body member for purposes of radially
expanding the sealing ring. Moreover, the engagement of these
surfaces locks, or anchors, the positions of the sealing ring and
body member with respect to each other, forms a fluid seal between
these elements and in general, secures the plug assembly in place
in the tubing string.
[0024] In accordance with various example implementations that are
described herein, the tapered engagement surfaces of the sealing
ring and body member of the plug assembly may be smooth surfaces;
surfaces having ratchet teeth; surfaces having smooth portions and
portions having ratchet teeth; and so forth.
[0025] As a more specific example, FIG. 1A depicts a well 100 in
accordance with some implementations. The well 100 includes a
laterally extending wellbore 120, which traverses one or more
hydrocarbon-bearing formations. For the specific implementation
depicted in FIG. 1A, the wellbore 120 is lined and supported by a
tubing string 130. The tubing string 130 may be cemented to the
wellbore 120 (i.e., the tubing string 130 may be a casing); or the
tubing string 130 may be anchored or secured, to the surrounding
formation(s) by one or multiple packers (i.e., the tubing string
130 may be installed in an "open hole wellbore"). For the specific
example of FIG. 1A, the tubing string 130 is a casing that has been
run into the wellbore 120, and a cementing operation has been
performed to place cement 140 in the annular region between the
exterior of the casing and the wall of the wellbore 120.
[0026] It is noted that although FIG. 1A depicts a laterally
extending wellbore, the technique systems that are disclosed herein
may likewise apply to vertically extending wellbores. Moreover, in
accordance with example implementations, the well 100 may contain
multiple wellbores, which contain tubing strings that are similar
to the tubing string 130 of FIG. 1A. The well 100 may be a subsea
well or may be a terrestrial well depending on the particular
implementation. Additionally, the well 100 may be an injection well
or may be a production well, depending on the particular
implementation. Thus, many implementations are contemplated, which
are within the scope of the appended claims.
[0027] As depicted in FIG. 1A, the tubing string 130 extends from a
heel end 141 of a lateral segment 121 of the wellbore 120 to a toe
end 143 of the segment 121. The lateral segment 121 may be
associated with multiple stages, which may be isolated and
stimulated separately.
[0028] For the specific example depicted in FIG. 1A, a plug
assembly 150 has been set and thus, anchored, or secured, to the
tubing string 130 at a target downhole location. For this example,
the plug assembly 150 is located in a zone, or stage, of the well
100 to be fractured. In this manner, as shown in FIG. 1A, hydraulic
communication with the surrounding formation may have been enhanced
through, for example, a perforating operation that formed
perforations 134 that extend through the surrounding tubing string
wall and into the surrounding formation. Hydraulic communication
may be enhanced using other techniques (abrasive jetting
operations, for example). The plug assembly 150 may be set at the
lower end of the zone to be fractured, as illustrated in FIG.
1A.
[0029] Referring to FIG. 1B, an untethered object (an activation
sphere, or ball 170, as an example), may be deployed inside the
central passageway of the tubing string 130 to land in a seat 154
of the plug assembly 150 for purposes of sealing a through
passageway of the set plug assembly to form a fluid barrier inside
the tubing string 130. In this regard, after the fluid barrier is
formed, a well stimulation operation may be performed that relies
on the fluid barrier. For example, a hydraulic fracturing operation
may be performed in which a fracturing fluid is pumped into the
tubing string 130, and the fluid barrier diverts the fluid into the
surrounding formation.
[0030] In the context of this application, an "untethered object"
refers to an object that is communicated downhole through the
passage of a tubing string along at least part of its path without
the use of a conveyance line (a slickline, a wireline, a coiled
tubing string, and so forth). As examples, the untethered object
may be a ball (or sphere), a dart or a bar. Regardless of its
particular form, the untethered object travels through the
passageway of the tubing string to land in the object catching seat
of the plug assembly to form a corresponding fluid obstruction, or
barrier.
[0031] Referring to FIG. 2, in accordance with example
implementations, the plug assembly 150 includes a sealing member,
or ring 220, which has two states: a radially retracted state for
purposes of running the plug assembly 150 downhole inside a tubing
string; and a radially expanded state for purposes of anchoring and
sealing the plug assembly 150 to the tubing string wall. As
depicted in FIG. 2, in accordance with example implementations, the
sealing ring 220 may be a slotted metal sealing ring similar to a
slotted metal sealing ring that is described in U.S. Patent
Publication No. US 2016/0333661, entitled, "METAL SEALING DEVICE,"
which has a publication date of Nov. 17, 2016, and is hereby
incorporated by reference in its entirety. Sealing rings other than
a slotted metal sealing ring may be used, in accordance with
further example implementations.
[0032] The plug assembly 150 further includes a tubular body member
230. In general, the body member 230 has an outer, tapered surface
(not depicted in FIG. 2), which engages an inner tapered surface
(not depicted in FIG. 2) of the sealing ring 220 for purposes of
radially expanding the sealing ring 220. Moreover, the contacting
tapered services both secure, or anchor, the sealing ring 220 to
the body 230 to lock, or secure, the sealing ring 220 in its
radially expanded state and form a fluid seal between the sealing
ring 220 and the body member 230.
[0033] As depicted in FIG. 2, in accordance with some
implementations, the plug assembly 150 may be run downhole inside
the tubing string 130 on a setting tool, which includes a setting
sleeve 210 and an inner mandrel. More specifically, when the plug
assembly 150 is at the target downhole location in which a fluid
barrier is to be formed, an actuator (not shown in FIG. 2) produces
an axial force along a longitudinal axis 201 to shear, shear screws
214 (which confine movement of the setting sleeve 210 when the plug
assembly 150 is being run downhole) to allow the setting sleeve 210
to move axially along the longitudinal axis 201 and force the
sealing ring 220 against the body member 230 to transition the
sealing sleeve 220 into its regularly expanded state.
[0034] Among the other features of the plug assembly 150, in
accordance with some implementations, the plug assembly 150 may
include one or multiple slips 256 for purposes of enhancing the
anchoring of the plug assembly 150 to the tubing wall, one or more
corresponding slip bases 260 for purposes of forcing the slips 256
against the tubing wall in response to the axial movement of the
setting sleeve 210, and a shear ring 254 for purposes of confining
movement of the slip base(s) 260 during the running of the plug
assembly 150 downhole. Moreover, as depicted in FIG. 2, in
accordance with some implementations, the setting tool may include
a lower body member 250 for purposes of providing a downhole stop
against which the setting sleeve 220 acts to radially expand the
sealing ring 220.
[0035] FIG. 3A is a cross-sectional view depicting the running of
the plug assembly 150 downhole inside the tubing string 130. As
shown, in this state, the plug assembly 150 has an overall radially
contracted outer diameter to allow the plug assembly 150 to freely
pass through the central passageway of the tubing string 130. When
the plug assembly 150 is at the targeted downhole location inside
the tubing string 130, the setting tool may then be remotely
activated (via a wireline-communicated command, for example), which
causes the setting tool to apply an axial force to the setting
sleeve 210 to set the plug assembly, as depicted in FIG. 3B. In
this manner, as shown in FIG. 3B, the setting sleeve 210 translates
along the longitudinal axis 201 and contacts the uphole end of the
sealing ring 220 to cause an inner tapered surface 312 of the
sealing ring 220 to slide against a tapered outer surface 312 of
the body member 230. Axial movement of the sealing ring 220, in
turn, causes the sealing ring 220 to radially expand, due to the
interaction of the tapered surfaces 310 and 312. Continued movement
of the setting sleeve continues until, as depicted in FIG. 3B, an
internal annular shoulder of the setting sleeve 210 contacts an
uphole end of the inner mandrel of the setting tool to cause the
mandrel to move the lower body member 250 to sheer pins 252 to
release the setting tool from the plug assembly 150. Before the
setting tool is released, however, the movement of the inner
mandrel engages an inner surface of the body member 230 to cause
the body member 230 to act against the slip bodies 260 to radially
expand the slips 256.
[0036] FIG. 3C depicts the plug assembly 150 after removal of the
setting tool and after deployment of an untethered object (such as
an activation ball 330), which lands in an internal, annular seat
of the body member 230 to form a fluid seal in the interior
passageway of the plug assembly 150. Moreover, with this internal
fluid seal and the corresponding fluid seals formed between the
body member 230 and seal ring 220, and the seal between the sealing
ring 220 and the tubing string wall, a fluid barrier is formed
inside the tubing string 130.
[0037] Referring to FIG. 4, in accordance with example
implementations, the inner surface 310 of the sealing ring 220 may
include annularly extending ratchet teeth 412, which are
constructed to engage corresponding ratchet teeth 414 of the outer
engagement surface 312 of the body member 230. In this manner, the
axial force produced by the setting tool slides the ratchet teeth
412 with respect to the ratchet teeth 414 so that when the axial
force is removed (due to the release of the setting tool), the
interaction between the ratchet teeth 412 and 414 secures, or
anchors, the sealing ring 220 relative to the body member 230.
Moreover, in accordance with some implementations, the engagement
of the ratchet teeth 412 and 414 form a fluid seal between the
sealing ring 220 and the body member 230.
[0038] In accordance with some implementations, the tapered surface
of the sealing ring 220 may be at an angle between 5 to 10 degrees
of the longitudinal axis 210, and in accordance with some
implementations, the angle may be approximately 7 degrees.
Moreover, in accordance with example implementations, the tapered
surface of the body member 230 may have the same taper angle as the
taper angle for the sealing ring 220.
[0039] In accordance with further example implementations, a plug
assembly may have a sealing ring and body member, which have
corresponding tapered surfaces without ratchet teeth. More
specifically, referring to FIG. 5, in accordance with further
example implementations, a plug assembly 500 may be deployed
downhole and include a sealing ring 520, which has an interior,
tapered and smooth surface (not depicted in FIG. 5) that is
constructed to physically engage a corresponding exterior tapered
and smooth surface (not depicted in FIG. 5) of a body member 530.
In general, some elements of the plug assembly 500 are similar to
the plug assembly 150 (FIG. 2), with different reference numerals,
such as reference numerals 520 and 530, being used to denote
different elements for the plug assembly 500.
[0040] Referring to FIG. 6A, similar to the plug assembly 150, the
plug assembly 500 may be run downhole inside the tubing string 150
in a radially contracted state and radially expanded, as depicted
in FIG. 6B, for purposes of setting the plug assembly 500. In this
manner, as shown in FIG. 6B, the setting of the plug assembly 500
includes axially moving the setting sleeve 210 to cause the sealing
ring 520 to regularly expand due to the physical interaction
between a smooth tapered interior surface 610 of the sealing ring
520 with a relatively smooth exterior tapered surface 612 of the
body member 530.
[0041] The tapered surfaces 610 and 612, in turn, perform dual
functions, in accordance with example implementations: the tapered
surfaces 610 and 612 form a fluid seal between the sealing ring 520
and body member 530; and the tapered surfaces 610 and 612 secure,
or lock, the sealing ring 520 to the body member 530 due to a
frictional contact force, which resists axial separation of these
elements when the setting tool removes the axially applied force to
leave the plug assembly 150 set inside the well, as depicted in
FIG. 6C. Moreover, as depicted in FIG. 6C, an untethered object
such as the activation ball 330, may be deployed inside the tubing
string 130 to land in a seat of the body member 530 for purposes of
forming a fluid barrier inside the tubing string 130.
[0042] In accordance with example implementations, the smooth,
tapered surfaces 610 and 612 may each have a tapered angle with
respect to the longitudinal axis 201 between 5 to 10 degrees (an
angle of 7 degrees, for example).
[0043] Other variations are contemplated, which are within the
scope of the appended claims. For example, as described above, the
plug assembly 150 (FIG. 2) includes a tapered surface having a
ratcheting profile, and the plug assembly 500 (FIG. 5) includes
smooth tapered surfaces. However, in accordance with further
example implementations, a plug assembly may have a combination of
surfaces. More specifically, referring to FIG. 7, in accordance
with some implementations, a plug assembly may have a sealing ring
720 and a body member 730, which have tapered surfaces that each
have ratchet teeth and smooth portions. In this regard, as shown in
FIG. 7, in accordance with some implementations, the ratchet teeth
may be located on the smaller inner diameter portions, and the
smooth portions may be located on the larger inner diameter
portions of the sealing ring 720 and body member 730.
[0044] Due to this relationship, when the setting tool sleeve 210
forces the sealing ring 720 into the position depicted in FIG. 7,
the ratchet teeth engage to lock the position of the sealing ring
720 with respect to the body member 730, and the smooth surfaces
engage each other to form a fluid seal between the sealing ring 720
and body member 730. In accordance with some implementations, the
inner surface of the sealing ring 720 and the outer surface of the
body member 730 may have a tapered angle with respect to the
longitudinal axis 201 between 5 to 10 degrees (a tapered angle of 7
degrees, for example).
[0045] Referring to FIG. 8, thus, in accordance with example
implementations, a technique 800 to form a fluid barrier inside a
tubing string in a well includes running (block 804) a plug
assembly inside the tubing string; setting (block 808) the plug
assembly in response to the application of an axial force; and
using (block 812) a physical engagement of an inner engagement
surface of a sealing ring of the plug assembly with an outer
engagement surface of a body member of the plug assembly to form a
seal between the sealing ring and the body member. The technique
includes using (block 816) contact of the outer surface of the ring
member with the tubing string to form a seal between the sealing
ring and the tubing string and secure the sealing ring to the
tubing string; and using (block 820) physical interaction between
the inner engagement surface and the outer engagement surface to
retain the ring member in the expanded state when the axial force
is removed.
[0046] The plug assembly may be constructed from one or multiple
degradable or dissolvable materials, in accordance with example
implementations. In this manner, although, in accordance with some
implementations, the plug assembly may be removed through a milling
operation, in accordance with further example implementations, one
or more components of the plug assembly may include degradable, or
dissolvable, materials to create a temporary fluid barrier so that
the segment, or zone, inside the tubing string above the plug
assembly may be fractured over a relatively short window of time (a
window of one to twelve hours, for example). After these
component(s) dissolve, the fluid barrier is thus removed, thereby
allowing the through passageway of the plug assembly to allow fluid
flow from zones below the plug assembly and access through the
region of the tubing string in which the fluid barrier was
previously formed.
[0047] In accordance with some implementations, the untethered
object (an activation ball, for example) may be formed from one or
multiple degradable, or dissolvable materials.
[0048] Thus, in accordance with example implementations, the plug
assembly and/or untethered object may include one or multiple
materials, which degrade, or dissolve, after the fracturing
operation has been completed. The degradable material(s) of the
plug assembly may ideally degrade over a relatively longer time
window (a time window of several days, weeks or months, as
examples) as compared to the time window over which the untethered
object degrades. Thus, a relatively fast dissolving untethered
object, such as an activation ball, may be deployed to seal the
through passageway of the plug assembly, thereby isolating the zone
above the plug assembly from other zones below the plug assembly.
After a well stimulation the relies on the fluid barrier is over,
the untethered object dissolves at a relatively fast rate, and then
the plug assembly may dissolve, at a relatively slower rate to
completely remove the restriction created by the plug assembly.
[0049] In accordance with example implementations, the dissolvable
or degradable material may be the same as one or more of the alloys
that are discussed in the following patents and patent
applications, which have an assignee in common with the present
application: U.S. Pat. No. 7,775,279, entitled, "DEBRIS-FREE
PERFORATING APPARATUS AND TECHNIQUE," which issued on Aug. 17,
2010; U.S. Pat. No. 8,211,247, entitled, "DEGRADABLE COMPOSITIONS,
APPARATUS COMPOSITIONS COMPRISING SAME, AND A METHOD OF USE," which
issued on Jul. 3, 2012; PCT Application Pub. No. WO 2016/085798,
entitled, "SHAPING DEGRADABLE MATERIAL," having a publication date
of Jun. 2, 2016; PCT Application Pub. No. WO 2016/085804, entitled,
"SEVERE PLASTIC DEFORMATION OF DEGRADABLE MATERIAL," having a
publication date of Jun. 2, 2016; PCT Application Pub. No. WO
2016/085806, entitled, "BLENDING OF WATER REACTIVE POWDERS," having
a publication date of Jun. 2, 2016; PCT Application Pub. No. WO
2015/184041, entitled, "DEGRADABLE POWDER BLEND," having a
publication date of Dec. 3, 2015; and PCT Application Pub. No. WO
2015/184043, entitled, "DEGRADABLE HEAT TREATABLE COMPONENTS,"
having a publication date of Dec. 3, 2015.
[0050] While the present techniques have been described with
respect to a number of embodiments, it will be appreciated that
numerous modifications and variations may be applicable therefrom.
It is intended that the appended claims cover all such
modifications and variations as fall within the scope of the
present techniques.
* * * * *