U.S. patent application number 15/415658 was filed with the patent office on 2018-07-26 for rotating stage collar.
The applicant listed for this patent is Tesco Corporation. Invention is credited to Hendrik Schalk Le Roux, Nick Mawford, Conrad Ojong Ojong.
Application Number | 20180209223 15/415658 |
Document ID | / |
Family ID | 62905735 |
Filed Date | 2018-07-26 |
United States Patent
Application |
20180209223 |
Kind Code |
A1 |
Ojong; Conrad Ojong ; et
al. |
July 26, 2018 |
ROTATING STAGE COLLAR
Abstract
The disclosed embodiments include a rotating stage collar. The
rotating stage collar includes an upper collar configured to couple
to a first length of tubular, a lower collar configured to couple
to a second length of tubular, and an inner sleeve disposed within
the upper collar and the lower collar, wherein the upper collar and
the lower collar are rotationally fixed to one another when the
inner sleeve is in a first position within the upper collar and the
lower collar, wherein the upper collar and the lower collar are
rotationally independent of one another when the inner sleeve is in
a second position within the upper collar and the lower collar, and
wherein the second position is axially beneath the first position
relative to a longitudinal axis of the rotating stage collar when
the rotating stage collar is positioned within a wellbore.
Inventors: |
Ojong; Conrad Ojong;
(Spring, TX) ; Le Roux; Hendrik Schalk;
(Lafayette, LA) ; Mawford; Nick; (Cypress,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tesco Corporation |
Houston |
TX |
US |
|
|
Family ID: |
62905735 |
Appl. No.: |
15/415658 |
Filed: |
January 25, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 17/08 20130101;
E21B 17/05 20130101; E21B 33/146 20130101; E21B 2200/06
20200501 |
International
Class: |
E21B 17/046 20060101
E21B017/046; E21B 34/10 20060101 E21B034/10; E21B 33/14 20060101
E21B033/14 |
Claims
1. A system, comprising: a rotating stage collar, comprising: an
upper collar configured to couple to a first length of tubular; a
lower collar configured to couple to a second length of tubular;
and an inner sleeve disposed within the upper collar and the lower
collar, wherein the upper collar and the lower collar are
rotationally fixed to one another when the inner sleeve is in a
first position within the upper collar and the lower collar,
wherein the upper collar and the lower collar are rotationally
independent of one another when the inner sleeve is in a second
position within the upper collar and the lower collar, and wherein
the second position is axially beneath the first position relative
to a longitudinal axis of the rotating stage collar when the
rotating stage collar is positioned within a wellbore.
2. The system of claim 1, wherein inner sleeve comprises a
plurality of locking dogs extending radially outward from the inner
sleeve through respective guide slots of the upper collar, the
lower collar comprises a plurality of locking slots, and the
plurality of locking dogs extends into the plurality of locking
slots and radially overlaps with the plurality of locking slots
when the inner sleeve is in the first position.
3. The system of claim 2, wherein the lower collar comprises a
cavity disposed axially beneath the plurality of locking slots
relative to the longitudinal axis of the rotating stage collar when
the rotating stage collar is positioned within the wellbore, and
the plurality of locking dogs is disposed within the cavity when
the inner sleeve is in the second position.
4. The system of claim 1, wherein the rotating stage collar
comprises a load nut disposed radially about the upper collar and
the lower collar, and the load nut is threaded to the lower
collar.
5. The system of claim 4, wherein the upper collar comprises a load
shoulder, and the load shoulder is axially captured between an
upper shoulder of the load nut and an axial end face of the lower
collar.
6. The system of claim 4, wherein the rotating stage collar
comprises a first thrust bearing disposed axially between the load
shoulder and the upper shoulder of the load nut and a second thrust
bearing disposed axially between the load shoulder and the axial
end face of the lower collar.
7. The system of claim 1, wherein the inner sleeve is axially
fixedly attached to the upper collar via a plurality of shear
screws when the inner sleeve is in the first position.
8. The system of claim 7, wherein the inner sleeve is rotationally
fixed to the upper collar via a plurality of locking dogs extending
through respective guide slots of the upper collar when the inner
sleeve is in the second position.
9. The system of claim 1, wherein the inner sleeve comprises a plug
seat formed in an inner diameter of the inner sleeve.
10. The system of claim 9, comprising a plug configured to land
against the plug seat and occlude an inner passage of the rotating
stage collar.
11. The system of claim 1, wherein the upper collar comprise a
plurality of cement ports formed in an outer surface of the upper
collar, and the inner sleeve occludes the plurality of cement ports
when the inner sleeve is in the first position.
12. The system of claim 11, wherein the plurality of cement ports
is open from an inner passage of the rotating stage collar to an
outer surface of the upper collar when the inner sleeve is in the
second position.
13. A system, comprising: a first tubular configured to be secured
within a wellbore; a second tubular configured to be secured within
the wellbore; and a rotating stage collar, comprising: an upper
collar coupled to the first tubular; a lower collar coupled to the
second tubular; a load nut disposed radially about the upper collar
and threaded to the lower collar; and an inner sleeve disposed
within the upper collar and the lower collar, wherein the upper
collar and the lower collar are rotationally fixed relative to one
another when the inner sleeve is in a first position within the
upper collar and the lower collar, and the upper collar and lower
collar are rotationally independent of one another when the inner
sleeve is in a second position within the upper collar and the
lower collar, and wherein the second position is axially beneath
the first position relative to a longitudinal axis of the rotating
stage collar when the rotating stage collar is positioned within
the wellbore.
14. The system of claim 13, wherein the first tubular comprises a
first length of casing, and the second tubular comprises a second
length of casing.
15. The system of claim 13, comprising a plug configured to land
against a plug seat of the inner sleeve to occlude an inner passage
of the rotating stage collar.
16. The system of claim 13, wherein the lower collar comprises a
plurality of slots formed in an inner diameter of the lower collar
and a cavity formed in the inner diameter of the lower collar,
wherein the cavity is axially beneath the plurality of slots
relative to the longitudinal axis of the rotating stage collar when
the rotating stage collar is positioned within the wellbore; and
wherein the inner sleeve comprises a plurality of locking dogs
extending radially outward from the inner sleeve, wherein the
plurality of locking dogs is radially aligned with the plurality of
slots relative to the longitudinal axis in the first position, and
wherein the plurality of locking dogs is radially aligned with the
cavity relative to the longitudinal axis in the second
position.
17. The system of claim 13, wherein the upper collar comprises a
plurality of ports extending from an outer surface of the upper
collar to an inner surface of the upper collar, wherein the inner
sleeve occludes the plurality of ports when the inner sleeve is in
the first position, and wherein the plurality of ports is open when
the inner sleeve is in the second position.
18. A method, comprising: coupling a lower collar of a rotating
stage collar to a first stage of casing; coupling an upper collar
of the rotating stage collar to a second stage of casing;
positioning the first stage of casing, the rotating stage collar,
and the second stage of casing into a wellbore; rotating the first
stage of casing, the rotating stage collar, and the second stage of
casing while completing a first stage cementing process; displacing
an inner sleeve of the rotating stage collar axially downward
within the upper collar and the lower collar to rotationally
disengage the upper collar from the lower collar; and rotating the
second stage of casing without rotating the first stage of casing
while completing a second stage cementing process.
19. The method of claim 18, wherein displacing the inner sleeve of
the rotating stage collar axially downward within the upper collar
and the lower collar comprises: launching a plug down the second
stage of casing to the rotating stage collar; landing the plug
against a plug seat of the inner sleeve; shearing pins coupling the
inner sleeve to the upper collar; and displacing a plurality of
locking dogs of the inner sleeve axially downward to disengage the
plurality of locking dogs from a plurality of slots formed in the
lower collar.
20. The method of claim 18, wherein displacing the inner sleeve of
the rotating stage collar axially downward within the upper collar
and the lower collar comprises opening a plurality of cement ports
formed in the upper collar, wherein each of the plurality of cement
ports extends from an inner surface of the upper collar to an outer
surface of the upper collar.
Description
FIELD OF DISCLOSURE
[0001] The present disclosure relates generally to the field of
well drilling operations. More specifically, embodiments of the
present disclosure relate to rotating stage collars for use with
casing and cementing in a down-hole environment.
BACKGROUND
[0002] In conventional oil and gas operations, a well is typically
drilled to a desired depth with a drill string, which includes
drill pipe and a drilling bottom hole assembly (BHA). Once the
desired depth is reached, the drill string is removed from the hole
and casing is run into the vacant hole. In some conventional
operations, the casing may be installed as part of the drilling
process. A technique that involves running casing at the same time
the well is being drilled may be referred to as
"casing-while-drilling."
[0003] Casing may be defined as pipe or tubular that is placed in a
well to prevent the well from caving in, to contain fluids, and to
assist with efficient extraction of product. When the casing is
properly positioned within a hole or well, the casing is typically
cemented in place by pumping cement through the casing and into an
annulus formed between the casing and the hole (e.g., a wellbore or
parent casing). As the cement is pumped through the casing and into
the annulus, the casing may be rotated within the wellbore to help
facilitate proper migration and settling of the casing within the
annulus. Once a casing string has been positioned and cemented in
place or installed, the process may be repeated via the now
installed casing string. For example, the well may be drilled
further by passing a drilling BHA through the installed casing
string and drilling. Further, additional casing strings may be
subsequently passed through the installed casing string (during or
after drilling) for installation. Indeed, numerous levels of casing
may be employed in a well, with each level having multiple stages.
For example, once a first string of casing is in place, the well
may be drilled further and another string of casing (an inner
string of casing) with an outside diameter that is accommodated by
the inside diameter of the previously installed casing may be run
through the existing casing. Additional strings of casing may be
added in this manner such that numerous concentric strings of
casing are positioned in the well, and such that each inner string
of casing extends deeper than the previously installed casing or
parent casing string.
BRIEF DESCRIPTION
[0004] In a first embodiment, a system includes a rotating stage
collar having an upper collar configured to couple to a first
length of tubular, a lower collar configured to couple to a second
length of tubular, and an inner sleeve disposed within the upper
collar and the lower collar, wherein the upper collar and the lower
collar are rotationally fixed to one another when the inner sleeve
is in a first position within the upper collar and the lower
collar, wherein the upper collar and the lower collar are
rotationally independent of one another when the inner sleeve is in
a second position within the upper collar and the lower collar, and
wherein the second position is axially beneath the first position
relative to a longitudinal axis of the rotating stage collar when
the rotating stage collar is positioned within a wellbore.
[0005] In a second embodiment, a system includes a first tubular
configured to be secured within a wellbore, a second tubular
configured to be secured within the wellbore, and a rotating stage
collar. The rotating stage collar includes an upper collar coupled
to the first tubular, a lower collar coupled to the second tubular,
a load nut disposed radially about the upper collar and threaded to
the lower collar, and an inner sleeve disposed within the upper
collar and the lower collar, wherein the upper collar and the lower
collar are rotationally fixed relative to one another when the
inner sleeve is in a first position within the upper collar and the
lower collar, and the upper collar and lower collar are
rotationally independent of one another when the inner sleeve is in
a second position within the upper collar and the lower collar, and
wherein the second position is axially beneath the first position
relative to a longitudinal axis of the rotating stage collar when
the rotating stage collar is positioned within the wellbore.
[0006] In a third embodiment, a method includes coupling a lower
collar of a rotating stage collar to a first stage of casing,
coupling an upper collar of the rotating stage collar to a second
stage of casing, positioning the first stage of casing, the
rotating stage collar, and the second stage of casing into a
wellbore, rotating the first stage of casing, the rotating stage
collar, and the second stage of casing while completing a first
stage cementing process, displacing an inner sleeve of the rotating
stage collar axially downward within the upper collar and the lower
collar to rotationally disengage the upper collar from the lower
collar, and rotating the second stage of casing without rotating
the first stage of casing while completing a second stage cementing
process.
DRAWINGS
[0007] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0008] FIG. 1 is a schematic representation of a well being
drilled, in accordance with an embodiment of the present
disclosure;
[0009] FIG. 2 is a schematic of a well with multiple stages of
casing run into a wellbore, in accordance with an embodiment of the
present disclosure;
[0010] FIG. 3 is a side view of a rotating stage collar coupling
two stages of casing, in accordance with an embodiment of the
present disclosure;
[0011] FIG. 4 is a cross-sectional side view, taken along line 4-4
of FIG. 3, of the rotating stage collar, illustrating the rotating
stage collar in a locked configuration, in accordance with an
embodiment of the present disclosure;
[0012] FIG. 5 is a cross-sectional side view of the rotating stage
collar, illustrating a plug landed within the rotating stage collar
and the rotating stage collar in a partially unlocked
configuration, in accordance with an embodiment of the present
disclosure; and
[0013] FIG. 6 is a cross-sectional side view of the rotating stage
collar, illustrating a plug landed within the rotating stage collar
and the rotating stage collar in a fully unlocked configuration, in
accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0014] The present disclosure relates generally to a rotating stage
collar for coupling two adjacent stages of tubular (e.g., casing)
run into a wellbore. During a mineral extraction process, a
wellbore may be drilled and lined with casing (e.g., pipe) to
prevent the wellbore from caving in, to contain fluids produced
from a well, and to assist with efficient extraction of minerals.
Once the casing is run into the wellbore, the casing may be
cemented in place via cement pumped through the casing and into the
annulus between the casing and the wellbore. In certain
applications, it is desirable to rotate the casing within the
wellbore as cement is pumped through the casing into the annulus.
Indeed, rotating the casing during the cementing process may
improve the displacement and flow of the cement into the annulus.
Rotating casing during cementing also helps reduce gas migration,
channeling, micro-annulus formation, zonal isolation, and other
issues associated with cementing.
[0015] Casing cementing processes may be completed in stages. More
specifically, a casing string having multiple stages (e.g.,
sections of the casing string) may be run into a wellbore, and
cement may be pumped into the annulus surrounding the one casing
string stage before the cement of a subsequent casing string stage
is pumped into place. As described in detail below, adjacent stages
or sections of the casing string may be coupled to one another via
a rotating stage collar to selectively enable relative rotation
between adjacent casing string stages. For example, a casing string
having first, second, and third stages may be run into the
wellbore. The first stage may be a lower stage, the second stage
may be an intermediate stage, and the third stage may be an upper
stage. After the casing string is run into the wellbore, cement may
be pumped through the casing string to fill the annulus surrounding
the first (e.g., lower) stage of casing while rotating the first,
second, and third stages to improve the cementing process. After
the first (e.g., lower) stage of casing is cemented, cement may be
pumped into through the casing string to fill the annulus
surrounding the second (e.g., intermediate) stage of casing while
rotating the second (e.g., intermediate) and third (e.g., upper)
stages, but not the first (e.g., lower) stage. To enable this
functionality, the first and second stages may be coupled to one
another with a first rotating stage collar. When the casing string
is initially run into the wellbore, the rotating stage collar may
be in a locked configuration, which keeps the first and second
stages rotationally fixed relative to one another. After the first
stage of the casing string is cemented in place, the rotating stage
collar may be actuated or triggered from the locked configuration
to an unlocked configuration (e.g., without lifting the casing
string at the surface). In the unlocked configuration, the first
and second stages of the casing string are rotationally independent
from one another. As a result, the second (and third) stages may be
rotated as cement is pumped into the annulus surrounding the second
stage without rotating the first stage of casing. In this manner,
the cement surrounding the first stage may be undisturbed after the
first stage cementing process is complete, while enabling rotation
of the second and third casing string stages during completion of
the second stage cementing process.
[0016] After the second stage cementing process is complete, a
second rotating stage collar coupling the second (e.g.,
intermediate) stage and the third (e.g., upper) stage may be
triggered or actuated from a locked to unlocked configuration, as
similarly described above. Thereafter, the third stage of the
casing string may be cemented in place while rotating the third
stage of the casing string without rotating the recently-cemented
second stage of the casing string. Details of the rotating stage
collar are described below. Furthermore, while the present
disclosure is described in the context of a casing stage cementing
process, the disclosed rotating stage collars may be used with
other processes, including plug cementing, squeeze cementing, liner
cementing, reverse cementing, primary cementing, remedial
cementing, and so forth.
[0017] Turning now to the drawings, FIG. 1 is a schematic
representation of a well 10 that is being drilled, in accordance
with present embodiments. In the illustrated embodiment, the well
10 includes a derrick 12, wellhead equipment 14, and several levels
of casing 16 (e.g., pipe). For example, the well 10 includes a
conductor casing 18 (e.g., first level of casing 16), a surface
casing 20 (e.g., second level of casing 16), and an intermediate
casing 22 (e.g., third level of casing 16). In certain embodiments,
the casing 16 may include 42 foot segments of oilfield pipe having
a suitable diameter (e.g., 133/8 inches) that are joined as the
casing 16 is lowered into a wellbore 24 of the well 10. As will be
appreciated, in other embodiments, the length and/or diameter of
segments of the casing 16 may be other lengths and/or diameters.
The casing 16 is configured to isolate and/or protect the wellbore
24 from the surrounding subterranean environment. For example, the
casing 16 may isolate the interior of the wellbore 24 from fresh
water, salt water, or other minerals surrounding the wellbore
24.
[0018] The casing 16 may be lowered into the wellbore 24 with a
running tool. As shown, once each level of casing 16 is lowered
into the wellbore 24 of the well, the casing 16 is secured or
cemented in place with cement 26. As described in detail below, the
cement 26 may be pumped into the wellbore 24 after each level of
casing 16 is landed in place within the wellbore 24. That is, each
level of casing 16 may be individually lowered within the wellbore
24 and supported by a casing hanger. Thereafter, the cement 26 may
be pumped through the casing 16 and into the wellbore 24, where the
cement 26 may set and secure the casing 16 in place, as shown. As
mentioned above, each level of casing 16 may include multiple
stages of casing 16. In the manner described below, adjacent stages
of casing 16 may be coupled to one another via rotating stage
collars that enable selective relative rotation of the stages of
casing 16. That is, the rotating stage collars enable adjacent
stages of casing 16 to be rotationally fixed to one another and
subsequently rotationally independent of one another. In the manner
described below, the rotating stage collars improve the casing
cementing process.
[0019] FIG. 2 is a schematic of the well 10 with multiple stages 50
of casing 16 run into the wellbore 24. For example, the casing 16
shown in FIG. 2 may be the intermediate casing 22 shown in FIG. 1
prior to cementing of the casing 16 within the wellbore 24.
However, in other embodiments, the casing 16 may be any other
casing 16 string run into the wellbore 24. In the illustrated
embodiment, the casing 16 includes a first stage 52 (e.g., a lower
stage), a second stage 54 (e.g., an intermediate stage), and a
third stage 56 (e.g., an upper stage). Each stage 50 of casing 16
may include one or more segments of oilfield pipe that are joined
together. The first and second stages 52 and 54 are coupled to one
another via a first rotating stage collar 58, and the second and
third stages 54 and 56 are coupled to one another via a second
rotating stage collar 60.
[0020] The first and second rotating stages collars 58 and 60
enable selective relative rotation of the stages of casing 16 that
the collars 58 and 60 couple to one another. Specifically, the
first rotating stage collar 58 enables selective relative rotation
of the second stage 54 and the first stage 52, and the second
rotating stage collar 60 enables selective rotation of the third
stage 56 and the second stage 54. This functionality is useful
during a casing cementing process, because an already-cemented
stage of casing 16 may be undisturbed while another stage of casing
16 is subsequently cemented. For example, in the illustrated
embodiment, the first, second, and third stages of casing 52, 54,
and 56 may be initially run into the wellbore 24. At this time, the
first and second rotating stage collars 58 and 60 may both be in a
locked configuration. Thus, the first and second stages 52 and 54
may be rotationally fixed relative to one another, and the second
and third stages 54 and 56 maybe rotationally fixed relative to one
another.
[0021] Once the first, second, and third stages of casing 52, 54,
and 56 are run into the wellbore 24, the cementing process may
begin. Specifically, cement 24 may be pumped down through the
casing 16 and into an annulus 62 between the casing 16 and the
wellbore 24, as indicated by arrows 64. To cement the first stage
52 of casing 16, cement 24 may be pumped into a first portion 66 of
the annulus 62 surrounding the first stage 52 of the casing 16
(e.g., below line 68). While the cement 24 is pumped into the first
portion 66 of the annulus 62, the entire casing 16 string (e.g.,
first, second, and third stages 52, 54, and 56) may be rotated by
the wellhead equipment 14, because the first and second rotating
stage collars 58 and 60 are both in the locked configuration. As
discussed above, rotation of the casing 16 during cementing
facilitates and improves the cementing process.
[0022] After the first portion 66 of the annulus 62 is filled with
cement 24, rotation of the casing 16 may be stopped, and the cement
24 may be allowed to set. While the cement 24 in the first portion
66 of the annulus 62 sets, the first rotating stage collar 58 may
be triggered or actuated into an unlocked configuration. This
actuation is described in further detail below with reference to
FIGS. 4-6. After the first rotating stage collar 58 is actuated,
the first and second stages 52 and 54 of casing 16 may rotate
independently of one another. More particularly, the second stage
54 of casing 16 may be rotated by the wellhead equipment 14 during
a subsequent cementing process without rotating the first stage 52
of casing 16, which is already cemented. As a result, the settling
and curing of the cement 24 in the first portion 66 of the annulus
62 may be undisturbed. Additionally, as described below, the first
rotating stage collar 58 may be triggered or actuated into an
unlocked configuration without lifting the casing 16 within the
wellbore 24, thereby further avoiding disturbance in the first
stage 52 and the cement 24 of the first portion 66.
[0023] As described in detail below, actuation of the first
rotating stage collar 58 may also open cement ports of the first
rotating stage collar 58 to enable cementing of the second stage 54
of casing 16. As a result, cement 24 may be pumped into a second
portion 70 of the annulus 62 surrounding the second stage 54 of the
casing 16 (e.g., below line 72), as indicated by arrows 74. While
the cement 24 is pumped into the second portion 70 of the annulus
62, the second and third stages 54 and 56 of casing 16 may be
rotated by the wellhead equipment 14, because the second rotating
stage collar 60 remains in the locked configuration. However, the
first stage 52 of casing 16 is not rotated, because the first
rotating stage collar 58 was previously actuated from the locked to
unlocked configuration, which enables relative rotation between the
second stage 54 and first stage 52.
[0024] After the second portion 70 of the annulus 62 is filled with
cement 24, rotation of the casing 16 may be stopped, and the cement
24 surrounding the second stage 54 may be allowed to set. While the
cement 24 in the second portion 70 of the annulus 62 sets, the
second rotating stage collar 60 may be triggered or actuated to an
unlocked configuration, as described below. After the second
rotating stage collar 60 is actuated, the second and third stages
54 and 56 of casing 16 may rotate independently of one another.
More particularly, the third stage 56 of casing 16 may be rotated
by the wellhead equipment 14 during a subsequent cementing process
without rotating the second stage 54 of casing 16, which is already
cemented. As a result, the settling and curing of the cement 24 in
the second portion 70 of the annulus 62 may be undisturbed.
Additionally, as described below, the second rotating stage collar
60 may be triggered or actuated into an unlocked configuration
without lifting the casing 16 within the wellbore 24, thereby
further avoiding disturbance in the second stage 54 and the cement
24 of the second portion 70.
[0025] As similarly mentioned above, actuation of the second
rotating stage collar 60 may open cement ports of the second
rotating stage collar 60 to enable cementing of the third stage 56
of casing 16. Thus, cement 24 may be pumped into a third portion 76
of the annulus 62 surrounding the third stage 56 of the casing 16,
as indicated by arrows 78. While the cement 24 is pumped into the
third portion 76 of the annulus 62, the third stage 56 of casing 16
may be rotated by the wellhead equipment 14, without rotating the
second stage 54 of casing 16, because the second rotating stage
collar 60 was previously actuated from the locked to unlocked
configuration.
[0026] FIG. 3 is a side view of an embodiment of the first rotating
stage collar 58 described above with reference to FIG. 2. It should
be noted that the second rotating stage collar 60 may have a
similar configuration with similar components. In the illustrated
embodiment, the first rotating stage collar 58 includes an upper
collar 100 (e.g., annular collar) and a lower collar 102 (e.g.,
annular collar). The upper collar 100 is coupled to the second
stage 54 of casing 16, while the lower collar 102 is coupled to the
first stage 52 of casing 16. For example, the upper collar 100 and
lower collar 102 may be coupled to the first and second stages 52
and 54, respectively, via a threaded connection, bolted connection,
or other suitable mechanical connection.
[0027] The upper and lower collars 100 and 102 are coupled to one
another with a load nut 104. In particular, the load nut 104
extends over and radially about the upper collar 100, and the load
nut 104 threads onto the lower collar 102. As described in further
detail below, the load nut 104 axially captures a load shoulder of
the upper collar 100 with the lower collar 102, which enables the
full weight of the first stage 52 and lower collar 102 to hang off
from the upper collar (100) while the casing 16 is run into the
well.
[0028] The first rotating stage collar 58 also includes shear
screws 106 extending radially inward from an outer surface 108 of
the upper collar 100. As described in detail below, the shear
screws 106 extend through the upper collar 100 and into an inner
sleeve of the rotating stage collar 58 to hold the inner sleeve in
place prior to actuation or the rotating stage collar 58. As
mentioned above, the rotating stage collar 58 further includes
cement ports 110. The cement ports 110 extend from the outer
surface 108 of the upper collar 100 to an inner circumferential
surface of the upper collar 100. However, as described below, when
the first rotating stage collar 58 is initially run into the
wellbore 24, the cement ports 110 are blocked or occluded by the
inner sleeve of the rotating stage collar 58. After the first
rotating stage collar 58 is actuated, the inner sleeve may be
axially displaced downward, and the cement ports 110 may be opened
or exposed to enable cement 24 flow from within the rotating stage
collar 58, through the cement ports 110, and into the annulus
62.
[0029] FIG. 4 is a cross-sectional side view, taken within line 4-4
of FIG. 3, of the first rotating stage collar 58. As described
above, the rotating stage collar 58 includes the upper collar 100
and the lower collar 102, which are coupled to one another via the
load nut 104. When the load nut 104 is threaded onto the lower
collar 102, an upper shoulder 120 of the load nut 104 axially
captures a load shoulder 122 of the upper collar 100 with an axial
end face 124 of the lower collar 102. The load shoulder 122 of the
upper collar 100 helps transfer weight from the first stage 52 of
casing 16 to the upper collar 102 and the second stage 54 of casing
16. However, a majority of the weight of the casing 16 may still be
supported by the wellhead equipment 14. To further enable support
of the second stage 52 casing 16 load, the first rotating stage
collar 58 includes thrust bearings 126 (e.g., bronze thrust
bearings). Specifically, a first thrust bearing 128 is disposed
between the axial end face 124 of the lower collar 102 and the load
shoulder 122, and a second thrust bearing 130 is disposed between
the load shoulder 122 and the upper shoulder 120 of the load nut
104. As will be appreciated, the thrust bearings 126 enable load
transfer from the upper collar 100 to the lower collar 102 while
also facilitating and enabling relative rotation between the upper
collar 100 and the lower collar 102.
[0030] As mentioned above, the first rotating stage collar 58 also
includes an inner sleeve 132 disposed within the upper and lower
collars 100 and 102. When the rotating stage collar 58 is initially
coupled to the first and second stages 52 and 54 of casing 16 and
run into the wellbore 24, the inner sleeve 132 is held in place
within the upper and lower collars 100 and 102 by the shear screws
106. For example, the rotating stage collar 58 may include 4, 5, 6,
7, 8, 9, 10, or more shear screws configured to hold the inner
sleeve 132 in place within the upper and lower collars 100 and 102.
When the inner sleeve 132 is held in place in the configuration
shown in FIG. 3, the inner sleeve 132 occludes or blocks the cement
ports 110 of the upper collar 100. Thus, cement 24 flowing through
the casing 16 string, and thus through an inner passage 134 of the
rotating stage collar 58, is blocked from flowing through the
cement ports 110. In certain embodiments, the inner sleeve 132 may
be formed from aluminum or other relatively soft metal to enable
drilling-out of the inner sleeve 132 after the casing cementing
process is completed.
[0031] Furthermore, when the inner sleeve 132 is held in place in
the configuration shown in FIG. 3, the rotating stage collar 58 is
in a locked configuration. That is, the upper collar 100 and lower
collar 102 are rotationally fixed relative to one another, thereby
blocking relative rotation of the first and second stages 52 and 54
of casing 16. Relative rotation of the upper and lower collars 100
and 102 is blocked via locking protrusions 136 or locking "dogs"
spaced circumferentially about the inner sleeve 132. In the
configuration shown in FIG. 4, the dogs 136 of the inner sleeve 132
extend through guide slots 137 of the upper collar 100 and into
locking slots 138 formed in the lower collar 102. In other words,
the dogs 136 are disposed radially within the locking slots 138 of
the lower collar 102 (e.g., relative to a longitudinal axis 143 of
the rotating stage collar 58), and thus rotation of the inner
sleeve 132 and upper collar 100 (which are coupled to one another
via the shear pins 120) relative to the lower collar 102 is
blocked.
[0032] As shown in FIG. 4, the locking slots 138 are formed in an
upper portion 140 of the lower collar 102. However, the locking
slots 138 are not formed in a lower portion 142, which is axially
beneath the upper portion 140 (e.g., relative to the longitudinal
axis 143 of the rotating stage collar 58), of the lower collar 102.
Instead, the lower portion 142 includes a cavity or annular groove
144 extending circumferentially about the lower portion 142 of the
lower collar 102. When the dogs 136 are disposed within the cavity
144 of the lower portion 142, circumferential movement of the dogs
136, the inner sleeve 132, and the upper collar 100 is
unrestricted. Therefore, to actuate the rotating stage collar 58
from a locked to unlocked configuration, the inner sleeve 132 of
the rotating stage collar 58 is displaced axially downward, as
indicated by arrow 146.
[0033] Axially displacement of the inner sleeve 132 is achieved via
launching of a plug down the casing 16 string and into the first
rotating stage collar 58. After the plug is launched, the plug will
travel down the casing 16 string and will land against a plug seat
148 of the inner sleeve 132. As described below, the plug enables
shearing of the shear screws 106 and downward axial displacement of
the inner sleeve 132 within the upper and lower collars 100 and
102. In the illustrated embodiment, the inner sleeve 132 of the
first rotating stage collar 58 has an inner diameter 150, which may
generally or approximately correspond with an outer diameter of the
plug. More specifically, the outer diameter of the plug may be
slightly larger than the inner diameter 150 of the seat 148 to
enable landing of the plug against the seat 148.
[0034] It will be appreciated that the inner diameter 150 of the
inner sleeve 132 of the first rotating stage collar 58 may be
smaller than an inner diameter of the inner sleeve of the second
rotating stage collar 60. The diameter of the inner sleeve of the
second rotating stage collar 60 may be larger to enable passage of
the plug that is launched to land against the plug seat 148 of the
first rotating stage collar 58. As a result, actuation of the
second rotating stage collar 60 may be achieved with another plug
having a larger diameter corresponding to the larger diameter of
the inner sleeve of the second rotating stage collar 60. Indeed,
each additional rotating stage collar that is used along the casing
16 string may include an inner sleeve having a plug seat with a
larger inner diameter than the plug seat inner diameter of the next
successive rotating stage collar located further downhole along the
casing 16 string. Similarly, for each additional rotating stage
collar used along the casing 16 string, a larger diameter plug will
be used to land against the respective plug seat of the rotating
stage collar to enable actuation of the rotating stage collar.
[0035] FIG. 5 is a cross-sectional side view of the first rotating
stage collar 58, illustrating a plug 200 landed against the plug
seat 148 of the inner sleeve 132. As discussed above, the plug 200
is launched down the casing 16 string from the wellhead equipment
14 to actuate the first rotating stage collar 58 from the locked
configuration shown in FIG. 4 into an unlocked configuration. That
is, the plug 200 is launched down the casing 16 to the first
rotating stage collar 58 when relative rotation between the first
stage 52 of casing 16 and the second stage 54 of casing 16 is
desired (e.g., during cementing of the second stage 54 of casing 16
after the first stage 52 of casing is cemented). It should be noted
that the first rotating stage collar 58 is actuated from the locked
configuration into the unlocked configuration without lifting the
casing 16 string (e.g., with the wellhead equipment 14). As a
result, the first stage 52 of casing 16 and the cement 24
surrounding the first stage 52 of casing 16 may be undisturbed when
the first rotating stage collar 58 is actuated for rotation of the
second stage 54 of casing 16.
[0036] As mentioned above, the plug 200 is landed against the plug
seat 148 of the inner sleeve 132. In the illustrated embodiment,
the plug 200 also includes a central passage 202. To launch the
plug 200 from the wellhead equipment 14, a ball 204 may be used to
block the central passage 202, build up pressure behind and above
the plug 200, and launch the plug 200 to the first rotating stage
collar 58. However, in other embodiments, the plug 200 may not
include the central passage 202, and thus the ball 204 may not be
used. In certain embodiments, the plug 200 may be a rubber or other
elastomeric material that may deform to create a seal with the
inner sleeve 132 to block cement 24 from passing the plug 200
within the inner sleeve 132.
[0037] After the plug 200 and ball 204 are landed within the first
rotating stage collar 58, cement 24 may be pumped down the casing
16, and pressure of the cement 24 may build up above the plug 200
and the ball 204. Eventually, the pressure will overcome the yield
strength of the shear pins 106, causing the shear pins 106 to shear
and the inner sleeve 132 to be displaced axially downward, as
indicated by arrow 206. As the inner sleeve 132 travels axially
downward, the dogs 136 of the inner sleeve 132 move along the guide
slots 137 of the upper sleeve 100 and from the upper portion 140 of
the lower collar 102 to the lower portion 142 of the lower collar
102. As discussed above, when the dogs 136 are disposed in the
upper portion 140, rotation of the inner sleeve 132 and the upper
collar 100 coupled to the inner sleeve 132 via the shear pins 106
is blocked via the locking slots 138 formed in the upper portion
140. However, when the dogs 136 of the inner sleeve 132 are moved
axially downward to the lower portion 142 of the inner sleeve 132,
the dogs 136 are disposed within the cavity 144 of the lower
portion 142 and are free to rotate. Thus, the inner sleeve 132 and
the upper collar 100 (which are rotationally coupled to one another
via the dogs 136 extending through the guide slots 137 of the upper
collar 100) are free to rotate relative to the lower collar 102. In
other words, the second stage 54 of casing 16 coupled to the upper
collar 100 may be freely rotated with the wellhead equipment 14
without rotating the lower collar 102 coupled to the first stage 52
of casing 16.
[0038] It should be noted that the first rotating stage collar 58
shown in FIG. 5 is not in the fully unlocked configuration. More
specifically, the dogs 136 of the inner sleeve 132 are not fully
landed against a lower shoulder 208 of the lower portion 142 of the
lower collar 102. Additionally, in the illustrated embodiment, the
cement ports 110 of the upper collar 100 are still occluded or
blocked by the inner sleeve 132. Indeed, the size (e.g., length) of
the inner sleeve 132 and/or the location of the cement ports 110
along the upper collar 100 is selected such that the cement ports
110 are occluded by the inner sleeve 132 until the dogs 136 of the
inner sleeve 132 are fully landed against the lower shoulder 208.
In this manner, cement 24 pressure above the plug 200 and the ball
204 may be contained (e.g., and not flow out of the cement ports
110) until the rotating stage collar 58 is in the fully unlocked
configuration. Once the dogs 136 are landed against the lower
shoulder 208, the inner sleeve 132 is axially beneath the cement
ports 110 and no longer blocks the cement ports 110, and cement 24
may freely flow out of the rotating stage collar 58 through the
cement ports 100. For example, FIG. 6 is a cross-sectional side
view of the first rotating stage collar 58, illustrating the dogs
136 of the inner sleeve 132 landed against the lower shoulder 208
of the lower collar 102. As indicated by arrows 220, cement 24 may
flow through the cement ports 110 into the annulus 62 between the
casing 16 string and the wellbore 24.
[0039] In certain embodiments, the first rotating stage collar 58
may include other components. For example, as shown in FIG. 6, the
rotating stage collar 58 may include one or more seals 240 (e.g.,
annular seals, elastomeric seals, etc.) disposed between the upper
collar 100 and lower collar 102 and/or between the inner sleeve 132
and the upper collar 100. The seals 240 may block bearing surfaces
242 between the upper collar 100 and lower collar 102 and/or
between the inner sleeve 132 and the upper collar 100 from becoming
contaminated. In certain embodiments, the bearing surfaces 242
between the upper collar 100 and lower collar 102 and/or between
the inner sleeve 132 and the upper collar 100 may be lubricated
(e.g., with grease or oil) when the rotating stage collar 58 is
assembled to facilitate relative rotation between the upper collar
100, lower collar 102, and/or inner sleeve 132 when the rotating
stage collar 58 is in the unlocked configuration shown in FIG.
6.
[0040] As describe above, the present disclosure relates generally
to the rotating stage collar 58 for coupling two adjacent stages of
casing 16 (e.g., first and second stages 52 and 54) run into the
wellbore 24. Once the casing 16 is run into the wellbore 24, the
casing may be cemented in place via cement 24 pumped through the
casing 16 and into the annulus 62 between the casing 16 and the
wellbore 24. The adjacent stages (e.g., first and second stages 52
and 54) of the casing 16 string may be coupled to one another via
the rotating stage collar 58 to selectively enable relative
rotation between adjacent casing string stages. For example, cement
24 may first be pumped through the casing 16 string to fill the
annulus 62 surrounding the first stage 52 of casing 16 while
rotating the first and second stages 52 and 54 to improve the
cementing process. After the first stage 52 of casing 16 is
cemented, the rotating stage collar 58 may be actuated or triggered
from the locked configuration into an unlocked configuration. In
the unlocked configuration, the first and second stages 52 and 54
of the casing 16 string are rotationally independent from one
another. As a result, the second stage 54 may be rotated as cement
24 is pumped into the annulus 62 surrounding the second stage 54
without rotating the first stage 52 of casing 16. Indeed, the
rotating stage collar 58 may be actuated from the locked
configuration to the unlocked configuration without lifting the
casing 16 string from the surface. In this manner, the cement 24
surrounding the first stage 52 may be undisturbed after the first
stage cementing process is complete, while enabling rotation of the
second stage 54 casing during completion of the second stage
cementing process.
[0041] While only certain features of the invention have been
illustrated and described herein, many modifications and changes
will occur to those skilled in the art. It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as fall within the true spirit of the
invention.
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