U.S. patent application number 15/384715 was filed with the patent office on 2017-04-13 for liner hanger and method for installing a wellbore liner.
This patent application is currently assigned to Resource Completion Systems Inc.. The applicant listed for this patent is Shane D'Arcy, John Hughes, James Wilburn Schmidt. Invention is credited to Shane D'Arcy, John Hughes, James Wilburn Schmidt.
Application Number | 20170101854 15/384715 |
Document ID | / |
Family ID | 52105654 |
Filed Date | 2017-04-13 |
United States Patent
Application |
20170101854 |
Kind Code |
A1 |
Hughes; John ; et
al. |
April 13, 2017 |
Liner Hanger and Method for Installing a Wellbore Liner
Abstract
A liner hanger assembly to run-in a liner on a liner hanger,
cement the liner in place and set the liner hanger in one trip.
Then, a wellbore treatment process can proceed while the running
string remains downhole or via a second trip. The liner hanger
assembly includes a liner hanger running tool and a liner
hanger.
Inventors: |
Hughes; John; (Calgary,
CA) ; Schmidt; James Wilburn; (Calgary, CA) ;
D'Arcy; Shane; (Calgary, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hughes; John
Schmidt; James Wilburn
D'Arcy; Shane |
Calgary
Calgary
Calgary |
|
CA
CA
CA |
|
|
Assignee: |
Resource Completion Systems
Inc.
Calgary
CA
|
Family ID: |
52105654 |
Appl. No.: |
15/384715 |
Filed: |
December 20, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14090661 |
Nov 26, 2013 |
9556714 |
|
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15384715 |
|
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|
61861651 |
Aug 2, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 21/00 20130101;
E21B 23/01 20130101; E21B 43/10 20130101; E21B 33/14 20130101; E21B
33/129 20130101 |
International
Class: |
E21B 43/10 20060101
E21B043/10; E21B 33/14 20060101 E21B033/14 |
Claims
1.-8. (canceled)
9. A method for installing a liner in a wellbore, the method
comprising: running into the wellbore with the liner secured to a
liner hanger and the liner hanger carried on a running string;
positioning the liner hanger and the liner in the wellbore; moving
cement through the running string, the liner hanger and the liner
until the cement fills at least a portion of an annulus between the
liner and a wall of the wellbore; pressuring up an inner diameter
of the running string and the liner hanger to set the liner hanger
in the wellbore; flushing residual cement from an inner bore of the
liner hanger and from an annular area above the liner hanger by
introducing a flushing fluid from the running string to the inner
bore and to the annular area; and allowing the cement to set.
10. The method of claim 9 wherein moving cement includes moving a
wiper plug through the liner hanger and liner to force the cement
from the liner into the annulus.
11. The method of claim 9 wherein the method proceeds from running
to flushing without tripping the running string to surface.
12. The method of claim 9 wherein flushing includes overcoming a
sealing structure between the running string and an upper end of
the liner hanger and circulating fluid past the sealing structure,
and the method further comprises, after flushing, restoring the
sealing structure.
13. The method of claim 9 wherein flushing includes moving flushing
liquid out through ports along a wall of the running string while
an end of the running string remains positioned in the liner
hanger.
14. The method of claim 12 wherein overcoming a sealing structure
includes reverse rotating the running string no more than a full
turn relative to the liner hanger and pulling the running string up
relative to the liner hanger.
15. The method of claim 9 further comprising, after allowing the
cement to set, conducting a wellbore treatment through the running
string, the liner hanger and the liner to treat the wellbore.
16. The method of claim 15 wherein the method proceeds from running
to conducting a wellbore treatment without tripping the running
string to surface.
17. The method of claim 9 wherein pressuring up includes setting a
packer and a set of slips on the liner hanger to engage the
wall.
18. The method of claim 9 wherein pressuring up includes increasing
the pressure to a pressure greater than any pressures applied to
the liner hanger while moving cement.
19. The method of claim 9 wherein the running string includes a
liner hanger running tool on which the liner hanger is carried and
the liner hanger running tool includes: a tubular body including a
base end for connection to the running string, an outboard end and
an inner diameter; a connector on the outboard end for releasably
engaging the liner hanger, the connector including a first J-type
connection structure; and the liner hanger includes: a mandrel with
an outer surface, an upper end including a running tool connector
including a second J-type connection structure for releasable
connection with the first J-type connection structure, a lower end
including a liner connector and an inner bore passing through the
mandrel, extending from the upper end to the lower end; a setting
mechanism on the outer surface for setting the liner hanger in a
well; and a hydraulic piston for driving the setting mechanism to
set in response to a pressure applied through the inner bore and
communicated to the hydraulic piston.
Description
FIELD
[0001] The present invention is directed to a wellbore tool and
method and, in particular, tools and methods for installing a
wellbore liner.
BACKGROUND
[0002] In non-monobore completions there is often a requirement to
install a larger, uphole (often called surface) casing to provide
hole support and a larger bore for other equipment. In such
completions, there may be a liner with a smaller diameter installed
below the larger casing inside the openhole. To anchor and seal
this liner within the wellbore from surface an established practice
is to set the liner on a liner hanger above the casing shoe of the
uphole casing. A substantial number of applications leave the liner
in an open hole bore beneath the casing but there is also a common
requirement to cement the liner in place. Hence the ability to
cement through the liner hanger is an important feature.
SUMMARY
[0003] In accordance with a broad aspect of the present invention,
there is provided a liner hanger assembly comprising: a liner
hanger running tool and a liner hanger; the liner hanger running
tool including: a tubular body including a base end for connection
to a running string, an outboard end and an inner diameter; a
connector on the outboard end for releasably engaging the liner
hanger, the connector including a first J-type connection
structure; and the liner hanger including: a mandrel with an outer
surface, an upper end including a running tool connector including
a second J-type connection structure for releasable connection with
the first J-type connection structure, a lower end including a
liner connector and an inner bore passing through the mandrel,
extending from the upper end to the lower end; a setting mechanism
on the outer surface for setting the liner hanger in a well; and a
hydraulic piston for driving the setting mechanism to set in
response to a pressure applied through the inner bore and
communicated to the hydraulic piston.
[0004] There is also provided a method for installing a liner in a
wellbore, the method comprising: running into the wellbore with the
liner secured to a liner hanger and the liner hanger carried on a
running string; positioning the liner hanger and liner in the
wellbore; moving cement through the running string, the liner
hanger and the liner until the cement fills at least a portion of
an annulus between the liner and a wall of the wellbore; pressuring
up an inner diameter of the running string and the liner hanger to
set the liner hanger in the wellbore; flushing residual cement from
an inner bore of the liner hanger and from an annular area above
the liner hanger by introducing a flushing fluid from the running
string to the inner bore and to the annular area; and allowing the
cement to set.
[0005] It is to be understood that other aspects of the present
invention will become readily apparent to those skilled in the art
from the following detailed description, wherein various
embodiments of the invention are shown and described by way of
illustration. As will be realized, the invention is capable for
other and different embodiments and its several details are capable
of modification in various other respects, all without departing
from the spirit and scope of the present invention. Accordingly the
drawings and detailed description are to be regarded as
illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] A further, detailed, description of the invention, briefly
described above, will follow by reference to the following drawings
of specific embodiments of the invention. These drawings depict
only typical embodiments of the invention and are therefore not to
be considered limiting of its scope. In the drawings:
[0007] FIG. 1 is a schematic illustration of a wellbore with an
uphole casing and a liner being installed therein.
[0008] FIGS. 2A to 2F are sections through a wellbore showing
sequential operations through a liner hanger.
[0009] FIG. 3 is an axial section along the long axis of a liner
hanger packer.
[0010] FIG. 4 is an axial section along a carrying tool.
[0011] FIG. 5 is an axial section along the carrying tool showing
fluid circulation paths.
[0012] FIG. 6 is an axial section through a carrying tool installed
in a liner hanger packer.
[0013] FIG. 7 is a schematic illustration of a wellbore with an
uphole casing and a liner being installed therein.
[0014] FIG. 8 is a schematic illustration of a wellbore in a
process following from that of FIG. 7.
[0015] FIG. 9 is a schematic illustration of a wellbore in a
process following from that of FIG. 8.
DESCRIPTION OF VARIOUS EMBODIMENTS
[0016] The description that follows and the embodiments described
therein are provided by way of illustration of an example, or
examples, of particular embodiments of the principles of various
aspects of the present invention. These examples are provided for
the purposes of explanation, and not of limitation, of those
principles and of the invention in its various aspects. In the
description, similar parts are marked throughout the specification
and the drawings with the same respective reference numerals. The
drawings are not necessarily to scale and in some instances
proportions may have been exaggerated in order more clearly to
depict certain features.
[0017] A liner hanger, liner hanger assembly and method for
installing a liner have been invented.
[0018] The liner hanger allows cement-through operations and can be
set by hydraulic manipulations. The liner hanger is capable of
being run and set on either liner or drill pipe. The liner hanger
is set in casing above the casing shoe to facilitate hanging a
liner beneath, which extends beyond the casing shoe, and provides a
seal between the liner and the installed casing. The liner hanger
is capable of withstanding the operational parameters of the
downhole application such as pressure, temperature and loading
conditions.
[0019] One embodiment of a liner hanger 10 is shown in FIG. 1. With
reference to FIG. 1, the liner hanger is installed at the uphole
end of a liner 12 to be installed in a wellbore 14 and the liner
hanger is carried on a running string 15, such as of tubing such
as, for example, of liner or drill pipe. The liner hanger 10
includes a liner connector 16, a running string connector 18, an
inner bore 20 extending through the liner hanger and on the liner
hanger's outer surface, a hydraulically actuable setting mechanism,
for example, including at least one of a hydraulically settable
packer 22 and hydraulically settable slips 24. The connectors 16,
18 permit the liner hanger to be connected between the running
string 15 and the liner 12 to be installed. The inner bore 20
permits cement and possibly other fluids to be flowed through the
liner hanger. The hydraulically settable packer 22 encircles the
liner hanger and permits an annular seal to be set in the annular
area about the liner hanger, when it is set in the well. The
hydraulically settable slips 24 permit the liner hanger to be
secured in the well with the liner hung below it. Since the liner
hanger is often secured in a cased section of the well, slips 24
are possibly formed to bite into the material of casing 25.
[0020] The liner hanger is employed to secure a liner in a well.
The liner hanger can be positioned in the well ahead of a cementing
operation. The liner can be cemented into the well by a process
where the cement is pumped down through the liner hanger and the
liner below it and out from the liner into the annulus, before the
cement returns up along the annulus of the liner (to cement the
annulus) and passes along the outer surface of the liner hanger
before returning back toward surface. The liner hanger may then be
set in the well, as by expanding the slips to engage the casing
and/or by expanding the packer. The setting operation may be
hydraulic, for example by pressuring up the inner bore of the liner
hanger to a pressure sufficient to expand the packer and the slips
to seal against and bite into, respectively, the casing. After the
liner hanger is set, the inner bore may be cleaned of residual
cement to ready it for further operations.
[0021] The process of positioning, cementing through, setting and
cleaning out the liner hanger can be completed in a single trip, if
desired. This may reduce complexity, time and cost over a
multi-trip system. When compared to mechanically set liner hangers,
that are set by string movements, the current liner hanger, which
is hydraulically settable by means of simple through-tubing
pressure fluctuations, offers simplicity as there are no complex
running tools required.
[0022] There are many applications of the liner hanger. One such
application is for running a horizontal liner for wellbore
completions. FIG. 1 shows a typical application, wherein the liner
hanger 10 is positioned in wellbore, by being run-in-hole on a
running string, which may, as shown, be liner (typically 4'' to 6''
diameter) with substantially the same inner diameter as inner bore
20 and as that of the liner 12. The liner hanger is located at the
appropriate depth in the casing.
[0023] The liner 12 includes a toe 12a that may be equipped in
various ways, may be valved or may be open. In one embodiment, toe
12a includes a valve such as a float shoe 26 and/or a float collar
28 for well control and circulation, arrows F, as illustrated in
FIG. 1.
[0024] It is useful to cement behind the liner as a completion
method in multi-stage frac operations. Cementing may provide good
zonal isolation and may provide some wellbore support. Thus, while
liner 12 can take many forms, a liner that is suitable for
multi-stage frac operations is of some interest. Thus, liner may be
a simple string of interconnected, bare tubulars or the tubulars
may include sites for fracturing, such as multi-stage fracturing,
therethrough. Thus, the liner may be bare pipe, for example, used
in abrasa-jet or perforating applications or cemented in
sleeves/ports 30, as illustrated in FIG. 1. These sleeves/ports 30
can take various forms including (but not limited to): cemented in
hydraulic or hydrostatic sleeves, cemented in hydraulic open
annular sleeves, hydraulic open burst ports, mechanical open
sleeves, ball drop sleeves, etc. These sleeves/ports 30 can
function a number of ways and can be opened, for example, using
straddle packer tools on coil tubing, mechanical shifting on coil
or pipe, ball drop, or any combination thereof. In all these
applications, the isolation method between the zones is cement,
with or without packers between adjacent ports. This has the
advantage of very reliable sealing/isolation and, if without
packers, low cost.
[0025] While the form of the liner may vary depending on the
particular completion method to be employed for the well (i.e. the
method that is used to stimulate the individual zones of the well),
the liner hanger can be used with these liners.
[0026] In a typical application as illustrated in FIG. 1, the liner
hanger 10 is assembled with the liner 12 connected therebelow
through connection 16. This assembly is run on the running string
15, such as liner as shown, to a desired setting depth above the
casing point 32 (i.e. which is the lower end of the uphole
casing).
[0027] Fluid may be circulated through the well during run-in of
the liner and liner hanger. The fluid may be circulated along the
route indicated by arrows F. Care may be taken to ensure that the
connector 18 between the running string and liner hanger 10 remains
engaged. A releasable lock may be employed at connector 18 for this
purpose.
[0028] With further reference to FIGS. 2A to 2F, once the liner
hanger is positioned at the appropriate depth (FIG. 2A), the
cementing equipment 34 is then rigged in at surface S. Equipment 34
is then lined up to cement. Equipment 34 may include a cement head
manifold containing a liner wiper plug 36, which is contained in
the cement head manifold until deployed.
[0029] Cement is then pumped down the running string 15, through
the liner hanger 10 and out through the toe 12a of the liner, for
example via the float shoe 26 and/or collar 28. As the cement C
exits the toe, it circulates up annulus 37 between the wellbore
wall (i.e. open hole below casing point 32 and cased above) and the
liner outer diameter (FIG. 1 and FIG. 2B). The cement is circulated
and spotted using volume calculations to a point above the unset
liner hanger 10.
[0030] During this process the wiper plug 36 is released from the
cement head 34 and acts to wipe the inside of the running string,
the liner hanger and the liner clean of cement and acts to separate
a chasing fluid CF from the cement C, as shown in FIG. 2C.
Eventually the plug lands against a stop, such as a landing collar
or the float collar 28/shoe 26 (depending on the liner
configuration). During the cementing and wiping processes pressure
will be required to circulate the cement and plug 36 and to
overcome hydrostatic pressure imbalances, as the cement and chasing
fluid will have different densities. Additional pressure may be
used to bump the plug to confirm landing on the stop. Once the plug
has landed against the stop, cement placement is concluded and the
liner hanger can be anchored, as by setting the packer 22 of the
liner hanger (FIG. 2D).
[0031] The setting mechanism, in its run-in condition (established
prior to run-in), is configured not to set during cement pumping
operations with an adequate safety margin. Thus, although
pressurized conditions are employed during cementing, the liner
hanger includes a mechanism to prevent premature anchoring during
these operations. In one embodiment, the setting mechanism of liner
hanger 10 is set by hydraulic pressure acting against a setting
mechanism including a piston. The setting mechanism is selected
that allows the piston to move if pressures above a selected level
are communicated to the piston. The mechanism can include, for
example, shear screws that can only be overcome by a selected
hydraulic pressure above those pressures generated during
cementing, including pumping of cement and movement of the wiper
plug.
[0032] Once plug 36 lands, the liner hanger is pressured up to
cause (i) the liner hanger packer 22 to expand out to fill an
annular segment of annulus 37 about the liner hanger and to seal
against the casing 25 and/or (ii) the slips 24 to expand out and
bite into the casing (FIG. 2D). The liner hanger is now set in
place in the casing. With the packer set, pressure from the
open-hole about liner 12 is isolated from conditions above the
packer and the annulus above the liner hanger can be isolated from
the liner inside. In addition, tubing movements such as may be
driven by temperature, pressure and/or weight effects may be
handled and resisted by the liner hanger slips 24 engaging the
wellbore wall, which in this embodiment is cased. This prevents the
liner string from being moved out of position.
[0033] After the liner hanger is set, the pressure may be bled off,
for example, to zero.
[0034] It is now time to clean cement from above the liner hanger
and to clean out the inner bore of the liner hanger if it contains
cement. In one embodiment, for example, if the liner hanger may
contain cement in its inner bore at least at the running string
connection and/or if there is residual cement that would interfere
with later operations through the liner hanger, the residual cement
should be removed. Thus, as shown in FIG. 2E, fluid (arrows CF),
may be circulated above the packer 22 and in the liner hanger inner
bore to ensure that the area above packer 22 and inner bore 20 are
substantially free of cement. To do so, the connection between
liner hanger 10 and running string 15 at connector 18 may be
disconnected to some degree to create an opening from inner
diameter to annulus 37 at the upper end 10a of liner hanger 10 and
the lower end 15a of running string 15 and cleaning fluid may be
introduced from the running string through the opening to the outer
surface of the liner hanger and into the annulus 37 between the
casing 25 running string 15. This cleaning fluid is able to
communicate with the annulus between the casing and liner hanger 10
above packer 22.
[0035] In one embodiment, running string 15 and/or liner hanger 10
at connector 18 may include ports 38 through their walls such that
an opening may be created between the parts without fully
separating the running string from the liner hanger.
[0036] The cement then is allowed to set to create a seal against
the axial passage of fluids along the annulus between the liner 12
and the wellbore wall downhole of the liner hanger 10. In
multi-stage operations, the cement provides good isolation between
zones and downhole of the liner hanger's packer 22.
[0037] After cleaning out the residual cement, the running string
can be pulled out or repositioned into (FIG. 2F) liner hanger 10,
as required. If desired, the running string can be repositioned
into the liner hanger without pulling out of the hole. In such an
embodiment, with running string 15 repositioned into liner hanger,
once the cement is set, a wellbore stimulation treatment can be
conveyed from running string 15, through liner hanger 10 and into
liner 12 to stimulate the well.
[0038] One embodiment of a liner hanger 110 is shown in greater
detail in FIG. 3. The liner hanger of FIG. 3 operates with a
running tool, here shown in the form of a stinger 140 (FIGS. 4 and
5). Stinger 140 is carried at the distal end of a running string
115 and operates with the connector 118 of liner hanger 110. Liner
hanger 110 and stinger 140 are shown connected in FIG. 6.
[0039] Stinger 140 includes an outboard end 140a that is intended
to make connection with liner hanger 110 and a base end 140b
through which a connection may be made to the running string 115.
Outboard end 140a in this embodiment is inserted into the upper end
110a of the liner hanger when the stinger 140 and the liner hanger
are secured together.
[0040] Liner hanger 110 includes a mandrel 142 having a tubular
form defining an inner bore 120 extending therethrough and an outer
surface 142a. Liner hanger 110 carries a packer 122, which is
mounted on the outer surface 142a, is annular in form to encircle
the mandrel and is substantially concentric to the long axis x
through the inner bore. Slips 124a, 124b are also carried on the
outer surface, adjacent the packer 122. While a single set of slips
may be employed, in this embodiment there are upper slips 124a and
lower slips 124b with the packer 122 therebetween.
[0041] Packer 122 and slips 124a, 124b are normally retracted (as
shown) and are settable, to extend radially outwardly to a diameter
greater than their retracted diameter, by axial compression of the
parts 122, 124a, 124b. In particular, upper slips 124a are
positioned against a stop wall 146 that prevents them from moving
axially upwardly over mandrel 142. On the other side of the upper
slips is a frustoconical surface 147 that is axially moveable
toward stop wall 146 to compress the upper slips therebetween. The
back sides 124a' of the upper slips are formed are ramped such that
they can be urged readily to ride up over surface 147, to drive
slips 124a radially outwardly, when surface 147 is moved toward
wall 146 and slips 124a are compressed between the surface and the
wall.
[0042] Packer 122 is a resilient, extrudable annular member that
can be compressed between axially moveable retainer rings 150 and
extrudes radially outwardly, when compressed.
[0043] Lower slips 124b are positioned between axially moveable
stop wall 148 and frustoconical surface 149. While frustoconical
surface 149 is axially moveable toward packer 122, slips 124b can
be compressed between wall 148 and surface 149. When compressed,
the backsides of slips 124b, which may be ramped, can be urged over
top of the frustoconical surface to become expanded outwardly.
[0044] The axial compression of slips 124a, 124b and packer 122 may
be driven by hydraulics, for example by a piston 151 having a
piston face 152, which is connected to drive stop wall 148.
Hydraulic fluid can be communicated from inner bore 120, through
ports 153 to a piston chamber 154 open to face 152. When chamber
154 is pressured up to a degree sufficient to shear a releasable
connection, such as pins 156, wall 148 moves to compress slips 124b
onto frustoconical surface 149, rings 150 against packer 122 and
slips 124a onto frustoconical surface 147.
[0045] The packer piston that accommodate many shear pins 156 to
provide pinning flexibility to account for cementing pressures.
This means the packer piston can be installed to remain unset until
after the cement is positioned correctly. This feature of pinning
prevents premature setting of the packer during cementing or
pumping operations. It also allows the packer to be set at a
comfortable pressure level when the cement is positioned at the
correct level in the wellbore.
[0046] The upper end 110a of the mandrel includes a running string
connector 118, herein shown as a J-type connection, which is
selected to allow the mandrel to be removably carried on a running
string via stinger 140.
[0047] The mandrel also includes a liner connector portion 116
selected to permit a liner to be durably connected to the mandrel
142. Herein connector portion 116 is a threaded end, such as a pin,
but other configurations are possible.
[0048] The running string connector connection 118 is positioned at
an upper end of the mandrel and the liner connector 116 is
positioned at a lower end of the mandrel. The running string
connector places an inner diameter ID of the running string and of
the stinger into communication with inner bore 120 and the liner
connector 116 places the inner diameter of the liner into
communication with the inner bore 120.
[0049] The running string connector connection 118 and stinger 140
are connectable to support the mandrel on the running string. As
noted above, connection 118 of FIG. 3, is a J-type connection and
is durable yet simple to manipulate. One of the stinger or the
connection 118 includes a key and the other part includes a
J-shaped keyway. In this embodiment, the liner hanger includes
keyway 160 and stinger 140 includes key 162. Stinger 140 and the
liner hanger can be secured together by axially sliding key 162
into an aligned open end 160a of the keyway and allowing or causing
the stinger to rotate slightly moves the key into the midportion of
the keyway and then into the locking region 160b of the keyway.
When weight is picked up the key will enter an upper portion 160b'
of the locking region 160b of the J-keyway and when the string is
pushed against the liner hanger, the key will reside in the lower
portion 160b'' of the locking region 160b of the keyway. Both the
upper and the lower portions, 160b' and 160b'', act as traps and
prevent relative rotation between the stinger and the liner hanger,
and therefore permit transmission of torque, when the connection is
in tension or in compression. More than one keyway and key may be
employed. For example, in the illustrated embodiment, three keys
are spaced apart the same circumference of the stinger and three
keyways are spaced apart about the same circumference of the
mandrel.
[0050] The connection between the stinger and the liner hanger also
includes a sealing assembly to substantially prevent fluid from
passing out of the inner bore through the interface between the
parts when they are connected by the key and keyway. For example,
the liner hanger may include a seal bore 164 into which seals 166
on the outer diameter of the stinger outboard end 140a can be
landed to create a seal with the seal bore. These structures of the
sealing assembly allow stinger 140, and therefore running string,
to have a substantially fluid tight connection with liner hanger
such that the connected parts can hold pressure when connected and
even after removal and re-entry of the stinger to the upper end of
the liner hanger.
[0051] Stinger lower end 140a in some embodiments may include a
mule shoe end edge 141, which is an angled edge, extending
non-orthogonal to the long axis x1, at its end to facilitate
insertion of the end into the liner hanger.
[0052] Also in some embodiments, outboard end 140a includes ports,
here formed as slots 138, opening through the wall thickness and at
least a portion having a reduced outer diameter, wherein the outer
diameter OD at that portion is less than the inner diameter of seal
bore 164, to provide space for circulation of fluids between the
surfaces. For example, in one embodiment, flutes 167 may be formed
on the outer surface of lower end 140a between mule shoe end 141
and slots 138. Slots 138 and flutes 167 are positioned between end
141 and seals 166, so they do not affect the sealing operation of
stinger 140 into the seal bore. Slots 138 may be positioned close
to seals 166 so that during removal of stinger 140 from seal bore
164, slots 138 move out of the seal bore just slightly after the
seals.
[0053] The connection between liner hanger 110 and the stinger may
also include a releasable lock, for ensuring the liner hanger and
stinger do not accidentally become disengaged during run in. The
releasable lock may include for example a shear connection for
example, a shear pin 169a that rides in an axial groove 169b. Shear
connection allows movement of the key in keyway locking region 160b
and even axial movement therein between ends 160b' and 160b'', but
the shear connection resists rotational movement between the
stinger and the liner hanger except if sufficient force is applied
to overcome the shear connection.
[0054] In use, the liner hanger of FIG. 3 is hydraulically set and
may be useful for permanent installs.
[0055] To be run into the wellbore, the liner hanger, with the
liner connected below, may be connected to the stinger, for example
by the connection of the one or more j-keys in the j-keyways (FIG.
6).
[0056] When the liner hanger is in a desired position in the
wellbore, pumping operations may be initiated. Weight may be set
through the running string atop the liner hanger 110 to ensure the
liner hanger doesn't move out of position during pumping
operations.
[0057] Cement is pumped down through the running string, the
stinger, the liner hanger and the liner to return up the annulus.
Once sufficient cement is pumped to fill a selected portion of the
annulus, the liner may be wiped. Liner hanger 110 has sufficient
internal clearance in inner diameter 120 to permit the passage of a
wiper plug. The wiper plug can be moved down through the liner
hanger and liner, pushes cement ahead of it and lands near the toe
of the liner. The running string, liner hanger and liner can be
pressured up above the plug.
[0058] Without removing the stinger from the liner hanger, the
packer and slips can be set hydraulically after cementing and after
passage of the wiper plug. To do so, tubing pressure may be
increased to shear pins 156, which allows piston 151 to compress
and expand slips 124a, 124b and packer 122. The slips and the
packer expand out through the liquid cement and engage the casing
wall.
[0059] After the packer and slips are set, cement may be cleared
from above the packer, the stinger may be removed from the upper
end, etc., according to the options described above. In one
embodiment, fluid may be circulated from the stinger into the
annulus above the packer to circulate out the annular cement. To do
so, in one embodiment, pressure may be increased slightly in the
string to ensure a positive pressure in the inner diameter to avoid
flow of the annular cement into the inner diameter 120 and to
permit pressure to be monitored to assess the process of
stinger/hanger disconnection, the stinger is removed from the liner
hanger. With a j-type connection, the stinger is moved down in the
liner hanger connection 118, as by setting down weight into the
string, and while pulling up, the stinger is rotated back to remove
the j-keys from the keyways. This may require that enough torque is
applied to overcome the shear connection 169a, 169b and may require
less than a full rotation, for example less than 3/4 of a turn or
substantially 1/2 turn, holding the torque in the string to release
the stinger. Thereafter, the stinger may be pulled out of the liner
hanger packer seal bore. As it comes out, if the string was
pressured up, the pressure falls off when the stinger is pulled of
the liner hanger, when seals 166 are removed from seal bore
164.
[0060] To remove residual cement from above the packer, clean fluid
CF (i.e. substantially free of cement) may be circulated as shown
in FIG. 5. If the stinger includes slots 138, fluid can pass both
through the slots and around end 141. Since slots 138 may be
positioned close to seals 166, during removal of stinger 140 from
seal bore 164, circulation can be initiated very soon after the
seals are free of the seal bore.
[0061] Continued circulation as the stinger is removed from the
liner hanger, cleans the liner hanger bore 120 of cement that may
have not been cleaned from the wiper plug run. Circulation may
continue, for example, till clean returns from the annulus are seen
at surface.
[0062] At this point, the method may proceed in a number of
different ways, in accordance with the plans for further wellbore
operations. For example, the running string and stinger 140 may be
pulled out of the hole.
[0063] Alternately, if further operations through the string 115
are of interest, the string and stinger 140 can be reinserted fully
into the liner hanger seal bore 164. If desired, continued
circulation of clean fluid, as the packer reenters, circulates out
any remaining cement fluid residue and confirms seals 166 have set
against the seal bore. If a J-type connection is employed and the
keys have been pulled out of the keyways, the stinger may be
aligned with the liner hanger and slowly set down. The keys ride in
the keyways and are urged toward the locking region 160b. A pull
test may be employed to confirm that the stinger is correctly
connected with the keys engaged in the keyways.
[0064] The capability exists, after the cement is set, to frac
through the liner below the liner hanger. This can be performed in
a single trip without ever having to pull the running string 115
out of the hole, if so desired.
[0065] The flexibility also exists, if desired, to remove the
running string easily at any time, before or after cementing, for
interventions or production pump reasons due to the use of a
releasable and reconnectable connection. In particular, the j-type
connection, facilitates disconnects and reconnects, requiring less
than a full rotation of string 115, which means fewer surface
manipulations and less rotation in a horizontal wellbore than a
connection requiring one or more full rotations.
[0066] As noted above, the running string may take various forms.
While the above-noted embodiments illustrate liner hanger 10, 110
run-in on liner (i.e. wherein the ID of string 115 is substantially
the same as the inner diameter through the liner), the liner hanger
may alternately be run-in on smaller diameter tubulars such as
drill pipe. Thus, FIGS. 7 and 8 show another wellbore assembly
wherein a liner hanger 210, similar to those described above, is
run on drill pipe 215 instead of liner. The drill pipe can be of
standard or heavy weight. Drill pipe may be useful over liner to
facilitate running the liner 212 below liner hanger 210 to total
depth (TD). This is since drill pipe allows more weight (i.e.
force) to be used to position the liner string at the correct
depth. For example, sometimes due to the large diameter of the
liner string or the wellbore trajectory, drilling drag is
significant and prevents the liner string from going any deeper. In
such circumstances, additional weight may be required to advance
the liner to TD. It is beneficial to look at torque and drag
modeling to give an estimation of the amount of weight required due
to dog leg severity and wellbore trajectory. In any of these cases,
the advantage of drill pipe is that, compared to liner, drill pipe
can apply additional weight and has greater flexibility, such that
buckling is less of a concern.
[0067] In the embodiment of FIGS. 7 and 8, liner assembly includes
liner hanger 210 and liner 212 and is carried on drill pipe running
string 215 and a compatible ID running tool such as a stinger 240.
Stinger 240 may be similar to that stinger of FIG. 4, including for
example seals, circulation ports and mule shoe, etc.
[0068] In the drill pipe variant of the cement through liner hanger
assembly, it may be necessary to employ a two-stage wiper plug
installation. In particular, because a wiper plug sized to act in
liner 212 could not pass through the smaller diameter drill pipe, a
two stage wiper plug installation including a large plug 236a and a
wiper dart 236b may be employed to wipe the liner. On surface there
may be a cement manifold containing drill pipe-sized wiper dart
236b and large plug 236a is installed in the liner assembly. The
cement head manifold is attached to the casing and drill pipe and
incorporates the drill pipe wiper dart. The dart is held inside the
cement manifold till required and can be released upon command.
[0069] Large plug 236a has a substantially cylindrically shaped
body with ends and an outer diameter wiping surface, for example
with fins, and which is sized to wipe the inner diameter of liner
212. Large plug 236a further includes an axial bore extending
through the body from end to end, though which fluids can pass.
During run in, large plug 236a is installed below the running
string in a section having a diameter substantially equal to the
inner diameter of the liner. In the illustrated embodiment, the
large plug 236a is positioned in stinger 240, but may also be
installed in liner hanger 210 below running string and stinger 240.
For example, liner wiper plug 236a may be installed releasably in
the inner diameter of stinger or liner hanger or liner, as by use
of a shear sleeve 237. Shear sleeve 237 may include a releasable
connection, such as a collet, that releasably secures the plug in
the inner diameter. Large plug 236a is, thus, in place during
run-in and cementing operations and fluids such as circulation
fluids and cement can pass through its axial bore.
[0070] Wiper dart 236b is sized to pass through drill pipe and to
land in the axial bore of large plug 236a. Wiper dart 236b is
launched from a cement head at surface and acts as a wiper and
fluid separation device. Wiper dart 236b, after it lands in wiper
plug 236a, blocks the axial bore and together with plug 236a forms
a piston that can be sheared out and moved through the liner by
fluid pressure to wipe the liner of cement. The combination of
wiper plug 236a with dart 236b engaged therein acts in the same way
as plug 36 described above.
[0071] In operation, initially the liner assembly including liner
hanger 210 and liner 212 is run-in hole carried on a drill pipe
running string with a compatible ID running tool.
[0072] After the liner assembly is run to depth and located at a
desired position above the casing point 232, the equipment at
surface is lined up to commence cementing operations.
[0073] Cementing operation commences including cementing down the
ID of the drill pipe (FIG. 7), through liner hanger 210 and the
axial bore of liner wiper plug 236a, through liner 212, out the toe
212a (including float shoe, etc.) and up the annulus. During this
process the drill pipe wiper dart 236b is released to clean the
drill pipe ID of cement and to act as a fluid separation barrier
and then lands into the liner wiper plug. It latches in place into
the plug and then, in response to pressure, the liner wiper plug
236a and wiper dart 236b assembly is sheared from the plug's
installed position to be pumped, arrow P, down the liner (FIG. 8).
When the assembly lands atop the float collar/shoe at toe 212a, it
can be bumped to confirm the assembly has landed. The volume of
cement pumped ahead of the wiper dart 236b is calculated to ensure
the cement level is positioned at the correct level, which is
usually just above the packer 222 of liner hanger 210.
[0074] The liner hanger is configured not to set during these
pumping and fluid imbalance scenarios via the piston setting
feature. However, after the cement has been placed and the liner
wiped (FIG. 9), the liner hanger inner bore 220 may be pressured up
to set the packer and slips inside the casing. Thereafter, further
operations may be undertaken, for example, the pressure may be bled
off.
[0075] To clear residual cement from the connection 218, pressure
may be increased by a small amount (for example, 1.7 Mpa (250 psi))
and in a manner similar to that described above in FIGS. 2E and 2F
and FIG. 5, the running string may be released from the liner
hanger. For example, the seals at this connection may be released
from the receptacle seal bore and circulation may be commenced to
clean out residual cement that may be inside the receptacle seal
bore and in the annulus above the set liner hanger. This will be
done till the circulation shows the clean fluid back at surface
from the annulus. Circulation can be continued as the running
string running tool is re-inserted into the set liner hanger to
clean out any cement fluid residue in seal bore receptacle.
[0076] In this embodiment, it is likely that running string 215 is
then disconnected and pulled out. Circulation can be continued as
running string 215 is pulled out of the hole. The running string is
then pulled to surface and the cement is allowed to set.
[0077] The option then exists to run-in a frac string with a
connector for the liner hanger packer or the full casing ID can be
left open for intervention or coiled tubing fracs or other reasons.
Thus, while a drill pipe running string does offer some advantages
for difficult installations, it does require a two-trip operation
for treating through the cemented-in liner.
[0078] Liner 212 is shown here with blank pipe ready for completion
techniques selected from the abrasive jetting method, coiled tubing
frac packer methods, perforating, etc.
[0079] Thus, the flexibility exists using the liner hanger to
run-in a liner assembly, cement it in place and set the liner
hanger in one trip. Then, depending on the running string employed,
a wellbore treatment process can proceed while the running string
remains downhole or via a second trip (where drill pipe is used as
the running string). The process allows the installation and
treatment through the liner according to many possible downhole
multi-stage completion frac options.
[0080] Some of these typical configurations are outlined but use of
the described hydraulic set, cement through liner hanger is not
limited to these outlined options and has the flexibility to be
adaptable for other applications including conventional vertical
completions or other applications.
[0081] The previous description of the disclosed embodiments is
provided to enable any person skilled in the art to make or use the
present invention. Various modifications to those embodiments will
be readily apparent to those skilled in the art, and the generic
principles defined herein may be applied to other embodiments
without departing from the spirit or scope of the invention. Thus,
the present invention is not intended to be limited to the
embodiments shown herein, but is to be accorded the full scope
consistent with the claims, wherein reference to an element in the
singular, such as by use of the article "a" or an is not intended
to mean "one and only one" unless specifically so stated, but
rather "one or more". All structural and functional equivalents to
the elements of the various embodiments described throughout the
disclosure that are known or later come to be known to those of
ordinary skill in the art are intended to be encompassed by the
elements of the claims. Moreover, nothing disclosed herein is
intended to be dedicated to the public regardless of whether such
disclosure is explicitly recited in the claims. No claim element is
to be construed under the provisions of 35 USC 112, sixth
paragraph, unless the element is expressly recited using the phrase
"means for" or "step for".
* * * * *