U.S. patent application number 10/561901 was filed with the patent office on 2007-05-03 for apparatus and method for sealing a wellbore.
Invention is credited to Philip Head, Paul George Lurie.
Application Number | 20070095532 10/561901 |
Document ID | / |
Family ID | 27676342 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070095532 |
Kind Code |
A1 |
Head; Philip ; et
al. |
May 3, 2007 |
Apparatus and method for sealing a wellbore
Abstract
A method for sealing a hole in a tubular in a wellbore
comprising: (A) locating the tubular patch adjacent the hole; (B)
(i) plastically expanding a first portion of the tubular patch
above the hole into annular sealing engagement with the tubular to
form a first annular seal and (ii) plastically expanding a second
portion of the tubular patch below the hole in the tubular into
annular sealing engagement with the tubular or the open hole to
form a second annular seal thereby sealing the hole in the tubular.
The patch may be a corrugated tube prior to expansion in order to
pass through restrictions and may have a section with an increased
wall thickness including a resilient seal.
Inventors: |
Head; Philip; (Surrey,
GB) ; Lurie; Paul George; (Surrey, GB) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Family ID: |
27676342 |
Appl. No.: |
10/561901 |
Filed: |
June 28, 2004 |
PCT Filed: |
June 28, 2004 |
PCT NO: |
PCT/GB04/02763 |
371 Date: |
December 21, 2005 |
Current U.S.
Class: |
166/277 ;
166/207 |
Current CPC
Class: |
E21B 41/0042 20130101;
E21B 43/105 20130101; E21B 29/10 20130101 |
Class at
Publication: |
166/277 ;
166/207 |
International
Class: |
E21B 33/10 20060101
E21B033/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2003 |
GB |
0315251.9 |
Claims
1-30. (canceled)
31. An apparatus for plastically expanding a tubular patch in a
wellbore comprising: (a) an optional gripping assembly comprising
at least one radially extendible gripping member for gripping the
interior wall of the tubular patch and a mechanical means for
radially extending the gripping member(s); (b) a rotatable expander
tool, disposable in the tubular patch, comprising a plurality of
expander elements radially extendible therefrom adapted to engage
with the interior wall of the tubular patch and a mechanical means
for radially extending the expander elements; and (c) at least one
electric motor for, optionally, supplying motive power to the
mechanical means for radially extending the gripping member(s) of
the optional gripping assembly, for supplying motive power to the
mechanical means for radially extending the expander elements of
the expander tool, and for providing rotation to the expander
tool.
32. An apparatus as claimed in claim 31 that is suspended from
wireline or electric coiled tubing.
33. An apparatus as claimed in claim 31 wherein the mechanical
means for radially extending the gripping member(s) of the gripping
assembly and/or for radially extending the expander elements of the
expander tool is a jack mechanism or a conical displacement
mechanism.
34. An apparatus as claimed in claim 31 wherein the expander
elements of the expander tool are rollers or balls.
35. An apparatus as claimed in claim 31 wherein the expander tool
is provided with a further mechanical means for moving the expander
elements of the expander tool longitudinally within the tubular
patch and the at least one electric motor (c) also provides motive
power to the further mechanical means.
36. An apparatus as claimed in claim 31 wherein the expander tool
is provided with a drive means for rotating the expander tool and
the at least one electric motor (c) also provides rotation to the
drive means.
37. An apparatus as claimed in claim 36 wherein the mechanical
means for radially extending the gripping member(s) of the gripping
assembly, the mechanical means for radially extending the expander
elements of the expander tool, the mechanical means for moving the
expander elements of the expander tool longitudinally within the
tubular patch and the drive means for rotating the expander tool
are provided with dedicated electric motors.
38. A method for sealing a hole in a tubular in a wellbore or for
sealing an open hole interval of a wellbore comprising: (A)
introducing a tubular patch system into the wellbore and locating
the system adjacent a hole in the tubular or adjacent the open hole
interval of the wellbore that it is desired to seal, the tubular
patch system comprising a tubular patch and an apparatus for
plastically expanding the tubular patch comprising (a) a gripping
assembly comprising at least one radially extendible gripping
member for gripping the interior wall of the tubular patch as the
patch is being introduced and located at the desired location in
the wellbore and a mechanical means for radially extending the
gripping member(s); (b) a rotatable expander tool, disposed in the
tubular patch, comprising a plurality of expander elements radially
extendible therefrom adapted to engage with the interior wall of
the tubular patch and a mechanical means for radially extending the
expander elements; and (c) at least one electric motor for
supplying motive power to the mechanical means for radially
extending the gripping member(s) of the gripping assembly, for
supplying motive power to the mechanical means for radially
extending the expander elements of the expander tool, and for
providing rotation to the expander tool; and (B) actuating the
expander tool to plastically expand the tubular patch to seal off
the hole in the tubular or to seal off the open hole portion of the
wellbore.
39. A method as claimed in claim 38 wherein the at least one
radially extendible gripping member engages with and grips the
interior wall of the tubular patch at the upper end thereof.
40. A method as claimed in claim 38 wherein a portion of the patch
is plastically expanded by rotating the expander tool and actuating
the mechanical means for radially extending the expander elements
of the expander tool so that the expander elements engage with the
interior wall of the patch and the patch is plastically expanded to
form a fluid tight annular (or ring) seal with the wall of the
tubular or with the open hole.
41. A method as claimed in claim 40 wherein the expander tool
comprises a further mechanical means for moving the expander
elements in a longitudinal direction within the patch and the
further mechanical means is electrically actuated to move the
expander elements of the expander tool longitudinally through the
patch thereby extending the annular seal or plastically expanding
the entire tubular patch.
42. A method as claimed in claim 40 wherein, after forming the
annular seal, the radially extendible expander elements of the
expander tool and the radially extendible gripping member(s) of the
gripping assembly are retracted and the apparatus is moved to a new
position in the patch to form a further annular seal.
43. A method as claimed in claim 42 wherein at least one annular
seal is formed above the hole in the tubular or above the open hole
interval of the wellbore and at least one annular seal is formed
below the hole in the tubular or below the open hole interval of
wellbore.
44. A method as claimed in claim 38 wherein the patch is deployed
in the wellbore at a location below a restriction, D.sub.1, and the
patch comprises a metal tube that has been deformed into an
irregularly shaped tube having a maximum external cross-sectional
dimension, D.sub.2, that is less than D.sub.1 and wherein after the
patch has passed through the restriction to the desired location in
the wellbore, the expander tool is actuated to reform the patch
into a substantially regular shaped tube having an external
diameter, D.sub.3, that is greater than D.sub.1, and to plastically
expand at least a portion of the reformed tube to an external
diameter, D.sub.4, to form a fluid tight annular seal with the wall
of the tubular or the wall of the open hole wellbore wherein the
expansion ratio, [(D.sub.4-D.sub.3)/D.sub.3].times.100, of the
reformed tube is in the range 10 to 30%.
45. A method as claimed in claim 44 wherein the tubular patch
system is passed to the selected location in the wellbore through
the production tubing.
46. A method as claimed in claim 44 wherein the deformed patch is a
longitudinally corrugated tube.
47. A method as claimed in claim 38 wherein the tubular metal patch
is provided with an outer resilient sealing member to provide an
improved seal with the tubular or with the wall of the open hole
wellbore.
48. A method as claimed in claim 38 wherein the patch is formed
from a plurality of tubular metal sections wherein the sections of
the patch are joined together using deformable and optionally
plastically expandable joints.
49. A method as claimed in claim 38 wherein at least one section of
the patch is of increased wall thickness, t.sub.1, compared with
the wall thickness, t.sub.2, of adjacent sections of the patch
(i.e. t.gtoreq.t.sub.2) and wherein the rotatable expander tool is
actuated to plastically expand the at least one section of metal
tube of increased wall thickness to form an annular seal with the
tubular or open hole wellbore.
50. A method as claimed in claim 49 wherein the section(s) of metal
tube of increased wall thickness, t.sub.1, is provided with an
annular recess or groove on the outer surface thereof having an
annular resilient sealing ring located therein and wherein the
mechanical means for radially extending the expander elements is
actuated to plastically expand the at least one section of metal
tube of increased wall thickness, t.sub.1, thereby forcing the
annular resilient sealing ring against the tubular or against the
wall of the open hole wellbore to form a fluid-tight annular
seal.
51. A method for sealing a hole in a tubular in a wellbore or for
sealing an open hole interval of a wellbore comprising: (A)
introducing a tubular patch into the wellbore and locating the
tubular patch adjacent the hole in the tubular or adjacent the open
hole interval of the wellbore; (B) (i) plastically expanding a
first portion of the tubular patch above the hole in the tubular or
above the open hole interval of the wellbore into annular sealing
engagement with the tubular or the open hole to form a first
annular seal and (ii) plastically expanding a second portion of the
tubular patch below the hole in the tubular or below the open hole
interval of the wellbore into annular sealing engagement with the
tubular or the open hole to form a second annular seal thereby
sealing the hole in the tubular or the open hole interval of the
wellbore.
52. A method as claimed in claim 51 wherein further portions of the
tubular patch are plastically expanded into annular sealing
engagement with the tubular or the open hole to form further
annular seals.
53. A method as claimed in claim 51 wherein the tubular patch is a
tubular section of a sandscreen that comprises at least one tubular
section and at least one screen section.
54. A method as claimed in claim 51 wherein the tubular patch is
deployed in the wellbore at a location below a restriction,
D.sub.1, and the patch comprises a metal tube that has been
deformed into an irregularly shaped tube having a maximum external
cross-sectional dimension, D.sub.2, that is less than D.sub.1 and
wherein after the patch has passed through the restriction to the
desired location in the wellbore, the patch is reformed into a
substantially regular shaped tube having an external diameter,
D.sub.3, that is greater than D.sub.1, and the first and second
annular seals are formed by plastically expanding the first and
second portions of the reformed tube to an external diameter,
D.sub.4, wherein the expansion ratio,
[(D.sub.4-D.sub.3)/D.sub.3].times.100, of the first and second
portions of the reformed tube is in the range 10 to 30%.
55. A method as claimed in claim 52 wherein the first, second and
optional further portion(s) of the patch that are plastically
expanded to form the annular seals with the tubular or open hole
are of increased wall thickness, t.sub.1, compared with the wall
thickness, t.sub.2, of adjacent portions of the patch.
56. A method as claimed in claim 51 wherein the ring seals are
formed using the apparatus as defined above.
57. A patch for deployment in a wellbore at a location below a
restriction, D.sub.1, the patch comprising a deformed irregularly
shaped metal tube having a maximum external diameter, D.sub.2,
wherein the patch is capable of being reformed into a substantially
regular shaped tube having an external diameter, D.sub.3, where
D.sub.2 is less than D.sub.1 and D.sub.3 is greater than D.sub.1,
and wherein at least a section of the reformed tube is capable of
being plastically expanded to an external diameter, D.sub.4,
wherein the expansion ratio, [D.sub.4-D.sub.3/D.sub.3].times.100,
of the reformed tube is in the range 10 to 30%.
58. A plastically expandable tubular metal patch wherein at least
one section of the metal tube is of a reduced inner diameter and
hence increased wall thickness, t.sub.1, compared with the wall
thickness, t.sub.2, of adjacent sections of the metal tube and the
difference in thickness, t.sub.1-t.sub.2, corresponds to the radial
distance over which the section of the metal tube of increased wall
thickness, t.sub.1, is to be plastically expanded.
59. A plastically expandable tubular metal patch as claimed in
claim 58 wherein the section(s) of metal tube of increased wall
thickness, t.sub.1, is provided with an annular recess or groove on
the outer surface thereof having an annular resilient sealing ring
located therein.
60. A method of hanging a liner string from a cased or lined
interval of a wellbore comprising: (A) introducing into the
wellbore a liner system comprising a liner string and an apparatus
for forming an annular seal between the liner string and the cased
or lined interval of the wellbore wherein the apparatus comprises
(a) a gripping assembly comprising at least one radially extendible
gripping member for gripping the interior wall of the liner string
as the liner string is being introduced into the wellbore and a
mechanical means for radially extending the gripping member(s); (b)
a rotatable expander tool, disposed in an upper portion of the
liner string, comprising a plurality of expander elements radially
extendible therefrom adapted to engage with the interior wall of
the liner string and a mechanical means for radially extending the
expander elements; and (c) at least one electric motor for
supplying motive power to the mechanical means for radially
extending the gripping member(s) of the gripping assembly, for
supplying motive power to the mechanical means for radially
extending the expander elements of the expander tool, and for
providing rotation to the expander tool; (B) locating the liner
system in the wellbore such that an upper section of the liner
string overlaps with a lower section of the cased or lined interval
of the wellbore; and (C) actuating the expander tool so that the
expander elements plastically expand a portion of the upper section
of the liner string to form an annular seal between the upper
section of the liner string and the lower section of the cased or
lined interval of the wellbore and optionally, actuating the
expander tool to form further annular seals between the upper
section of the liner string and the lower section of the cased or
lined interval of the wellbore.
Description
[0001] The present invention relates to an apparatus and method for
forming an annular seal between a patch and a tubular in a wellbore
or between a patch and an open hole wellbore.
[0002] In the course of completing an oil and/or gas well, it is
common practice to run a string of protective casing into the well
bore and then to run production tubing inside the casing. The
annulus between the casing and the surrounding formation is then
sealed with a deposit of cement to prevent fluid from flowing
through the annulus from one formation zone to another. If the
casing traverses a hydrocarbon-bearing zone of the formation, the
casing is perforated to create flow apertures through the casing
and cement so that the formation fluids can flow into the well.
Such perforations may subsequently be sealed using an expandable
sealing member, preferably in the form of a radially expandable
tubular metal patch lowered into the wellbore through the
production tubing on a conventional patch setting tool. A patch may
also be used to seal holes in the casing caused by corrosion or to
reinforce corroded casing sections which have not yet become
perforated. Still other applications, such as bridging the gap
between sections of parted casing will also be apparent to those
skilled in the art. In some completions, however, the wellbore is
uncased, and an open face is established across the hydrocarbon
bearing zone. A patch may also be used in such open face wellbores
in order to increase the mechanical strength of the wellbore wall
or to seal off an open face zone, for example, a water-producing
zone. Where the patch is used to increase the mechanical strength
of the wellbore wall, the patch is subsequently perforated where it
traverses a hydrocarbon bearing zone of the formation. In other
completions, a sandscreen is used in open face wellbores. Suitably,
the sandscreen that is run into the open face wellbore comprises
one or more tubular ("patch") sections that lie across one or more
non-hydrocarbon-bearing intervals of the wellbore, for example, a
water-producing interval, and one or more screen sections that lie
across one or more hydrocarbon-bearing intervals of the wellbore.
Generally, an external casing packer is set in the annulus formed
between the tubular section(s) of the sandscreen and the open face
wellbore at each end of the tubular section(s). A cement slurry may
also be introduced into the annulus formed between the tubular
section(s) and the open face wellbore to ensure that the
non-hydrocarbon-bearing interval(s), for example, water producing
interval(s) is effectively sealed off. It would therefore be
advantageous to eliminate the requirement for the external casing
packers and for cementing the tubular section(s) of a
sandscreen.
[0003] According to US 2003/0015246, perhaps the most common prior
art approach to sealing perforations in a casing has been to use a
patch comprising a cylindrical steel sleeve with a rubber-like
gasket material bonded to the outer surface of the steel sleeve.
Generally, for deployment, the patch is wrapped about an expansion
device which is typically a mechanically operated expander plug and
is subsequently lowered through the production tubing to the
uncovered perforation. Upon reaching the perforation the patch is
expanded to seal the perforation. Typically the patch is held in
place in the well casing by friction. However, in many wells there
are one or more restrictions in the production tubing with the
minimum restriction imposing a limit on the diameter of the
unexpanded patch. During expansion of the patch, the radial
thickness of the wall of the cylindrical steel sleeve decreases. In
order to mitigate the risk of the expanded patch collapsing under
the external pressure exerted by the formation fluids, the maximum
expansion ratio for a tubular metal patch is about 30%. A problem
therefore arises when the minimum restriction in the production
tubing is small compared with the diameter of the wellbore as it
may not be possible to expand the patch to form a fluid-tight seal
with the casing or the wall of an open hole wellbore without
exceeding the maximum expansion ratio.
[0004] A solution to this problem has been to use a vertically
corrugated metal liner (for example, as described in U.S. Pat. No.
3,203,451) wherein the external cross-sectional perimeter of the
corrugated liner is greater than the internal cross-sectional
circumference of the casing but the maximum external
cross-sectional dimension of the corrugated liner is less than the
internal diameter of the casing so the liner can be inserted into
the casing. After the liner is placed at the desired location in
the casing, an expander tool is run through the corrugated liner to
cause it to assume a cylindrical shape inside the casing. The liner
is thus left in substantially maximum compressive hoop stress. An
expansion tool comprising an expanding cone, a collet head and
collet spring arms is described. The arms have outwardly enlarged
portions which perform the final forming action to force the
corrugated liner into a substantially cylindrical shape as the cone
and collet head are pulled through the corrugated tube. It is said
that the expression "expanding" the liner into contact with the
casing may be misleading. The expanding cone does expand the liner
in the sense that it forces the outer ridges of the corrugations
outwardly until they come in contact with the casing. Then the
inner corrugations are, in a sense, expanded radially outwardly
until they come in contact with the casing. It would therefore be
evident to the person skilled in the art that the reformed liner is
merely elastically reformed and is not subsequently plastically
expanded to form a seal with the wellbore wall.
[0005] An apparatus and a method for expanding a liner patch, in
particular, a corrugated liner patch, in a tubular to seal a hole
therein is described in WO 98/214444. The apparatus comprises a
body having a top portion, a bottom portion and a middle portion,
the middle portion having an outer diameter greater than the top
portion and an outer diameter greater than the bottom portion; a
first set of fingers disposed around the top portion of said body
and a second set of fingers disposed around the bottom portion of
said body; the arrangement being such that, in use, said fingers
can be urged radially outwardly by displacement thereof over said
middle portion (collet expander). Preferably, a cone is located
above said body to facilitate deformation of the liner patch. The
liner patch is expanded over the cone and finally over the fingers
as the apparatus is pulled all of the way through the liner patch.
Again, the term expansion refers to elastically reforming the patch
as opposed to plastically expanding the reformed patch.
[0006] It is an object of the present invention to provide a method
and apparatus for forming an annular fluid-tight seal between at
least a portion of a plastically expandable tubular patch and the
wall of a wellbore (an open face wellbore or a cased/lined
wellbore).
[0007] It is also an object of the present invention to provide a
patch comprising a metal tube that is capable of being deformed
such that in its deformed state the patch can pass through a
restriction in a wellbore to the location where the patch is to be
deployed. Once at the desired location in the wellbore, the patch
may be elastically reformed into a substantially regular tubular
shape having an outer diameter greater than the minimum restriction
in the wellbore and subsequently at least a portion of the reformed
tubular patch may be plastically expanded to form a fluid tight
seal with the wall of the wellbore (open face wellbore, or a
cased/lined wellbore) wherein the expansion ratio for the reformed
patch is in the range 10 to 30%.
[0008] Thus, according to a first embodiment of the present
invention there is provided an apparatus for plastically expanding
a tubular patch in a wellbore comprising: [0009] (a) an optional
gripping assembly comprising at least one radially extendible
gripping member for gripping the interior wall of the tubular patch
and a mechanical means for radially extending the gripping
member(s); [0010] (b) a rotatable expander tool, disposable in the
tubular patch, comprising a plurality of expander elements radially
extendible therefrom adapted to engage with the interior wall of
the tubular patch and a mechanical means for radially extending the
expander elements; and [0011] (c) at least one electric motor for,
optionally, supplying motive power to the mechanical means for
radially extending the gripping member(s) of the optional gripping
assembly, for supplying motive power to the mechanical means for
radially extending the expander elements of the expander tool, and
for providing rotation to the expander tool.
[0012] According to a second embodiment of the present invention
there is provided a method for sealing a hole in a tubular in a
wellbore or for sealing an open hole interval (also referred to as
an "open face interval") of a wellbore comprising: [0013] (A)
introducing a tubular patch system into the wellbore and locating
the system adjacent a hole in the tubular or adjacent the open hole
interval of the wellbore that it is desired to seal, the tubular
patch system comprising a tubular patch and an apparatus for
plastically expanding the tubular patch comprising (a) a gripping
assembly comprising at least one radially extendible gripping
member for gripping the interior wall of the tubular patch as the
patch is being introduced and located at the desired location in
the wellbore and a mechanical means for radially extending the
gripping member(s); (b) a rotatable expander tool, disposed in the
tubular patch, comprising a plurality of expander elements radially
extendible therefrom adapted to engage with the interior wall of
the tubular patch and a mechanical means for radially extending the
expander elements; and (c) at least one electric motor for
supplying motive power to the mechanical means for radially
extending the gripping member(s) of the gripping assembly and to
the mechanical means for radially extending the expander elements
of the expander tool, and for providing rotation to the expander
tool; and [0014] (B) actuating the expander tool to plastically
expand the tubular patch to seal off the hole in the tubular or to
seal off the open hole portion of the wellbore.
[0015] The apparatus for plastically expanding the tubular patch
may be run into the wellbore suspended from conventional wireline
(a reinforced steel cable encasing one or more electrical wires or
segmented electrical conductors) which provides support for the
weight of the apparatus and electrical power for actuating the
components of the expansion tool. Alternatively, the apparatus may
be run into the wellbore suspended from electric coiled tubing.
Suitable electric coiled tubing is described in UK patent
application no. GB 2359571-A which is herein incorporated by
reference.
[0016] Suitably, the apparatus may comprise a single electric motor
for providing motive power to the mechanical means for radially
extending the gripping member(s) of the gripping assembly, for
providing motive power to the mechanical means for radially
extending the plurality of expander elements of the expander tool
and for rotating the expander tool, typically via a drive means.
Alternatively, the mechanical means for radially extending the
gripping member(s), the mechanical means for radially extending the
plurality of expander elements and the drive means for rotating the
expander tool may be provided with dedicated electric motors. For
avoidance of doubt, the mechanical means for radially extending the
gripping member(s) of the gripping assembly and the mechanical
means for radially extending the expander elements of the expander
tool are also capable of radially retracting the gripping member(s)
and expander elements respectively.
[0017] Preferably, the mechanical means for radially extending and
retracting the expander elements of the expander tool is a jack
mechanism or a cone displacement mechanism comprising a conical
member that is moveable in a longitudinal direction with respect to
the expander elements such that the expander elements are displaced
radially outwardly or inwardly over the tapering surface of the
conical member. Any other suitable electrically actuated mechanical
means known to the person skilled in the art for radially extending
and retracting the expander elements may also be employed.
Suitably, the drive means for rotating the expander tool is a
rotatable shaft. Thus, the electric motor provides rotational
movement to an output shaft that is connected to the expander tool
to provide rotation thereto.
[0018] It is also envisaged that the expander tool may be
hydraulically actuated via at least one hydraulic pump. Thus,
electric power supplied to the motor may be used to operate the
pump to provide pressurised fluid to the expander tool to radially
extend the expander elements. For example, the pressurised fluid
may be used to actuate the cone displacement mechanism.
Alternatively, the pressurised fluid may be used to directly urge
the expander elements radially outwards into engagement with the
interior wall of the patch. In addition, a shaft extending from the
hydraulic pump may provide rotational motion to the expansion tool.
Typically, the apparatus of the present invention may comprise a
reservoir for a hydraulic fluid disposed in a housing. Suitably,
the expansion tool is arranged below the housing. Alternatively,
the pressurised fluid may be filtered wellbore fluid.
[0019] During the running in operation, the interior wall of the
tubular patch, preferably, a tubular metal patch, is gripped by the
least one radially extendible gripping member of the gripping
assembly, for example, by at least one radially extendible "slip".
Preferably, the at least one radially extendible gripping member
grips the interior wall of the tubular metal patch at the upper end
thereof. Suitably, the gripping member(s) comprises teeth or other
gripping elements. Preferably, the apparatus is provided with a
plurality of "slips", preferably 2 to 4 slips. Suitable "slips" for
use with the patch would be well known to the person skilled in the
art. Preferably, the mechanical means for radially extending and
retracting the gripping member(s) of the gripping assembly may be a
jack mechanism or a cone displacement mechanism, as described above
for the expander tool. Preferably, the gripping assembly remains
fixed in place in the tubular patch while the expander tool is
rotated i.e. the gripping assembly does not rotate with the
expander tool. It is also envisaged that the radially extendible
gripping member(s) of the gripping assembly may be hydraulically
actuated, as described above for the expander tool. Thus, the
electric motor may drive a hydraulic pump thereby providing
pressurised fluid to the gripping assembly to radially extend the
gripping member(s).
[0020] Suitably, as an alternative to holding the patch at the
desired location using at least one radially extendible gripping
member, an upper section of the patch may be fixed in position in
the wellbore by means of a plurality of mechanical dimples, for
example circular shaped dimples arranged circumferentially around
the tubing at the desired location, as described in FIG. 16 of U.S.
Pat. No. 6,223,823 which is herein incorporated by reference.
Suitably, at least 3 dimples are provided. The mechanical dimples
may be activated by means of internal pressure applied by the
expander elements of the expander tool. Preferably, a resilient
annular sealing member is provided on the external surface of the
patch in the vicinity of the dimples to impart an anchoring surface
against which the dimples engage thus improving the contact between
the patch and the wall of the tubular (for example, the casing or
liner of a wellbore) or with the open hole wellbore (open face
wellbore). Thus, the gripping assembly may be omitted from the
apparatus of the present invention.
[0021] Once the tubular patch system has been lowered to a level
proximate a perforation or a damaged section of a tubular (for
example, casing or liner) or the system lies within an open hole
interval of the wellbore, at least a portion of the tubular patch
is plastically expanded by rotating the expander tool and actuating
the mechanical means for radially extending the expander elements
such the expander elements engage with the interior wall of the
patch and a portion of the patch is plastically expanded against
the wall of the tubular (for example, casing or liner) or the wall
of the open hole wellbore thereby forming an annular fluid-tight
seal. Suitably, the expander elements of the expander tool are
rollers or balls that may be radially extended or retracted via the
electrically actuated mechanical means (for example, a jack
mechanism or cone displacement mechanism). Preferably, the rollers
have a longitudinal length of from 0.5 to 5 inches, for example 0.5
to 3 inches with the longitudinal length of the annular seal
corresponding to the longitudinal length of the rollers. Where the
radially extendible elements of the expander tool are balls, the
annular seal has a longitudinal length of approximately half the
ball diameter. The diameter of the balls and hence the longitudinal
length of the annular seal is dependent upon the internal diameter
of the wellbore and the external diameter of the tubular patch. For
example, where a 3 inch external diameter tubular patch is deployed
in a wellbore having a 4.5 inch internal diameter casing, the balls
preferably have a diameter of at least 1.5 inch, preferably, 1.5 to
3 inches, for example about 2 inches. Accordingly, the annular seal
preferably has a longitudinal length of 0.75 to 1.5 inches.
[0022] Preferably, the expander tool is also provided with an
electrically actuated mechanical means for moving the radially
extendible expander elements of the expander tool longitudinally
within the tubular patch thereby extending the annular seal.
Preferably, the mechanical means is a screw mechanism. Suitably,
the screw mechanism is actuated by means of a dedicated electric
motor. Accordingly, the apparatus of the present invention may be
used to form a seal along the entire length of the patch by
gradually moving the expander tool through the patch.
Alternatively, the apparatus of the present invention may be used
to form a plurality of annular (ring) seals. Preferably the annular
(ring) seals have a curved profile to mitigate the risk of the seal
being put under stress which can lead to increased corrosion of the
patch and/or the tubular.
[0023] Preferably, the annular (or ring) seal is formed by
partially expanding a portion of the tubular metal patch and then
longitudinally extending the expanded portion before further
expanding the portion of the tubular metal patch and then further
longitudinally extending the expanded portion of the tubular metal
patch and repeating these steps until the portion of the patch is
plastically expanded against the wall of the tubular or against the
open hole and a fluid tight annular (or ring) seal is formed
between the patch and the wall of the tubular or the open hole
respectively. The patch is now locked in place in the tubular or in
the open hole and the radially extendible expander elements may be
retracted and the gripping member(s) of the gripping assembly (for
example, slips) unset before moving the apparatus to a new position
in the patch. The gripping member(s) of the gripping assembly (for
example, slips) is then reset and a further annular (or ring) seal
may be formed as described above. Preferably, the apparatus is
provided with sensors for monitoring the expansion of the patch and
the position of the expansion tool and gripping assembly in the
wellbore thereby ensuring that the ring seals are formed at the
desired location in the wellbore.
[0024] Suitably, the apparatus of the present invention may be used
to deploy a patch comprising an inner metal tube and an outer
resilient sealing member. Suitably, the inner metal tube is formed
from steel, preferably, carbon steel. As discussed above, the
thickness of the inner metal tube will be a function of the
diameter of the wellbore and the yield and tensile strength of the
metal forming the tube. Preferably, the thickness of the inner
metal tube is in the range 0.25 to 0.5 inches. Preferably, the
outer resilient sealing member is formed from an elastomeric
material that is resistant to the well environment, i.e.
temperature, pressure, well fluids, and the like. Suitably, the
elastomeric material is selected from rubber (for example, silicone
rubber), polymers of ethylene-propylene diene monomer (EPDM),
polytetrafluoroethylene, polyphenylene sulfide, and
perfluoroelastomers. The outer resilient sealing member may be a
sheath extending along substantially the entire length of the patch
or may comprise at least one outer resilient sealing ring arranged
at a location where it is desired to form an annular fluid-tight
seal with the casing, liner or the wall of the open hole wellbore
and having a length corresponding to the longitudinal length of the
annular seal. Typically the patch may be provided with a plurality
of outer resilient sealing rings thereby allowing a plurality of
annular fluid-tight seals to be formed. Typically, the outer
resilient sealing rings have a longitudinal length of 1 to 5
inches. Suitably, the outer resilient sealing rings are arranged at
the upper and lower ends of the patch although the sealing rings
may also be arranged at intervals along the patch, for example,
every 0.5 to 2 feet. Typically, the thickness of the outer
resilient sealing member (sheath or ring) is in the range 0.05 to
0.15 inches, for example, about 0.1 inches. Suitably, the outer
resilient sealing member may be adhered to the inner metal tube.
Alternatively, the inner metal tube may be a tight fit within the
outer resilient annular sealing member.
[0025] Where a tubular patch is to be used to seal a hole in a
tubular (or to seal off an open hole interval of the wellbore), at
least one ring seal is formed above the hole (or above the open
hole interval that it is desired to seal) and at least one ring
seal is formed below the hole (or below the open hole
interval).
[0026] Thus, according to a third embodiment of the present
invention there is provided a method for sealing a hole in a
tubular in a wellbore or for sealing an open hole interval of a
wellbore comprising: [0027] (A) introducing a tubular patch into
the wellbore and locating the tubular patch adjacent the hole in
the tubular or adjacent the open hole interval of the wellbore;
[0028] (B) (i) plastically expanding a first portion of the tubular
patch above the hole in the tubular or above the open hole interval
of the wellbore into annular sealing engagement with the tubular or
the open hole to form a first annular seal and (ii) plastically
expanding a second portion of the tubular patch below the hole in
the tubular or below the open hole interval of the wellbore into
annular sealing engagement with the tubular or the open hole to
form a second annular seal thereby sealing the hole in the tubular
or the open hole interval of the wellbore.
[0029] Preferably, the tubular patch is located in the desired
position in the wellbore and the annular seals are formed using the
apparatus of the first embodiment of the present invention.
[0030] In order to strengthen the seal, a plurality of annular
seals may be formed above and below the hole in the tubular or
above and below the open hole interval of the wellbore. An
advantage of sealing off the hole in a tubular or of sealing off an
open hole interval of the wellbore by forming annular seals between
the patch and the tubular or the open hole interval is that there
is no requirement to plastically expand the entire patch. Suitably,
the open hole interval of the wellbore may be an interval that
requires hydraulic isolation, for example, a water-producing
interval of the wellbore. An advantage of hydraulically isolating
an open hole interval of a wellbore using the method of the third
embodiment of the present invention is that this allows external
casing packers and the use of cement to be eliminated.
[0031] The method of the third embodiment of the present invention
may also be used in conjunction with a sandscreen comprising at
least one tubular ("patch") section and at least one screen section
where the sandscreen is run into a wellbore until the screen
section(s) lie across a hydrocarbon-bearing interval of an open
hole wellbore and the tubular section(s) lies across an interval of
the open hole wellbore that it is desired to hydraulically isolate.
It is envisaged that the sandscreen may be run into the wellbore
supported by the gripping assembly of the apparatus of the first
embodiment of the present invention. If necessary, the apparatus
may be provided with a traction device to assist in placing the
sandscreen at the desired location in the open hole wellbore,
particularly, where the wellbore is a deviated wellbore (for
example, a side track or lateral well). It is also envisaged that
the sandscreen may be deployed in the wellbore using a conventional
"running-in" tool before passing the apparatus of the first
embodiment of the present invention through the sandscreen
(supported on wireline or electric coiled tubing) to the location
where it is desired to form the annular fluid-tight seals, in which
case the gripping assembly may be omitted from the apparatus.
Preferably, at least one annular fluid-tight seal is formed at each
end of the tubular ("patch") section(s) of the sandscreen.
Preferably, a plurality of rings seals may be formed at intervals
along the entire length of the tubular ("patch")section(s) of the
sandscreen.
[0032] Suitably, the apparatus of the first embodiment of the
present invention and the methods of the second and third
embodiments of the present invention may be used to deploy a
tubular metal patch in a wellbore at a location below a
restriction, D.sub.1, wherein the patch is capable of being
deformed into an irregularly shaped tube having a maximum external
cross-sectional dimension, D.sub.2, and of being subsequently
elastically reformed into a substantially regularly shaped tube
having an external diameter, D.sub.3, wherein D.sub.2 is less than
D.sub.1 and D.sub.3 is greater than D.sub.1, and wherein at least a
section of the reformed tube is capable of being plastically
expanded to an external diameter, D.sub.4, to form a fluid tight
annular seal with the wall of a tubular (for example, casing or
liner of a wellbore) or the wall of an open hole interval of a
wellbore and wherein the expansion ratio,
[(D.sub.4-D.sub.3)/D.sub.3].times.100, is in the range 10 to 30%,
preferably 20 to 30%, for example 25 to 30%.
[0033] By plastically expanded is meant that the expanded shape is
maintained when an expansion pressure is no longer being
applied.
[0034] Suitably, the deformed tube may be reformed into a tube of
substantially uniform external diameter (i.e. a tube having a
substantially circular transverse cross-section), preferably, into
its original tubular shape, prior to plastically expanding at least
a section of the reformed tube to form an annular fluid-tight seal
with the tubular or open hole. Alternatively, a section of the
deformed tube may be reformed and plastically expanded to form an
annular seal prior to reforming and optionally plastically
expanding the remainder of the deformed tube.
[0035] Suitably, production tubing is run into the wellbore and the
patch is deployed in the wellbore through the production tubing.
Typically, the production tubing has one or more restrictions
therein such that the deformed patch must be capable of passing
through the minimum restriction in the production tubing.
[0036] Preferably, the metal tube is deformed into a longitudinally
corrugated tube of the types well known to the person skilled in
the art. It is also envisaged that the metal tube may be deformed
into any other shape that is capable of passing through the
restriction, D.sub.1, for example, the patch may be deformed to put
a groove therein, as described in U.S. Pat. No. 3,489,220, which is
herein incorporated by reference. Suitably, the metal tube may be
deformed to a size smaller than the restriction, D.sub.1, using a
set of rollers located above the wellhead.
[0037] Typically, the deformed metal tube has a maximum external
diameter, D.sub.2, that is slightly less than the restriction,
D.sub.1, for example 5 to 10% less than the restriction, D.sub.1.
At least a portion of the reformed tubular patch is capable of
being plastically expanded to form an annular fluid tight seal with
the wall of the wellbore wherein the total expansion ratio for the
deformed tube, [(D.sub.4-D.sub.2)/D.sub.2].times.100 is 40 to 50%
with the proviso that the expansion ratio for the reformed tube,
[(D.sub.4-D.sub.3)/D.sub.3].times.100, is in the range 10 to 30%,
preferably 20 to 30%, for example 25 to 30%.
[0038] Suitably, the patch may be deployed in a cased wellbore, a
lined wellbore or an open hole wellbore with the patch forming an
annular fluid tight seal with the wall of the casing, liner or the
open hole respectively. It is envisaged that a plurality of
portions of the reformed patch may be plastically expanded to form
a plurality of annular seals. Alternatively, the deformed tubular
patch may be reformed and plastically expanded along substantially
the entire length thereof.
[0039] Suitably, the patch may be from 10 to 1000 feet in length,
preferably, 30 to 600 feet, more preferably 50 to 300 feet, for
example, 100 to 200 feet. The patch may be formed from tubular
metal sections having a length of 5 to 40 feet, preferably 20 to 30
feet. The sections of the patch may be joined together using
conventional flush joints having a maximum diameter smaller than
the minimum restriction in the wellbore, in which case there is no
requirement to deform the joints. Alternatively, the sections of
the patch may be joined together using deformable joints. Suitably,
the deformable joint comprises a male connection on a first tubular
metal section of the patch and a female connection on a second
tubular metal section of the patch where the male and female
connections are provided with interlockable complementary
formations such that when the joint is deformed and subsequently
reformed, the complementary formations of the male and female
connections do not break apart. For example, the male and female
connections may be provided with interlockable dovetailed threads.
Preferably, the deformable joint is also capable of being
plastically expanded to allow the patch to be plastically expanded
along its entire length. Suitable expandable joints are well known
to the person skilled in the art and may be adapted to be
interlockable, for example, by employing interlockable dovetailed
threads.
[0040] Suitably, the elastically deformable and plastically
expandable metal patch is formed from steel, for example, a low
carbon steel or other suitable metal alloy. Typically, the
elastically deformable and plastically expandable metal patch may
be provided with an outer resilient sealing member (sheath or
ring), as described above. Preferably, the elastically deformable
and plastically expandable metal patch is coated with a resilient
material, typically an elastomeric material, to provide an improved
annular seal with the tubular (for example, casing or liner) or
with the wall of the open hole interval of the wellbore upon
plastic expansion of the reformed tube. Preferably, the elastomeric
material is resistant to the well environment, i.e. temperature,
pressure, well fluids, and the like. Suitable elastomeric materials
are as described above.
[0041] As discussed above, the thickness of the wall of the metal
tube decreases as it is plastically expanded. The required
thickness of the wall after expansion is a function of the diameter
of the wellbore and the yield and tensile strength of the metal
forming the tube. In general, as the wellbore diameter increases it
is necessary to increase the thickness of the wall of the
plastically expanded metal tube in order for the tube to apply
sufficient force to seal the hole in the tubular (for example,
perforations in the casing or liner of the wellbore) or to seal the
open hole wellbore. Preferably, the thickness of the wall of the
plastically expanded metal tube is in the range 0.25 to 0.5 inches
for a plastically expanded tube having an internal diameter of 6 to
8 inches. Typically, the thickness of the coating of resilient
material is in the range 0.05 to 0.2 inches, for example, about 0.1
inch.
[0042] In yet a further embodiment of the present invention there
is provided a patch that may be deployed in a wellbore using the
apparatus and method of the present invention. Suitably, the patch
may be deployed at a location below a restriction, D.sub.1, the
patch comprising a metal tube having an outer diameter small enough
to pass through the restriction wherein at least one section of the
metal tube is of increased wall thickness, t.sub.1, compared with
the wall thickness, t.sub.2, of adjacent sections of the metal tube
(i.e. t.sub.1>t.sub.2) and wherein the at least one section of
metal tube of increased wall thickness is capable of being
plastically expanded to form an annular (or ring) seal. Preferably,
the patch is capable of being deployed through production tubing.
Preferably, the difference in wall thickness, t.sub.1-t.sub.2,
corresponds to the radial distance through which the section of
metal tube of increased thickness is plastically expanded to form
an annular fluid-tight seal. Preferably, the section of metal tube
of increased wall thickness, t.sub.1, has a reduced inner diameter
compared with adjacent sections of the tube of wall thickness,
t.sub.2. Preferably, after plastic expansion of the section of tube
of increased thickness the inner diameter of the plastically
expanded section of tube is substantially the same as the inner
diameter of the adjacent non-plastically expanded sections of the
metal tube. Preferably, prior to expansion the patch has a
substantially uniform outer diameter:
[0043] The section(s) of metal tube of increased wall thickness may
be plastically expanded against the metal casing or metal liner of
a wellbore to form a metal to metal annular seal. It is also
envisaged that the section(s) of tube of increased wall thickness
may be coated with a resilient material, preferably, an elastomeric
material, in order to provide an improved seal in an open hole
wellbore. Suitable elastomeric materials are as described
above.
[0044] Preferably, the section(s) of metal tube of increased wall
thickness, t.sub.1, may be provided with an annular recess or
groove on the outer surface thereof having an annular resilient
sealing member, for example, an O-ring located therein. Preferably,
the annular resilient sealing member is formed of an elastomeric
material. Suitable elastomeric materials are as described above.
Expansion of the section(s) of the metal tube of increased wall
thickness, t.sub.1, will force the annular resilient sealing member
against the metal casing or metal liner of a wellbore or against
the wall of an open hole wellbore thereby forming a fluid-tight
seal.
[0045] The patch of this further embodiment of the present
invention is preferably plastically expanded using the apparatus of
the first embodiment of the present invention. However, it is also
envisaged that the patch may be deployed using any conventional
expansion tool, in particular, an expansion tool having
hydraulically actuated, radially expandable members, as described
in U.S. 2001/0045284, which is herein incorporated by
reference.
[0046] When the apparatus of the first embodiment of the present
invention is used to reform a deformed tubular patch, for example,
a longitudinally corrugated tube, at least a portion of the tube is
first reformed into its original tubular shape using the expander
elements of the expander tool before plastically expanding the
portion of reformed tube to form an annular (or ring) seal between
the patch and the casing or liner or open hole wellbore.
Preferably, the deformed tubular patch is reformed along the entire
length thereof. Suitably, a plurality of portions of the reformed
tubular patch may be plastically expanded using the apparatus of
the present invention to form a plurality of annular (or ring)
seals or, alternatively, the entire tubular patch may be
plastically expanded to form a seal with the wall of the casing,
liner or the open hole wellbore.
[0047] In a further aspect of the present invention, the apparatus
of the first embodiment of the present invention may be used to
form an annular (or ring) seal between a liner string and a cased
or lined interval of a wellbore such that the annular (or ring)
seal acts as a liner hanger in addition to sealing the annulus
between the liner and the wall of the cased or lined interval of
wellbore. Thus, the ring seal must be capable of taking the weight
of the liner string. Preferably, the "liner hanger" comprises a
plurality of ring seals, for example, 2 to 5 annular seals.
Typically, the liner string is lowered into the wellbore, supported
by the radially extendible gripping member(s) of the gripping
assembly, until the upper section of the liner string overlaps the
lower section of the cased or lined interval of the wellbore with
the expander tool located in the upper section of the liner string.
The expander elements of the expander tool are then extended
radially outwardly into engagement with the interior wall of the
liner string and a portion of the liner string is plastically
expanded against the casing or lining to form an annular fluid
tight ring seal between the upper section of the liner string and
the lower section of the cased or lined interval of wellbore. Where
the liner string is deployed in a deviated wellbore (lateral or
side track wellbore), the apparatus of the first embodiment of the
present invention may be provided with a tractor for running the
liner string into the deviated wellbore. It is also envisaged that
a prior art means for running the liner string into a wellbore may
be employed. Once the liner string is in place in the wellbore, the
apparatus of the first embodiment of the present invention may run
into the wellbore to form the "liner hanger". As would be evident
to the person skilled in the art, the gripping assembly may be
omitted from the apparatus when the liner string is run into the
wellbore using a prior art "running-in" means.
[0048] The present invention will now be illustrated by reference
to FIGS. 1 to 10.
[0049] FIG. 1 is a transverse cross-sectional view illustrating a
deformable tubular patch in an undeformed state 1, and deformed
into a longitudinally corrugated tube 2 having a maximum outer
diameter, D.sub.2 less than the minimum restriction 3 in a
wellbore. FIG. 2 shows the patch reformed into its original tubular
shape 4 and in a plastically expanded state 5. FIG. 3, illustrates
a deformable and plastically expandable dovetail joint 6 for
joining sections of the deformable tubular metal patch.
[0050] FIG. 4 is a longitudinal cross sectional view showing a
tubular metal patch 10 in position in a cased wellbore 11 prior to
expansion of the patch against the casing wall 12. The patch 10 is
provided with a section 13 of decreased internal diameter and hence
increased wall thickness. FIG. 5 shows the patch after a metal to
metal ring seal 14 has been formed at the location of the section
of decreased internal diameter.
[0051] FIG. 6 illustrates a modified patch of the type shown in
FIGS. 4 and 5 wherein the section 13 of patch of decreased internal
diameter and hence increased wall thickness is provided with an
external groove 17 adapted to receive an O-ring, 15, formed from an
elastomeric material. FIG. 7 shows the patch in annular (or ring)
sealing engagement with the walls of a wellbore 16 which may be
either a cased or lined wellbore or an open hole wellbore.
[0052] Referring to FIG. 8, a production tubing 20 having a
restriction 21 is positioned within the casing 22 of a wellbore. A
liner 23 is hung from the casing 22 via a casing hanger 24. An
apparatus for deploying a tubular metal patch 25 is lowered into
the wellbore through the production tubing 20 suspended from a
wireline 26. The apparatus comprises a connector 27, a controller
28, a first electric motor 29 for actuating a screw mechanism (not
shown) for radially extending and retracting slips 30, and an
expander tool comprising a jack mechanism 31 for radially extending
and retracting rollers 32, and a rotatable shaft 33 that extends
from a second electric motor 34 through patch 25 to a third
electric motor 35. The second electric motor 34 actuates the jack
mechanism 31 and a means (not shown) for driving the rotatable
shaft 33 while the third electric motor 35 actuates a screw
mechanism (not shown) for moving the rollers 32 in a longitudinal
direction within the patch 25. The slips 30 are shown in their
radially extended position gripping the tubular metal patch 25.
Once the patch 25 is in the desired location in the wellbore, the
shaft 33 is rotated and the rollers 32 are gradually radially
extended to plastically expand the patch until the patch forms an
annular fluid tight seal with the wall of the liner 23. At various
stages during the radial extension of the rollers 32, the third
electric motor 35 actuates the screw mechanism to move the rollers
upwardly and downwardly within the patch 25 thereby extending the
annular seal. FIG. 9 shows the result of this operation with a
section of the patch 25 plastically expanded to form an annular
seal 36 with the wall of liner 23. Referring to FIG. 10, the
rollers 32 and slips 30 are retracted before moving the expansion
tool to a new position in the patch and radially extending the
slips 30 to grip the interior wall of the patch. The expansion tool
is then actuated to plastically expand the new section of patch, as
discussed above. The third electric motor 35 may be provided with a
"steady" having a centraliser 37 that engages with the liner 23.
This operation may be repeated until the entire lower section of
the patch has been plastically expanded against the wellbore wall.
As shown in FIG. 11, the apparatus may then be moved upwardly
through the wellbore until the expander tool is located in the
upper 38 unexpanded part of the patch 25. The slips 30 are then
radially extended to engage with the wall of the casing 22 and the
expander tool actuated as described above to plastically expand the
upper section 38 of the tubular metal patch. The rollers 32 and
slips 30 may then be retracted and the apparatus removed from the
wellbore by pulling the wireline leaving behind the plastically
expanded patch in annular sealing engagement with the wall of the
liner 23. Although the installation of the patch is described in
relation to a vertical wellbore, the apparatus of the present
invention may also be deployed in a deviated well, for example, a
side track or lateral well. If necessary, the apparatus may be
provided with a tractor to assist in moving the tubular patch
through the deviated well.
* * * * *