U.S. patent application number 13/129415 was filed with the patent office on 2011-10-20 for modifying expansion forces by adding compression.
Invention is credited to Mark Wilson Anderson, Donald Bruce Campo, Robert Lance Cook, Darrell Scott Costa.
Application Number | 20110253394 13/129415 |
Document ID | / |
Family ID | 42198756 |
Filed Date | 2011-10-20 |
United States Patent
Application |
20110253394 |
Kind Code |
A1 |
Anderson; Mark Wilson ; et
al. |
October 20, 2011 |
MODIFYING EXPANSION FORCES BY ADDING COMPRESSION
Abstract
A method for expanding a tubular in a borehole, the tubular
having upper and lower ends, the system comprises a) applying a
compressive load to the upper end of the tubular and b) expanding
the tubular by moving an expansion device relative to the tubular
while maintaining the compressive load. Step a) may include resting
a weight on the upper end of the tubular or applying hydraulic
pressure to the upper end of the tubular. The lower end of the
tubular may engage the formation before step b) or as a result of
step b).
Inventors: |
Anderson; Mark Wilson;
(Rijswijk, NL) ; Campo; Donald Bruce; (Richmond,
TX) ; Cook; Robert Lance; (Katy, TX) ; Costa;
Darrell Scott; (Katy, TX) |
Family ID: |
42198756 |
Appl. No.: |
13/129415 |
Filed: |
November 16, 2009 |
PCT Filed: |
November 16, 2009 |
PCT NO: |
PCT/US2009/064501 |
371 Date: |
June 30, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61115787 |
Nov 18, 2008 |
|
|
|
Current U.S.
Class: |
166/387 |
Current CPC
Class: |
E21B 43/103
20130101 |
Class at
Publication: |
166/387 |
International
Class: |
E21B 33/12 20060101
E21B033/12 |
Claims
1. A method for expanding a tubular in a borehole, the tubular
having upper and lower ends and an expansion device positioned
below the upper end, the method comprising: a) applying a
compressive load to the upper end of the tubular; and b) expanding
the tubular by moving the expansion device toward the upper end of
the tubular while maintaining said compressive load.
2. The method of claim 1 wherein step a) includes resting a weight
on the upper end of the tubular.
3. The method of claim 1 wherein step a) includes applying
hydraulic pressure to the upper end of the tubular.
4. The method of claim 3 wherein step a) includes forming a
moveable fluid seal above the upper end of the tubular and applying
fluid pressure above the seal so as to cause the seal to bear on
the upper end of the tubular.
5. The method of claim 3 wherein step a) includes forming a
hydraulic chamber above the upper end of the tubular and applying
fluid pressure within the chamber so as to cause the chamber to
bear on the upper end of the tubular.
6. The method of claim 5 wherein the expansion device is a mandrel
and applying fluid pressure to the chamber also causes the mandrel
to move relative to the tubular.
7. The method of claim 1, further including the step of engaging
the formation with the lower end of the tubular before step b).
8. The method of claim 7 wherein the lower end of the tubular does
not engage the formation before step b).
9. The method of claim 8 wherein the lower end of the tubular
engages the formation as result of step b).
10. The method of claim 7, further including the step of resting
the tubular on the bottom of the borehole before step b).
Description
RELATED APPLICATIONS
[0001] This application claims priority to application Serial No.
61/115,787 and is related to application Serial No. 61/115,779,
filed concurrently herewith, entitled "Modifying Expansion Forces
by Adding Compression."
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
TECHNICAL FIELD OF THE INVENTION
[0003] The present disclosure relates generally to a system and a
method for expanding an expandable casing in a drilled hole. More
particularly, the present invention relates to methods for reducing
the amount of expansion force that is required to expand the
casing.
BACKGROUND OF THE INVENTION
[0004] Conventionally, when a wellbore is created, a number of
casings are installed in the borehole to prevent collapse of the
borehole wall and to prevent undesired outflow of drilling fluid
into the formation or inflow of fluid from the formation into the
borehole. The borehole is drilled in intervals whereby a casing
which is to be installed in a lower borehole interval is lowered
through a previously installed casing of an upper borehole
interval. As a consequence of this procedure the casing of the
lower interval typically has a smaller diameter than the casing of
the upper interval. Thus, the casings are in a nested arrangement
with casing diameters decreasing in downward direction. Cements is
typically provided between the outer surfaces of the casings and
the borehole wall to seal the casings from the borehole wall.
[0005] As a consequence of this nested arrangement, a relatively
large borehole diameter is required at the upper part of the
wellbore. Such a large borehole diameter involves increased costs
due to heavy casing handling equipment, large drill bits and
increased volumes of drilling fluid and drill cuttings. In
addition, the small diameter casing that is required at the bottom
of the hole may not allow desired flow rates of drilling fluid. For
these reasons, it may be desirable to expand the diameter of one or
more strings of casing so as to reduce the diameter reduction(s)
that would otherwise be necessary. Expandable casings are known in
the art.
[0006] Expanding the diameter of an upper casing interval allows
lower casing intervals to have a greater diameter, since wider
sections of pipe will fit through the expanded upper interval
casing. Expansion of the casing may be accomplished by passing a
mandrel through the casing, among other techniques. The mandrel is
typically frustoconical in shape and has a diameter greater than
the unexpanded diameter of the casing. In a bottom-up technique,
the mandrel is typically placed at the bottom of the casing
interval before the casing interval is inserted into the borehole.
In some instances, the expandable casing may be lowered into the
borehole on the mandrel. After the casing and the mandrel are
placed into the borehole, the mandrel is drawn upward through the
unexpanded casing, thereby expanding the casing.
[0007] If the expandable casing is resting on and supported by the
mandrel, applying an upward force on the mandrel will cause the
casing to move upward. In other instances, the casing may not be
supported on the mandrel, but the available upward force on the
mandrel is insufficient to overcome the expansion force required to
begin radially expanding the casing. In either case, it is desired
to reduce the expansion force that is required.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The following figures form part of the present specification
and are included to further demonstrate certain aspects of the
present claimed subject matter, and should not be used to limit or
define the present claimed subject matter. Consequently, a more
complete understanding of the present embodiments and further
features and advantages thereof will be acquired by referring to
the following description taken in conjunction with the
accompanying drawings, wherein:
[0009] FIG. 1 is a schematic diagram depicting a system for
expanding a pipe, according to one embodiment of the present
invention;
[0010] FIG. 2 is a schematic diagram depicting another system for
expanding a pipe, according to a second embodiment of the
invention;
[0011] FIG. 3 is a schematic diagram depicting yet another system
for expanding a pipe, according to a third embodiment of the
invention;
[0012] FIG. 4 is a schematic diagram depicting yet another system
for expanding a pipe, according to a fourth embodiment of the
present invention; and
[0013] FIG. 5 is a schematic diagram depicting yet another system
for expanding a pipe, according to a fifth embodiment of the
invention.
[0014] It is to be noted, however, that the appended drawings
illustrate only certain embodiments of the present claimed subject
matter and are, therefore, not to be considered limiting of the
scope of the present claimed subject matter, as the present claimed
subject matter will admit to other equally effective
embodiments.
[0015] It will be understood that the Figures are not to scale and
are not intended to illustrate the size or relative sizes of the
components. In addition, it will be understood that the concepts
that are illustrated herein with respect to a vertical borehole are
equally applicable to curved, deviated, and otherwise non-vertical
boreholes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Referring to FIG. 1, a first liner 124 is placed inside a
borehole 126 within a formation 128. If the well is offshore,
borehole 126 is drilled from a rig resting on the seafloor, a
floating rig, or other vessel. In that case, a riser 132,
comprising a long tube of steel from the sea floor to a surface
vessel, allows drilling mud to be pumped into borehole 126 and
returned to the surface.
[0017] As is known in the art, first liner 124 has an upper end
134, which may be fixed in the borehole by filling the annulus
between first liner 124 and formation 128 with cement. Upper end
134 may be coupled to a blowout preventer (BOP) 138, which can be
closed in the event that excess formation pressure threatens to
blow out the well.
[0018] In a typical operation, a drilling cycle continues until the
desired depth is reached, whereupon the drill bit is removed and
first liner 124 is lowered into the borehole. First liner 124 is
then expanded and/or cemented, if desired. The drill bit is then
reinserted into borehole 126, though first liner 124, and a second
drilling cycle begins and continues until the next desired depth is
reached. The drill bit is again removed, and second liner 140 is
inserted through first liner 124 and into borehole 126. The outer
diameter of second liner 140 is smaller than the inner diameter of
first liner 124, providing clearance as second liner 140 is passed
through first liner 124. Liner 140 has an upper end 144 and a lower
end 146.
[0019] If desired, second liner 140 may be expanded, and the
drilling cycles can be continued through first liner 124 and second
liner 140. Typically, one or more intervals of casing will already
be positioned in borehole 126 before second liner 140 is placed in
borehole 126.
[0020] Expansion of liner 140 may be carried out by pulling an
expansion cone 102 upwardly through liner 140. Alternatively,
expansion may be carried out by providing a hydraulic expansion
device that provides a radial expansion force and is moved
incrementally through liner 140. Regardless of how expansion is
carried out, it is necessary to overcome the yield strength of the
pipe in order to deform it to its expanded diameter.
[0021] Expansion cone or mandrel 102 preferably includes a narrow
portion 104 that can fit within liner 140 and a wide portion 106
that has a larger diameter than liner 140. The wide portion 106
preferably has a diameter that is smaller than the inner diameter
of first liner 124, so that that mandrel 102 can be removed from
the casing and drawn up to the surface after expanding liner
140.
[0022] Mandrel 102 is preferably suspended from a drill string 154
or other guide string, such as are known in the art, that passes
through liner 124 and liner 140. As it passes through liner 140,
mandrel 102 will plastically deform liner 140 radially outward,
thereby increasing the inner diameter (and, generally, the outer
diameter) of liner 140.
[0023] In accordance with one embodiment of the present invention,
a pressure mechanism 114 is applied to liner 140 in order to
facilitate expansion of liner 140. For example, in the embodiment
of FIG. 1, a ballast pipe 120 may be included at the upper end of
second liner 140. Ballast pipe 120 preferably remains within first
liner 124 when second liner 140 has been lowered to its desired
depth. The weight of ballast pipe 120 applies downward compressive
force on the upper end of liner 140. The weight of ballast pipe 120
and the weight of liner 140 itself result in a combined axial
compressive load at the bottom of liner 140.
[0024] It has been found that applying an axial compressive load to
an expandable pipe decreases the radial expansion force that is
required to plastically deform the pipe. Thus, applying a ballast
pipe 120 to the upper end of liner 140 results in a reduction of
the required expansion force. When liner 140 is resting on mandrel
102, the added weight of ballast pipe 120 also results in an
increased expansion force applied by the expansion cone to the
liner 140. Thus, if the required expansion force is decreased and
the applied expansion force is increased until the two become
equal, the application of a ballast pipe or other weighting device
to the upper end of liner 140 can be used to initiate radial
expansion of liner 140. Even if liner 140 is not resting on mandrel
102, such as in cases where liner 140 is resting on the borehole
bottom, the added weight of ballast pipe 120 still results in a
reduction of the required expansion force. Thus, the use of a
ballast pipe or other weighting device is advantageous regardless
of whether liner 140 is supported on the expansion device and
regardless of whether the expansion device is moving upwardly or
downwardly through liner 140.
[0025] During expansion, liner 140 will have an expanded portion
156 and an unexpanded portion 158. As mandrel 102 continues to be
drawn upward from lower end 146 toward upper end 144, expanded
portion 156 will lengthen until there is nothing left of unexpanded
portion 158. Mandrel 102 is preferably sufficiently narrow to fit
through first liner 124 and be retrieved from the surface when
drawn upward by a pipe string or other device 154.
[0026] It should be noted that mandrel 102 need not move upward
relative to second liner 140; downward movement is also
contemplated. Similarly, and as discussed below, liner 140 may be
pushed downward over mandrel 102, or both items may move
simultaneously relative to the borehole. Also, radial expansion
force may be applied to liner 140 without use of a mandrel, such as
through application of hydraulic pressure or mechanical force. If
desired, explosives or high-pressure chemical reactions may also or
alternatively be used to move mandrel 102 through the pipe.
[0027] FIG. 2 is a schematic diagram depicting another system for
expanding a pipe, and includes at least one aspect of the present
invention. The various elements shown in FIG. 2 are similar to
like-numbered elements of FIG. 1. However, as shown in the system
of FIG. 2, the ballast that is shown as a separate device 120 in
FIG. 1 may instead comprise part of liner 140. For example, liner
140 will be slid entirely though first liner 124 until a desired
portion 142 is below liner 124. The portion 143 of liner 140 that
lies within liner 124 functions as a weight resting on the lower
portion 142 of liner 140. As described above, the weight of upper
portion 143 increases compressive force, reduces required expansion
force, and may increase applied expansion force in lower portion
142. In this embodiment, it is preferred to provide means, such as
are known in the art, for severing the portion of the pipe that
serves as ballast from the rest of the pipe, so that the ballast
can be removed from the borehole.
[0028] It will be understood that various other mechanisms for
providing a weight or ballast pipe may be used. For instance, the
ballast pipe may have a diameter that is unequal to the diameter of
liner 140, with the result that ballast pipe cannot rest directly
on liner 140. In these instances, the weight of the ballast pipe
can be transferred to liner 140 by any suitable weight transfer
mechanism at the interface between the ballast pipe and liner 140.
Devices for coupling the ballast pipe or weight to liner 140
include but are not limited to hooks, pegs, teeth, braces, or the
like, which may engage corresponding holes, slots, ridges or the
like, or otherwise engage liner 140. The weight of ballast pipe 120
is thus preferably supported until mandrel 102 has passed fully
through expandable portion 142, whereupon the weight of ballast
pipe 120 is transferred to mandrel 102 for removal from the
borehole.
[0029] Of course, if liner 140 is supported on the expansion
device, it is preferred that the total downward force at bottom of
second liner 140 not be so great that it overcomes the expansion
force prematurely, or liner 140 would slide down over mandrel 102
before it was lowered to the desired position. Thus, either the
ballast can be applied to the upper end of liner 140 after liner
140 has been positioned at the desired axial position in the
borehole, or the ballast can be applied when liner 140 is not
resting on the expansion device. In the former case, it will be
preferred to provide some means for preventing the expanded liner
140 from falling downwardly into the borehole, such as by ensuring
that the expanded liner 140 engages the borehole wall.
Alternatively, the bottom of the expandable can be supported by
something other than mandrel 102, e.g. either the expandable is
resting on the borehole bottom or the bottom of the expandable has
been expanded (using a jack) and is "set" against the borehole
wall. In that case, the added compression merely makes it easier to
expand the expandable.
[0030] Mandrel 102 may have a starting angle that provides a
relatively large axial compression and a relatively small radial
expansion to lower end 146 of liner 140 as mandrel 102 enters liner
140. Mandrel 102 may also have an expansion angle that is more
tapered than the starting angle and that provides a relatively
smaller axial compression and relatively greater radial expansion
than the starting angle as mandrel 102 moves through second liner
140. A reverse situation is also possible: mandrel 102 may have a
starting angle that is very tapered and that provides a relatively
large radial expansion and only a relatively small axial
compression to liner 140. Mandrel 102 may also have an expansion
angle that is provides more axial compression and less radial
expansion than the starting angle. Mandrels with more than two
angles are also contemplated.
[0031] Ballast pipe 120 may comprise any suitable material and need
not be expandable. Any weight or other means of providing an axial
compression, force or pressure on second liner 140 may be used as
ballast pipe 120. Liner 140 is preferably fabricated of an
expandable material. Thus, mandrel 102 simply carries ballast pipe
120 out of the borehole when mandrel 102 is withdrawn from the
well.
[0032] FIG. 3 is a schematic diagram depicting yet another system
for expanding a pipe. The various elements shown in FIG. 3 are
similar to like-numbered elements of FIG. 1 and FIG. 2. However, as
shown in the system of FIG. 3, ballast pipe 120 may be replaced by
other means of providing axial compression on liner 140. If
desired, for example, a pressure mechanism 114 may include a cup
122 (or a gripper, or a wedge) adjacent to upper end 144 of liner
140. The application of fluid pressure behind (above) cup 122 will
cause cup 122 to deform against the inside of liner 124, forming a
seal. Further pressure will cause cup 122 to bear on upper end 144
of liner 140. In this manner, cup 122 can apply a compressive force
to upper lip 144 of liner 140, thereby resulting in the same
benefits as ballast member 120. Stationary while an upward
compressive force or pressure is applied to lower lip 146 of second
liner 140.
[0033] Referring now to FIG. 4 pressure mechanism 114 includes an
alternative mechanism for providing axial compression to liner 140.
In this embodiment, pressure mechanism 114 includes a first
diaphragm 148, which may be coupled to first liner 124, and a
second diaphragm 150, which may be coupled to upper lip 144 of
second liner 140. First diaphragm 148 is preferably not coupled to
string 154. A hydraulic line 152 provides fluid access to the space
159 between first and second diaphragms 148, 150. Pumping fluid
through line 152 into space 159 results in the application of a
compressive force to upper end 144 of liner 140. In contrast to the
embodiment shown in FIG. 3, the embodiment shown in FIG. 4 does not
require filling the entire volume of liner 124 with pressurized
fluid. Hydraulic line 152 may comprise a hose or other suitable
device, such as are known in the art.
[0034] Referring now to FIG. 5, pressure mechanism 114 may
alternatively include a upper diaphragm 148 that is coupled to
mandrel 102, rather than to first liner 124. Hydraulic line 152
supplies fluid pressure to the space 159 between upper diaphragm
148 and lower diaphragm 150. In this embodiment, the fluid pressure
will force lower diaphragm 150 downward from first diaphragm 148,
while simultaneously forcing upper diaphragm 148 upward, thereby
drawing mandrel 102 upward through liner 140. Upper diaphragm 148
and lower diaphragm 150 cooperate to apply an axial compressive
force to second liner 140.
[0035] In the embodiments shown in to FIG. 4 and to FIG. 5, the
application of hydraulic pressure will result in increased
compressive force on liner 140.
[0036] In one implementation, the downward compressive force that
is applied to liner 140 will approximately equal the upward axial
force that is applied by the mandrel. Accordingly, the upward axial
force applied by the mandrel and the compressive force in the
second axial direction will provide a net zero axial force, such
that the only net force on the pipe is radially outward. In another
implementation, the compressive force that is applied in the second
axial direction will be substantially greater than the upward axial
force that is applied by the mandrel. In this case, if the liner is
not resting on something (such as the borehole bottom), the
downward force may be sufficient to move the pipe past the mandrel.
In another implementation, the bottom of the pipe engages the
borehole wall such that the wall applies a downward force in
opposition to the upward force applied by the mandrel. In this
case, the applied compressive facilitates expansion by reducing the
required expansion force. In another, less desirable
implementation, the upward axial force that is applied by the
mandrel causes the mandrel to move upward through the pipe, while
expanding the pipe.
[0037] In some embodiments, a jack may be used to initiate
deformation (i.e. movement of the mandrel relative to the pipe).
The pressure mechanism serves to increase compressive force on the
pipe at the expansion point, thereby reducing the expansion
(jacking) force.
[0038] Several implementations and embodiments have thus been
described. It will be appreciated, however, that other
implementations and embodiments will also be substituted within the
scope of this disclosure. For example, the mandrel may be replaced
with an electromechanical device (such as a motor) that can apply a
radial force that is greater than the tension within the drill
string, and that is also greater than the weight of the fluid in
the well. The electromechanical device may also include a sensor
that can detect cracks or other structural problems within the
pipe, and may be able to adjust a magnitude of the radial force in
accordance with an ability of the pipe to sustain the radial force
without damage.
[0039] Thus, although the invention has been described with
reference to several exemplary embodiments, it is understood that
the words that have been used are words of description and
illustration, rather than words of limitation. Although the
invention has been described with reference to particular means,
materials and embodiments, the invention is not intended to be
limited to the particulars disclosed; rather, the invention extends
to all functionally equivalent structures, methods, and uses such
as are within the scope of the appended claims.
* * * * *