Setting Tool
BACKGROUND OF THE INVENTION
[0001] Expandable liner hangers are generally used to secure a liner within a
previously set casing or liner string. These types of !iner hangers are typically set by
expanding the liner hangers radially outward into gripping and sealing contact with the
previous casing or liner string. Many such liner hangers are expanded by use of hydraulic
pressure to drive an expanding cone or wedge through the liner hanger.
[0002] The expansion process is typically performed by means of a running tool or
setting tool used to convey the liner hanger and attached liner into a welibore. The
running tool or setting tool may be interconnected between a work string (e.g., a tubular
string made up of drill pipe or other segmented or continuous tubular elements) and the
liner hanger.
[0003] If the liner hanger is expanded using hydraulic pressure, then the running
tool or setting too! is generally used to control the communication of fluid pressure, and
flow to and from various portions of the liner hanger expansion mechanism, and between
the work string and the liner. The running tool or setting tool may also be used to control
when and how the work string is released from the liner hanger, for example, after
expansion of the liner hanger, in emergency situations, or after an unsuccessful setting of
the liner hanger.
[0004] The running tool or setting tool is also usually expected to provide for
cementing therethrough, in those cases in which the liner is to be cemented in the
welibore. Some designs of the running or setting too! require a bal! or cementing plug to
be dropped through the work string at the completion of the cementing operation and
prior to expanding the liner hanger.
[0005] In running tools or setting tools that expand a liner hanger using hydraulic
pressure, multiple stacked pistons may be employed to apply force to an expanding cone
or wedge to drive it through the liner hanger. The force required to expand the liner
hanger may vary widely due to factors such as friction, casing tolerance and piston sizing.
In addition, the pistons may be exposed to internal pressure in the tool during cementing
of the liner and/or release of a cementing plug and/or circulation of drilling fluids through
the liner and the welibore, thereby risking premature expansion of the liner hanger.
Accordingly, hydraulic pressures in the tool must be carefully monitored during activities
undertaken prior to expanding the liner hanger.
SUMMARY OF THE INVENTION
[0006] In an embodiment, a downhole setting too! is disclosed. The tool comprises
a tool housing and a hollow mandrel, the mandrel being situated in the housing. The tool
further comprises a piston situated between the mandrel and the too! housing and a collar
situated between the mandrel and the tool housing, wherein the tool housing, the
mandrel, the piston and the collar define an annulus. The tool further comprises a first
valve, wherein in a closed position the first va!ve blocks a path of f!uid communication
between the interior of the mandrel and the annulus.
[0007] n an embodiment, a downhole setting tool is provided. The too! comprises
a tool housing, a hol!ow mandrel having at least one transverse hole that runs from an
interior of the mandre! to an exterior of the mandrel, the mandrel being situated in the
housing, and a piston situated between the mandrel and the tool housing. The tool
further comprises a collar situated between the mandrel and the too! housing, wherein the
tool housing, the mandrel, the piston and the collar define an annulus. The tool further
comprises a vent hole situated in the col!ar, the vent hole forming a path of fluid
communication between the annulus and a second annulus partially defined by the collar
and the tool housing.
[0008] In an embodiment, a method of setting a liner hanger in a we!lbore using a
downhole setting too! is disclosed. The method comprises providing a downhole setting
too! comprising a too! housing, a mandrel, a piston, and a collar, wherein the piston and
the collar define a first annulus, and wherein the too! housing, the mandre!, and the collar
partially define a second annulus. The method further comprises placing the downhole
setting tool into the wel!bore, the interior of the mandrel and the second annulus being
subjected to an ambient wellbore pressure as the downhole setting tool is placed into the
welibore. The method further comprises adjusting a pressure in the first annu!us to
approximately the ambient welibore pressure by bleeding fluid from the second annulus
into the first annulus via a first valve situated in the collar, between the first annulus and
the second annulus. The method further comprises pressurizing the interior of the
mandrel to a pressure greater than the ambient wellbore pressure. The method further
comprises opening a second valve situated between an interior of the mandrel and the
first annuius, forcing a portion of a fluid situated in the mandrel into the first annuius, and
forcing the piston in a downhole direction with respect to the mandrel.
[0009] These and other features will be more clearly understood from the following
detailed description taken in conjunction with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present disclosure, reference is
now made to the following brief description, taken in connection with the accompanying
drawings and detailed description, wherein like reference numerals represent like parts.
[001 1 FIG. a is a schematic cross-sectional view of a portion of an embodiment
of a setting tool.
[0012] FIG. 1 is a schematic cross-sectional view of a further portion of the
embodiment of a setting tool illustrated in FIG. 1a.
[0013] FIG. 1c is a schematic cross-sectional view of a further portion of the
embodiment of a setting tool illustrated in FIG. 1a.
[0014] FIG. d is a schematic cross-sectional view of a further portion of the
embodiment of a setting tool illustrated in FIG. 1a .
[0015] FIG. 2 is a schematic cross-sectional view of a detail of the embodiment of
the setting tool shown in FIG. 1.
[001 6] FIG. 3 is a schematic cross-sectional view of a further embodiment of a
setting tool.
[0017] FIG. 4 is a schematic cross-sectional view of the setting too! embodiment of
FIG. 3, after a piston-type valve has been opened.
[0018] FIG. 5 is a schematic cross-sectional view of a further embodiment of a
setting tool.
[0019] FIG. 6 is a schematic cross-sectional view of a detail of the embodiment of
the setting tool shown in FIG. 5.
[0020] FIG. 7 is a schematic cross-sectional view of a further embodiment of a
setting tool.
[0021] FIG. 8 is a schematic cross-sectional view of a detail of the embodiment of
the setting tool shown in FIG. 7.
[0022] FIG 9 is a flow chart of a method for setting a liner hanger in a wel!bore.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] It should be understood at the outset that although illustrative
implementations of one or more embodiments are illustrated below, the disclosed
assemblies and methods may be implemented using any number of techniques, whether
currently known or not yet in existence. The disclosure should in no way be limited to the
illustrative implementations, drawings, and techniques illustrated below, but may be
modified within the scope of the appended claims along with their full scope of
equivalents.
[0024] Unless otherwise specified, any use of the term "couple" describing an
interaction between elements is not meant to limit the interaction to direct interaction
between the elements and may also include indirect interaction between the elements
described in the following discussion and in the claims, the terms "including" and
"comprising" are used in an open-ended fashion, and thus should be interpreted to mean
"including, but not limited to Reference to up or down will be made for purposes of
description with "up," "upper," "upward," "upstream" or "uphole" meaning toward the
surface of the welibore and with "down," "lower," "downward," "downstream" or
"downhole" meaning toward the terminal end of the well, regardless of the welibore
orientation. The various characteristics mentioned above, as well as other features and
characteristics described in more detail below, will be readily apparent to those skilled in
the art with the aid of this disclosure upon reading the foiiowing detailed description of the
embodiments, and by referring to the accompanying drawings.
[0025] In an embodiment, a liner setting too! is provided which includes a hollow
cylindrical tool housing coupled to liner hanger expansion cones; a hollow mandrel that is
situated inside the tool housing and is configured to convey pressurized fluid through the
setting tool; and one or more force multiplier pistons that are situated inside the tool
housing, are rigidly attached to the tool housing and are configured to slide along the
mandrel. When a liner hanger is to be expanded against a casing in a welibore,
pressurized fluid from the mandrel may be allowed into an annulus, i.e.. a cylinder,
bounded by the tool housing, the mandrel, the force multiplier piston and a coupling rigidly
attached to the mandrel. Upon exposure to the pressurized fluid, the cylinder and the too!
housing are forced downhole relative to the mandrel. Simultaneously, the expansion
cones, which are attached to the tool housing, are forced through the liner hanger and
expand the liner hanger against the casing. Much of the functionality of the !iner setting
tool may be repurposed to other usage, for example in setting packers, by minor design
modifications such as removing an expansion cone from the setting tool.
[0026] The above-described setting tool may be referred to as an annulus
differential pressure operated tool, since during operation of the too!, at least a portion of
an annulus situated between the tool housing and the mandrel is subjected to an ambient
downhole pressure, whereas an interior of the mandrel is subjected to a higher fluid
pressure generated by fluid pumps. One problem shared by known annulus differential
pressure operated tools, in which hydraulic force is applied to force multiplier pistons for
the purpose of driving expansion cones through a liner hanger, is that the pistons are in
constant fluid communication with the interior of the mandrel and are thus always
subjected to the pressure in the mandrel. Accordingly, when, e.g., a cementing plug is
run through the mandrel, or cement is pumped through the mandrei for the purpose of
cementing a liner to the wellbore, or wellbore servicing fluids are circulated through the
mandrel, the pistons are subjected to forces that could possibly expand the liner hanger
prematurely.
[0027] The setting too! disclosed in the present application responds to the abovementioned
problem of known annulus differentia! pressure operated tools by situating a
valve between the interior of the mandrel and one or more of the pistons, which is
configured to open only at a mandrel pressure significantly higher than mandrei pressures
experienced during, e.g., release of a cementing plug, cementing of the liner, or
circulation of wellbore servicing fluids. The valve may be, e.g., a rupture disk configured
to fail at a setpoint mandrel pressure, or a piston-type valve having a piston held in place
by a shear pin configured to fail when subjected to a force corresponding to a setpoint
mandrel pressure. In this manner, the liner hanger may be prevented from expanding
prematurely.
[0028] In addition, in order to prevent the portion of the tool housing surrounding
the annulus bounded by the tool housing, the mandrel, the force multiplier piston and the
coupling from collapsing when the setting tool is run into the wellbore and the tool housing
is subjected to ambient downho!e pressure, a second valve is situated in the coupling,
between the annulus and a second annu!us that is at the ambient downhoie pressure.
The second va!ve, e.g., a vent hole, a velocity valve or a spring-loaded check valve allows
pressurized fluid from the second annulus to bleed into the annulus when a pressure
differential develops between the second annulus and the first annulus. Accordingly, the
second valve prevents the tool housing surrounding the annulus from collapsing under
downhoie conditions.
[0029] FIG. 1a, FIG. b, FIG. 1c and FIG. 1d are schematic cross-sectiona! views
of portions of an embodiment of a setting tool 100 along a length of the setting tool 00.
The setting tool 100 may be attached to a downhoie end of a work string via an upper
adapter 1 0 and may be used to attach a liner hanger 1 0 to a casing situated in a
wel!bore. In addition, the setting tool 00 may be used to convey cement that is pumped
down the work string, down an interior of a liner attached to a downhoie end of the setting
tool 100, and up an annulus situated between the Iiner and a wall of a wellbore, for the
purpose of cementing the Iiner to the welibore. In order to be able to convey cement to
the annulus and to expand the Iiner hanger 120, the setting tool 100 may comprise a
series of mandrels 110 , 130, 1 0, 150 which are interconnected and sealed by collars,
e.g., couplings 160, 170, 180. As set forth above, the mandrel 110 may also be referred
to as upper adapter 110 and may connect the setting tool 100 to the work string in
addition, a mandrel at a downhoie end of the setting tool 100 may be referred to as a
collet mandrel 190. The mandrels 10, 130, 140, 150, 190 are capable of holding and
conveying a pressurized fluid, e.g., cement slurry, hydraulic fluid, etc.
[0030] In an embodiment, the setting tool 00 may further comprise pistons 200,
2 10 and respective pressure chambers or annuli 220, 230, which are in fluid
communication with mandrels 140, 150 via at least one pressurization port 240, 250,
respectively, and alternatively, via a plurality of pressurization ports 240, 250,
respectively. In addition, the setting tool 100 may include expansion cones 270, which
are situated downhoie from the pistons 200, 2 10. As is apparent from FIG. c, the
expansion cones 270 have an outer diameter greater than an inner diameter of a section
of the iiner hanger 120 downhoie from the expansion cones 270.
[0031 ] In an embodiment, the Iiner hanger 120 may be expanded against a waii of
the casing after the liner has been cemented to the wai of the wellbore. To expand the
Iiner hanger 120, a hydraulic fluid may be pumped down the work string and into the
mandrels 110, 130, 140, 150, 190 at a pressure that may range from 2500 psi to 10000
psi. The hydraulic fluid may enter the annuli 220, 230 via pressurization ports 240, 250
and exert a force on pistons 200, 2 10 . The couplings 170, 180, which form uphole-side
boundaries of the annuli 220, 230, are rigidly attached to mandrels 130, 140 and 40,
150, respectively, whereas pistons 200, 2 10 and expansion cones 270 are rigidly
attached to a tool housing 280. In addition, the pistons 200, 210 and the expansion
cones 270 may move longitudinally with respect to the mandrels 10, 130, 140, 150, 190.
When a sufficient pressure has built up in the mandrels 110, 130, 140, 150, 190 and the
annuli 220, 230, the pistons 200, 210, along with the tool housing 280 and the expansion
cones 270, are forced downhole with respect to the mandrels 110, 130, 140, 150, 190. In
an embodiment, the mandrei 130 and tool housing 280 may define an annu!us 320.
Since the outer diameter of the expansion cones 270 is greater than the inner diameter of
the liner hanger 120 and the liner hanger 120 is longitudinally fixed in position in the
wellbore, a portion of the Iiner hanger 120 in contact with the expansion cones 270 is
expanded against the casing as the expansion cones 270 are forced downhole.
[0032] FIG. 2 is a schematic cross-sectional view of Detail A of the embodiment of
the setting tool 100 shown in FIG. 1b. As is apparent from FIG. 2, the annulus 220 is
bounded by mandrel 140, tool housing 280, piston 200 and coupling 170. A contact
surface of the coupling 170 and the tool housing 280 may be sealed by an O-ring 172,
and a contact surface of the piston 200 and the mandrel 140 may be sealed by an O-ring
202. In addition, at least one pressurization port 240, and alternatively, a plurality of
pressurization ports 240 may provide a path of fluid communication between an interior of
the mandrel 1 0 and the annulus 220, via which path the annulus 220 may be
pressurized.
[0033] In an embodiment, in order to avoid premature application of liner hanger
expansion forces to the piston 200, a valve, e.g., a rupture disk 290, may be positioned
between outer ends of the pressurization ports 240 and the annulus 220. In so doing, a
valve annulus 300 may be formed, which is bounded by the mandrel 140, the coupling
170 and the rupture disk 290. The vaive annuius 300 is in fluid communication with the
interior of the mandrel 140 via pressurization ports 240, and a path of fluid communication
from the valve annulus 300 to the annuius 220 is blocked by the rupture disk 290. The
rupture disk 290 may be designed to fail at a differential pressure greater than a
differentia! pressure to which the rupture disk 290 would be exposed during cementing of
the liner, release of a cementing plug or circulation of drilling fluids. For example, the
rupture disk 290 may be designed to fail at a differential pressure of about 4000 psi to
about 9000 psi. in this manner, the piston 200 is not subjected to the pressure in the
mandrel 140 until the liner hanger 1 0 is ready to be expanded.
[0034] In an embodiment, the coupling 170 may include a vent hole 3 10, which
extends through the coupling 70, from the annulus 220 to a further annulus 320 partially
defined by mandrel 130, coupling 70 and tool housing 280. The annuius 320 may be
exposed to an ambient wellbore pressure as the setting too! 100 is lowered into the
wellbore. Therefore, the vent hole 3 10 may allow the ambient wellbore pressure, which
may reach levels of 30,000 psi or greater, to be bled into the annuius 220, thereby
preventing the too! housing 280 from collapsing at annulus 220 as the setting tool 100 is
lowered into the weilbore.
[0035] n operation, the setting tool 100, the liner hanger 20 and the attached liner
are lowered into the wel!bore to a position at which the !iner hanger 20 is to be attached.
In an embodiment, the mandrels 110, 130, 140, 150, 190 and the annulus 320 may be
exposed to the ambient wellbore pressure, so fluid at the ambient wel!bore pressure may
bleed through the vent hole 3 10 into the annuius 220. When the liner hanger 1 0 is to be
expanded, a fluid may be pumped down the mandrels 110, 130, 140. 50, 190 at a
pressure greater than the ambient wellbore pressure. At a mandrel pressure of about
3000 psi to about 9000 psi greater than ambient, the rupture disk 290 will burst, thereby
allowing pressurized fluid from the mandrel 140 to enter the annulus 220 and apply a
force to the piston 200. The force may cause the piston 200 and the tool housing 280 to
move downhole with respect to the mandrels 130, 140 and force the expansion cones
270 through the liner hanger 120. In addition, since a diameter of the pressurization ports
240 may be about 1 times to about 0 times greater than a diameter of the vent hole 3 10,
any fluid loss through the vent hole 3 10 during the pressurization of annulus 220 and the
displacement of the piston 200 may easily be compensated for by fluid pumps that
pressurize the mandrels 130, 140.
[0036] FIG. 3 is a schematic cross-sectional view of a further embodiment of the
setting tool 100. The present embodiment of setting too! 100 differs from the embodiment
shown in F!G. 2 in that a piston-type valve 330 is used to isolate the fluid pressure in the
mandrel 140 from the annuius 220 until the liner hanger 0 is to be expanded. In an
embodiment, the piston-type valve 330 may comprise a valve piston 340; a plug 350, with
which the vaive piston 340 may mate, and which may be rigidly attached to the coupling
70; and a shear screw 360, which may releasably fix the valve piston 340 in position with
respect to the coup!ing 70 and the plug 350. A mating surface of the valve piston 340
and the plug 350 may be sealed by an O-ring 370, and the valve piston 340 may be
sea!ed with respect to the coupling 170 by a further O-ring 380.
[0037] In operation, pressure between the annuius 320 and the annuius 220 may
again be equalized via the vent hole 3 10, as the setting tool 00 is lowered into the
wellbore. When the liner hanger 120 is to be expanded, the mandrel 140 may be
pressurized, and fluid from the mandrel 140 may travel through the pressurization ports
240 into the valve annuius 300 and exert a longitudinal force on a shoulder 390 of the
valve piston 340. When a force applied by the pressurized fluid in the mandre! 140 to the
shoulder 390 of the valve piston 340 is sufficient to overcome a shear strength of the
shear screw 360, the shear screw 360 breaks and the valve piston 340 is forced upho!e
with respect to coupling 170 and out of engagement with plug 350, thereby allowing fluid
in the mandrel 140 to enter the annuius 220, exert pressure on the piston 200 and force
the piston 200 downho!e. F!G. 4 illustrates the embodiment of the setting too! 100 of FIG.
3 after the shear screw 360 has been sheared and the valve piston 340 has been forced
away from the plug 350. In addition, as in the embodiment of FIG. 2, any fluid lost
through the vent hole 310 during the pressurization of annuius 220 and the displacement
of the piston 200 may be compensated for by the fluid pumps that pressurize the
mandrels 30, 140.
[0038] FIG. 5 is a schematic cross-sectional view of a further embodiment of the
setting too! 100. The embodiment of FIG. 5 differs from that of F!G. 2 in that a velocity
valve 400 is used in place of the vent hole 310. As is apparent from FIG. 5 and the detail
of the velocity valve 400 illustrated in FIG. 6, the velocity valve 400 may be situated in
coupling 170, in a path of fluid communication between annulus 220 and annulus 320. In
an embodiment, the velocity valve 400 may comprise a valve stem 402, which is
supported in a longitudinal through-hole 420 of the coupling 70 by a plug 404 and a
sleeve 406. In an embodiment, a downhole portion of the plug 404 may be situated in the
longitudinal through-hole 420, and an uphole portion of the plug 404 may be situated
outside of the through-hole 420 and may rest against an uphole-side end face 173 of the
coupling 70. The plug 404 may be positively fixed in position in the through-hole 420
and with respect to the coupling 170 by a lip 174. In addition, the plug 404 may include a
through-hole 408, inside which the valve stem 402 may move longitudinally with respect
to the plug 404. In an embodiment, the plug 404 may be made of a metal, metal alloy,
composite material, high-strength plastic, or other material able to withstand high
temperatures and pressures and a corrosive environment present in a weilbore. In an
embodiment, the plug 404 may be extruded or molded or press-fit into the through-hole
420 or fixed in the through-hole 420 in another suitable manner known to one skilled in
the art. In an embodiment, the plug 404 may be comprised of steel material and may
threadingly engage with the through-hole 420.
[0039] In an embodiment, a spring 4 10 may be biased between a downhole-side
end face 4 12 of the plug 404 and a flange 414, which is situated at a downhole-side end
of the sleeve 406 and, in a neutral position of the velocity valve 400, rests against a
shoulder 1 5 of the coupling 170. In addition, the valve stem 402 may be held in the
sleeve 406 and the plug 404 by a valve stem flange 4 16 . which abuts against the flange
414 of the sleeve 406, and a retaining ring 4 8, which, in the neutral position of the
velocity valve 400, may rest against an uphole-side end face 422 of the plug 404.
[0040] In an embodiment, when the velocity valve 400 is in the neutral position,
i.e., when no longitudinal force is applied in an uphole direction to a valve head 424 of the
valve stem 402 or a longitudinal force less than a force applied to sleeve 406 by spring
4 10 is applied in an uphole direction to valve head 424, the velocity valve 400 is
configured to be open, i.e., the valve head 424 is not seated on a valve seat 426, and
fluid may flow between annuli 220, 320 via a bypass hole 430, which is in fluid
communication with through-hole 420 and runs generally parallel to the through-hole 420.
[0041] In operation, since the neutral position of the velocity valve 400 is an open
position, as the setting tool 100 is lowered into the wellbore, pressure between the
annulus 320 and the annulus 220 may be equalized in a manner similar to the setting tool
embodiments of FIGURES 2 and 3 , via a flow of fluid from annulus 320 to annulus 220.
In addition, as is the case with the setting too! embodiment of FIG. 2 , when the liner
hanger 1 0 is to be expanded, fluid may be pumped down the mandrels 110 , 130, 140,
50, 190 at a pressure sufficient to break the rupture disk 290. When the rupture disk
290 fails, fluid in the mandrel 140 may enter the annulus 220 via valve annulus 300, exert
pressure on the piston 200 and force the piston 200 downhole.
[0042] In an embodiment, as the annulus 220 is pressurized, fluid from the annulus
220 may initially flow past the valve head 424, into through-hole 420, through bypass hole
430 and into annulus 320. However, in contrast to the setting too! embodiments of
FIGURES 2 and 3 that comprise vent hole 3 10, when a pressure drop from annulus 220
to annulus 320 increases such that a force exerted on valve head 424 by the fluid in
annulus 220 is greater than a sum of a force applied to sleeve 406 by spring 4 10 and a
force applied to an uphoie-side end of valve stem 402 and retaining ring 4 18 by fluid in
annulus 320, the vaive stem 402 is forced in a direction of annulus 320 until valve head
424 lands on the valve seat 426, and the flow of fluid from annulus 220 to annulus 320 is
interrupted. Furthermore, since the velocity valve 400 may be closed during and after
expansion of the liner hanger 1 0, the present embodiment of the setting tool 100 may be
used to pressure-test the liner.
[0043] FIG. 7 is a schematic cross-sectional view of a further embodiment of the
setting tool 100. The embodiment of the setting tool 100 of FIG. 7 differs from the
embodiment illustrated in FiG. 2 in that the vent hole 310 is replaced by a spring-loaded
check valve 440, which is situated in the coupling 70, in a path of fluid communication
between annulus 220 and annulus 320. In addition, a second spring-loaded check vaive
470 is situated in the coupling 170, in a path of fluid communication between the annulus
220 and the interior of the mandrel 140. The spring-loaded check vaive 440 may be
oriented such that the vaive 440 opens in response to a positive pressure differential from
the annulus 320 to the annulus 220 and remains closed in response to a positive
pressure differential from the annulus 220 and the annulus 320. In addition, the springioaded
check valve 470 may be oriented such that it opens in response to a positive
pressure differential from the annulus 220 to the interior of the mandrel 140 and remains
closed in response to a positive pressure differential from the interior of the mandrel 140
to the annulus 220.
[0044] In an embodiment, the spring-loaded check va!ve 440, of which a detail is
shown in FIG. 8, may comprise a valve stem 442, which is supported in a longitudinal
through-hole 480 in coupling 170 by a hollow, cylindrical dog 444 and a sleeve 446. The
coupling 170 may include a bypass hole 490, which is in fluid communication with the
through-hole 480 and runs generally parallel to the through-hole 480. The dog 444
includes a through-bore 448, in which a portion of the valve stem 442 is situated, as well
as a circular seat 450, in which a retaining ring 452 rigidly fixed to the valve stem 442 is
seated.
[0045] In an embodiment, a spring 454 is biased between a downhole end face
456 of the dog 444 and a flange 458, which constitutes a downhole end of the sleeve 446
and rests against a shoulder 460 formed in the coupling 70. In addition, the springloaded
check valve 440 is configured such that in a neutral state of the valve 440, i.e.,
when no longitudinal forces are acting on an uphole-side end of the valve stem 442, the
retaining ring 452 and the dog 444 and on an uphole-side end face of a valve head 462 of
the valve stem 442 via bypass hole 490, or a sum of longitudinal forces acting on the
uphole-side end of the valve stem 442, the retaining ring 452 and the dog 444 and on the
uphole-side end face of valve head 462 via bypass hole 490 is less than a sum of a force
exerted by spring 454 on dog 444 and a force exerted on a downhoie-side end face of
valve head 462 by a fluid in annulus 220, the spring-loaded check valve 440 is in a closed
state, i.e., the force exerted by the spring 454 pushes the dog 444, the retaining ring 452
and the valve stem 442 uphole, and the force exerted by the fluid in annulus 220 on vaive
head 462 pushes the valve stem 442 uphole, until the valve head 462 rests against a
valve seat 464 situated at a downhole end of the through-hole 480.
[0046] In an embodiment, the second spring-loaded check valve 470 may be
substantially identical to spring-loaded check valve 440 and may be configured to be
closed in a neutral state of the valve 470.
[0047] In operation, as in the other embodiments of the setting tool 100 illustrated
in FIG. 2, FIG, 3 , F!G. 4 , FIG. 5 and FIG. 6, the interior of the mandrels 130, 140 and the
annulus 320 are exposed to an ambient wellbore pressure as the setting tooi 00 is
lowered into the wellbore. Accordingly, since the pressure in the annulus 320 and the
interior of the mandrel 140 increases with increasing depth of the setting tool 100 and the
spring-loaded check valves 440, 470 and the rupture disk 290 are initially all closed, a
positive pressure differential develops from annulus 320 to annulus 220 and from the
interior of the mandrel 140 to annulus 220. If this positive pressure differential were to
become too large, the tool housing 280 would collapse and destroy the setting tool 100.
However, as is evident from FIG. 8, if the pressure in annulus 320 increases such that a
total force applied by a pressurized fluid in annulus 320 to uphole side ends of the valve
stem 442 and the dog 444, as well as to the uphole-side end of the valve head 462 via
bypass hole 490, becomes greater than the combined forces of the spring 454 on the dog
444 and the pressurized fluid in annulus 220 on a downhole-side end of the valve head
462, then the valve stem 442 and the dog 444 are forced downhole, thereby lifting valve
head 462 off the valve seat 464 and allowing fluid from annulus 320 to bleed into annulus
220 via bypass hole 490. In an embodiment, the spring-loaded check valve 440 is
configured to open in response to a positive pressure differential from annulus 320 to
annulus 220 ranging from about 1 psi to about 5000 psi.
[0048] Conversely, If the setting tool 100 needs to be reversed up the wellbore or
up and out of the wellbore, or if the setting tooi 100 passes through a region in which the
ambient wellbore pressure decreases sharply, a positive pressure differential may
develop from the annulus 220 to the interior of the mandrel 140 and to the annulus 320. If
this positive pressure differential becomes too great, it could conceivably damage the
rupture disk 290 and/or the tool housing 280 and/or pose a risk to personnel handling the
setting tool 100 outside of the wellbore. Accordingly, in an embodiment, if the positive
pressure differential from the annulus 220 to the interior of the mandrel 140 exceeds a
threshold value ranging from about 1 psi to about 5000 psi, the spring-loaded check valve
470 opens to allow pressurized fluid from the annulus 220 to bleed into the interior of the
mandrel 140.
[0049] in further regard to the operation of the embodiment of the setting tool 00
illustrated in FIG. 7 and FIG. 8, as in the setting tool embodiments of FIG. 2 , FIG. 3 , FIG.
4 and FIG. 5, when the liner hanger 1 0 is to be expanded, fluid may be pumped down
the mandrels 110, 130, 140, 150, 190 at a pressure sufficient to break the rupture disk
290. When the rupture disk 290 fails, fluid in the mandrel 140 may enter the annulus 220
via valve annulus 300, exert pressure on the piston 200 and force the piston 200
downhole. However, in contrast to the setting tool embodiments of FIG. 2 and FIG. 5, the
spring-loaded check valves 440, 470 remain closed during pressurization of the annulus
220, and therefore, no pressurized fluid from the annulus 220 bleeds into the annulus
320.
[0050] Turning now to FIG. 9 , a method 600 for setting a liner hanger in a weilbore
is described. The setting tool comprises a tool housing, a mandrel, a piston, a collar, a
first valve and a second valve. The tool housing, the mandrel, the piston and the collar
define an annulus. The tool housing and the collar partially define a second annulus.
The first valve is situated between an interior of the mandrel and the annulus. The
second vaive is situated in the collar, between the annulus and the second annulus.
[0051] At block 6 0 , the setting tool is placed into the weilbore, whereby an interior
of the mandrel and the second annulus is subjected to an ambient weilbore pressure. At
block 620, a pressure in the annulus is adjusted to approximately the ambient weilbore
pressure by bleeding fluid from the second annulus into the annulus via the second valve.
At block 630, the interior of the mandrel is pressurized to a pressure greater than the
ambient weilbore pressure. At block 640, the first valve is opened. At block 650, a
portion of a fluid situated in the mandrel is forced into the annulus. At block 660, the
piston is forced in a downhole direction with respect to the mandrel.
[0052] While embodiments of the invention have been shown and described,
modifications thereof can be made by one skilled in the art without departing from the
spirit and teachings of the invention. The embodiments described herein are exemplary
only, and are not intended to be limiting. Many variations and modifications of the
invention disclosed herein are possible and are within the scope of the invention. For
example, the techniques described above may be applied to a fraction of the piston
subassemblies and still obtain a force multiplying effect and/or force aggregation effect
with those particular piston subassemblies. For example, if the techniques are applied to
3 piston subassemblies of a string of 6 piston subassemblies, the force generated by the
three piston subassemblies collectively may be said to multiply the force of one piston
subassembly three times or to aggregate the force generated by each of the three piston
subassemblies, thereby reducing the force needed to be produced by one of these three
piston subassemblies to expand the subject liner hanger. For example, in the
embodiment of the setting too! 00 illustrated in FIG. 3, the vent ho!e 3 10 may be
replaced with a velocity va!ve or a spring-!oaded check valve. In addition, in the
embodiments of the setting too! 00 illustrated in FIG. 2, F!G. 5 and FIG. 7, an additional
rupture disk may be connected between the pressurization ports 240 and the annulus 220
as a redundancy, in case one of the rupture disks fails to burst at a desired pressure
differential. Furthermore, in an embodiment, a rupture disk or a piston-type valve may be
utilized with an additional piston or pistons. Furthermore, the setting too! 100 may be
designed for setting tools and/or subassemblies other than liner hangers, for example for
setting packers.
[0053] Where numerical ranges or limitations are express!y stated, such express
ranges or limitations should be understood to include iterative ranges or limitations of
like magnitude falling within the expressly stated ranges or limitations (e.g., from about
1 to about 10 includes, 2 , 3 , 4 , etc.; greater than 0.1 0 includes 0.1 1, 0.1 2. 0.1 3 , etc.).
For example, whenever a numerical range with a lower limit. RL, and an upper limit, RL
is disclosed, any number falling within the range is specifically disclosed !n particular,
the fol!owing numbers within the range are specifically disclosed: R=R +k* {R ,-R ) ,
wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent
increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, 50
percent, 5 1 percent, 52 percent, , 95 percent, 96 percent, 97 percent, 98 percent, 99
percent, or 00 percent. Moreover, any numerical range defined by two R numbers as
defined in the above is also specifically disclosed. Use of the term "optionally" with
respect to any element of a claim is intended to mean that the subject element s
required, or alternatively, is not required. Both alternatives are intended to be within the
scope of the claim. Use of broader terms such as comprises, includes, having, etc.
should be understood to provide support for narrower terms such as consisting of,
consisting essentialiy of, comprised substantially of, etc.
[0054] Accordingly, the scope of protection is not limited by the description set out
above but is only limited by the claims which foilow, that scope including ail equivalents of
the subject matter of the claims. Each and every claim is incorporated into the
specification as an embodiment of the present invention. Thus, the claims are a further
description and are an addition to the embodiments of the present invention.
CLAIMS
What we claim as our invention is:
. A downhole setting tool, comprising;
a too! housing;
a hollow mandrel situated in the tool housing;
a piston situated between the mandrel and the tool housing;
a collar situated between the mandrel and the tool housing, wherein the tool
housing, the mandrel, the piston and the collar define an annulus; and
a first valve that, in a closed position, blocks a path of fluid communication
between the interior of the mandrel and the annulus.
2. The downhole setting tool of claim 1, wherein the downhole setting tool is operable to
one of set a packer or set a liner hanger.
3. The downhole setting tool of claim , wherein the first valve comprises a rupture
disk.
4. The downhole setting tool of claim 1, wherein the first valve comprises a valve
piston.
5. The downhole setting tool of claim 4, wherein the first valve further comprises a
plug configured to mate with the valve piston.
6 . The downhole setting tool of claim 1, further comprising a second valve situated in
the collar between the annulus and a second annulus partially defined by the collar and
the tool housing.
7. The downhole setting tool of claim 6 , wherein the second valve comprises a
velocity valve that assumes an open position when a pressure in the annulus is
approximately equal to a pressure in the second annulus.
8 . The downhole setting too! of claim 7, wherein the velocity valve is configured to
close when the pressure in the annulus is greater than the pressure in the second
annulus by a threshold value.
9. The downhole setting too! of claim 6, wherein the second valve comprises a
spring-loaded check valve.
10. The downhole setting too! of claim 9 , wherein the spring-!oaded check vaive is
configured to open when a pressure in the second annuius s greater than a pressure in
the annuius by a threshold value.
. The downhole setting tool of claim 9 , wherein the mandrei has a transverse hole
that runs from an interior of the mandrel to an exterior of the mandrei, further comprising a
second spring-loaded check valve situated at the end of the transverse hole, wherein, in a
closed position, the second spring-loaded check valve blocks the path of fluid
communication between the interior of the mandrel and the annuius via the transverse
hole.
12. The downhole setting tool of claim 11, wherein the second spring-loaded check
valve is configured to open when a pressure in the annuius is greater than a pressure in
the mandrel by a threshold value.
3. A downhole setting tool, comprising;
a tool housing;
a hollow mandrei having at least one transverse hole that runs from an interior of
the mandrel to an exterior of the mandrel, the mandrel being situated in the
tool housing;
a piston situated between the mandrel and the tool housing;
a collar situated between the mandrel and the tool housing, wherein the tool
housing, the mandrel, the piston and the collar define an annuius; and
a vent hole situated in the collar, the vent hole forming a path of fluid
communication between the annuius and a second annuius partially defined
by the collar and the tool housing.
4. The downhole setting tool of claim 13, further comprising a first valve situated at an
end of the at least one transverse hole, wherein in a closed position, the first valve blocks
a path of fluid communication between the interior of the mandrel and the annuius via the
at least one transverse hole, wherein the first valve comprises a rupture disk.
15. The downhole setting tool of claim 3, further comprising a first valve situated at an
end of the at least one transverse hole, wherein in a closed position, the first valve blocks
a path of fluid communication between the interior of the mandrel and the annuius via the
at least one transverse hole, wherein the first valve comprises a valve piston.
6. A method of setting a liner hanger in a wellbore using a downhoie setting tool, the
method comprising:
providing a downhoie setting too! comprising a tool housing, a mandrel, a piston,
and a collar, wherein the tool housing, the mandrel, the piston, and the
collar define a first annulus, wherein the too! housing, the mandrel, and the
coi!ar partially define a second annulus;
placing the downhoie setting tool into the wellbore, the interior of the mandrel and
the second annulus being subjected to an ambient wellbore pressure as the
downhoie setting tool is placed into the wellbore;
adjusting a pressure in the first annulus to approximately the ambient wellbore
pressure by bleeding fluid from the second annulus into the first annulus via
a first valve situated in the collar, between the first annulus and the second
annulus;
pressurizing the interior of the mandrel to a pressure greater than the ambient
wellbore pressure;
opening a second valve situated between an interior of the mandrel and the first
annulus;
forcing a portion of a fluid situated in the mandrel into the first annulus; and
forcing the piston in a downhoie direction with respect to the mandre!.
1 . The method of claim 16, wherein adjusting a pressure in the first annulus to
approximately the ambient wellbore pressure comprises forcing the first valve from a
closed position into an open position.
18. The method of claim 17, further comprising after adjusting a pressure in the first
annulus to approximately the ambient wellbore pressure, closing the first valve.
19. The method of claim 16 , further comprising after forcing a portion of a fluid situated
in the mandrel into the first annulus, bleeding a portion of a fluid situated in the first
annulus into the second annulus via the first valve.
20. The method of claim 19, further comprising after bleeding a portion of a fluid
situated in the first annulus into the second annulus via the first valve, closing the first
valve.