Low Equivalent Circulation Density 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 liner 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 wellbore. 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 tool 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 also may be used to control
when and how the work string is released from the liner hanger, for example, after
expansion of the liner hanger or after an unsuccessful setting of the liner hanger.
[0004] The running tool or setting tool may provide for cementing therethrough, in
those cases in which the liner is to be cemented in the wellbore. Some designs of the
running or setting tool employ a ball or cementing plug that is dropped through the work
string at the completion of the cementing operation and prior to expanding the liner
hanger. However, at substantial depths and/or in highly deviated wellbores, it may take a
very long time for the ball to reach the running or setting tool, during which time cement
may be setting up around the drill pipe and potentially causing the drill pipe to get stuck.
In addition, the ball may not reach the running or setting tool at all. Furthermore, the
cementing plug may not be able to be landed correctly on a corresponding float collar.
SUMMARY OF THE INVENTION
[0005] In an embodiment, a downhole oilfield tool assembly is disclosed. The tool
assembly comprises a mandrel, a valve oriented to block downwards flow through the
mandrel in a closed position, and a first piston located above the valve and at least partly
around an outside of the mandrel. The first piston is configured to develop motive force
from a pressure differential between an interior of the mandrel and an exterior of the
downhole oilfield tool assembly.
[0006] In an embodiment, a downhole setting tool is disclosed. The setting tool
comprises a ball valve, a collet mandrel rotatably disposed in the setting tool, the collet
mandrel comprising collet mandrel teeth, and an actuator collar comprising actuator collar
teeth, the actuator collar teeth engaging with the collet mandrel teeth so as to torsionally
lock the collet mandrel to the actuator collar, and a first piston situated uphole from the
ball valve.
[0007] In an embodiment, a method of hydraulically releasing a flapper valve of a
setting tool configured to set a liner inside a casing is disclosed. The flapper valve
comprises a flapper piston and a spring-loaded flapper mounted to a head of the flapper
piston. The setting tool comprises at least one piston situated uphole from the flapper
valve, a flapper prop configured to hold the flapper in an open position, a flapper housing
inside which the flapper piston is disposed, and a shear screw fixing the flapper piston to
the flapper housing. The method comprises pressurizing a space between the flapper
piston and the flapper housing and downhole from the head of the flapper piston to a first
pressure and pressurizing a space uphole from the head of the flapper piston to a second
pressure greater than the first pressure by an amount sufficient to overcome a shear
strength of the shear screw. The method further comprises shearing the shear screw,
forcing the flapper piston downhole relative to the flapper housing and the flapper prop
such that the flapper clears the flapper prop, and closing the flapper.
[0008] In an embodiment, a method of setting a liner inside a casing is disclosed. The
method comprises actuating a valve to block downwards flow through a setting tool,
developing a pressure differential between an interior of the setting tool above the valve
and an exterior of the setting tool, and setting the liner inside the casing responsive to the
pressure differential.
[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.
[0011] FIG. 1A is a schematic cross-sectional view of a portion of an embodiment of a
setting tool.
[0012] FIG. 1B 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. 1D 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 an embodiment of a valve
mechanism.
[0016] FIG. 3A is a schematic front view of an embodiment of a collet mandrel
included in the valve mechanism of FIG. 2 .
[0017] FIG. 3B is a schematic cross-sectional view of an embodiment of a flapper prop
included in the valve mechanism of FIG. 2 .
[0018] FIG. 3C is a schematic cross-sectional view of an embodiment of a collet prop
included in the valve mechanism of FIG. 2 .
[0019] FIG. 3D is a schematic cross-sectional view of the embodiment of the valve
mechanism of FIG. 2
[0020] FIG. 4A is a schematic cross-sectional view of the embodiment of the valve
mechanism of FIG. 2, prior to release of a flapper.
[0021] FIG. 4B is a schematic cross-sectional view of the embodiment of the flapper
mechanism of FIG. 2, after hydraulic release of the flapper.
[0022] FIG. 4C is a schematic cross-sectional view of the embodiment of the flapper
mechanism of FIG. 2, after mechanical release of the flapper.
[0023] FIG. 5 is a schematic cross-sectional view of a further embodiment of a valve
mechanism.
[0024] FIG. 6A is a schematic cross-sectional view of a further embodiment of a valve
mechanism.
[0025] FIG. 6B is a schematic cross-sectional view of the embodiment of the valve
mechanism of FIG. 6A, after mechanical release of a flapper.
[0026] FIG. 7A is a schematic cross-sectional view of a further embodiment of a valve
mechanism.
[0027] FIG. 7B is a schematic cross-sectional view of the embodiment of the valve
mechanism of FIG. 7A, after mechanical release of a flapper.
[0028] FIG. 8A is a schematic cross-sectional view of a further embodiment of a valve
mechanism, in which a ball valve is closed.
[0029] FIG. 8B is a schematic cross-sectional view of the embodiment of the valve
mechanism of FIG. 8A, in which the ball valve is open.
[0030] FIG. 8C is a schematic front view of an embodiment of a collet mandrel
included in the valve mechanism of FIG. 8A.
[0031] FIG. 8D is a schematic front view of an embodiment of an actuator collar
included in the valve mechanism of FIG. 8A.
[0032] FIG. 8E is a schematic perspective view of an embodiment of a slider pin
included in the valve mechanism of FIG. 8A.
[0033] FIG. 8F is a schematic perspective view of an embodiment of a slider sleeve
included in the valve mechanism of FIG. 8A.
[0034] FIG. 9 is a flow chart of a method for hydraulically releasing a flapper valve.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0035] 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.
[0036] 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 also may 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 wellbore and with "down," "lower," "downward," "downstream" or
"downhole" meaning toward the terminal end of the well, regardless of the wellbore
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 following detailed description of the
embodiments, and by referring to the accompanying drawings.
[0037] A downhole tool assembly having a valve located below one or more pistons
is disclosed, where in a closed position the valve blocks downwards flow through the
downhole tool assembly. In an embodiment, locating the valve below the one or more
pistons promotes composing the downhole tool assembly with two or more pistons.
Incorporating additional pistons, for example additional piston subassemblies, promotes
delivering increased piston force without increasing pressure differentials to excessive
amplitudes. For example, when a piston subassembly structure is actuated by the
pressure difference between an interior of the downhole tool assembly and an exterior of
the downhole tool assembly, coupling a second piston subassembly to the a first piston
subassembly may produce two times as much piston force as the first piston
subassembly alone, when the pressure difference is fixed. Increasingly heavy gauge
liners are being deployed into wellbores, demanding increased force applied to expansion
mechanisms and/or expansion cones to expand and hang the liners. It is contemplated
that the downhole tool assembly with the valve located below or downhole of the one or
more pistons may have application in low equivalent circulation density (ECD) service
jobs.
[0038] FIG. 1A, FIG. 1B, FIG. 1C and FIG. 1D are schematic cross-sectional views of
portions of an embodiment of a setting tool 100 along a length of the setting tool 100.
The setting tool 100 may be attached to a downhole end of a work string via an upper
adapter 110 and may be used to attach a liner hanger 120 to a casing situated in a
wellbore. In addition, the setting tool 100 may be used to convey cement that is pumped
down the work string, down an interior of a liner attached to a downhole end of the setting
tool 100, and up an annulus situated between the liner and a wall of a wellbore, for the
purpose of cementing the liner to the wellbore. In order to be able to convey cement to
the annulus and to expand the liner hanger 120, the setting tool 100 may comprise a
series of mandrels 110, 130, 140, 150 which are interconnected and sealed by couplings
160, 170, 180. As set forth above, the mandrel 110 also may be referred to as upper
adapter 110 and may connect the setting tool 100 to the work string. In addition, a
mandrel at a downhole end of the setting tool 100 may be referred to as a collet mandrel
190. The mandrels 110, 130, 140, 150, 190 are capable of holding and conveying a
pressurized fluid, e.g., cement slurry, hydraulic fluid, etc.
[0039] In an embodiment, the setting tool 100 may further comprise pistons 200, 2 10
and respective pressure chambers 220, 230, which are in fluid communication with
mandrels 140, 150 via pressurization ports 240, 250, respectively. In addition, the setting
tool 100 may include expansion cones 270, which are situated downhole from the pistons
200, 210. As illustrated in FIG. 1C, the expansion cones 270 have an outer diameter
greater than an inner diameter of a section of the liner hanger 120 downhole from the
expansion cones 270.
[0040] In an embodiment, the liner hanger 120 may be expanded against a wall of
the casing after the liner has been cemented to the wall of the wellbore. To expand the
liner 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 1000
psi. The hydraulic fluid may enter the pressure chambers 220, 230 via pressurization
ports 240, 250 and exert a force on pistons 200, 210. In some contexts, the pistons 200,
2 10 may be said to develop motive force from a pressure differential between the interior
of the mandrel and an exterior of the tool 100. The couplings 170, 180, which form
uphole-side boundaries of the pressure chambers 220, 230, are rigidly attached to
mandrels 130, 140 and 150, respectively, whereas pistons 200, 210 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 110, 130,
140, 150, 190. When a sufficient pressure has built up in the mandrels 110, 130, 140,
150, 190 and the pressure chambers 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. 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 liner hanger 120 in contact
with the expansion cones 270 is expanded against the casing as the expansion cones
270 are forced downhole.
[0041] In regard to FIG. 1D, in an embodiment, the setting tool 100 may further
comprise a valve mechanism 300, which is situated downhole from pistons 200, 2 10 and
liner hanger 120 and is configured to close off a route of fluid communication between the
collet mandrel 190 and an interior of the liner after the liner has been cemented to the wall
of the wellbore. Various embodiments of the valve mechanism 300 will be described
below in the discussion of FIG. 2, FIG. 4A, FIG. 4B, FIG. 4C, FIG. 5, FIG. 6A, FIG. 6B,
FIG. 7A, FIG. 7B, FIG. 8A and FIG. 8B.
[0042] FIG. 2 is a schematic cross-sectional view of an embodiment of a valve
mechanism 400. The valve mechanism 400 may comprise a housing 410, which is rigidly
attached to the liner at a downhole end of the housing 4 10 . The valve mechanism 400
also may comprise a setting sleeve 420, which is situated uphole from the housing 410
and rigidly attached to the housing 410 at an uphole end of the housing 4 10, and to which
the liner hanger 120 is rigidly attached at an uphole end of the setting sleeve 420. In an
embodiment, the valve mechanism 400 may further comprise a collet 430, which is
situated at an uphole end of the valve mechanism 400 and is torsionally locked to the
setting sleeve 420, as well as a collet prop 440, which is torsionally locked to the collet
430 and comprises collet prop teeth 450 that run longitudinally along a portion of a length
of the collet prop 440 and are spaced along an inner circumference of the collet prop 440.
The collet prop teeth 450 are clearly seen in the schematic cross-sectional view of the
collet prop 440 shown in FIG. 3C.
[0043] In further regard to FIG. 2, a schematic front view of the collet mandrel 190 is
shown in FIG. 3A. The collet mandrel 190 is rotatably disposed in the setting sleeve 420
and the housing 410. In addition, a portion of the collet mandrel 190 is situated in a
through-bore 442 of the collet prop 440. In an embodiment, the collet mandrel 190
comprises collet mandrel teeth 460, which are situated near an uphole end of the collet
mandrel 190, run longitudinally along a portion of a length of the collet mandrel 190 and
are spaced along an outer circumference of the collet mandrel 190. In addition, the collet
mandrel 190 may comprise second collet mandrel teeth 540, which are situated near a
downhole end of the collet mandrel 190, run longitudinally along a portion of the length of
the collet mandrel 190 and are spaced along the outer circumference of the collet
mandrel 190. In an embodiment, the collet mandrel teeth 460 engage with the collet prop
teeth 450 such that an angular slack 456 is present between the teeth 450, 460. The
angular slack 456 may be about 20 degrees to about 40 degrees, alternatively about 25
degrees to about 35 degrees, alternatively about 30 degrees. The angular slack 456 is
shown clearly in FIG. 3D.
[0044] In addition to interaction of the collet mandrel 190 and the collet prop 440 via
the collet prop teeth 450 and the collet mandrel teeth 460, the collet mandrel 190 and the
collet prop 440 may be torsionally locked to one another by a shear screw 462 in the runin
state of the tool 100. Shear screw 462 is shown in FIG. 4A. In an embodiment
illustrated in FIG. 3D, which shows a schematic cross-sectional view of valve mechanism
400 at section A-A in FIG. 2, the collet mandrel teeth 460 and the collet prop teeth 450
may be in engagement and the shear screw 462 may be placed such that, in a first
rotational position of the collet mandrel 190 and a first rotational direction of the collet
mandrel 190, e.g., clockwise or right-hand rotation (using a downhole direction as a frame
of reference), side faces 464 of the collet mandrel teeth 460 facing, e.g., in a clockwise or
right-hand direction, abut corresponding side faces 452 of the collet prop teeth 450 facing,
e.g., in a counterclockwise or left-hand direction, and the collet mandrel 190 and the collet
prop 440 are torsionally locked to one another by both their corresponding teeth 460, 450
and the shear screw 462 in a run-in state of the tool 100. In the same embodiment, in the
first rotational position, but in a second rotational direction of the collet mandrel 190, e.g.,
counterclockwise or left-hand rotation, side faces 466 of the collet mandrel teeth 460
facing, e.g., in a counterclockwise or left-hand direction, are separated from side faces
454 of the collet prop teeth 450 facing, e.g., in a clockwise or right-hand direction, by the
angular slack 456, such that the collet mandrel 190 and collet prop 440 are torsionally
locked to one another by the shear screw 462 in the run-in state of the tool 100. In
addition, it should be pointed out that for the sake of clarity, in FIG. 3D, the collet prop 440
and collet mandrel 190 are each shown as having only four teeth 450, 460. However, the
collet prop 440 and collet mandrel 190 may have as many teeth as allowed by structural
considerations and desired angular slack 456. Furthermore, the orientation of the collet
prop teeth 450 and collet mandrel teeth 460 may be reversed so that the side faces 464
of the collet mandrel teeth 460 facing, e.g., in a clockwise or right-hand direction are
separated from the side faces 452 of the collet prop teeth 450 facing, e.g., in a
counterclockwise or left-hand direction, by the slack 456.
[0045] In an embodiment, the valve mechanism 400 may further comprise a flapper
valve 470, which comprises a flapper piston 480, a flapper 490 pivoted at an uphole end
of the flapper piston 480 and a flapper spring 500 that applies a closing force to the
flapper 490. The flapper piston 480 may be situated in a flow bore of a flapper housing
5 10 and fixed in position with respect to the flapper housing 5 10 by a shear screw 5 12. In
addition, the flapper housing 5 10 may include a subsurface release (SSR) cementing
plug system connection 520 at a downhole end of the flapper housing 5 10.
[0046] In further regard to FIG. 2, in an embodiment, the valve mechanism 400 may
further comprise a member 530, e.g., a flapper prop 530, which is configured to prop the
flapper 490 open in a first longitudinal position of the flapper prop 530. The flapper prop
530 may comprise flapper prop teeth 550, which are situated at an uphole end of the
flapper prop 530 and, in the first rotational position of the collet mandrel 190, engage with
downhole end faces 542 of the second collet mandrel teeth 540. A schematic crosssectional
view of the flapper prop 530 is shown in FIG. 3B.
[0047] In an embodiment, the valve mechanism 400 may further comprise a spring
housing 560, which is generally cylindrical in shape and torsionally locked to the collet
prop 440 by a torque pin 564, and inside which a portion of the flapper prop 530 not in
engagement with the flapper 490 is situated. As is apparent from FIGURES 2, 3a and 3b,
a spring 570, which is biased between a shoulder 532 of the flapper prop 530 and an
inwardly projecting flange 562 at a downhole end of the spring housing 560, forces
flapper prop teeth 550 against the downhole end faces 542 of the second collet mandrel
teeth 540, when the collet mandrel 190 is in the first rotational position.
[0048] In operation, after the liner has been cemented in the wellbore, the flapper 490
may be closed in order to allow sufficient pressure to be built up uphole from the flapper
valve 470, to energize pistons 200, 2 10, and thereby to expand the liner hanger 120. In
the embodiment of the valve mechanism 400 shown in FIG. 2, the flapper 490 may be
released either hydraulically or mechanically. The hydraulic-release embodiment is
discussed below in reference to FIG. 4A and FIG. 4B, and the mechanical-release
embodiment is discussed below in reference to FIG. 3, FIG. 4A and FIG. 4C.
[0049] FIG. 4A and FIG. 4B respectively illustrate schematic cross-sectional views of
the embodiment of the valve mechanism 400 of FIG. 2, prior to release of the flapper 490
and after hydraulic release of the flapper 490. To release the flapper 490 hydraulically, a
fluid may be pumped down the mandrels 130, 140, 150, 190 at a second pressure greater
than a first pressure prevailing in an annulus 580 situated between the flapper housing
5 10 and the housing 4 10. Since an area of contact of a downhole end of the flapper prop
530 and a flapper piston head 482 is not sealed, an annular space 590 uphole from the
flapper piston head 482 and roughly bounded by the flapper piston head 482, the flapper
housing 510 and the spring housing 560 is subjected to the second pressure in the
mandrels 130, 140, 150, 190.
[0050] In addition, a second annular space 600 situated below the flapper piston
head 482 and bounded by the flapper piston 480 and the flapper housing 5 10 is in fluid
communication with annulus 580 via a vent hole 610 and is therefore subjected to the first
pressure. When a pressure differential of the second and first pressures is sufficient to
overcome a shear strength of the shear screw 512, a force of friction of an O-ring 484
disposed between the flapper piston head 482 and the flapper housing 510, and a force
of friction of an O-ring 486 disposed between the flapper housing 5 10 and the flapper
piston 480, the shear screw 512 may shear and the flapper piston 480 may be forced
down the flow bore of the flapper housing 5 10 to a limit stop 620 situated on the flapper
housing 5 10. As shown in FIG. 4B, when the flapper piston head 482 approaches the
limit stop 620, the flapper 490 is moved clear of the flapper prop 530, and the flapper
spring 500 forces the flapper 490 into a closed position.
[0051] FIG. 4A and FIG. 4C respectively illustrate schematic cross-sectional views of
the embodiment of the valve mechanism 400 of FIG. 2 before release of the flapper 490
and after mechanical release of the flapper 490. As set forth above and illustrated in FIG.
2 and FIG. 3D, in the first rotational position of the collet mandrel 190 and the first
rotational direction of the collet mandrel 190, e.g., clockwise or right-hand rotation, the
collet mandrel 190 is torsionally locked to the collet prop 440 by the collet prop teeth 450,
the collet mandrel teeth 460 and the shear screw 462. In addition, in the first rotational
position of the collet mandrel 190, the flapper prop 530 props the flapper 490 open, and
the flapper prop teeth 550 rest against downhole end faces 542 of the second collet
mandrel teeth 540 under the force of the spring 570 biased between the flange 562 of the
spring housing 560 and the shoulder 532 of the flapper prop 530.
[0052] However, in the first rotational position of the collet mandrel 190 and the
second rotational direction of the collet mandrel 190, e.g., counterclockwise or left-hand
rotation, the collet prop 440 and the collet mandrel 190 are torsionally locked to one
another by the shear screw 462 in the run-in state of the tool 100. Thus, in an
embodiment, if a left-hand torque sufficient to overcome a shear strength of the shear
screw 462 is applied to the collet mandrel 190, the shear screw 462 will shear and the
collet mandrel 190 will rotate through the slack 456 and into a second rotational position
of the collet mandrel 190, where the side faces 466 of the collet mandrel teeth 460 abut
the side faces 454 of the collet prop teeth 450. Furthermore, as the collet mandrel 190 is
rotated from the first rotational position into the second rotational position, the downhole
end faces 542 of the second collet mandrel teeth 540 rotate out of alignment with the
flapper prop teeth 550 and into a position in which the flapper prop teeth 550 are aligned
with gaps 544 between the second collet mandrel teeth 540 that are wider than the
flapper prop teeth 550. Gaps 544 and contact ends 546 are illustrated in FIG. 3A. Thus,
since the second collet mandrel teeth 540 are no longer able to apply a reaction force
against the spring 570, the spring 570 forces the flapper prop 530 uphole until the flapper
prop teeth 550 contact ends 546 of the gaps 544. As the flapper prop teeth 550 slide
through the gaps 544 to the ends of the gaps 546, the downhole end of the flapper prop
530 moves uphole and free of the flapper 490, thereby allowing the flapper spring 500 to
close the flapper 490.
[0053] FIG. 5 is a schematic cross-sectional view of a further embodiment of a valve
mechanism. A valve mechanism 700 shown in FIG. 5 differs from the embodiment of the
valve mechanism 400 shown in FIG. 2 and FIG. 4A, FIG. 4B, and FIG. 4C in that a
flapper valve 770 comprised by valve mechanism 700 does not comprise a flapper piston,
and a flapper 790 comprised by the valve mechanism 700 is mounted directly to a flapper
housing 710. In addition, since no portion of a length of the flapper housing 710 is
reserved for downhole displacement of a flapper piston, the length of the flapper housing
7 10 may be less than a length of the flapper housing 510. Furthermore, the flapper 790
may be mechanically released in a manner analogous to flapper 490, by shearing shear
screw 462; rotating collet mandrel 190 with respect to collet prop 440 so as to align
flapper prop teeth 550 with gaps 544 between second collet mandrel teeth 540; and
displacing flapper prop 530 uphole via spring 570 so that the downhole end of flapper
prop 530 clears the flapper 790 and the flapper spring 500 closes the flapper 790.
[0054] FIG. 6A and FIG. 6B schematically illustrate cross-sectional views of a further
embodiment of a valve mechanism 800 prior to and after mechanical release of a flapper
890, respectively. The embodiment of the valve mechanism 800 of FIG. 6A and FIG. 6B
differs from the embodiment of the valve mechanism 400 of FIG. 2 in that a different
member, e.g., a collet mandrel 820, props a flapper 890 open, and a flapper piston 880
includes flapper piston teeth 850 that engage with flapper housing teeth 840 present on a
flapper housing 810. In some contexts the flapper piston 880 may be referred to as a
flapper seat. This structure is referred to herein as a flapper piston 880 to suggest its
response to a pressure differential and the role of this response in deployment and/or
actuation of the flapper 890, but it is understood that those skilled in the art may
sometimes refer to it instead as a flapper seat. In an embodiment, the collet mandrel 820
extends through the collet prop 440 and a spring housing 860 to a flapper valve 870,
which comprises the flapper piston 880 and the flapper 890, which, in turn, is springmounted
to the flapper piston 880. In a first rotational position of the collet mandrel 820, a
lug 822 situated at a downhole end of the collet mandrel 820 engages with a
corresponding notch 882 in the flapper piston 880 and torsionally locks the flapper piston
880 to the collet mandrel 820. In an embodiment, the spring 570 is biased between an
uphole end 832 of the flapper piston 880 and a shoulder 862 of a spring housing 860,
which is torsionally locked to collet prop 440 by torque pin 564 and torsionally locked to
flapper housing 8 10 by a torque pin 566. In the first rotational position of the collet
mandrel 820, the flapper piston teeth 850 engage with uphole end faces 842 of the
flapper housing teeth 840 and are pressed against the uphole end faces 842 by a force of
the spring 570.
[0055] In operation, the flapper 890 of the present embodiment of the valve
mechanism 800 may be released via rotation of the collet mandrel 820 and rotation and
translation of the flapper piston 880 as follows. The collet mandrel teeth 460 of collet
mandrel 820 and the collet prop teeth 450 of collet prop 440 interact as described with
respect to FIG. 2 and FIG. 3D such that when, for example, a left-hand or
counterclockwise torque is applied to the collet mandrel 820, the shear screw 462 may be
sheared and the collet mandrel 820 may be rotated through slack 456 from the first
rotational position to a second rotational position. As the collet mandrel 820 is rotated
from the first rotational position to the second rotational position, the flapper piston teeth
850 are rotated out of engagement with uphole end faces 842 of the flapper housing teeth
840 and into alignment with gaps 844, which are situated between adjacent flapper
housing teeth 840 and are wider than flapper piston teeth 850. Since in the second
rotational position of the collet mandrel 820, the flapper housing teeth 840 can no longer
apply a reaction force to the flapper piston teeth 850 in opposition to the force of the
spring 570, the flapper piston 880 is forced downhole by the spring 570 such that the
flapper piston teeth 850 slide into the gaps 844 between the flapper housing teeth 840
until coming to rest against ends 846 of the gaps 844. In addition, as the flapper piston
880 is moved downhole, the flapper 890 is moved free of the collet mandrel 820, thereby
enabling the flapper spring 500 to force the flapper 890 into a closed position.
[0056] FIG. 7A and FIG. 7B respectively illustrate schematic cross-sectional views of
a further embodiment of a valve mechanism 900 prior to and after mechanical release of
a flapper 990. The valve mechanism 900 differs from the valve mechanism 800
illustrated in FIG. 6A and FIG. 6B in that in a flapper valve 970 comprising the flapper 990
and a flapper piston 980, a different member, e.g., the flapper piston 980, props the
flapper 990 open and is moved downhole to release the flapper 990. In addition, the
flapper 990 is spring-mounted to a spring housing 960. In an embodiment, a collet
mandrel 920 extends through the collet prop 440 to the flapper piston 980, and, in a first
rotational position of the collet mandrel 920, the collet mandrel 920 is torsionally locked to
the flapper piston 980 by the lug 822, which engages with the notch 882 in the flapper
piston 980. In an embodiment, the spring 570 is biased between the shoulder 862 of the
spring housing 960 and a flange 932 of the flapper piston 980. In the first rotational
position of the collet mandrel 920, flapper piston teeth 950 of the flapper piston 980
engage with the uphole end faces 842 of the flapper housing teeth 840 and are pressed
against the uphole end faces 842 by a force of the spring 570.
[0057] In operation, the flapper 990 of the present embodiment of the valve
mechanism 900 may be released via rotation of the collet mandrel 920 and rotation and
translation of the flapper piston 980 as follows. The collet mandrel teeth 460 of collet
mandrel 920 and the collet prop teeth 450 of collet prop 440 interact as described with
respect to FIG. 2 and FIG. 3D such that when, for example, a left-hand or
counterclockwise torque is applied to the collet mandrel 920, the shear screw 462 may be
sheared and the collet mandrel 920 may be rotated through slack 456 from the first
rotational position to a second rotational position. As the collet mandrel 920 is rotated
from the first rotational position to the second rotational position, the flapper piston teeth
950 are rotated out of engagement with the uphole end faces 842 of the flapper housing
teeth 840 and into alignment with gaps 844, which are situated between adjacent flapper
housing teeth 840 and are wider than flapper piston teeth 950. Since in the second
rotational position of the collet mandrel 920, the flapper housing teeth 840 can no longer
apply a reaction force to the flapper piston teeth 950 in opposition to the force of the
spring 570, the flapper piston 980 is forced downhole by the spring 570, such that the
flapper piston teeth 950 slide into the gaps 844 between the flapper housing teeth 840.
Simultaneously, the flapper housing teeth 840 enter gaps 984 between the flapper piston
teeth 950 until the flapper piston 980 comes to rest with the uphole end faces 842 of the
flapper housing teeth 840 abutting ends 986 of the gaps 984. As the flapper piston teeth
950 slide into the gaps 844 between the flapper housing teeth 840, an uphole end of the
flapper piston 980 slides free of the flapper 990, thereby enabling the flapper spring 500
to force the flapper 990 into a closed position.
[0058] FIG. 8A and FIG. 8B illustrate schematic cross-sectional views of an
embodiment of a valve mechanism 1000 comprising a ball valve 1040, FIG. 8A illustrating
the ball valve 1040 in a closed position and FIG. 8B illustrating the ball valve 1040 in an
open position. The embodiment of the valve mechanism 1000 shown in FIGURES 8a
and 8b differs from the embodiments of the valve mechanisms 400, 700, 800 and 900 in
that the ball valve 1040 is used in place of a flapper valve to close off a route of fluid
communication between a collet mandrel 1020 of the valve mechanism 1000 and an
interior of the liner after the liner has been cemented to the wall of the wellbore; the spring
housing 560, 860, 960 is replaced by a coupling 1010 that is torsionally locked to the
collet prop 440; and the flapper housing 5 10, 710, 810 is replaced by a ball housing 1030,
which is torsionally locked to the coupling 101 0 by the torque pin 566, and inside which
the ball valve 1040 is situated. However, as is the case with the embodiments of the
valve mechanism 400, 700, 800 and 900, the collet mandrel 1020, of which a schematic
side view is shown in FIG. 8C, is rotatably disposed in the setting sleeve 420 and the
housing 410, comprises collet mandrel teeth 460 that engage with the collet prop teeth
450 of the collet prop 440 as described with regard to FIG. 2, and is torsionally locked to
the collet prop 440 by shear screw 462 in the run-in state of the tool 100.
[0059] In an embodiment, the ball valve 1040 may comprise a ball 1080, inside which
a flow bore 1082 is situated, and which is supported by an upper seat 1090 and a lower
seat 2000. The ball valve 1040 may also comprise a slider sleeve 1070, of which a
schematic perspective view is shown in FIG. 8F, and which is torsionally locked to the ball
housing 1030 by a torque pin 1074. The ball valve 1040 may further comprise an
actuator collar 1050, of which a schematic side view is shown in FIG. 8D, and which
comprises actuator collar teeth 1054 that engage with second collet mandrel teeth 1022
of the collet mandrel 1020 and torsionally lock the actuator collar 1050 to the collet
mandrel 1020.
[0060] In an embodiment, the upper seat 1090 may be situated in a depression in a
downhole end of the collet mandrel 1020, and the lower seat 2000 may be situated in a
depression in an uphole end of the slider sleeve 1070, so that the ball 1080 and seats
1090, 2000 are supported between the collet mandrel 1020 and the slider sleeve 1070.
In addition, the ball 1080 may be prestressed in the upper and lower seats 1090, 2000 by
a spring, e.g., a wave spring 2010, which is situated between the upper seat 1090 and
the collet mandrel 1020.
[0061] In an embodiment, the ball valve 1040 may further comprise a slider pin 1060,
of which a schematic perspective view is shown in FIG. 8E, which is slidably supported in
a longitudinal groove 1072 situated at an outer circumference of the slider sleeve 1070,
and which comprises a first projection 1062 that may be bulbous in shape and engages
with a first surface bore 1084 of the ball 1080. In addition, the actuator collar 1050 may
include an actuator pin 1052, which is rigidly attached to the actuator collar 1050, projects
longitudinally from a downhole end of the actuator collar 1050, and includes a second
projection 1056 that may be bulbous in shape and engages with a second surface bore
1086 of the ball 1080.
[0062] In an embodiment, the first projection 1062 and the first surface bore 1084
may form a first ball joint, and the second projection 1056 and the second surface bore
1086 may form a second ball joint, which, along with the upper seat 1090 and the lower
seat 2000, constrain a movement of the ball 1080. Using a longitudinal axis of the valve
mechanism 1000 as a "horizontal" axis, the upper and lower seats 1090, 2000 limit the
movement of the ball 1080 to rolling motions about the longitudinal valve mechanism
axis, as well as pitching and yawing motions about axes perpendicular to the longitudinal
valve mechanism axis. In addition, the slider pin 1060 further constrains the movement of
the ball 1080 to rotation about axes passing through the first projection 1062, as well as a
pitching motion due to the capability of the slider pin 1060 of sliding longitudinally in the
groove 1072 of the slider sleeve 1070. Furthermore, the actuator pin 1052 further
constrains the movement of the ball 1080 to rotation about axes passing through the
second projection 1056, as well as a rolling motion due to the capability of the actuator
pin 1052 of orbiting the longitudinal valve mechanism axis.
[0063] In operation, in an embodiment, the ball valve 1040 of the valve mechanism
1000 may be closed via rotation of the collet mandrel 1020 and rotation of the ball 1080
as follows. The collet mandrel teeth 460 of collet mandrel 1020 and the collet prop teeth
450 of collet prop 440 interact as described with respect to FIG. 2 and FIG. 3D such that
when, for example, a left-hand or counterclockwise torque is applied to the collet mandrel
1020, the shear screw 462 may be sheared and the collet mandrel 1020 may be rotated
through slack 456, in a first rotational direction, from a first rotational position to a second
rotational position. In the first rotational position of the collet mandrel 1020, the ball valve
1040 is open, i.e., the flow bore 1082 of the ball 1080 is in approximate alignment and
fluid communication with flow bores of the collet mandrel 1020 and the slider sleeve 1070,
as shown in FIG. 8B.
[0064] In an embodiment, as the collet mandrel 1020 is rotated from the first
rotational position to the second rotational position, the actuator pin 1052 and the second
projection 1056 are orbited about the longitudinal valve mechanism axis, thereby
imparting a rolling motion to the ball 1080 and allowing the ball 1080 to rotate about axes
passing through the second projection 1056. However, the slider pin 1060
simultaneously constrains the above-mentioned rolling motion while allowing the ball
1080 to undergo a pitching motion and rotation about axes passing through the first
projection 1062. The above-mentioned constraints cause the ball 1080 to rotate into a
closed position, in which the flow bore 1082 of the ball 1080 is no longer in fluid
communication with the flow bores of the collet mandrel 1020 and the slider sleeve 1070
and a longitudinal axis of the flow bore 1082 is approximately perpendicular to the
longitudinal valve mechanism axis. The above-mentioned closed position of the ball
valve 1040 is shown in FIG. 8A.
[0065] In an embodiment, after having been closed, the ball valve 1040 may be
reopened by rotating the collet mandrel 1020 in a second rotational direction, from the
second rotational position to the first rotational position. The reopening capability of the
ball valve 1040 may allow the route of fluid communication through the setting tool 100 to
be reopened in case the ball valve 1040 is prematurely closed, and also may allow tools
or fluids to pass through the setting tool 100 after expansion of the liner hanger 120.
[0066] FIG. 9 is a flow chart of a method 1200 for hydraulically releasing a flapper
valve of a setting tool configured to set a liner hanger inside a casing. At block 121 0, a
space between a flapper piston and a flapper housing and downhole from a head of the
flapper piston is pressurized to a first pressure. At block 1220, a space uphole from the
head of the flapper piston is pressurized to a second pressure greater than the first
pressure by an amount sufficient to overcome a shear strength of a shear screw. It is
understood that the difference between the second pressure and the first pressure
corresponds to the pressure differential across the flapper piston and hence the motive
force for moving the flapper piston and shearing the shear screw. As illustrated in FIG. 2,
the shear screw rigidly fixes the flapper piston to a flapper housing. At block 1230, the
shear screw is sheared. At block 1240, the flapper piston is forced downhole relative to
the flapper housing and a flapper prop such that a flapper clears the flapper prop. At
block 1250, the flapper is closed.
[0067] In an embodiment, a method of setting an apparatus inside a wellbore is
taught. The method may comprise using a downhole tool to set a liner in a casing, to set
a packer in a casing or in an open hole, or to set some other apparatus inside a wellbore.
The method may comprise actuating a valve to block downwards flow through the setting
tool, for example, downwards flow of drilling fluid and/or hydraulic fluid. The method may
further comprise developing a pressure differential between an interior of the setting tool
above the valve and an exterior of the setting tool. For example, a greater pressure may
be developed inside the setting tool and above the valve with reference to the hydrostatic
pressure in the wellbore outside the setting tool by action of hydraulic pumps operated at
a surface proximate to the wellbore. The method may further comprise setting a liner in
the casing, setting a packer, or setting some other apparatus in the wellbore. The force
for performing the setting may be derived from the pressure differential between the
interior of the setting tool and the exterior of the setting tool. For example, in an
embodiment, downwards force for setting may be developed by a piston responsive to
the pressure differential, wherein the piston forms a part of the setting tool or a sub
assembly coupled to the setting tool. The piston is located above the valve.
[0068] In an embodiment, two or more pistons may be located above the valve and
may form a portion of the setting tool or may form a portion of one or more sub
assemblies. Using two or more pistons may permit developing greater setting force than
would otherwise be developed by a single piston. By coupling the two or more pistons,
the force developed may be approximately the sum of the force developed by each
individual piston. It is contemplated that the setting tool of this method may be
substantially similar to the setting tool described above. The valve may be implemented
by one of the multiple embodiments of flapper valves described further above.
Alternative, the valve may be implemented by a ball valve as described further above.
[0069] 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. For example, in an embodiment, the valve
mechanism 400 shown in FIG. 2 may be modified to eliminate the spring 570 between the
flapper prop 530 and the spring housing 560, to rigidly attach the flapper prop 530 to the
collet mandrel 190, to attach a lug to the collet mandrel 190 or flapper prop 530, and to
form a J-slot, e.g., a helical slot, in the spring housing 560 in which the lug is configured to
travel. In this manner, the flapper 490 may be released by rotating the collet mandrel 190
and simultaneously translating the collet mandrel 190 and flapper prop 530 uphole, along
the helical slot, and free of the flapper 490. Thus, 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.
[0070] Where numerical ranges or limitations are expressly 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, 0.13, etc.).
For example, whenever a numerical range with a lower limit, RL, and an upper limit, Ru,
is disclosed, any number falling within the range is specifically disclosed. In particular,
the following numbers within the range are specifically disclosed: R=RL +k* (Ru-RJ,
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 100 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 is
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 essentially of, comprised substantially of, etc.
[0071] Accordingly, the scope of protection is not limited by the description set out
above but is only limited by the claims which follow, that scope including all 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.

What we claim as our invention is:
1. A downhole oilfield tool assembly, comprising:
a mandrel;
a valve oriented to block downwards flow through the mandrel in a closed position;
and
a first piston located above the valve and positioned at least partly around an
outside of the mandrel, wherein the first piston is configured to develop
motive force from a pressure differential between an interior of the mandrel
and an exterior of the downhole oilfield tool assembly.
2. The downhole oilfield tool assembly of claim 1, further comprising an expansion
mechanism, wherein the first piston is coupled to the expansion mechanism and is
operable to deliver motive force to the expansion mechanism to expand the liner hanger.
3. The downhole oilfield tool assembly of claim 1, further comprising a second piston
located above the valve and positioned at least partly around the outside of the mandrel.
4 . The downhole oilfield tool assembly of claim 1, wherein the valve is a flapper
valve, the flapper valve comprising a flapper and a flapper spring biased so as to exert a
closing force on the flapper, wherein the tool assembly further comprises one of a flapper
prop to hold the flapper in an open position and a collet mandrel rotatably disposed
concentric with the mandrel to hold the flapper in an open position
5. The downhole oilfield tool assembly of claim 4, wherein the flapper valve may be
released by at least one of hydraulic actuation and mechanical actuation.
6. The downhole oilfield tool assembly of claim 4, further comprising:
a flapper housing concentric with the mandrel, wherein the flapper valve further
comprises a flapper piston slidably disposed within the flapper housing, the
flapper being rotationally mounted to the flapper piston;
a spring housing; and
a spring biased between the spring housing and the flapper.
7. The downhole oilfield tool assembly of claim 6, wherein the tool assembly
comprises a collet mandrel rotatably disposed concentric with the mandrel wherein in a
first rotational position of the collet mandrel, the collet mandrel is torsionally locked to the
flapper piston, the flapper piston comprises a plurality of flapper piston teeth, the flapper
housing comprises a plurality of flapper housing teeth, in the first rotational position of the
collet mandrel, the flapper piston teeth engage with end faces of the flapper housing
teeth, and where in a second rotational position of the collet mandrel, the flapper piston
teeth engage with and are forced by the spring into gaps between the flapper housing
teeth.
8. The downhole oilfield tool assembly of claim 1, wherein the valve is a ball valve
and the ball valve is selectively coupled to rotary motion of the mandrel to actuate open in
response to rotary motion of the mandrel in a first direction and to actuate closed in
response to rotary motion of the mandrel in a second direction, the second direction
opposite of the first direction.
9. The downhole oilfield tool assembly of claim 8, wherein the ball valve comprises a
ball having a hole that is constrained by a lug coupled to a valve housing, wherein the ball
further has a slot that is engaged by a lug coupled to the mandrel, wherein the lug slides
in the slot when the mandrel rotates, thereby coupling rotation of the mandrel with
actuating the valve to open and to close.
10. A downhole setting tool, comprising:
a ball valve;
a collet mandrel rotatably disposed in the setting tool, the collet mandrel
comprising collet mandrel teeth; and
an actuator collar comprising actuator collar teeth, the actuator collar teeth
engaging with the collet mandrel teeth so as to torsionally lock the collet
mandrel to the actuator collar; and
a first piston situated uphole from the ball valve.
11. The downhole setting tool of claim 10, further comprising:
a slider pin comprising a first projection configured to engage with a first bore in a
ball of the ball valve;
an actuator pin rigidly connected to the actuator collar, the actuator pin comprising
a second projection configured to engage with a second bore in a ball of the
ball valve; and
a slider sleeve comprising a longitudinal groove, the slider pin configured to slide in
the longitudinal groove.
12. The downhole setting tool of claim 11, wherein the actuator pin and the slider pin
constrain a pitch, a yaw and a roll of the ball such that the ball valve may be closed by
rotating the collet mandrel in a first rotational direction and opened by rotating the collet
mandrel in a second rotational direction.
13. The downhole setting tool of claim 10, further comprising a second piston situated
uphole from the ball valve.
14. A method of setting a liner inside a casing, comprising:
actuating a valve to block downwards flow through a setting tool;
developing a pressure differential between an interior of the setting tool above the
valve and an exterior of the setting tool; and
setting the liner inside the casing responsive to the pressure differential.
15. The method of claim 14, wherein setting the liner is performed at least in part by a
first piston that applies a downwards force based on the pressure differential, wherein the
first piston is located above the valve.
16. The method of claim 15, wherein setting the liner is further performed at least in
part by a second piston that applies a downwards force based on the pressure
differential, wherein the second piston is located above the valve.
17 . The method of claim 14, wherein the valve is a flapper valve and wherein actuating
the valve comprises hydraulically releasing a flapper of the flapper valve.
18. The method of claim 14, wherein the valve is a flapper valve and wherein actuating
the valve comprises rotating a mandrel component of the setting tool.
19. The method of claim 14, wherein the valve is a ball valve and wherein actuating
the valve comprises rotating a mandrel component of the setting tool in a first direction.
20. The method of claim 19, after actuating the valve to block downwards flow through
the setting tool, actuating the valve to allow downwards flow through the setting tool.