FIELD OF INVENTION
Methods and apparatus are presented for transfer of tensile and
rotational loads on a tool assembly from an external sleeve mandrel to an inner
mandrel. The arrangement allows easier make-up of lengthy tool assemblies on
5 a rig or derrick floor since the external load-bearing sleeve allows for a normal
tool-joint for assembly and disassembly. The upper external mandrel sleeve and
lower internal mandrel sleeve are connected by a load cross-over joint which
allows relative movement of a displacement or setting assembly.
10 BACKGROUND OF INVENTION
Oil and gas hydrocarbons are naturally occurring in some
subterranean formations. A subterranean formation containing oil or gas is
sometimes referred to as a reservoir. A reservoir may be located under land or
off shore. Reservoirs are typically located in the range of a few hundred feet
15 (shallow reservoirs) to a few tens of thousands of feet (ultra-deep reservoirs).
In order to produce hydrocarbons, a wellbore is drilled through a
hydrocarbon-bearing zone in a reservoir. In a cased-hole wellbore or portion
thereof, a casing is placed, and typically cemented, into the wellbore providing
a tubular wall between the zone and the interior of the cased wellbore. A tubing
20 string can then be run in and out of the casing. Similarly, tubing string can be
run in an uncased wellbore or section of wellbore. As used herein, "tubing
string" refers to a series of connected pipe sections, joints, screens, blanks,
cross-over tools, downhole tools and the like, inserted into a wellbore, whether
used for drilling, work-over, production, injection, completion, or other
25 processes. Further, in many cases a tool can be run on a wireline or coiled
tubing instead of a tubing string, as those of skill in the art will recognize. A
wellbore can be or include vertical, deviated, and horizontal portions, and can
be straight, curved, or branched.
During completion of an open-hole wellbore portion, a completion
30 tubing string is placed into the wellbore. The tubing string allows fluids to be
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D E L H I . 2.-3-Q3-2Q.1.5 1 7 : 2 6 .
introduced into, or flowed from, a remote portion of the wellbore. A tubing
string is created by joining multiple sections of pipe together, typically via male
right-handed threads at the bottom of an upper section of pipe and
corresponding female threads at the top of a lower section of pipe. The two
5 sections of pipe are connected to each other by applying a right-hand torque to
the upper section of pipe while the lower section of pipe remains relatively
stationary. The joined sections of pipe arc then lowered into the wellbore. The
process is referred to as "making up" a string. The tools used in the string are
often assembled, or made-up, on the rig floor. In fact, this may be required for
10 lengthy tools inserted by a standard rig.
It is typical in hydrocarbon wells to "set" or actuate a downhole
tool, such as expansion tools, packers, bridge plugs, gauge hangers, straddles,
wellhead plugs, cement retainers, through-tubing plugs, etc. Setting of tools is
often done in conjunction with other wellbore operations. For example, a tubing
15 string is run into a wellbore to hang an expandable liner, cement around the
liner, and then expand the liner. The string is then disconnected from the
installed liner and hanger and retrieved to the surface.
In a typical liner hanger tool string, the tensile load and rotational
load on the string is carried through an internal mandrel. The relative motion
20 required for setting the tool, and the transfer of setting loads, is typically done
using a non-load bearing external cylinder or sleeve. For example,
commercially available from Halliburton Energy Services, Inc., is a Versaflex
(trade name) running tool having such a configuration. If the tools are made-up,
such as in two halves, on the rig floor, this arrangement is cumbersome,
25 requiring make-up of the mandrel assembly and make-up of the external
cylinder assembly, including seals. For most applications, the use of the
assembled parts with seals also requires a pressure test prior to use. Such tests
can be awkward, time-consuming or even impossible on the rig floor.
Consequently, there is a need for an improved manner of design,
30 assembly and use of running tools.
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IP'O DELHI 23.-D5-2Q-1.5 1.7:'2 6
SUMMARY OF THE INVENTION
A downhole tool assembly is presented for use in a wellbore, the
tool having a mandrel assembly for substantially bearing the tensile and
5 rotational loads placed on the tool assembly during run-in to the wellbore, a
displacement assembly for substantially bearing displacement loads and for
providing relative movement to the mandrel assembly, the displacement
assembly for actuating a actuatable tool attached to the mandrel assembly. The
mandrel assembly has an upper mandrel positioned radially outward of the
10 displacement assembly and a lower mandrel positioned radially inward of the
displacement assembly. A load cross-over mandrel transfers the tensile and
rotational loads between the upper and lower mandrels. The load cross-over
mandrel has a plurality of passages which allow corresponding rods of the
displacement assembly to slide therethrough. The rods transfer the
15 displacement loads from actuators above the rods to an actuable tool below the
rods.
For example, an expandable liner hanger and cementing tool is run
into a wellbore. After cementing operations, the expandable liner hanger is
expanded using a cone or the like. The expansion is powered by hydraulic
20 pressure-up in the tool string which operates piston assemblies of the
displacement assembly. The movement of the pistons causes movement of a set
of displacement load rods which extend through passages in a laterally
extending portion of the mandrel assembly. The mandrel assembly bears the
tensile and torsional loads and has an upper mandrel positioned radially
25 outward of the displacement assembly, a lower mandrel positioned radially
inward of the displacement assembly, and a load cross-over mandrel
transferring load between the upper and lower mandrels. In a preferred
embodiment, the load cross-over mandrel defines several longitudinal passages
through which rods of the displacement assembly slide. The tool string can also
30 include release assemblies, etc. The arrangement of the mandrel assembly
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IPO DELH.I 2:3-8.5-2815 1 J : 26
allows for quick and easy assembly or make-up on a rig floor and eliminates the
need for a pressure test on the assembled tool.
BRIEF DESCRIPTION OF THE DRAWINGS
5 For a more complete understanding of the features and advantages
of the present invention, reference is now made to the detailed description of
the invention along with the accompanying figures in which corresponding
numerals in the different figures refer to corresponding parts and in which:
Figure 1 is a schematic view of an exemplary embodiment of a
10 running tool according to an aspect of the invention with Figures 1A-B in
longitudinal cross-section and Figure 1C in radial cross-section;
Figure 2 is a cross-sectional view of one embodiment of an
exemplary tool having a load cross-over joint according to an aspect of the
invention with Figures 2A-R being sequential drawings of an exemplary tool in
15 cross section according to aspects of the invention.;
Figure 3 is a cross-sectional view taken along line 3-3 of Figure 2
looking downward;
Figure 4 is a cross-sectional view taken along line 4-4 of Figure 2
looking upward;
20 Figure 5 is a cross-sectional view taken along line 5-5 of Figure 2
looking upward;
Figure 6 is a cross-sectional view taken along line 6-6 of Figure 2
looking downward; and
Figure 7 is a cross-sectional view taken along line 7-7 of Figure 2
25 looking upward.
It should be understood by those skilled in the art that the use of
directional terms such as above, below, upper, lower, upward, downward and
the like are used in relation to the illustrative embodiments as they are depicted
in the figures, the upward direction being toward the top of the corresponding
30 figure and the downward direction being toward the bottom of the
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DELHI 2 . 5 - 0 5 - 2 0 1 5 1 ? : 2 6 •
corresponding figure. Where this is not the case and a term is being used to
indicate a required orientation, the Specification will state or make such clear.
DESCRIPTION OF INVENTION W.R.T. DRAWINGS
5 While the making and using of various embodiments of the
present invention are discussed in detail below, a practitioner of the art will
appreciate that the present invention provides applicable inventive concepts
which can be embodied in a variety of specific contexts. The specific
embodiments discussed herein are illustrative of specific ways to make and use
10 the invention and do not limit the scope of the present invention. The
description is provided with reference to a vertical wellbore; however, the
inventions disclosed herein can be used in horizontal, vertical or deviated
wellbores. As used herein, the words "comprise," "have," "include," and all
grammatical variations thereof are each intended to have an open, non-limiting
15 meaning that does not exclude additional elements or steps. It should be
understood that, as used herein, "first," "second," "third," etc., are arbitrarily
assigned, merely differentiate between two or more items, and do not indicate
sequence. Furthermore, the use of the term "first" does not require a "second,"
etc. The terms "uphole," "downhole," and the like, refer to movement or
20 direction closer and farther, respectively, from the wellhead, irrespective of
whether used in reference to a vertical, horizontal or deviated borehole. The
terms "upstream" and "downstream" refer to the relative position or direction in
relation to fluid flow, again irrespective of the borehole orientation. Although
the description may focus on a particular means for positioning tools in the
25 wellbore, such as a tubing string, coiled tubing, or wireline, those of skill in the
art will recognize where alternate means can be utilized. As used herein,
"upward" and "downward" and the like are used to indicate relative position of
parts, or relative direction or movement, typically in regard to the orientation of
the Figures, and does not exclude similar relative position, direction or
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IPO .. DE L.B 1. 2.3- 8 5 - 2 0 1 5 1 7. : 2:6
movement where the orientation in-use differs from the orientation in the
Figures.
A purpose of the inventions described herein is to greatly simplify
rig floor assembly of extended length Liner Hanger Running Tools and the like.
5 Although the description is provided in reference to a liner hanger running tool,
those of skill in the art will recognize additional running tools and assemblies in
which the inventive features can be used. Typical liner hanger running tools
consist of an outer cylinder to transfer expansion force and inner mandrel to
transfer running tool loads. Make-up of two halves of the normal running tool
10 on the rig floor requires make-up of the inner mandrel and the outer cylinder.
This is an awkward process and it is time consuming. Additionally traditional
make-up connections require a pressure test after assembly which is difficult or
prohibitive to conduct on the rig floor. This invention requires only a simple
tool joint connection to be made up to connect two halves of a tool on the rig
15 floor, and no pressure testing would be required. Normally, the tensile and
torsion loads are all transferred through the inner mandrel and the external
cylinder applies the displacement forces onto the expansion cone. This
mechanism allows the loading of the inner and outer members to be reversed
for the force multiplier section of the tool because, through the crossover body,
20 the functions of the outer and inner members are reversed back to provide
normal tool operation.
Figures 1A-B are cross-sectional schematics of an exemplary
running tool with load cross-over assembly according to an aspect of the
invention. Figures 1A-B is a schematic, cross-sectional view of a liner hanger
25 running tool according to an aspect of the invention. Figure IC is a cross
section drawing taken at line A-A of Figure 1A.A liner hanger running tool
assembly 50 is shown generally having a displacement assembly 100 which,
among other things, bears the displacement load during actuation, and a tensile
and torsional load-bearing assembly 200 which, among other things, bears the
30 tensile and torsional load placed on the tool during run-in, pull-out of hole and
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P O . D E L HI. 2 1 - © 5 - 2MI 5 1 ? : 2 6
operation. The running tool assembly 50 is generally divided into an upper
portion 52 and lower portion 54.
The tensile and torsional load-bearing assembly 200 is generally
comprised of a substantially cylindrical upper mandrel 202 and a substantially
5. cylindrical lower mandrel 204. The use of the term "mandrel" does not indicate
that the mandrel is positioned at a radially inward, interior, or axial location in
the tool; instead, "mandrel" is used to indicate the portions of the tool carrying
the tensile load through the tool. Where the tool parts are locked rotationally,
the mandrel carries the torsional loads on the tool as well. The term "mandrel"
10 also is not meant to indicate that the mandrel is solid in cross-section. In fact,
both the upper and lower mandrels described herein define interior passageways
for the transmission of fluid, cement, and the like, or for encasing portions of
the displacement assembly, pistons, piston sleeves or rods, and the like. In prior
art tools, the tensile load-bearing mandrel is positioned interior to the tool
15 housing and interior to the displacement assembly, namely, the sliding sleeves,
piston sleeves, or the like, of the displacement assembly.
The displacement assembly 100 has an upper displacement
assembly 102 and a lower displacement assembly 104. The displacement
assembly 100 provides for relative motion between the displacement assembly
20 and tensile load-bearing assembly and carries the displacement loads during
displacement, setting or expansion. In prior art tools, the displacement
assembly, often a series of hydraulically actuated piston assemblies, is
positioned radially outward from or around an inner tensile and rotational loadbearing
mandrel.
25 According to an aspect of the invention, the upper mandrel 202 is
positioned exterior to or radially outward from the upper displacement
assembly 102. Hence, the tensile load in the upper section 52 of the tool
assembly is carried exterior to the upper displacement assembly. Stated another
way, the upper displacement assembly 102 is positioned within (and relatively
30 moves within) the upper mandrel 202, and the displacement load is carried
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IP'O DELH-Z.. 23-Q3- 231 5- i 7 : 26
interior to the upper mandrel. The upper mandrel preferably forms the outer
housing of the tool assembly, as shown, however, the upper mandrel can have a
protective sleeve or other member positioned exterior thereto.
The lower mandrel 204 is positioned interior to or radially inward
5 from the lower displacement assembly 104. Hence, the tensile load in the lower
section 54 of the tool assembly is carried interior to the lower displacement
assembly 104. Stated another way, the lower displacement a33cmbly 104 is
positioned exterior to (and relatively moves outside of) the lower mandrel 204,
and the displacement load is carried exterior to the lower mandrel. The lower
10 mandrel is preferably the inner-most portion of the tool along the lower section,
defining the passageway 56 along that section, however, the inner mandrel can
have pass-through sleeves and the like positioned radially inward thereof.
Transferring the tensile load from the upper, exterior mandrel 202
to the lower, interior mandrel 204 is a load cross-over joint 300. The load cross-
15 over joint 300 also allows relative movement of the displacement assembly
therethrough, effectively transitioning the movable displacement assembly from
interior the upper mandrel to exterior the lower mandrel. In a preferred
embodiment, the cross-over joint is a slip joint. The load cross-over joint can
also be referred to as a cross-over mandrel. A tensile load path can be traced
20 through the running tool assembly through the upper mandrel 202, through load
cross-over joint 300, to lower mandrel 204. Similarly, a displacement load path
can be traced through the upper displacement assembly 102 (bypassing the load
cross-over tool 300), and into the lower displacement assembly 104.
The tensile load-bearing assembly 200 more particularly includes
25 an upper mandrel 202, which is shown as a generally cylindrical member.
Multiple such members can be joined together to create a longer upper mandrel.
As seen, the upper mandrel 202 is made-up of a first, second and third upper
mandrel member, 210, 212 and 214, respectively. The members 210 and 212
are joined by a tensile load cylinder coupling 215. Similarly, the second and
30 third members 212 and 214 are connected by a tool joint coupling 216. Stated
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ELHI 2:3-03-2-01.5 1.7:26
another way, the upper mandrel can be thought of as comprising the first,
second and third mandrel members 210, 212 and 214, as well as their
connections, the tensile load coupling 215 and upper and lower members of the
tool joint coupling 216. The third upper mandrel member 214 is attached to the
5 load cross-over joint 300.
The tool joint coupling 216 is a typical make-up joint used in
many oilfield tools. It is easy to assemble, can be assembled on a rig floor, and
does not require associated o-rings or seals, and so does not require a pressure
test after connection. The tool joint coupling 216 has an upper joint coupling
10 member 218 which releasably connects to a lower tool joint coupling member
220.
The lower mandrel assembly 208 has a lower mandrel 204
attached to the load cross-over joint 300. The lower mandrel extends downward
and can interact with the release or collet assembly, such as is known in the art.
15 The lower mandrel assembly can be made-up of multiple members, such as
attached lengths of inner mandrel to provide desired length, or tubular members
serving additional functions, such as a collet sleeve, etc.
The mandrel assembly is designed to provide the load-bearing
capacity of a typical inner mandrel. The cross-sectional area, material, tensile
20 strength and other characteristics of the exemplary cross-over mandrel are
sufficient to bear the tensile load applied to the mandrel. For example, the
mandrel assembly is capable of holding up a liner string. Further, the mandrel
assembly bears the torsional loading on the string as well in most embodiments.
However, unlike the typical mandrel, the cross-over mandrel provides tensile
25 load-bearing members exterior to the displacement assembly at an upper end of
the tool and tensile load-bearing members interior to the displacement assembly
at a lower end of the tool. The tensile and rotational load-bearing path, in the
embodiment shown, passes through the following members: the first upper
mandrel member 210, the tensile load cylinder coupling 215, second mandrel
30 member 212, upper tool joint coupling member 218, lower tool joint coupling
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IP-Q--DEL.K.X. 23.-B3.~2Ql 5... 1.7 : 26
member 220, third mandrel member 214, load cross-over joint 300, and lower
mandrel 204.
The mandrel assembly members can also serve additional
functions. For example^ the load cylinder coupling 214 provides a lower face
5 232 on which high pressure fluid in piston chamber 112a acts. Seals 115 are
provided as necessary. The interior surface of the upper mandrel member 202
provides a surface on which the piston 110a moves and partially defines the
chambers 112a and 116a. Similarly, the upper and lower tool joint coupling
members 218 and 220 partially define pressure chambers 116a and 112b.
10 Details such as these are known in the art and not described in detail. Further,
mandrel assembly members can provide motion limiting surfaces and
shoulders, abutment and landing shoulders, connecting pins, and the like.
An exemplary displacement assembly 100 has one or more piston
assemblies 106. Multiple piston assemblies 106 can be arranged in a
15 longitudinal series, as is known in the art, to increase displacement force or
stroke length of the tool. Each piston assembly 106 includes a piston rod or
sleeve 108, piston 110, high pressure chamber 112, and a pressure port 114 for
communicating hydraulic pressure to the corresponding pressure chamber. In
the preferred embodiment, the hydraulic pressure is supplied by pressuring-up
20 on the fluid in the interior passageway 56 of the tool assembly. The pressure is
transferred from the interior passageway, through the pressure ports and into
the pressure chambers. Pressure causes movement of the piston. In a preferred
embodiment, the high pressure chambers 112 are defined in an annular space
between mandrel and displacement sleeve. Low pressure vent chambers 116 are
25 provided adjacent each piston, opposite high pressure chambers 112, with fluid
in the vent chambers vented through vent ports 118 to the exterior of the tool.
Various seals 115 can be employed, as is known in the art, between piston
sleeves, pistons, couplings, etc.
The embodiment in Figure 1A shows two piston assemblies 106a-
30 b, with corresponding parts labeled with corresponding letters in each
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IPQ. DELHI 23-Q5-2.D15. 1? - 2.6
assembly. More or fewer piston assemblies may be used, but for lengthy tool
assemblies or applications requiring greater displacement force or stroke, it is
anticipated that multiple piston assemblies will be used. Further, the exemplary
embodiment shown has a piston assembly above the joint coupling assembly
5 400, and one piston assembly below. This is an exemplary arrangement and
multiple piston assemblies can be positioned above or below the joint coupling
assembly.
The displacement assembly 100 further includes an assembly for
transferring the displacement load to an expansion cone, packer slip assembly,
10 etc. The exemplary lower displacement assembly 104 seen here is an expansion
assembly. The lowest piston assembly, here piston 110b, transfers displacement
motion and force to an upper expansion sleeve 120. Extending longitudinally
downward from the upper expansion sleeve are a plurality of displacement load
transfer members 122. The displacement load transfer members, or "fingers,"
15 transfer displacement load to the lower expansion sleeve 124 and thence to the
expansion cone 126. The expansion cone 126 is displaced longitudinally to
expand the expandable liner hanger 400.
Figure IB provides a cross-sectional view of the load cross-over
joint 300. The displacement load transfer members 122 pass through
20 corresponding openings 302 in the load cross-over joint 300. Exemplary load
transfer members 122 are shown, namely, four members extending through four
corresponding openings 302. However, other numbers of load transfer members
and openings can be used. Further, although a preferred cross-sectional shape of
the members 122 is shown, other shapes can be employed. The cross-over joint
25 300 is shown in an exemplary embodiment, defining an exterior annular portion
304, an interior annular portion 306, and webs 308 connecting the annular
portions and extending radially between adjacent openings 302. The cross-over
joint 300 also defines a portion of interior passageway 56 for passage of fluids
therethrough. The interior passageway 56 can be defined by several members
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XPCt DEL H.I 2.3-Q3.-2-GH..5. 1? :-2 6
including piston sleeves, couplings, pistons, cross-over mandrel, lower mandrel,
collet sleeve, etc.
After completion of the downhole operation, the running tool
assembly is released from the expanded or set downhole tool. Here, the running
tool is disconnected from the now-expanded liner hanger. Several types of
disconnection assembly are known in the art, one of which is a collet assembly
402. The collet a33embly includes a collet 404 with lugs 406 latched into
corresponding recesses 408 on the interior of the hanger. A collet prop nut 410
maintains the collet in locked position to the liner hanger. The collet is
disconnected from the liner hanger by placing weight-down on the tool
assembly.
Additional tool members can be employed as are known in the art,
such as debris sleeve 412, pass-through sleeve 414, etc.
Figure 2 is a cross-sectional view of one embodiment of an
exemplary tool having a load cross-over joint according to an aspect of the
invention. Figures 2A-R are sequential drawings of an exemplary tool in cross
section according to aspects of the invention.
Turning to Figure 2, a liner hanger running tool assembly 1050 is
presented having a displacement assembly 1100, including a displacement loadbearing
assembly 1101, and a tensile and torsional load-bearing assembly 1200.
The upper end of the assembly 1050 seen in the Figure 2 A, is a piston assembly
interior to a tensile load-bearing cylinder or mandrel, as discussed herein. Not
shown, uphole of the assembly, are additional piston assemblies, running tool,
tool string, etc., as are known in the art. Piston assemblies are known in the art
and can be stacked or arranged in series to provide additional stroke force or
displacement as needed. Similarly, not shown downhole of the assembly of
Figure 2R, is further liner hanger, liner, disconnect assembly such as a collet
assembly, etc., as are known in the art. The liner hanger running tool assembly
1050 is shown generally having a displacement assembly 1100 having a
displacement load-bearing assembly 1101, and a tensile and torsional load-
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HI 2.3-D3-2.D1S 17:2.6
bearing assembly 1200. The running tool assembly 1050 is generally divided
into an upper portion 1052 and lower portion 1054.
The tensile and torsional load-bearing assembly 1200 is generally
comprised of a substantially cylindrical upper mandrel 1202 and a substantially
5 cylindrical lower mandrel 1204. The upper and lower mandrels carry the tensile
and torsional loads placed on the assembly during use. The upper and lower
mandrels both define a fluid flow passageway therethrough for allowing, for
example, cement, treatment fluid, hydraulic pressure fluid, and the like, to pass
through the mandrels and assembly. Generally, the through-passageway 1056
10 extends from the upper to the lower end of the assembly and can be defined at
various portions by the interior surface of the displacement assembly, the
interior surface of the mandrel assembly, by a sleeve positioned in the assembly
for that purpose, etc. Both the upper and the lower mandrel described herein
define interior passageways for transmission of fluid, cement, and the like, or
15 for encasing portions of the displacement assembly, pistons, piston sleeves or
rods, and the like.
The displacement assembly 1100 has an upper displacement
assembly 1102 and a lower displacement assembly 1104. The displacement
assembly 1100 provides for relative motion between the displacement assembly
20 and tensile load-bearing assembly and carries the displacement loads during
displacement, setting or expansion of an actuated tool positioned below the
displacement assembly.
The upper mandrel 1202 is positioned exterior to or radially
outward from the upper displacement assembly 1102. Hence, the tensile and
25 torsional loads in the upper section 1052 of the tool assembly 1050 are carried
exterior to the upper displacement assembly. Stated another way, the upper
displacement assembly 1102 is positioned within, and moves relative to and
within, the upper mandrel 1202. The displacement load is carried interior to the
upper mandrel. The upper mandrel preferably forms the outer housing of the
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E*E.L.HX 2.3.-&3-20.1.5 1.7."-2£
tool assembly, as shown, however, the upper mandrel can have a protective
sleeve or other member positioned exterior thereto.
The lower mandrel 1204 is positioned interior to or radially inward
from the lower displacement assembly 1104. Hence, the tensile load in the
5 lower section 1054 of the tool assembly is carried interior to the lower
displacement assembly 1104. Stated another way, the lower displacement
assembly 1104 is positioned exterior to (and relatively moves outside of) the
lower mandrel 1204, and the displacement load is carried exterior to the lower
mandrel. The lower mandrel is preferably the inner-most portion of the tool
10 along the lower section, defining the passageway 1056 along that section.
However, the inner mandrel can have pass-through sleeves, valves such as a
ball-drop seat valve, support sleeves, pins and joints, and the like, positioned
radially inward thereof.
Transferring the tensile load from the upper, exterior mandrel
15 1202 to the lower, interior mandrel 1204, is a load cross-over joint 1300. The
load cross-over joint 1300 also allows movement of the displacement assembly
therethrough, effectively transitioning the movable displacement assembly from
interior the upper mandrel to exterior the lower mandrel. A tensile load path, T,
can be traced through the running tool assembly through the upper mandrel
20 1202, through load cross-over joint 1300, to lower mandrel 1204. Similarly, a
displacement load path, D, can be traced through the upper displacement
assembly 1102 (bypassing the load crossover tool 1300), and into the lower
displacement assembly 1104.
The tensile load-bearing assembly 1200 more particularly includes
25 an upper mandrel 1202, which is shown as a generally cylindrical member.
Multiple such members can be joined together to create a longer upper mandrel.
As seen, the upper mandrel 1202 is made-up of a first, second and third upper
mandrel member, 1210, 1212 and 1214, respectively. The members 1210 and
1212 are joined by a tensile load cylinder coupling 1215. Similarly, the second
30 and third members 1212 and 1214 are connected by a tool joint coupling 1216.
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IFO. DEL.H.I.. 2,3-B3r'2,B:lS I ? : 2:6
The third upper mandrel member 1214 is attached to the load cross-over joint
1300.
The tool joint coupling 1216 is a typical make-up joint used in
many oilfield tools. It is easy to assemble, can be assembled on a rig floor, and
5 does not require associated pressure o-rings or seals, and so does not require a
pressure test after connection. The tool joint coupling 1216 has an upper joint
coupling member 1218 which releasably connects, at connection 1219, to a
lower tool joint coupling member 1220. The upper tool joint coupling 1218
includes parts known in the art, including threads, seals, connector pin
10 assemblies 1221, contact surfaces 1223, etc. Similarly, the lower tool joint
coupling 1220 includes contact surface 1225, threads, connector pin assemblies
1227,
The lower mandrel assembly 1208 has a lower mandrel 1204
attached to the load cross-over joint 1300. The lower mandrel extends
15 downward and can interact with the release or collet assembly, expansion cone,
etc., such as is known in the art.
The mandrel assembly is designed to provide the load-bearing
capacity of a typical inner mandrel. The cross-sectional area, material, tensile
strength and other characteristics of the exemplary cross-over mandrel are
20 sufficient to bear the tensile load applied to the mandrel. For example, the
mandrel assembly is capable of holding up a liner string. Further, the mandrel
assembly bears the torsional loading on the string as well in most embodiments.
However, unlike the typical, mandrel, the cross-over mandrel provides tensile
load-bearing members exterior to the displacement assembly at an upper end of
25 the tool and tensile load-bearing members interior to the displacement assembly
at a lower end of the tool. The tensile and rotational load-bearing path, in the
embodiment shown, passes through the following members: the first upper
mandrel member 1210, the tensile load cylinder coupling 1215, mandrel
member 1212, upper tool joint coupling member 1218, lower tool joint
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ILMI 23-05-• 20.1:S 1.7 : 2.6..
coupling member 1220, mandrel member 1214, load cross-over joint 1300, and
lower mandrel 1204.
The mandrel assembly members can also serve additional
functions. For example, the load cylinder coupling 1215 provides a downward
5 face 1232 on which high pressure fluid in piston chamber 112a acts. The load
"cylinder coupling 1215 also includes threaded connections 1215a, providing a
tensile load path from the upper mandrel 1210, through the coupling 1215, and
into upper mandrel member 1212. Pin assemblies 1215b, such as torque pin
assemblies, are provided to rotationally lock and connect the load cylinder
10 coupling 1215 to the upper mandrel members 1210 and 1212. Other types of
equivalent load cylinder couplings or attachments can be used, as are known in
the art. Seals 1115 are provided between parts as necessary. The exemplary
load cylinder coupling 1215 is slidably engaged at surface 1215c, to piston rod
1108a.
15 The interior surface of the upper mandrel member 1202 provides a
surface on which the piston 1110a slides and partially defines the pressure
chambers 1112a and 1116a. Similarly, the upper and lower tool joint coupling
members 1218 and 1220 partially define pressure chambers 1116a and 1112b at
surfaces 1218a and 1220a respectively. Further, mandrel assembly members
20 can provide motion limiting shoulders and the like.
An exemplary displacement assembly 1100 has one or more piston
assemblies 1106. Multiple piston assemblies 1106a-b can be arranged in series,
as known in the art, to increase displacement force or stroke length of the tool.
Each piston assembly 1106a-b includes a corresponding piston rod or sleeve
25 1108a-b, piston 11 lOa-b, a high pressure chamber 1112a-b, and a pressure port
1114a-b for communicating hydraulic pressure to the corresponding high
pressure chamber. In the preferred embodiment, the hydraulic pressure is
supplied by pressuring-up on the fluid in the interior passageway 1056 of the
tool assembly. The pressure is transferred from the interior passageway 1056,
30 through the pressure ports 1114 and into the pressure chambers 1112. Pressure
-17-
1PO. DEL-HX 23-83-2Q15 1.7:26
forces relative movement of the piston 1110. In a preferred embodiment, the
high pressure chambers 1112 are defined in an annular space between the
mandrel and displacement sleeve. Preferably, low pressure vent chambers
1116a-b are provided adjacent each piston, opposite the high pressure chambers
5 1112a-b, with fluid in the vent chambers vented through vent ports 1118 to the
exterior of the tool. Various seals 1115 can be employed, as is known in the art,
between piston sleeves, pistons, couplings, etc.
For example, the piston 1110a is an annular piston housed
between the upper mandrel 1212 and annular piston rod or sleeve 1108a. The
10 piston 1110a is in sliding engagement with the mandrel at surface 1113a. The
piston 1110a abuts piston rod 1108a at a shoulder 1115a, such that downward
motion of the piston rod drives the piston downward. The piston 1110a also
abuts a lower piston rod 1108b at shoulder 1117a, such that movement of the
piston downward moves the piston rod downward. Fluid from the bore 1056 of
15 the string is pressured up and communicates pressure through pressure ports
1114a to the high pressure chamber 1112a. The upward facing surfaces 1111a
of the piston are acted upon by the high pressure, thus moving the piston
downward. The high pressure chamber 1112a, in this embodiment, is defined
by the interior surface of the upper mandrel 1212, the exterior surface of the
20 piston rod 1108a, the lower surface 1232 of the load cylinder coupling 1215,
and the upper and other surfaces of the piston 1110a. As the piston moves
downward, it increases pressure in vent chamber 1116a. Fluid in the vent
chamber exits the tool via vent ports 1118a. Screens, tortuous paths, etc., may
intervene to prevent debris problems. In the embodiment shown, fluid from the
25 vent chamber 1116a exits the tool through vent port 1118a in upper mandrel
1212 after passing through a preliminary port 1119a through upper tool joint
coupling 1218.
The embodiment in Figure 2 shows two piston assemblies 1106ab,
with corresponding parts labeled with corresponding letters in each
30 assembly. More or fewer piston assemblies may be used, but for lengthy tool
-18-
I P Q DELHI. 2 3 - D 3 - 2 Q I . 5 17'ZB'
assemblies or applications requiring greater displacement force Or stroke, it is
anticipated that multiple piston assemblies will be used. Further, the exemplary
embodiment has one piston assembly above and another below, the joint
coupling assembly 1400. This is an exemplary arrangement and multiple piston
5 assemblies can be positioned above and/or below the joint coupling assembly.
The displacement assembly 1100 further includes an assembly for
transferring the displacement load to an expansion cone, packer slip assembly,
etc. The exemplary lower displacement assembly 1104 seen here is an
expansion assembly, although only a portion of the expansion assembly is
10 shown. The lowest piston assembly, here piston 1110b, transfers displacement
motion and force to an upper expansion sleeve 1120. The upper expansion
sleeve abuts, at shoulder 1121, a pass-through displacement member 1122.
The pass-through displacement assembly 1122,. in a preferred
embodiment, has a plurality, here four, longitudinally extending displacement
15 load transfer members 1122a-d, or "fingers." The pass-through displacement
assembly is so-called since it transfers displacement load and motion past the
tensile load cross-over assembly. The displacement load fingers transfer
displacement load to the lower expansion sleeve 1124 and thence to an
expansion cone (not shown). The lower expansion sleeve 1124 can be
20 assembled from multiple members 1124a-b, which abut at cooperating shoulder
1125. The expansion cone is displaced longitudinally downward to expand the
expandable liner hanger 1400. The pass-through displacement assembly can
comprise multiple parts in connection or abutment and have differing structure
from the exemplary embodiment shown. The pass-through displacement
25 assembly, in an embodiment, includes one or more annular members extending
between and connecting to the multiple fingers. The annular members can be
removably attached to the fingers, such as by threads, pins, etc., for assembly
purposes and to transfer displacement forces. The annular member may also
serve to provide shoulders or interactive parts to limit displacement, for
30 example.
-19,
E.Ltt'I. 23-03-2G1.5 1.7 : 26 .
The pass-through displacement assembly load transfer members
1122a-d are under load during displacement or actuation of the tool assembly.
The transfer members are of relatively wider cross-section, as compared to the
upper expansion sleeve 1120 for example, to support the displacement load.
5 Further, since the fingers will tend to fail by buckling under load, radial support
is provided by an upper cross-over mandrel guide 1203, positioned radially
inward from the fingers, and an exterior radial support sleeve 1205, positioned
radially outward from the fingers and extending from the cross-over joint 1300
to a debris sleeve 1412.
10 The exemplary load cross-over joint 1300 transfers tensile and
torsional load from the upper mandrel 1200, at sleeve 1214, to the lower
mandrel 1204. The load cross-over joint (or cross-over mandrel) is threadedly
attached at threads 1310 to upper mandrel 1214, transferring tensile load
between the members. Further, pins (not shown) at pin hole 1312 transfer
15 torque between the upper mandrel and cross-over mandrel. The cross-over joint
1300 is preferably formed having an exterior or outer annular ring 1304 and an
interior or inner annular ring 1306 joined by radially extending webs 1308. The
webs and rings define four pass-through openings 1302 which allow
longitudinal movement of the displacement load fingers 1122 therethrough.
20 Longitudinally extending downward is lower inner mandrel 1204.
Longitudinally extending upward, attached to the joint at connection 1311 by
pins or the like, is the cross-over mandrel guide 1203, which also acts as a
radial support sleeve for the fingers. Both the mandrel guide and lower inner
mandrel are preferably substantially cylindrical, as shown, further defining the
25 passageway 1056. Further, both preferably have cooperating longitudinal
grooves or splines which cooperate with the fingers 1122. Further reference is
made to Figures 3-7.
Figure 3 is a cross-sectional view of the tool assembly taken along
line 3-3 of Figure 2K, looking downward. Like numbers refer to like parts and
30 will not all be addressed here. Of note, the upper surfaces of the displacement
-20-
load transfer members 1122a-d (fingers) are seen cooperating with
corresponding longitudinal splines 1320 and grooves 1322 of the mandrel guide
1203.
Figure 4 is a cross-sectional view of the tool assembly taken along
5 line 4-4 of Figure 2L, looking upward. Like numbers refer to like parts and will
not all be addressed here. Of note, the fingers 1122 are seen cooperating with
corresponding splines 1320 and grooves 1322 of mandrel guide 1203.
Figure 5 is a cross-sectional view of the tool assembly taken along
line 5-5 of Figure 2N, looking upward. Like numbers refer to like parts and will
10 not all be addressed here. Of note, the fingers 1122 are seen cooperating with
corresponding splines 1324 and grooves 1326 of load cross-over joint (crossover
mandrel) 1300. The splines and grooves, note, preferably provide surfaces
which cooperate with all four sides of the corresponding finger. However, also
note that at this cross-section, the cross-over mandrel 1300 defines an interior
15 annular ring 1306 while defining exterior annular sectional spaces 1307. Pin
assemblies are seen at 1312.
Figure 6 is a cross-sectional view of the tool assembly taken along
line 6-6 of Figure 2N, looking downward. Like numbers refer to like parts and
will not all be addressed here. Of note, the fingers 1122 are seen cooperating
20 with corresponding passages 1302. The cross-over mandrel defines an exterior
annular ring 1304, interior annular ring 1308, and radially extending webs 1308
extending between the rings.
Figure 7 is a cross-sectional view taken along line 7-7 of Figure
2P, looking upward. Like numbers refer to like parts and will not all be
25 addressed here. Of note, lower mandrel 1204 is seen in cross-section having
cooperating splines 1330 and grooves 1332 corresponding to fingers 1122. The
bottom surfaces of the fingers are seen. The cooperating splines, grooves and
fingers described herein allow relative longitudinal motion between the parts
while providing rotational locking and radial support for the fingers.
After completion of the downhole operation, the running tool
assembly is released from the set downhole tool. Several types of disconnection
assembly are known in the art, one of which is a collet assembly. A collet
sleeve 1403 is seen connected to the lower mandrel 1204 at connection 1401.
5 The collet is disconnected from the liner hanger by placing weight-down on the
tool assembly. The collet assembly is not shown in Figure 2 and not discussed
in detail.
Additional tool members can be employed as are known in the art,
such as debris sleeve 1412, pass-through sleeve 1414, etc.
10 For disclosure regarding prior art piston assemblies, specifically
force multiplier piston assemblies, see U.S. Patent Application Publication No.
2012/0186829, to Brock, explaining piston multiplier use and optional methods
and apparatus for protection of the piston inlet ports, etc., which is incorporated
herein by reference for all purposes. Also see U.S. Patent Nos. 5,437,330 to
15 Gambertoglio; 5,553,672 to Smith, Jr., et al.; 5,170,844 to George, et al.;
7,562,712 to Cho; and U.S. Patent Application Publication Nos. 2002/0070032
to Maguire; 2009/0107686 to Watson; all of which are incorporated herein by
reference for all purposes.
For further disclosure regarding installation of a liner string in a
20 wellbore casing, see U.S. Patent Application Publication No. 2011/0132622, to
Moeller, which is incorporated herein by reference for all purposes. For further
disclosure regarding cementing procedures and tools, see the other references
incorporated herein. For disclosure regarding expansion cone assemblies and
their function, see U.S. Patent No. 7,779,910, to Watson, which is incorporated
25 herein by reference for all purposes. For further disclosure regarding hydraulic
set liner hangers, see U.S. Patent No. 6,318,472, to Rogers, which is
incorporated herein by reference for all purposes.
The collet assembly is not described herein in detail since such are
known in the art. For further disclosure regarding collets, see U.S. Patent
30 Application Serial No; 13/587,596, filed November 1, 2011, to Stautzenberger,
incorporated herein by reference for all purposes. Disclosure regarding release
collet assemblies can also be found in the other references incorporated herein.
Several tools in oil and gas operations include a collet and a collet prop, such as
expansion tools and retrieving tools. A collet is generally fitted around the
5 outside of a mandrel. The collet commonly includes at least one concentric ring
and collet fingers that extend from the ring. The object the collet attaches and
releases from generally includes recesses that correspond to lugs on the collet
fingers. The collet fingers are biased to contract around the outer diameter of
the mandrel. A collet prop is used to maintain the collet fingers in a desired
10 position until actuation is desired. Another example of a tool that can include a
collet is an expansion tool. Prior to expansion, a tubing string, such as a liner,
can be suspended from the collet via collet finger lugs that engage recesses in
the tubing string. The collet fingers are rigid and can support the weight of the
tubing string only when the collet prop is located under the collet. These tools
15 often include an outer cylinder and an inner mandrel. Typically, the outer
cylinder and inner mandrel are prevented from moving relative to the tubing
string, via a shouldered connection. Once the desired tool operation is
completed, such as expansion of the tubing string, the shouldered connection is
separated and there is free movement of the outer cylinder or inner mandrel
20 with respect to the tubing string. Upon separation of the shouldered connection,
the collet prop can be moved, also called dropped. Typically, this is
accomplished by moving either the inner mandrel or the outer cylinder
downward with respect to the tubing string. The movement of the outer cylinder
or inner mandrel causes the collet prop to move out from underneath the collet.
25 The collet prop is dropped below the collet so the collet fingers are allowed to
flex toward the lower mandrel. The tool and running tool string are
disconnected, and the string pulled out of hole.
Exemplary methods of use of the invention are described, with the
understanding that the invention is determined and limited only by the claims.
30 Those of skill in the art will recognize additional steps, different order of steps,
and that not all steps need be performed to practice the inventive methods
described.
In preferred embodiments, the following methods are disclosed;
the steps are not exclusive and can be combined in various ways. A method for
5 performing an oilfield operation in a subterranean wellbore extending through a
hydrocarbon-bearing zone, the method comprising the steps of: positioning a
downhole tool assembly on a work string, the downhole tool assembly having a
mandrel assembly for bearing the tensile and rotational load on the assembly,
and a displacement assembly for movement in relation to the mandrel
10 assembly; bearing the tensile and rotational load on the downhole tool assembly
along a load path positioned radially outward from an upper portion of the
displacement assembly; bearing the tensile and torsional load on the downhole
tool assembly along a load path positioned radially inward from a lower portion
of the displacement assembly; and moving the displacement assembly in
15 relation to the mandrel assembly. The method can further comprise the steps of:
bearing the tensile and torsional load on the tool assembly along a load path
that radially crosses the displacement assembly; longitudinally moving a
portion of the displacement assembly through cooperating passages in the
mandrel assembly; moving a plurality of displacement load transfer rods
20 longitudinally through a corresponding plurality of passages through a radially
extending portion of the mandrel assembly.
Persons of skill in the art will recognize various combinations and
orders of the above described steps and details of the methods presented herein.
While this invention has been described with reference to illustrative
25 embodiments, this description is not intended to be construed in a limiting
sense. Various modifications and combinations of the illustrative embodiments
as well as other embodiments of the invention, will be apparent to person
skilled in the art upon reference to the description. It is, therefore, intended that
the appended claims encompass any such modifications or embodiments.

We Claim:
1. A downhole tool assembly for use in a wellbore, the assembly comprising:
a mandrel assembly fur substantially bearing the tensile and
5 rotational loads placed on the tool assembly during run-in to the wellbore;
a displacement assembly for substantially bearing displacement
loads and for providing relative movement to the mandrel assembly, the
displacement assembly for actuating a actuatable tool attached to the mandrel
assembly; and
10 wherein the mandrel assembly has an upper mandrel positioned
radially outward of the displacement assembly, the lower mandrel positioned
radially inward of the displacement assembly, and a load cross-over mandrel
interconnected between the upper and lower mandrels and operable to transfer
tensile and rotational load between the upper and lower mandrels.
15
2. A downhole tool assembly as claimed in claim 1, wherein the displacement
assembly has an upper displacement assembly positioned longitudinally
upward of the load cross-over mandrel, a lower displacement assembly
positioned longitudinally downward of the load cross-over mandrel, and a
20 pass-through displacement assembly positioned between and operable to
transfer displacement load between the upper and lower displacement
assemblies.
3. A downhole tool assembly as claimed in claim 2, wherein the load cross-
25 over mandrel includes a plurality of passageways extending longitudinally
therethrough, and wherein the pass-through displacement assembly includes
a corresponding plurality of displacement load transfer members extending
through the corresponding plurality of passageways.
4. A downhole tool assembly as claimed in claim 3, wherein the plurality of
displacement load transfer members are longitudinally extending rods.
5. A downhole tool assembly as claimed in claim 1, wherein the displacement
5 assembly includes at least one piston assembly, the piston assembly
operable to move the displacement assembly in relation to the mandrel
assemhfy.
6. A downhole tool assembly as claimed in claim 5, wherein the piston
assembly is operable in response to a change in a wellbore fluid.
10
7. A downhole tool assembly as claimed in claim 1, wherein the displacement
assembly includes at least one piston assembly having a piston rod and a
piston, the at least one piston assembly operable in response to increased
wellbore fluid pressure.
15
8. A downhole tool assembly as claimed in claim 7, wherein the mandrel
assembly and displacement assembly define a tool bore extending
longitudinally therethrough and operable to convey changes in wellbore
fluid from the surface to a location downhole.
20
9. A downhole tool assembly as claimed in claim 2, wherein the upper and
lower displacement assemblies are sleeves.
10. A downhole tool assembly as claimed in claim 2, wherein the upper, lower
25 and pass-through displacement assemblies are of a substantially uniform
outer diameter.
11. A downhole tool assembly as claimed in claim 1, wherein the cross-over
mandrel defines an inner annular ring, an outer annular ring, and a plurality
30 of longitudinal passageways extending through the cross-over mandrel for
cooperating with corresponding displacement assembly load transfer
members.
12. A downhole tool assembly as claimed in claim 1, wherein the downhole
5 tool assembly is connected to an expandable liner hanger tool string, the
displacement assembly is operable to expand the liner hanger, and the
mandrel assembly supports a release tool for releasing the string from the
liner hanger.
10 13. A downhole assembly as claimed in claim 2, wherein the downhole tool
assembly is capable of being assembled on a rig floor.
14. A downhole tool assembly as claimed in claim 13, wherein the upper
displacement assembly includes a tool joint.
15
15. A downhole tool assembly as claimed in claim 14, wherein assembly of the
tool assembly does not require a pressure test.
16. A downhole tool assembly as claimed in claim 14, wherein at least one
20 piston assembly is positioned above the tool joint and wherein at least one
piston assembly is positioned below the tool joint, the piston assemblies
operable to move the displacement assembly in relation to the mandrel
assembly.
25 17. A method of performing an oilfield operation in a subterranean wellbore
extending through a hydrocarbon-bearing zone, the method comprising the
steps of:
positioning a downhole tool assembly on a work string, the
downhole tool assembly having a mandrel assembly for bearing the
tensile and rotational load on the assembly, and a displacement
assembly for movement in relation to the mandrel assembly;
bearing the tensile and rotational load on the downhole tool
assembly along a load path positioned radially outward from an upper
5 portion of the displacement assembly;
bearing the tensile and torsional load on the downhole tool
assembly along a load path positioned radially inward from a lower
portion of the displacement assembly; and
moving the displacement assembly in relation to the mandrel
10 assembly.
18. A method as claimed in claim 17, further comprising the step of bearing the
tensile and torsional load on the tool assembly along a load path that
radially crosses the displacement assembly.
15
19. A method as claimed in claim 18, further comprising the step of
longitudinally moving a portion of the displacement assembly through
cooperating passages in the mandrel assembly.
20 20. A method as claimed in claim 19, further comprising the step of moving a
plurality of displacement load transfer rods longitudinally through a
corresponding plurality of passages through a radially extending portion of
the mandrel assembly.