Note: Descriptions are shown in the official language in which they were submitted.
MODULAR DOWNHOLE TOOL RESERVOIR SYSTEM
Cross-Reference to Related Applications
[0001] This application claims the benefit of priority of PCT Application
Serial
Number US20/40795 filed on July 2nd, 2020 and U.S. Provisional Patent
Application
Serial Number 62/870,665 filed on July 3rd, 2019; both being incorporated by
reference
herein.
BACKGROUND
[0002] The present disclosure relates to a bottom hole assembly including a
modular
downhole reservoir system which facilitates isolation of a subterranean
formation
surrounding a downhole tubular.
Background
[0003] A bottom hole assembly is an apparatus that is adapted for use within a
borehole
that extends into the earth to reach a target subterranean formation that is
expected to
contain valuable hydrocarbons, such as oil, gas and combinations thereof. A
bottom hole
assembly may be run into an existing borehole on a wireline that may provide a
physical
tether as well as providing connections for electrical power delivery and data
communication between the bottom hole assembly and a computer system at the
surface
near the borehole. Furthermore, a bottom hole assembly may include one or more
downhole tools, components or subsystems that perform one or more functions of
the
bottom hole assembly.
[0004] Certain downhole tools which may also be known as setting tools or more
specifically, inflatable packer setting tools, and may include a pump for
delivering
pressurized fluid to an isolation tool; for example, a plug, a packer, or an
inflatable
packer which may also be part of a bottom hole assembly. The setting tool
using the
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pump may be used to draw in well-fluid present within a borehole to pressurize
and
deliver the well-fluid to the isolation tool.
[0005] Isolation tools require a range of fluid pressures to adequately set
within a
borehole. During the delivery of the fluid to an isolation tool, a low
pressure may be
required to expand and contact the borehole; for example, less than 200 psi.
Depending
on the operational objective of an isolation tool installation in a borehole,
the final set
pressure, a high pressure, may be as much as 5,000 psi or greater.
Additionally,
depending on volume and inflation flowrates, the final set may require over
one hour to
achieve.
[0006] Certain boreholes may contain well-fluid that is incompatible with
downhole
pumps. For example, in some cases the well-fluid may be heavy mud, corrosive
fluids or
gas for which the pump is not intended or capable to operate with.
Furthermore, some
isolation tools may be incompatible with certain well-fluids which may
otherwise be used
to pressure such an isolation tool. In these cases, downhole tools known as
downhole
reservoir systems exist which allow an operator to carry a reservoir fluid
downhole
within a borehole from surface, which is compatible with the pump and/or the
isolation
tool. The reservoir fluid is filled in the reservoir system prior to deploying
the bottom
hole assembly within the borehole and may be for example, water, hydraulic
oil, another
fluid, or combination thereof.
[0007] Current state of the art reservoir systems are positioned within the
bottom hole
assembly tool string above the pump and often increase the effective outer
diameter of
the bottom hole assembly to facilitate routing the reservoir fluid to the pump
intake. This
is a disadvantage with the current state of the art reservoir systems, as it
is advantageous
to keep the effective outer diameter of the bottom hole assembly small. A
small diameter
bottom hole assembly may be conveyed through more restrictive production well
tubing
applications.
[0008] When the bottom hole assembly is run on electric wireline, positioning
the
reservoir system above the setting tool also requires the routing of the
wireline or other
electrical conductors through the reservoir system to the setting tool, which
complicates
the design and deployment of the reservoir system.
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[0009] A bottom hole assembly, including a setting tool, a reservoir system
and an
isolation tool, may be deployed within the borehole, such that the reservoir
system
delivers a volume of reservoir fluid to the pump, so that the isolation tool
receives
pressurized reservoir fluid from the pump and may be pressurized at various
locations
within the borehole. In this manner, the bottom hole assembly may be used to
isolate
segments of the borehole for water-shut off, pressure isolation, sand
isolation; or in
conjunction with a formation fracturing process, formation treatment process,
other
processes, or other downhole operations.
BRIEF SUMMARY
[0010] One embodiment provides a modular downhole tool reservoir system
comprising a first and second reservoir module. Each reservoir module
comprises a
reservoir fluid volume, a housing, a low pressure tube, a high pressure tube,
a piston
slidably sealed in the housing, the piston exposed on a first surface to well-
fluid
communicated through one or more ports in the housing and isolating the
reservoir fluid
volume exposed to a second surface of the piston. The second reservoir is
disposed to
deliver the second reservoir fluid volume to the low-pressure tube of the
first reservoir
module.
[0011] In another embodiment, a bottom hole assembly comprises the modular
downhole tool reservoir system and a setting tool including a pump having in
intake and
an output, wherein the first reservoir module is disposed to deliver the first
and second
reservoir fluid volumes to the intake, and the output is disposed to deliver
the first and
second reservoir fluid volumes to the high-pressure tube of the first
reservoir module and
the high pressure tube of the second reservoir module fluidically connected
thereto.
[0012] In another embodiment, the bottom hole assembly, further comprises an
isolation tool disposed to receive the first and second reservoir fluid
volumes from the
high-pressure tubes.
[0013] In a further embodiment, there is provided a method of isolating a
segment of
the borehole, the method comprising the steps of: deploying the BHA on
wireline;
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positioning the BHA near or within a tubular segment such that the isolation
tool is in a
position to isolate the desired segments of the borehole upon pressurization;
activating
the setting tool to draw in the first and second reservoir fluid volumes and
deliver the
volumes to the isolation tool; pressurizing the isolation tool to engage the
borehole;
isolating a segment of the borehole above the isolation tool from a segment of
the
borehole below the isolation tool.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] FIG. 1 is a block diagram of a bottom hole assembly including a cable
head, a
setting tool, a reservoir system and an isolation tool.
[0015] FIGS. 2A-C are diagrams of a bottom hole assembly, the bottom hole
assembly
including a cable head, a setting tool, a reservoir system and an isolation
tool being run
into a borehole on a wireline, the isolation tool in the borehole set to
isolate a borehole
region above the isolation tool from a segment of borehole below the isolation
tool and
the isolation tool left in the borehole.
[0016] FIG. 3 is cross-section views of a reservoir module.
[0017] FIG. 4 on drawing page 4 and 5, is a break-out section view of bottom
hole
assembly including a setting tool and a reservoir system including two
reservoir modules.
The drawing on page 5 continues from the drawing on page 4, from and to
Section X-X.
[0018] FIG. 5 is a close-up view of the dash enclosed area of FIG.4.
[0019] FIG 6. is a close-up partial section view of a section of a reservoir
module.
[0020] FIG. 7 is a partial section view of a section of a reservoir system.
[0021] FIG. 8 is a partial section of reservoir system connected to an
isolation tool.
DETAILED DESCRIPTION
[0022] One embodiment provides a downhole tool for use within a borehole that
extends into a subterranean formation. The downhole tool comprises a reservoir
module.
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The reservoir module comprises a reservoir fluid volume, a housing, upper and
lower
endcaps, a piston, a high-pressure tube, a low-pressure tube and a coupler.
The upper and
lower endcaps disposed within and are secured at opposing ends of the housing;
a high
pressure tube including an inner and outer surface residing inside a low
pressure tube
including an inner and outer surface, extends from an upper region to the
lower region of
the housing, which is secured and fluidically connected with the upper end cap
by the
coupler and secured to the lower endcap; the piston is slidably sealed in the
housing and
on the low pressure tube. The piston is exposed on a first surface to well-
fluid
communicated through one or more well-fluid ports in the housing and isolates
the
reservoir fluid volume contained in the housing and exposed to a second
surface of the
piston.
[0023] The well-fluid may be a liquid, gas or a combination thereof. The well-
fluid
may be air, oil, water, mud, brine, corrosive fluid, a gas fluid, another
fluid, any fluid
present in a subterranean borehole, or a combination thereof.
[0024] The housing comprises a housing bore and may secure to a second
reservoir
module housing, a setting tool, an adapter to fluidically connect to an
isolation tool, or to
another downhole tool.
[0025] The upper and lower endcaps comprise passages which facilitate low-
pressure
fluid communication from a lower end of the reservoir module to the upper end
of
reservoir module, through a passage formed by the outer surface of the high
pressure tube
and the inner surface of the low-pressure tube. The upper endcap additionally
comprises
a high-pressure passage which facilitates high pressure communication from an
upper
end of the reservoir module to and through the high-pressure tube to the lower
end of the
reservoir module.
[0026] The piston comprises a through-hole with a rod seal to slidably seal
the piston to
the outer surface of the low-pressure tube and a piston seal to slidably seal
on the housing
bore of the housing. The piston may further comprise glide rings or bushings
to ensure
that it may smoothly travel the length of the housing bore and the low-
pressure tube.
When the pressure of the well-fluid acts on the first surface of the piston,
the piston
forces the reservoir fluid volume through upper endcap passages of the upper
end cap.
Date recue / Date received 2021-12-13
[0027] In an embodiment, the reservoir module may further comprise a spring
disposed
within the housing bore, surrounding the low-pressure tube, in contact with
the first
surface of the piston and in contact with an upper end of the lower endcap.
The spring
may function to apply a force to the piston thereby pressurizing the reservoir
fluid
volume.
[0028] In a preferred embodiment, the downhole tool comprises a second
reservoir
module and is connected to the first reservoir module. The reservoir fluid
volume of the
second or lower reservoir module is fluidically connected to the reservoir
fluid volume of
the first or upper reservoir module and the high-pressure tube of the second
or lower
reservoir module is fluidically connected to the high-pressure tube of the
first or upper
reservoir module.
[0029] In an embodiment, the downhole tool includes a third or more reservoir
modules, each reservoir fluid volume fluidically connected to the next and
upper
reservoir fluid volume and each high-pressure tube of one reservoir module
fluidically
connected to the high pressure tubes of the other reservoir modules.
[0030] In a further embodiment, a bottom hole assembly is provided which
comprises
the downhole tool and a setting tool including a pump having an intake and an
output.
The first reservoir module disposed to deliver reservoir fluid volume of the
first and
second reservoir module to the intake and the output is disposed to deliver
the first and
second reservoir fluid volumes to the high-pressure tube of the first
reservoir module and
the high pressure tube of the second reservoir module fluidically connected
thereto.
[0031] In a preferred embodiment the downhole tool may be positioned downhole
of
the setting tool.
[0032] In an embodiment the downhole tool may be positioned uphole of the
setting
tool.
[0033] In a preferred embodiment, the bottom hole assembly further comprises
an
isolation tool disposed to receive fluid from the high-pressure tubes.
[0034] In an embodiment, the isolation tool is an inflatable packer.
[0035] In an embodiment, the isolation tool is an inflatable straddle packer.
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[0036] In an embodiment, the isolation tool is a bridge plug.
[0037] In an embodiment, the isolation tool is a production packer.
[0038] In an embodiment, the isolation tool is a permanent packer.
[0039] In an embodiment, the isolation tool is a cement retainer.
[0040] In an embodiment, the isolation tool is a frac plug.
[0041] The bottom hole assembly may be connected to a wireline that extends
from a
wireline unit or truck located near an opening into the borehole. The wireline
may be
used to provide physical support of the bottom hole assembly as it is raised
and lowered
into and within the borehole, supply electrical power to electronic components
therein,
and/or provide for data communication between the bottom hole assembly and
control
systems outside the borehole. While the wireline may be sufficient for raising
and
lowering the bottom hole assembly within a substantially vertical wellbore or
segment of
a wellbore, the bottom hole assembly may further include a tractor that can
push or pull
the downhole tool along the borehole regardless of the orientation of the
borehole, such
as in a horizontal segment of a borehole.
[0042] Statements made herein referring to a component being "above", "below",
"uphole", "downhole", "upper" or "lower" relative to another component should
be
interpreted as if the downhole tool or bottom hole assembly has been run into
a wellbore.
It should be noted that even a horizontal wellbore, or any non-vertical
wellbore, still has
an "uphole" direction defined by the path of the wellbore that leads to the
surface and a
"downhole" direction that is generally opposite to the "uphole" direction.
[0043] In an embodiment, a method is provided for the delivery of fluid out of
a bottom
hole assembly, the method comprising the steps of deploying the bottom hole
assembly
including a downhole tool, and a first and second reservoir module including a
first
reservoir fluid volume and a second reservoir fluid volume, respectively;
activating the
bottom hole assembly; a piston within the second reservoir module forcing the
second
reservoir fluid volume to the lower end of the first reservoir module and into
a low
pressure tube therethrough; the first reservoir module delivering the first
reservoir fluid
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volume to the downhole tool and fluidically connecting the second reservoir
fluid volume
to the downhole tool.
[0044] In a preferred embodiment, wherein the bottom hole assembly further
comprises
an isolation tool, there is provided a method of isolating a segment of a
borehole, the
method comprising the steps of: filling a first and second reservoir module
with fluid
volumes prior to deployment; deploying the bottom hole assembly on wireline
into the
borehole; positioning the bottom hole assembly near or within a tubular
segment such
that the isolation tool is in a position to isolate the desired segments of
the borehole upon
pressurization; activating the downhole tool to draw in the first and second
reservoir fluid
volumes and deliver the volumes to the isolation tool; pressurizing the
isolation tool to
engage the borehole; isolating a segment of the borehole above the isolation
tool from a
segment of the borehole below the isolation tool.
[0045] In an embodiment, wherein the bottom hole assembly further comprises a
locating tool, the method further includes using the locating tool to locate
the desired
tubular segment.
[0046] In an embodiment, the locating tool is a mechanical locating tool.
[0047] In an embodiment, the locating tool is a wireline tool.
[0048] In an embodiment, the locating tool is an electromagnetic induction
tool.
[0049] In an embodiment, the locating tool is a casing collar locator.
[0050] FIG. 1 is a block diagram of a bottom hole assembly 10 including a
cable head
15, a setting tool 50 including a motor module 20 and a pump module 30, a
reservoir
system 80 and an isolation tool 100. The reservoir system 80 may include one
or more
reservoir modules 60. See FIG. 4.
[0051] FIGS. 2A-C are schematics of an operation using the bottom hole
assembly 10.
In FIG. 2A the bottom hole assembly 10 is run into the borehole 6. The bottom
hole
assembly includes a cable head 15, a setting tool including a motor module 20
and a
pump module 30, a reservoir system 80, and an isolation tool 100, being run
into the
borehole 6 on a wireline 5 and in communication with a surface system 22. The
borehole
6 has a downhole direction 7, an uphole direction 8 and an inner wall 9. In
FIG. 2B the
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isolation tool 100 in the borehole 6 is set near a subterranean formation 11
to isolate a
borehole 6 region above the isolation tool 100 from a segment of borehole 6
below the
isolation tool 100. In FIG. 2C the isolation tool 100 is left in the borehole
6 and the
remainder of the bottom hole assembly 10 removed from the borehole 6.
[0052] FIG. 3 is cross-section views of a reservoir module 60. The reservoir
module 60
includes a reservoir fluid chamber 59, a housing 70, upper end cap 68, lower
endcap 67, a
piston 71, a high-pressure tube 74, a low-pressure tube 73 and a coupler 76.
The upper
end cap 68 is secured at the upper end of the housing 70. The lower endcap is
secured to
the lower end of the housing 70 and sealed therein. The coupler 76 is secured
and sealed
to the lower end of the upper endcap 68 and secures and seals high-pressure
tube 74
which is also secured at the lower endcap 67. A high-pressure passage 66 is
routed
through the reservoir module 60. The high pressure passage 66 is formed by a
central
through-hole of the upper endcap 68 which is sealed and fluidically connected
to a
through-hole of coupler 76, which is further sealed and fluidically connected
to the
interior of the high pressure tube 74. The high-pressure tube 74 is routed
through the
lower endcap 67 and is surrounded by the low-pressure tube 73. Near the upper
end of
the low-pressure tube 73, low pressure tube holes 75 fluidically connect fluid
from the
interior of the low-pressure tube 73 to the exterior of the low-pressure tube
73. The
region exterior the low-pressure tube 73 is fluidically connected to upper
endcap passage
69 of upper endcap 68. The lower end cap 67 comprises one or more lower end
cap
passages 65 which are fluidically connected to the region interior the low-
pressure tube
73 and exterior the high-pressure tube 74. The piston 71 is slidably sealed in
the housing
70 and on the low-pressure tube 73. The piston 71 is exposed on a piston first
surface 78
to well-fluid communicated through one or more well-fluid ports 77 in the
housing 70
and isolates the reservoir fluid chamber 59 in the housing 70 and exposed to a
piston
second surface 79. The piston 71 comprises a through-hole with a rod seal 88
to slidably
seal the piston 71 to the outer surface of the low-pressure tube 73 and a
piston seal 89 to
slidably seal on the housing bore 87. The piston 71 may further comprise glide
rings 90
to ensure that it may smoothly travel the length of the housing bore 87 and
the low-
pressure tube 73. A spring 72 is disposed within the housing 70 surrounding
the low-
pressure tube 73, is in contact with the piston first surface 78 and in
contact with an upper
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end of the lower endcap 67. When the reservoir fluid chamber 59 is filled with
a
reservoir fluid volume; for example, prior to deployment, the spring 72
functions to apply
a force to the piston 71 thereby pressurizing the reservoir fluid volume
within the
reservoir fluid chamber 59.
[0053] FIG. 4 is a break-out section view of bottom hole assembly including a
setting
tool 50 and a reservoir system 80 including an upper reservoir module 60, a
lower
reservoir module 60A, and a bottom adapter 62. The upper reservoir module 60
is
secured and sealed to the lower end of the setting tool pump module 30. See
also FIG.5.
The high-pressure passage 66 is sealed and fluidically connected to pump
output 84. The
upper end cap passage 69 of the upper reservoir module 60 is fluidically
connected to
pump chamber 82 which is in fluid communication with pump intake ports 83. The
housing 70 of upper reservoir module 60 is secured and sealed to the upper end
of the
housing 70 of the lower reservoir module 60A. The high-pressure tube 74
extending
through the upper reservoir module 60 and the respective lower end cap 67, is
sealed
within the high-pressure passage 66 of the upper endcap 68 of the lower
reservoir module
60A. The lower end cap passages 65 of the upper reservoir module 60 lower
endcap 67,
is in fluid communication with upper endcap passage 69 of upper endcap 68 of
the lower
reservoir module 60A. The bottom adapter 62 is secured and sealed to the lower
end of
the lower reservoir module 60A. The high-pressure passage 66 of the bottom
adapter 62
is sealed to the high-pressure tube 74 of the lower reservoir module 60A. Fill
port 63 is in
fluid communication with fill passage 64, which is in fluid communication with
the lower
endcap passage 65 of the lower endcap 67 of the lower reservoir module 60A.
[0054] The fill port 63 may be used to fill the reservoir fluid chambers 59
with a
volume of reservoir fluid; for example, prior to deployment in a borehole 6.
The pressure
of the reservoir fluid being filled may act on the piston second surface 79 of
the upper
reservoir module 60 and the lower reservoir module 60A and may compress
springs 72
such that the piston seals 89 of the upper reservoir module 60 piston 71 and
the lower
reservoir module 60A piston 71 are temporarily unsealed from their respective
housing
bores 87 by entering larger bores 91 of the respective housings 70. In this
manner, air or
other gas within the reservoir fluid chambers 59 may be expelled from the
reservoir
Date recue / Date received 2021-12-13
system 80. FIG. 6 is partial section view close-up of depicting a piston in
this
temporarily unsealed position.
[0055] When the bottom hole assembly 10 reservoir fluid chambers 59 are filled
with
reservoir fluid volumes and are exposed to well-fluid pressure; for example,
when
deployed in a borehole 6, the pressure will act on the first piston surfaces
78 of the
pistons 71 of the respective reservoir modules 60 and 60A. The piston 71 of
the lower
reservoir module 60A will translate in the uphole direction 8 and deliver the
reservoir
fluid volume in the reservoir fluid chamber 59 to upper endcap passage 69 of
upper
endcap 68 of the lower reservoir module 60A. The fluid volume will then flow
into the
lower endcap passage 65 of the lower endcap 67 of the upper reservoir module
60. The
fluid will then flow into a space created by the inner surface of the low-
pressure tube 73
and the outer surface of the high-pressure tube 74 of the upper reservoir
module 60. The
fluid will then flow out of low-pressure tube holes 75 of the low-pressure
tube 73 of
upper reservoir module 60 and into the upper endcap passage 69 of the upper
endcap 68
of the upper reservoir module 60. From the upper endcap passage 69 of the
upper endcap
68 of the upper reservoir module 60, the fluid will flow into the pump chamber
82 and
into the pump intake ports 83. The piston 71 of the upper reservoir module 60
will
translate in the uphole direction 8 and deliver the reservoir fluid volume in
the reservoir
fluid chamber 59 of the upper reservoir module 60, to upper endcap passage 69
of upper
endcap 68 of the upper reservoir module 60. From the upper endcap passage 69
of the
upper endcap 68 of the upper reservoir module 60, the fluid will flow into the
pump
chamber 82 and into the pump intake ports 83. The pump 85 will pressurize the
reservoir
fluid volumes and deliver it to the high-pressure passage 66 through the
reservoir system
80.
[0056] FIG. 7 is a partial section view of the reservoir system 80 with the
pistons 71
shown after they have translated in the uphole direction 8 and delivered the
reservoir
fluid volumes from the reservoir fluid chambers 59 to the pump 85.
[0057] In an alternative embodiment, the pistons translate in the downhole
direction to
deliver the reservoir fluid volumes to the pump.
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[0058] FIG. 8 is a partial section view of how a reservoir system 80 may be
connected
to an isolation tool 100. The bottom adapter 62 of the reservoir system 80 is
secured to
the isolation tool 100 and the high-pressure passage 66 is in fluid
communication with the
isolation tool 100.
[0059] The terminology used herein is for the purpose of describing particular
embodiments only and is not intended to limit the scope of the claims. As used
herein,
the singular forms "a", "an" and "the" are intended to include the plural
forms as well,
unless the context clearly indicates otherwise. It will be further understood
that the terms
"comprises" and/or "comprising," when used in this specification, specify the
presence of
stated features, integers, steps, operations, elements, components and/or
groups, but do
not preclude the presence or addition of one or more other features, integers,
steps,
operations, elements, components, and/or groups thereof. The terms
"preferably,"
"preferred," "prefer," "optionally," "may," and similar terms are used to
indicate that an
item, condition or step being referred to is an optional feature of the
embodiment.
[0060] The corresponding structures, materials, acts, and equivalents of all
means or
steps plus function elements in the claims below are intended to include any
structure,
material, or act for performing the function in combination with other claimed
elements
as specifically claimed. Embodiments have been presented for purposes of
illustration
and description, but it is not intended to be exhaustive or limited to the
embodiments in
the form disclosed. Many modifications and variations will be apparent to
those of
ordinary skill in the art after reading this disclosure. The disclosed
embodiments were
chosen and described as non-limiting examples to enable others of ordinary
skill in the art
to understand these embodiments and other embodiments involving modifications
suited
to a particular implementation.
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