Note: Descriptions are shown in the official language in which they were submitted.
CA 02751967 2011-09-12
Title
Hydraulic Sleeve with Early Release Prevention
This application claims priority on US Provisional Patent Application No.
61/381,509 filed September 10, 2010, incorporated herein by reference.
io FIELD OF THE INVENTION
[001] The present application relates to a tool having a lateral window in the
tool
and a system for opening the lateral window and preventing unintended opening
of
the window.
DESCRIPTION OF THE PRIOR ART
[002] Downhole tools must be activated remotely to avoid having to trip the
tools
hundreds or thousands of feet out of the hole to change their function or
setting.
There are a few ways currently used to address a particular tool. These
include a
combination of lifting ("tension"), setting down ("compression"), and
rotating. The
use of J tools, shear pins, springs and packers with these motions help bring
about
desired changes in the tools and can be used to sequentially or individually
address
multiple downhole tools. In recent decades, balls having a specified diameter
have
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been used to drop down tubing and through or into a tool to cause a particular
action or to block a particular passage.
[003] The present invention shows in a preferred embodiment using an
insertable
plug or dart to open a lateral window, wherein when said dart or plug is not
inserted
s pressure flow cannot unintentionally open the lateral window. A shear pin or
other
device may be used to control the amount of force required to open the lateral
window and to pin the window in place when not needed.
[004] None of the above inventions and patents, taken either singly or in
combination, is seen to describe the instant invention as claimed.
SUMMARY
[005] The present invention uses an internal sleeve slidably received within a
tubular housing. The sleeve and outer housing may have windows that
selectively
1s align or the sleeve may move out of alignment with the window to allow
fluid
passage through a window. Movement of the sleeve within the housing is
controlled
by inserting a dart or plug in the interior of the sleeve to allow pressure to
act on the
plug or dart to move the sleeve a set amount to open the lateral window. A
shear
pin or other device may be used to control the amount of force necessary to
open
the window and further ensure unintended opening of the lateral window. The
use
of the removable dart or plug both prevents unintentional forces from opening
the
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window and increases the amount of throughput through the sleeve as compared
to
when valve structure is installed within the tool.
[006] Accordingly, it is a principal object of a preferred embodiment of the
invention
to provide a downhole tool that can be activated and deactivated by a plug or
dart
inserted within the tool.
[007] It is another object of the invention to provide a down hole tool that
has a
shear pin to prevent unintended operation of the device.
[008] It is a further object of the invention to provide a downhole tool
having an
activation device such as a dart or plug that can be inserted and removed to
limit
io flow interruption through the device.
[009] Still another object of the invention is to provide a downhole tool that
has a
number of window tools that can be activated in any order by inserting a dart
or
bridge plug at the desired tool to activate that tool and only that tool.
[010] It is an object of the invention to provide improved elements and
arrangements thereof in an apparatus for the purposes described which is
inexpensive, dependable and fully effective in accomplishing its intended
purposes.
[011] These and other objects of the present invention will be readily
apparent
upon review of the following detailed description of the invention and the
accompanying drawings. These objects of the present invention are not
exhaustive
and are not to be construed as limiting the scope of the claimed invention.
Further, it
must be understood that no one embodiment of the present invention need
include
all of the aforementioned objects of the present invention. Rather, a given
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embodiment may include one or none of the aforementioned objects. Accordingly,
these objects are not to be used to limit the scope of the claims of the
present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[012] Fig. 1 is an exemplary embodiment of a downhole tool showing at least
one
aspect of the invention in the closed position.
[013] Fig. 2 is an exemplary embodiment of a downhole tool showing at least
one
aspect of the invention in the open position.
[014] Fig. 3 is a diagrammatic view of a system according to at least one
aspect of
the present invention.
[015] Similar reference characters denote corresponding features consistently
throughout the attached drawings.
is DETAILED DESCRIPTION
[016] The present invention according to at least one aspect is to a downhole,
window tool 10 having a device for activating a lateral window on the tool in
preparation for well processes such as fracturing and production without
having to
run the tool out of the hole to change the mode of the tool.
[017] The downhole window tool 10 is designed to be installed on a drill
string 60
or similar device. As shown in Figure 3, a number of the tools 10 may be
installed
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and separated a large distance apart by spacers 62 or the like of sufficient
length so
that when installed the opening 18 of each window tool 10 aligns with an
opening 64
of the well casing 66. While only two tools are shown, any number of tools may
be
used. The drill string and components may be connected at the top to a tank 68
at
a location above the surface to contain produced fluids.
[018] As shown in Figures 1 and 2, an individual downhole, window tool may
comprise an outer housing 12, which is substantially tubular in shape. An
upper sub
16 and lower sub 14 may be connected at either end of the tool by threads,
screws,
shear pins or the like. The outer housing has an opening 18, which is
preferably
io formed as a number of slots or openings around the circumference of the
housing
but may be one continuous opening. The purpose of these openings is to allow
fluid
communication between an area within the housing and the area outside of the
housing when the opening 18 is uncovered by an internal sleeve 20. The
internal
sleeve is arranged to slide within the outer housing 12 between a closed
position as
shown in Figure 1 and an open position as shown in Figure 2. A stop 22 may be
installed in the outer housing 12 to control the distance that the internal
sleeve may
slide. The slide may be anchored by a button or detent 26 extending from the
slide
being located in the outer housing. The sleeve 20 below the lower surface of
the
slide will prevent the stop button from sliding out of the housing thus will
maintain
the stop in place. The ends of the stop may provide an upper and/or lower
limit to
the sliding motion of the sleeve. The stop may alternatively be used to
connect the
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opposite ends of the housing, but preferably the housing is made of a one
piece unit
with the stop installed between the housing and the sleeve.
[019] In the preferred embodiment, the sleeve is arranged within the outer
housing
to slide between the closed position and the open position. To prevent
unintentional
operation of the sleeve, the sleeve may be pinned in the closed position by a
shear
pin 24 or the like. The shear pin will shear under a preselected pressure to
allow
the sleeve to slide to the open position. The present design as will be
discussed
hereinunder further prevents unintentional opening by reducing the number of
pressure surfaces within the window tool that could be acted upon to open the
1o window (i.e., "activate the sleeve"). Previous designs show a ball valve
dropped
through the tool to plug a valve seat to operate the sleeve movement under
fluid
pressure. Because the ball is of a very limited size compared to the diameter
of the
housing, the valve seat itself blocks a great deal of flow through the tool,
which
could potentially cause the sleeve to prematurely move. Additionally, the
valve seat
restriction acts to restrict the total amount of flow through the tool from
lower window
tools and thus may reduce the production flow through the drill string.
[020] The present invention by contrast uses a removable bridge plug 30 or
dart to
activate the tool. A recess, internal flange or abutment in the sleeve may be
used to
capture the plug or dart when installed. The plug or dart acts to block flow
through
the tool allowing pressure to build up until it exceeds the shear point of the
shear pin
holding the sleeve in place. The fluid pressure then acts to move the sleeve
away
from the window 18 to allow communication through the window to an outer zone
or
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further tubing, etc. The walls of the recess retaining the plug cause the
sleeve to
travel with the plug instead of allowing the plug to slide along the sleeve.
The walls
allow forces to be transferred from the plug (or dart) to the sleeve.
[021] The use of a dart or bridge plug also allows easier selection of the
tool on
which to operate. A casing collar locator tool (T CU) or similar device may be
used
to track the depth of a tool or portion of a tool. By tracking the depth of
windows in
the down hole and the depth of the bridge plug or dart, the dart may be place
precisely into a desired window tool and inflated or otherwise fixed in place
in a
particular window tool. Subsequent pressurization of the interior of the
window tool
io from the surface will cause the pressure to act on the bridge plug or dart
and thus
on the sleeve, shearing the pin 24 and moving the sleeve to the open position.
The
sleeve will then stay open until processing is completed and the tool removed
to the
surface. The plug or dart may be removed if flow is desired to a location
below the
tool, such as to a lower tool using a known bridge plug or dart removal tool.
[022] While this invention has been described as having a preferred design, it
is
understood that it is capable of further modifications, uses and/or
adaptations of the
invention following in general the principle of the invention and including
such
departures from the present disclosure as come within the known or customary
practice in the art to which the invention pertains and as maybe applied to
the
central features hereinbefore set forth, and fall within the scope of the
invention and
the limits of the appended claims. It is therefore to be understood that the
present
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invention is not limited to the sole embodiment described above, but
encompasses
any and all embodiments within the scope of the following claims.
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