Note: Descriptions are shown in the official language in which they were submitted.
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RFID CONTROL DART
Cross-Reference to Related Applications
[0001] This application is a nonprovisional application which claims priority
from U.S.
provisional application number 61/976,128, filed April 7, 2014, the entirety
of which is hereby
incorporated by reference in its entirety.
Technical Field/Field of the Disclosure
[0002] The present disclosure relates generally to tools for use in a
wellbore, and specifically to
a control dart for a selectively openable port sleeve for use in hydraulic
fracturing operations.
Background of the Disclosure
[0003] During the drilling of a well for oil and gas, in some earthen
formations, oil and gas
production may be significantly increased through the use of enhanced oil
recovery including
hydraulic fracturing. In a hydraulic fracturing operation, a mixture of fluid
and proppant
(referred to herein as fracturing fluid) is pumped at high pressure into the
formation, causing the
formation to fracture. Proppant, such as sand, is included in the fracturing
fluid to, for example,
help keep the fractures open and thus increase porosity of the formation. In
order to fracture a
formation, a downhole tool, referred to herein as a hydraulic fracturing
string, is placed within
the wellbore. The hydraulic fracturing string may include a number of downhole
tools including
packers, cement collars, and one or more fracturing sleeves. A fracturing
sleeve is a downhole
tool which includes one or more apertures which may be opened to allow the
hydraulic
fracturing of the formation surrounding it.
[0004] In some instances, the hydraulic fracturing string including the
fracturing sleeves is
cemented in the wellbore before the hydraulic fracturing operation takes
place. The fracturing
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sleeves are then opened sequentially, through the use of, for example,
hydraulic pressure, control
balls, control darts, or electromechanical operations, and fracturing fluid is
pumped at high
pressure into the surrounding wellbore to complete the fracturing operation.
The downhole
environment in which the fracturing sleeves are located may be very harsh and
may lead to
damage of any electronic equipment placed therein.
Summary
[0005] The present disclosure provides for an RFID control dart for use with a
downhole tool.
The RFID control dart may include an outer cover, the outer cover being
generally cylindrical in
shape; at least one locking dog adapted to, when in an extended position,
extend in a generally
radial direction from the outer cover and, when in a retracted position,
remain generally within
the outer cover; an electronic controller, the electronic controller including
an RFID reader, the
electronic controller adapted to extend or retract the locking dog in response
to reading a
preselected identification code from an RFID tag with the RFID reader; and a
power source
adapted to provide electric power to the electronic controller and the at
least one locking dog.
[0006] The present disclosure also provides for a method for reconfiguring a
downhole tool. The
method may include providing an RFID control dart. The RFID control dart may
include an
outer cover, the outer cover being generally cylindrical in shape; at least
one locking dog adapted
to, when in an extended position, extend in a generally radial direction from
the outer cover and,
when in a retracted position, remain generally within the outer cover; an
electronic controller, the
electronic controller including an RFID reader, the electronic controller
adapted to extend or
retract the locking dog in response to reading a preselected identification
code from an RFID tag
with the RFID reader; and a power source adapted to provide electric power to
the electronic
controller and the at least one locking dog. The method may further include
providing a
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downhole tool. The downhole tool may be coupled to a tool string. The downhole
tool may be
adapted to be actuated by the control dart when the locking dogs are in the
extended position.
The method may also include positioning at least one RFID tag at a position
generally closer to
the surface than the downhole tool, the RFID tag readable by the RFID reader
and having a
unique identification code, the RFID tag being an unpowered, passive type RFID
tag;
configuring the RFID control dart with an identification code corresponding to
the identification
code of the RFID reader; pumping the RFID control dart through the tool
string; reading the
identification code with the RFID reader; matching the identification code
read by the RFID
reader with the preprogrammed code; extending the locking dogs; actuating the
downhole tool.
[0007] The present disclosure also provides for a system. The system may
include an RFID
control dart for use with a downhole tool. The RFID control dart may include
an outer cover, the
outer cover being generally cylindrical in shape; at least one locking dog
adapted to, when in an
extended position, extend in a generally radial direction from the outer cover
and, when in a
retracted position, remain generally within the outer cover; an electronic
controller, the electronic
controller including an RFID reader, the electronic controller adapted to
extend or retract the
locking dog in response to reading a preselected identification code from an
RFID tag with the
RFID reader; and a power source adapted to provide electric power to the
electronic controller
and the at least one locking dog. The system may also include a downhole tool,
the downhole
tool coupled to a tool string, the downhole tool adapted to be actuated by the
control dart when
the locking dogs are in the extended position. The system may also include an
RFID tag coupled
to the tool string positioned generally closer to the surface than the
downhole tool, the RFID tag
readable by the RFID reader and having a unique identification code, the RFID
tag being an
unpowered, passive type RFID tag.
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Brief Description of the Drawings
[0008] The present disclosure is best understood from the following detailed
description when
read with the accompanying figures. It is emphasized that, in accordance with
the standard
practice in the industry, various features are not drawn to scale. In fact,
the dimensions of the
various features may be arbitrarily increased or reduced for clarity of
discussion.
[0009] FIG. 1 depicts an overview of a hydraulic fracturing operation
consistent with
embodiments the present disclosure.
[0010] FIG. 2a depicts an RFID control dart consistent with embodiments of the
present
disclosure in the retracted position.
[0011] FIG. 2b depicts an RFID control dart consistent with embodiments of the
present
disclosure in the extended position.
[0012] FIGS. 3a-d depict an RFID control dart passing through a fracturing
string consistent
with embodiments of the present disclosure
Detailed Description
[0013] It is to be understood that the following disclosure provides many
different embodiments,
or examples, for implementing different features of various embodiments.
Specific examples of
components and arrangements are described below to simplify the present
disclosure. These are,
of course, merely examples and are not intended to be limiting. In addition,
the present
disclosure may repeat reference numerals and/or letters in the various
examples. This repetition
is for the purpose of simplicity and clarity and does not in itself dictate a
relationship between
the various embodiments and/or configurations discussed.
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[0014] FIG. 1 depicts an overview of a hydraulic fracturing operation
consistent with
embodiments of the present disclosure. Hydraulic fracturing string 101 is
placed into wellbore 10
by drilling rig 20. Hydraulic fracturing string 101 is positioned so that
fracturing sleeves 103 are
aligned with the section of wellbore 10 desired to be hydraulically fractured.
In some
embodiments, hydraulic fracturing string 101 includes cementing collar 105
which serves to, for
example, allow cement 107 to flow from the interior of hydraulic fracturing
string 101 to the
annular space between hydraulic fracturing string 101 and wellbore 10. In some
embodiments,
hydraulic fracturing string 101 may also include packer 109 to, for example,
contain cement 107
within only the desired section of wellbore 10. Packer 109 may be an
inflatable packer, swellable
packer, or any other zonal isolation packer known in the art.
[0015] Once cement 107 has cured or packers are set, the fracturing operation
may commence.
Fracturing sleeves 103 may be selectively opened (as discussed below),
allowing for fluid
communication between the interior of hydraulic fracturing string 101 and
wellbore 10. High
pressure fracturing fluid is introduced into hydraulic fracturing string 101
and passes through the
open fracturing sleeve 103 to hydraulically fracture (12) the surrounding
formation.
Subsequently, another fracturing sleeve 103 may be opened, and the fracturing
operation may
continue.
[0016] In some embodiments of the present disclosure, one or more fracturing
sleeves 103 may
be actuated by an RFID control dart. As depicted in FIGS. 2a, 2b, RFID control
dart 201 may be
generally cylindrical in shape and include outer cover 203. Outer cover 203
may have a rounded
or tapered nose 205 adapted to, for example, allow RFID control dart 201 to
more easily traverse
the interior of a tubular. RFID control dart 201 may be adapted to be pumped
through a tool
string, such as the previously discussed hydraulic fracturing string and
selectively engage with
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one or more sliding sleeves. As depicted in FIG. 2b, RFID control dart 201 may
include one or
more extendible locking dogs 207. Locking dogs 207 may be selectively extended
or refracted by
an electronic controller positioned within RFID control dart 201. In some
embodiments, the
electronic controller may include an RFID reader. As understood in the art, an
RFID, or radio-
frequency identification, reader may include a radio transceiver capable of
recognizing an
identification code stored in one or more RFID tags. RFID tags, as understood
in the art, may be
active or passive circuits designed to, when interrogated by an RFID reader,
transmit their unique
identification code to the RFID reader.
[0017] In some embodiments, the electronic controller may also include a power
source and an
electrical actuator adapted to extend or retract locking dogs 207. In some
embodiments, in
response to detecting an RFID tag having a predetermined identification code,
the electronic
controller may cause the extension of locking dogs 207.
[0018] In some embodiments, RFID control dart 201 may also include one or more
seals 209
adapted to seal RFID control dart 201 within a tubular member. Seals 209 may,
for example,
allow RFID control dart 201 to be pumped by fluid pressure through the
tubular. Additionally,
seals 209 may, for example, allow fluid pressure to be transferred through
RFID control dart 201
into a downhole tool having a dart catcher as described below.
[0019] In some embodiments of the present disclosure, each fracturing sleeve
103 as depicted in
FIG. 1 may include an RFID tag with a known and unique identification code.
The electronic
controller of RFID control dart 201 may be configurable to activate when a
specific RFID tag
identification code is detected. As understood in the art, passive type RFID
tags may be powered
or unpowered. Because of the harsh environment in wellbore 10, any power
sources such as
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batteries may be corroded or otherwise destroyed before being used. In some
embodiments of the
present disclosure, the RFID tags may be unpowered, passive type RFID tags. As
understood in
the art, an unpowered, passive type RFID tag responds, as previously
discussed, to an
interrogation signal from the RFID reader with its identification code while
not relying on a
dedicated power source other than that attached to the RFID reader.
Additionally, the RFID tags
may be protected from the downhole environment by, for example, being
installed or attached in
the wall of the corresponding fracturing sleeve 103. In some embodiments, the
RFID tags may
be installed or attached in a separate tubular or casing device. In some
embodiments, the RFID
tags may be selectively attachable to the outside or inside wall of a tubular
of the tool string.
[0020] As depicted in FIG. 3a, RFID control dart 201 is pumped through
hydraulic fracturing
string 101. As RFID control dart 201 passes through each fracturing sleeve
303a-d, the electronic
controller detects the identification code of each RFID tag 305a-d. As an
example, RFID control
dart 201 may be configured to reconfigure RFID control dart 201 and extend
locking dogs 207
when a target identification code corresponding with that of RFID tag 305b of
fracturing sleeve
303b is received.
[0021] In operation, RFID control dart 201 is pumped through fracturing string
101 with locking
dogs 207 in a retracted position, thus allowing it to pass freely through dart
catchers 307a-d
positioned within each fracturing sleeve 303a-d. As RFID control dart 201
passes through
fracturing sleeve 303a, the identification code of RFID tag 305a is received.
RFID control dart
201 recognizes that this identification code does not match the preselected
target identification
code. Locking dogs 207 thus remain in the retracted position.
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[0022] As depicted in FIG. 3b, as RFID control dart 201 passes through
fracturing sleeve 303b,
the identification code of RFID tag 305b is received. RFID control dart 201
recognizes that this
identification code does match the target identification code. As a result,
locking dogs 207 are
extended as RFID control dart 201 moves from fracturing sleeve 303b to 303c.
[0023] As RFID control dart 201 moves through fracturing sleeve 303c, the
extended locking
dogs 207 interfere with dart catcher 307c of fracturing sleeve 303c, thus
retaining control dart
201 within fracturing sleeve 303c as depicted in FIG. 3c. Once RFID control
dart 201 is
captured, fluid pressure applied to control dart 201 may be transferred into
fracturing sleeve
303c. In some embodiments, fracturing sleeve 303c may include a sliding sleeve
309c adapted to
open one or more apertures 311c when sliding sleeve 309c is moved by RFID
control dart 201.
As depicted in FIG. 3d, fluid pressure exerted on RFID control dart 201 may
cause sliding sleeve
309c to slide, thus selectively opening apertures 311c.
[0024] Although described in terms of a fracturing sleeve, one having ordinary
skill in the art
with the benefit of this disclosure will understand that RFID control dart 201
may be used to
control any downhole tool actuatable by a control dart. For example, the
downhole tool may be,
without limitation, a sliding sleeve for production or injection control,
primary or secondary
cementing tool, production testing chamber or device, actuation mechanism for
setting a packer,
liner hanger or similar device, choke for production or injection control, or
a tool for selectively
setting a tubing or casing plug in a particular location to control production
or injection. By
replacing a standard dart catcher with a dart catcher configured to only catch
RFID control dart
201 when locking dogs 207 are in the extended position, any such downhole tool
may be
reconfigured to use RFID control dart 201. Furthermore, in some embodiments,
RFID control
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dart 201 may include features common to standard downhole darts, including,
without limitation,
one or more wipers.
[0025] The foregoing outlines features of several embodiments so that a person
of ordinary skill
in the art may better understand the aspects of the present disclosure. Such
features may be
replaced by any one of numerous equivalent alternatives, only some of which
are disclosed
herein. One of ordinary skill in the art should appreciate that they may
readily use the present
disclosure as a basis for designing or modifying other processes and
structures for carrying out
the same purposes and/or achieving the same advantages of the embodiments
introduced herein.
One of ordinary skill in the art should also realize that such equivalent
constructions do not
depart from the spirit and scope of the present disclosure and that they may
make various
changes, substitutions and alterations herein without departing from the
spirit and scope of the
present disclosure.
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