U.S. patent application number 13/398431 was filed with the patent office on 2013-08-22 for methods and systems for wiping surfaces when performing subterranean operations.
This patent application is currently assigned to HALLIBURTON ENERGY SERVICES. The applicant listed for this patent is Patrick Lyle Cherney, Gary Joe Makowiecki. Invention is credited to Patrick Lyle Cherney, Gary Joe Makowiecki.
Application Number | 20130213658 13/398431 |
Document ID | / |
Family ID | 47790514 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130213658 |
Kind Code |
A1 |
Makowiecki; Gary Joe ; et
al. |
August 22, 2013 |
METHODS AND SYSTEMS FOR WIPING SURFACES WHEN PERFORMING
SUBTERRANEAN OPERATIONS
Abstract
Improved darts and methods of using these darts in subterranean
wells are disclosed. The improved dart comprises a foam portion and
a rubber portion coupled to the foam portion. A dart nose is
coupled to at least one of the foam portion and the rubber portion.
The foam portion and the rubber portion are configured to interface
with an inner surface of at least one of a well bore wall, a pipe,
and a casing string.
Inventors: |
Makowiecki; Gary Joe;
(Duncan, OK) ; Cherney; Patrick Lyle; (Duncan,
OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Makowiecki; Gary Joe
Cherney; Patrick Lyle |
Duncan
Duncan |
OK
OK |
US
US |
|
|
Assignee: |
HALLIBURTON ENERGY SERVICES
|
Family ID: |
47790514 |
Appl. No.: |
13/398431 |
Filed: |
February 16, 2012 |
Current U.S.
Class: |
166/311 ;
166/153 |
Current CPC
Class: |
E21B 33/16 20130101;
B08B 9/0554 20130101 |
Class at
Publication: |
166/311 ;
166/153 |
International
Class: |
E21B 37/04 20060101
E21B037/04 |
Claims
1. A dart comprising: a foam portion; a rubber portion coupled to
the foam portion; and a dart nose coupled to at least one of the
foam portion and the rubber portion; wherein the foam portion and
the rubber portion are configured to interface with an inner
surface of at least one of a well bore wall, a pipe, and a casing
string.
2. The dart of claim 1, wherein the foam portion is made from a gel
material.
3. The dart of claim 1, wherein the rubber portion is made from
polyurethane.
4. The dart of claim 1, wherein the foam portion and the rubber
portion are detachably coupled.
5. The dart of claim 4, wherein at least one of a threaded
engagement, a bolt, and a screw detachably couples the foam portion
to the rubber portion.
6. The dart of claim 1, wherein the foam portion and the rubber
portion are non-detachably coupled.
7. The dart of claim 1, wherein the foam portion comprises at least
one of a conical portion, a cylindrical portion, an elliptical
portion and a combination thereof.
8. The dart of claim 1, wherein the rubber portion comprises at
least one of a conical portion, a cylindrical portion, an
elliptical portion and a combination thereof.
9. A method of cleaning a restriction in a casing comprising:
placing a dart in the restriction; wherein the dart comprises a
foam portion coupled to a rubber portion; passing the dart through
the restriction; wherein at least one of the foam portion and the
rubber portion cleans an inner surface of the restriction; and
directing the dart out of the restriction to a wider portion of the
casing; wherein a diameter of the wider portion of the casing
exceeds a diameter of the restriction; and wherein the rubber
portion interfaces with an inner surface of the wider portion of
the casing before the foam portion interfaces with an inner surface
of the wider portion of the casing.
10. The method of claim 9, wherein the foam portion is made from a
gel material.
11. The method of claim 9, wherein the rubber portion is made from
polyurethane.
12. The method of claim 9, wherein the foam portion and the rubber
portion are detachably coupled.
13. The method of claim 12, wherein at least one of a threaded
engagement, a bolt, and a screw detachably couples the foam portion
to the rubber portion.
14. The method of claim 9, wherein the foam portion and the rubber
portion are non-detachably coupled.
15. The dart of claim 9, wherein the foam portion comprises at
least one of a conical portion, a cylindrical portion, an
elliptical portion and a combination thereof.
16. The dart of claim 9, wherein the rubber portion comprises at
least one of a conical portion, a cylindrical portion, an
elliptical portion and a combination thereof.
Description
BACKGROUND
[0001] The present disclosure generally relates to subterranean
operations. More particularly, the present disclosure relates to
improved darts and methods of using these darts in subterranean
wells.
[0002] During the drilling and construction of subterranean wells,
casing strings ("casing") are generally introduced into the well
bore. To stabilize the casing, a cement slurry is often pumped
downwardly through the casing, and then upwardly into the annulus
between the casing and the walls of the well bore. One concern
regarding this process is that, prior to the introduction of the
cement slurry into the casing, the casing generally contains a
drilling fluid or some other servicing fluid that may contaminate
the cement slurry. To prevent this contamination, a plug, often
referred to as a cementing plug or a "bottom" plug, may be placed
into the casing ahead of the cement slurry as a boundary between
the two. The plug may perform other functions as well, such as
wiping fluid from the inner surface of the casing as it travels
through the casing, which may further reduce the risk of
contamination.
[0003] Similarly, after the desired quantity of cement slurry is
placed into the well bore, a displacement fluid is commonly used to
force the cement into the desired location. To prevent
contamination of the cement slurry by the displacement fluid, a
"top" cementing plug may be introduced at the interface between the
cement slurry and the displacement fluid. This top plug also wipes
cement slurry from the inner surfaces of the casing as the
displacement fluid is pumped downwardly into the casing. Sometimes
a third plug may be used, for example, to perform functions such as
preliminarily calibrating the internal volume of the casing to
determine the amount of displacement fluid required, or to separate
a second fluid ahead of the cement slurry (e.g., where a preceding
plug may separate a drilling mud from a cement spacer fluid, the
third plug may be used to separate the cement spacer fluid from the
cement slurry).
[0004] When performing subterranean operations, it may be desirable
to keep different fluids separate and wipe the drillpipe or tubing
string clean of cement, fluids or debris. Typically, the methods
used involve a positive displacement plugging device, often
referred to as a "dart." Typically, rubber darts or foam darts are
used when performing subterranean operations. However, both rubber
darts and foam darts have certain drawbacks.
[0005] Rubber darts generally comprise two or more rubber "fins"
that flare outwardly from a mandrel or stem. Such fins are
generally sized to engage the inside wall of the pipe in which they
are deployed. Because its fins prevent a dart from free falling to
the plug, a pressure differential, or otherwise downward flow of
fluid, usually is applied to force the dart to the plug. It is
often desirable for the dart to pass through restrictions such as,
for example, mechanical setting tools, diverters and liner running
tools. However, rubber darts are not typically well suited for
passing through such restrictions. Specifically, once passed
through a restriction, rubber darts often experience a reduction in
wiping efficiency. For instance, when a rubber dart that has passed
through a restriction is used to clean cement in a casing it often
leaves behind a large amount of cement.
[0006] Foam darts, such as those disclosed in U.S. Pat. No.
6,973,966, have a high parting stretch ratio compared to the
conventional molded rubber darts, which means they can pass through
small restrictions without a reduction in their cleaning
efficiency. While the foam darts typically have a higher wiping
efficiency, they also suffer from some disadvantages. For instance,
the foam darts typically do not expand to their original size fast
enough after passing through a restriction. Accordingly, after
passing through a restriction and while collapsed, the foam darts
may not wipe the casing effectively. Additionally, once a foam dart
is collapsed due to passage through a restriction and before it
expands to it original size it may not be in contact with the inner
surface of the casing. As a result, the foam dart may free fall to
the bottom of the casing string causing it to "land" early.
SUMMARY
[0007] The present disclosure generally relates to subterranean
operations. More particularly, the present disclosure relates to
improved darts for use in subterranean wells.
[0008] In one exemplary embodiment, the present disclosure is
directed to a dart comprising: a foam portion; a rubber portion
coupled to the foam portion; and a dart nose coupled to at least
one of the foam portion and the rubber portion; wherein the foam
portion and the rubber portion are configured to interface with an
inner surface of at least one of a well bore wall, a pipe, and a
casing string.
[0009] In another exemplary embodiment, the present disclosure is
directed to a method of cleaning a restriction in a casing
comprising: placing a dart in the restriction; wherein the dart
comprises a foam portion coupled to a rubber portion; passing the
dart through the restriction; wherein at least one of the foam
portion and the rubber portion cleans an inner surface of the
restriction; and directing the dart out of the restriction to a
wider portion of the casing; wherein a diameter of the wider
portion of the casing exceeds a diameter of the restriction; and
wherein the rubber portion interfaces with an inner surface of the
wider portion of the casing before the foam portion interfaces with
an inner surface of the wider portion of the casing.
[0010] The features and advantages of the present invention will be
apparent to those skilled in the art from the description of the
preferred embodiments which follows when taken in conjunction with
the accompanying drawings. While numerous changes may be made by
those skilled in the art, such changes are within the spirit of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These drawings illustrate certain aspects of some of the
embodiments of the present invention, and should not be used to
limit or define the invention.
[0012] FIG. 1 is a perspective view of a composite dart in
accordance with one embodiment of the present invention.
[0013] FIG. 2 is a side view of the foam portion of a composite
dart in accordance with an embodiment of the present invention.
[0014] FIG. 3 is a side view of the foam portion of a composite
dart in accordance with another embodiment of the present
invention.
[0015] FIGS. 4A-4C depict a schematic showing a composite dart as
it passes through a work string in accordance with an embodiment of
the present invention.
[0016] While embodiments of this disclosure have been depicted and
described and are defined by reference to example embodiments of
the disclosure, such references do not imply a limitation on the
disclosure, and no such limitation is to be inferred. The subject
matter disclosed is capable of considerable modification,
alteration, and equivalents in form and function, as will occur to
those skilled in the pertinent art and having the benefit of this
disclosure. The depicted and described embodiments of this
disclosure are examples only, and not exhaustive of the scope of
the disclosure.
DETAILED DESCRIPTION
[0017] Illustrative embodiments of the present invention are
described in detail herein. In the interest of clarity, not all
features of an actual implementation may be described in this
specification. It will of course be appreciated that in the
development of any such actual embodiment, numerous
implementation-specific decisions may be made to achieve the
specific implementation goals, which may vary from one
implementation to another. Moreover, it will be appreciated that
such a development effort might be complex and time-consuming, but
would nevertheless be a routine undertaking for those of ordinary
skill in the art having the benefit of the present disclosure.
[0018] The terms "couple" or "couples," as used herein are intended
to mean either an indirect or a direct connection. Thus, if a first
device couples to a second device, that connection may be through a
direct connection, or through an indirect electrical or mechanical
connection via other devices and connections. The term "upstream"
as used herein means along a flow path towards the source of the
flow, and the term "downstream" as used herein means along a flow
path away from the source of the flow. The term "uphole" as used
herein means along the drillstring or the hole from the distal end
towards the surface, and "downhole" as used herein means along the
drillstring or the hole from the surface towards the distal
end.
[0019] It will be understood that the term "oil well drilling
equipment" or "oil well drilling system" is not intended to limit
the use of the equipment and processes described with those terms
to drilling an oil well. The terms also encompass drilling natural
gas wells or hydrocarbon wells in general. Further, such wells can
be used for production, monitoring, or injection in relation to the
recovery of hydrocarbons or other materials from the subsurface.
This could also include geothermal wells intended to provide a
source of heat energy instead of hydrocarbons.
[0020] The present disclosure generally relates to subterranean
operations. More particularly, the present disclosure relates to
improved darts for use in subterranean wells.
[0021] Referring now to FIG. 1, a composite dart in accordance with
an exemplary embodiment of the present disclosure is denoted
generally with reference numeral 100. The composite dart 100
includes a foam portion 102 coupled to a rubber portion 104. At the
tip of the composite dart 100 is a dart nose 106.
[0022] Although the exemplary composite dart 100 of FIG. 1 includes
a foam portion 102 coupled to a first distal end of a rubber
portion 104 and a dart nose 106 coupled to a second distal end of
the rubber portion 104, the present disclosure is not limited to
this particular arrangement. Accordingly, in another embodiment
(not shown) the foam portion 102 may be positioned between the
rubber portion 104 and the dart nose 106 instead. Specifically, the
rubber portion 104 may be coupled to a first distal end of the foam
portion 102 with the dart nose 106 coupled to the second distal end
of the foam portion 102. Accordingly, the foam portion 102 may be
located downstream or upstream from the rubber portion 104.
[0023] The foam portion 102 and the rubber portion 104 may be
coupled to one another by any suitable means known to those of
ordinary skill in the art. For instance, the foam portion 102 and
the rubber portion 104 may be detachably or non-detachably coupled
to each other. Specifically, in certain embodiments the foam
portion 102 and the rubber portion 104 may be non-detachably
coupled to each other by welding them together. In other
embodiments, the foam portion 102 and the rubber portion 104 may be
detachably bolted to each other or may be coupled to each other by
fasteners such as, for example, screws. In yet another embodiment a
threaded engagement may be used to couple the foam portion 102 and
the rubber portion 104 in a detachable manner. In embodiments where
the foam portion 102 and the rubber portion 104 are detachably
coupled to one another, each component of the composite dart 100
may be replaced independent of the other. Accordingly, the
replacement costs associated with using the composite dart 100 may
be reduced because the operator may be able to only replace one of
the foam portion 102 and the rubber portion 104 without having to
dispose of the whole composite dart 100.
[0024] The foam portion 102 of the composite dart is not limited to
any specific shape or geometry. Specifically, in one embodiment,
the foam portion 102 may include a cylindrical portion and a
conical portion as shown in FIG. 1. However, the foam portion may
have any suitable geometry depending on the desired performance
characteristics and job requirements. For instance, the foam
portion 102 may be conical, cylindrical, elliptical, or a
combination thereof. Moreover, the foam portion may be made from
any suitable materials, including, but not limited to, a gel
material.
[0025] The foam portion 102 may be any foamable material, such as a
polymer, including, but not limited to, open-cell foams having
natural rubber, nitrile rubber, styrene butadine rubber,
polyurethane, or any other foamable material. Any open-cell foam
having a sufficient density, firmness, and resilience may be
suitable for the desired application, depending on the compression
and strength requirements of the given application.
[0026] In one embodiment, the rubber portion 104 may comprise of a
plurality of wiper cups. Although three wiper cups are shown in
FIG. 1, as would be appreciated by those of ordinary skill in the
art, with the benefit of this disclosure, the present disclosure is
not limited to any specific number of wiper cups. In fact, instead
of using wiper cups, the rubber portion 104 may be polyurethane. As
would be appreciated by those of ordinary skill in the art, with
the benefit of this disclosure, the rubber portion 104 may have any
suitable geometry depending on the desired performance
characteristics and job requirements. For instance, the rubber
portion 104 may be conical, cylindrical, elliptical, or a
combination thereof.
[0027] The rubber portion 104 may be made of any suitable material.
In one embodiment, the rubber portion 104 may be made of
hydrogenated nitrile or regular nitrile. In certain embodiments,
the materials used for making the foam portion 102 and the rubber
portion 104 may be selected to balance the ability of the
components to conform to restrictions in their path against their
ability to resist wear and tear.
[0028] The foam portion 102 and the rubber portion 104 of the
composite dart 100 may be sized to properly engage the inner wall
of the largest diameter casing through which the composite dart 100
will pass. For example, foam portion 102 may wipe clean the inner
wall of a drill pipe as composite dart 100 travels the length of
the drill pipe, which length may extend the entire length of the
well bore. The foam portion 102 may also readily compress to pass
through relatively small diameter restrictions without requiring
excessive differential pressure to push the composite dart 100 to a
desired location. For instance, the composite dart 100 may be used
to wipe clean the inner wall of a drill pipe having an inner
diameter that varies along its length. The foam portion 102 may
have a substantially cylindrical shape with a tapered leading edge
and/or trailing edge, or it may have a constant cross section.
Alternatively, foam portion 102 may be reticulated, may have one or
more ribs or fins or may have an otherwise varied cross section.
When ribs or fins are present, gaps created in foam portion 102 may
be at least partially filled with a different material, such as a
filtering material or a foam with a different hardness. Generally,
the outer diameter or other radial dimension of foam portion 102
and/or the rubber portion may exceed the corresponding dimension of
the dart nose 106.
[0029] The composite dart 100 may thus conform to varying inside
diameters and restrictions, allowing the use of specific tools
which require restrictive orifices. Additionally, the composite
dart 100 may adapt to more casing string sizes, resulting in fewer
specific assembly configurations.
[0030] Accordingly, the composite dart 100 disclosed herein allows
the foam portion 102 and the rubber portion 104 to operate in
tandem, with each compensating for the drawbacks of the other.
Specifically, the foam portion 102 may wipe the casing more
effectively than the rubber portion 104. For instance, the foam
portion 102 may be better suited for cleaning restrictions. At the
same time, because the foam portion 102 is coupled to the rubber
portion 104, there will be no early landing. Specifically, the
rubber portion 104 will engage the inner surface of the casing. As
a result, the composite dart 100 remains in position and will not
free fall through the casing even if the foam portion 102 has been
compressed and has not expanded to its original size.
[0031] As the composite dart 100 moves downhole through the casing,
it may effectively wipe and displace fluids in casings of different
diameters including large diameter work strings. The composite dart
100 may then compress radially as it passes through one or more
severe restrictions (such as internal upset tool joints), while
continuing to wipe and displace fluids. Once the composite dart 100
emerges from such restrictions, the rubber portion 104 prevents an
early landing of the composite dart 100 by engaging the casing,
pipe wall or well bore walls before the foam portion 102 expands to
its original shape.
[0032] In one embodiment, foam portion 102 may have at least two
different compositions. For example, as illustrated in FIGS. 2-3,
foam portion 102 may include a core of foam 50 that may be attached
to the dart nose 106 or the rubber portion 104 (shown in FIG.
1).
[0033] Core 50 may be surrounded by outer portion 60 of foam
portion 102. Core 50 may be formed such that portions of core 50
have a diameter approximately equal to the diameter of outer
portion 60, while other portions of core 50 have a smaller diameter
than the diameter of outer portion 60 (shown in FIG. 2).
Alternatively, core 50 may have a uniform diameter that is smaller
than the diameter of outer portion 60 (shown in FIG. 3). In this
embodiment, foam portion 102 may be sized to achieve adequate
cleanup and displacement in larger of casing and liner above a
severe restriction and core 50 may be sized to achieve adequate
cleanup and displacement in casing and liner below restriction 90
(shown in FIG. 4B). In certain exemplary embodiments, the core 50
may have a hardness of about 90 IFD and outer portion 60 may have a
hardness of about 50 IFD.
[0034] The composite dart 100 may have a dart nose 106 to sealingly
engage a plug. Dart nose 106 may have a diameter or other radial
dimension that is smaller than the corresponding diameter or radial
dimension of the foam portion 102 and the rubber portion 104. In
one embodiment, the dart nose 106 may be a separate component
coupled to a leading end of the rubber portion 104 as shown in FIG.
1. In another embodiment, the foam portion 102 may be placed
between the rubber portion 104 and the dart nose 106 with the dart
nose 106 coupled to the foam portion 102 instead. In certain
embodiments, the inner bore of dart nose 106 may be threaded to
engage the corresponding foam portion 102 or rubber portion 104 to
which it must attach, allowing the use of other shaped nose pieces
in accordance with the desired shape for the plug with which the
composite dart 100 will interact. For example, in one embodiment
the dart nose 106 may be tapered to facilitate entry of the
composite dart 100 into the plug.
[0035] The dart nose 106 may be constructed from any material
suitable for use in the subterranean environment in which composite
dart 100 may be placed. For example, dart nose 106 may be
constructed from a drillable material such as plastics, phenolics,
composite materials, high strength thermoplastics, aluminum, glass,
and/or brass.
[0036] Referring to FIGS. 4A-4C, the composite dart 100 may
progress down a casing string (FIG. 4A) while maintaining contact
with the casing string through various restrictions. As the
composite dart 100 is compressed radially (FIG. 4B) to pass through
the restriction 90, the foam portion 102 is easily compressed and
cleans the restriction 90. As the composite dart 100 exits the
restriction 90 (FIG. 4C), the rubber portion 104 which is not as
compressible as the foam portion 102 remains in contact with the
work string and prevents a free fall of the composite dart 100.
Specifically, although the foam portion 102 may be deformed upon
exiting the restriction 90 and may not be in contact with the walls
of the work string, the rubber portion 104 remains in contact with
the work string and holds the composite dart 100 in place.
[0037] The composite dart 100 may then be moved through the tubular
string until it reaches restriction 90. This movement may be caused
via pumping down the tubular string and/or differential pressure.
The composite dart 100 may be allowed to compress radially as it
moves through restriction 90, and allowed to expand to maintain
contact with the tubular string after passing through restriction
90. The composite dart 100 may continue through tubular string,
causing it to travel through the drill pipe until it contacts the
plug. Once the dart nose 106 has contacted its mating seat profile
within the plug, a differential pressure may be applied across the
sealing diameter of the dart nose 106 and its mating seat profile
so as to "activate" the plug, or cause the plug to be deployed so
as to carry out an intended function within the casing. For
example, a plug may be activated to cause it to detach from a work
string and travel through the casing in order to serve as a spacer
between different fluids that are desirably segregated.
[0038] Thus, the composite dart 100 may be capable of cleaning and
displacing fluids in a large-size casing string and/or liner,
passing through one or more severe restrictions, and cleaning and
displacing fluids in a smaller size pipe and/or tool before landing
on a seat. Although the present disclosure describes the operation
of the composite dart 100 in conjunction with a casing string, as
would be appreciated by those of ordinary skill in the art, with
the benefit of this disclosure, the composite dart 100 may also be
introduced into a drill pipe or other tubular strings within the
well bore at the surface.
[0039] Therefore, the present invention is well adapted to attain
the ends and advantages mentioned as well as those that are
inherent therein. The particular embodiments disclosed above are
illustrative only, as the present invention may be modified and
practiced in different but equivalent manners apparent to those
skilled in the art having the benefit of the teachings herein.
Furthermore, no limitations are intended to the details of
construction or design herein shown, other than as described in the
claims below. It is therefore evident that the particular
illustrative embodiments disclosed above may be altered or modified
and all such variations are considered within the scope and spirit
of the present invention. Also, the terms in the claims have their
plain, ordinary meaning unless otherwise explicitly and clearly
defined by the patentee.
* * * * *