U.S. patent application number 13/687862 was filed with the patent office on 2014-05-29 for metalized polymer components for use in high temperature pumping applications.
This patent application is currently assigned to GE OIL & GAS ESP, INC.. The applicant listed for this patent is GE OIL & GAS ESP, INC.. Invention is credited to Steven Alan Howell, Brian Paul Reeves, Chengbao Wang.
Application Number | 20140147301 13/687862 |
Document ID | / |
Family ID | 49726892 |
Filed Date | 2014-05-29 |
United States Patent
Application |
20140147301 |
Kind Code |
A1 |
Reeves; Brian Paul ; et
al. |
May 29, 2014 |
METALIZED POLYMER COMPONENTS FOR USE IN HIGH TEMPERATURE PUMPING
APPLICATIONS
Abstract
A seal section for use in a downhole submersible pumping system
includes a housing and a seal bag located within the housing. The
seal bag includes a substrate having a plurality of substrate
surfaces and a metal coating layer on at least one of the plurality
of substrate surfaces. The substrate can optionally be configured
as a cylindrical form that includes an interior surface and an
exterior surface. In particularly preferred embodiments, the
substrate is seamless and fabricated from an extruded
fluoropolymer. The metal coating layer preferably comprises a metal
selected from the group consisting of titanium, stainless steel,
nickel, chrome, silver and gold. The metalized seal bag exhibits
increased durability and decreased permeability to liquids and
gases at elevated temperatures.
Inventors: |
Reeves; Brian Paul; (Edmond,
OK) ; Wang; Chengbao; (Oklahoma City, OK) ;
Howell; Steven Alan; (Oklahoma City, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GE OIL & GAS ESP, INC. |
Oklahoma City |
OK |
US |
|
|
Assignee: |
GE OIL & GAS ESP, INC.
Oklahoma City
OK
|
Family ID: |
49726892 |
Appl. No.: |
13/687862 |
Filed: |
November 28, 2012 |
Current U.S.
Class: |
417/313 ;
277/336; 277/500 |
Current CPC
Class: |
E21B 43/128 20130101;
F04B 47/06 20130101; F04B 39/00 20130101; F04B 53/16 20130101 |
Class at
Publication: |
417/313 ;
277/336; 277/500 |
International
Class: |
F04B 39/00 20060101
F04B039/00; E21B 43/12 20060101 E21B043/12 |
Claims
1. A seal section for use in a downhole submersible pumping system,
the seal section comprising: a housing; a shaft extending through
the housing; and a seal bag located within the housing, wherein the
seal bag comprises: a substrate having a plurality of substrate
surfaces; and a metal coating layer on at least one of the
plurality of substrate surfaces.
2. The seal section of claim 1, wherein the substrate is
substantially cylindrical and wherein the plurality of substrate
surfaces includes an interior surface and an exterior surface.
3. The seal section of claim 2, wherein the substrate is seamless
and fabricated from an extruded fluoropolymer.
4. The seal section of claim 3, wherein the metal coating layer
comprises a metal selected from the group consisting of titanium,
stainless steel, nickel, chrome, silver and gold.
5. The seal section of claim 3, wherein the metal coating layer
comprises at least two metals selected from the group consisting of
titanium, stainless steel, nickel, chrome, silver and gold.
6. The seal section of claim 3, wherein the metal coating layer is
deposited on the at least one of the plurality of substrate
surfaces using a method selected from the group consisting of
vacuum deposition and sputtering.
7. The seal section of claim 6, wherein the metal coating layer is
deposited on the at least one of the plurality of substrate
surfaces in a thickness ranging from about 1,000 angstroms to about
25,000 angstroms.
8. The seal section of claim 7, wherein the metal coating layer is
deposited on the at least one of the plurality of substrate
surfaces in a thickness of about 10,000 angstroms.
9. The seal section of claim 1, wherein the metal coating layer is
deposited on each of the plurality of substrate surfaces.
10. A seal section for use in a downhole submersible pumping
system, the seal section comprising: a housing; and a shaft
extending through the housing; a seal bag located within the
housing; and at least one o-ring seal, wherein the at least one
o-ring seal is manufactured from an elastomer, and wherein the at
least one o-ring seal comprises: an outer surface; and a metal
coating layer on the outer surface.
11. The seal section of claim 10, wherein the metal coating layer
comprises a metal selected from the group consisting of titanium,
stainless steel, nickel, chrome, silver and gold.
12. The seal section of claim 11, wherein the metal coating layer
comprises at least two metals selected from the group consisting of
titanium, stainless steel, nickel, chrome, silver and gold.
13. The seal section of claim 10, wherein the metal coating layer
is deposited on the at least one of the plurality of surfaces using
a method selected from the group consisting of vacuum deposition
and sputtering.
14. The seal section of claim 10, wherein the metal coating layer
is deposited on the at least one of the plurality of surfaces in a
thickness ranging from about 1,000 angstroms to about 25,000
angstroms.
15. A seal bag for use in a pumping system, the seal bag
comprising: a substrate having a plurality of substrate surfaces;
and a metal coating layer on at least one of the plurality of
substrate surfaces.
16. The seal bag of claim 15, wherein the substrate is
substantially cylindrical and wherein the plurality of substrate
surfaces includes an interior surface and an exterior surface.
17. The seal bag of claim 16, wherein the substrate is seamless and
fabricated from an extruded fluoropolymer.
18. The seal bag of claim 17, wherein the metal coating layer
comprises a metal selected from the group consisting of titanium,
stainless steel, nickel, chrome, silver and gold.
19. The seal bag of claim 17, wherein the metal coating layer
comprises at least two metals selected from the group consisting of
titanium, stainless steel, nickel, chrome, silver and gold.
20. The seal bag of claim 15, wherein the metal coating layer is
deposited on the at least one of the plurality of substrate
surfaces in a thickness ranging from about 1,000 angstroms to about
25,000 angstroms.
21. An o-ring seal comprising: a ring-shaped body manufactured from
an elastomer; an exterior surface on the ring-shaped body; and a
metal coating layer on the exterior surface.
22. The o-ring seal of claim 21, wherein the ring-shaped body is
fabricated from an extruded fluoropolymer.
23. The o-ring seal of claim 21, wherein the metal coating layer
comprises a metal selected from the group consisting of titanium,
stainless steel, nickel, chrome, silver and gold.
24. The o-ring seal of claim 21, wherein the metal coating layer is
deposited on the at least one of the plurality of substrate
surfaces in a thickness ranging from about 1,000 angstroms to about
25,000 angstroms.
25. A downhole pumping system comprising: a motor; a pump connected
to the motor; and one or more metalized polymer components selected
from the group consisting of seal bags, mechanical seal bellows,
o-ring seals and pothead connectors, wherein each of the one or
more metalized polymer components comprises: a substrate having a
plurality of substrate surfaces; and a metal coating layer on at
least one of the plurality of substrate surfaces.
26. The downhole pumping system of claim 25, wherein the metal
coating layer comprises a metal selected from the group consisting
of titanium, stainless steel, nickel, chrome, silver and gold.
27. The downhole pumping system of claim 26, wherein the metal
coating layer is deposited on the at least one of the plurality of
substrate surfaces in a thickness ranging from about 1,000
angstroms to about 25,000 angstroms.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to the field of submersible
pumping systems, and more particularly, but not by way of
limitation, to a seal section separation bag for use within a
submersible pumping system.
BACKGROUND
[0002] Submersible pumping systems are often deployed into wells to
recover petroleum fluids from subterranean reservoirs. Typically,
the submersible pumping system includes a number of components,
including one or more fluid filled electric motors coupled to one
or more high performance pumps. Each of the components and
sub-components in a submersible pumping system must be engineered
to withstand the inhospitable downhole environment, which includes
wide ranges of temperature, pressure and corrosive well fluids.
[0003] Components commonly referred to as "seal sections" protect
the electric motors and are typically positioned between the motor
and the pump. In this position, the seal section provides several
functions, including transmitting torque between the motor and
pump, restricting the flow of wellbore fluids into the motor,
protecting the motor from axial thrust imparted by the pump, and
accommodating the expansion and contraction of motor lubricant as
the motor moves through thermal cycles during operation. Many seal
sections employ seal bags to accommodate the volumetric changes and
movement of fluid in the seal section. Seal bags can also be
configured to provide a positive barrier between clean lubricant
and wellbore fluid.
[0004] As the use of downhole pumping systems extends to new
applications, traditional bladder systems may fail under
inhospitable downhole environments. For example, the use of
downhole pumping systems in combination with steam assisted gravity
drainage (SAGD) technology exposes bladder components to
temperatures in excess of 500.degree. F. To increase the resistance
of the bladder to degradation under these increasingly hostile
environments, manufacturers have employed durable polymers,
including various forms of polytetrafluoroethylene (PTFE), as the
preferred material of construction. More recently, manufacturers
have employed the use of perfluoroalkoxy (PFA) fluoropolymers. The
use of PFA as the material of construction in seal bags is
disclosed in U.S. Pat. No. 8,246,326 issued Aug. 21, 2012 and
assigned to GE Oil & Gas ESP, Inc.
[0005] Although PTFE and PFA provide suitable materials of
construction of many pumping applications, at extreme temperatures
and elevated pressure differentials, even these materials may
exhibit some permeability to liquids and gases. Of particular
concern is the potential for liquid water permeation through the
seal bags at extreme temperatures. There is, therefore, a need for
an improved seal bag, seal sections and submersible pumping systems
that overcome the deficiencies of the prior art. It is to this and
other needs that the present invention is directed.
SUMMARY OF THE INVENTION
[0006] In a preferred embodiment, the present invention provides a
seal section for use in a downhole submersible pumping system. The
seal section includes a housing and a seal bag located within the
housing. The seal bag comprises a substrate having a plurality of
substrate surfaces and a metal coating layer on at least one of the
plurality of substrate surfaces. The substrate can optionally be
configured as a cylindrical form that includes an interior surface
and an exterior surface. In particularly preferred embodiments, the
substrate is seamless and fabricated from an extruded
fluoropolymer. The metal coating layer preferably comprises a metal
selected from the group consisting of titanium, stainless steel,
nickel, chrome, silver and gold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an elevational view of a submersible pumping
system constructed in accordance with a presently preferred
embodiment.
[0008] FIG. 2 is a cross-sectional view of a first preferred
embodiment of a seal section for use with the submersible pumping
system of FIG. 1.
[0009] FIG. 3 is a perspective view of a first alternative version
of the seal bag of FIG. 2.
[0010] FIG. 4 is a perspective view of a second alternative version
of the seal bag of FIG. 2.
[0011] FIG. 5 is an exaggerated cross-sectional view of an o-ring
seal from the seal section of FIG. 2.
[0012] FIG. 6 is a cross-sectional view of a mechanical seal that
includes a metalized polymer bellows.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] In accordance with a preferred embodiment of the present
invention, FIG. 1 shows an elevational view of a pumping system 100
attached to production tubing 102. The pumping system 100 and
production tubing 102 are disposed in a wellbore 104, which is
drilled for the production of a fluid such as water or petroleum.
As used herein, the term "petroleum" refers broadly to all mineral
hydrocarbons, such as crude oil, gas and combinations of oil and
gas. The production tubing 102 connects the pumping system 100 to a
wellhead 106 located on the surface. Although the pumping system
100 is primarily designed to pump petroleum products, it will be
understood that the present invention can also be used to move
other fluids. It will also be understood that, although each of the
components of the pumping system are primarily disclosed in a
submersible application, some or all of these components can also
be used in surface pumping operations.
[0014] The pumping system 100 preferably includes some combination
of a pump assembly 108, a motor assembly 110 and a seal section
112. The motor assembly 110 is preferably an electrical motor that
receives power from a surface-mounted motor control unit (not
shown). When energized, the motor assembly 110 drives a shaft that
causes the pump assembly 108 to operate. The seal section 112
shields the motor assembly 110 from mechanical thrust produced by
the pump assembly 108 and provides for the expansion of motor
lubricants during operation. The seal section 112 also isolates the
motor assembly 110 from the wellbore fluids passing through the
pump assembly 108. Although only one of each component is shown, it
will be understood that more can be connected when appropriate. It
may be desirable to use tandem-motor combinations, multiple seal
sections, multiple pump assemblies or other downhole components not
shown in FIG. 1.
[0015] Referring now to FIG. 2, shown therein is a cross-sectional
view of the seal section 112. The seal section 112 includes a
housing 114, a shaft 116, a seal bag 118, a support tube 120 and
first and second bag plates 122a, 122b. The seal bag 118 is
configured to prevent the contamination of clean motor lubricants
with wellbore fluids. The shaft 116 transfers mechanical energy
from the motor assembly 110 to the pump assembly 108. The bag
support tube 120 provides support for the seal bag 118 and shields
the shaft 116 as its passes through the seal bag 118. For the
purposes of the instant disclosure, the terms "bag seal assembly"
will refer to the seal bag 118, the bag support tube 120 and the
first and second bag plates 122a, 122b. In addition to the bag seal
assembly, the seal section 112 may also include seal guides 124, a
plurality of ports 126 and one or more o-ring seals 128. The o-ring
seals 128 are located at various positions within the seal section
112 and limit the migration of contaminants and well fluids into
the clean lubricant.
[0016] For purposes of illustration, the bag seal assembly is
disclosed as contained within the seal section 112. It will be
understood, however, that the bag seal assembly could be installed
elsewhere in the pumping system 100. For example, it may be
desirable to integrate the bag seal assembly within the motor
assembly 110 or pump assembly 108.
[0017] Referring now also to FIGS. 3 and 4, shown therein is a side
perspective view of a preferred embodiment of the seal bag 118. The
seal bag 118 preferably includes a substrate 130, a first end 132
and a second end 134. In preferred embodiments, the substrate 130
is substantially configured as an elongated cylinder with an inner
surface 136 and an outer surface 138.
[0018] In preferred embodiments, the substrate 130 is fabricated
from an elastomer or other polymer, such as, for example PTFE, PFA,
or polyvinyl chloride (PVC). Unlike prior art bladders, the seal
bag 118 includes a metal coating layer 140 of chemically stable and
inert metal or metal alloy. Presently preferred metals include
titanium, stainless steel, nickel, chrome, silver and gold, and
alloys for each of these metals. It will be appreciated that the
metal coating layer 140 may be produced with combinations of
multiple metals and metal alloys. In alternate preferred
embodiments, the seal bag 118 is provided with a multilayered
coating that includes two or more metal coating layers 140. For
these multilayered embodiments, it will be appreciated that each
metal coating layer 140 may be prepared using different metals and
metal alloys.
[0019] The metal coating layer 140 is preferably applied to at
least one of the exterior surface 138 (FIG. 3) and the interior
surface 136 (FIG. 4) with a suitable metal deposition process.
Presently preferred metallization processes include vacuum
metallization and sputtering. Both deposition processes are
well-established in the art. In preferred embodiments, the metal
coating layer 140 has a thickness between about 1,000 and about
25,000 angstroms. In a particularly preferred embodiment, the
thickness of the metal coating layer 140 is about 10,000 angstroms.
The metalized seal bags 118 of the preferred embodiments
significantly decrease the liquid and gas permeability through the
underlying substrate 130.
[0020] Alternatively, the metal coating layer 140 is provided as a
foil laminate over the substrate 130. In this alternate embodiment,
the foil metal coating layer 140 may be adhered to the substrate
with adhesives, mechanical fasteners or chemical bonding.
[0021] In a particularly preferred embodiment, the substrate 130 is
manufactured from PFA and includes a titanium or titanium alloy
metal coating layer 140 on the exterior surface 138 that is
approximately 10,000 angstroms thick. PFA is commercially available
from a number of sources, including E.I. du Pont de Nemours and
Company and Daikin Industries. Like PTFE, PFA exhibits favorable
resistance to corrosive chemicals and elevated temperatures. Unlike
PTFE, however, PFA is melt-processable using conventional injection
molding and screw extrusion mechanisms. The ability to extrude or
mold PFA permits the construction of a seamless, unitary substrate
130. Furthermore, seal bags 118 manufactured using PFA experience
less stretching during the expansion and contraction cycle than
comparable PTFE-based bags. These characteristics favor PFA as a
substrate for metallization because it is easier to achieve a more
uniform coating along the seamless bag, and metal coating layer 140
is less likely to separate, crack, flake or peel from the substrate
due to stretching and contraction.
[0022] Turning now to FIG. 5, shown therein is a close-up,
cross-sectional view of one of the o-ring seals 128. The o-ring
seal 128 includes a ring-shaped body 146 that is preferably
manufactured from a durable elastomer, synthetic rubber or
fluoropolymer that exhibits favorable wear and permeability
characteristics. Suitable elastomers include fluoropolymer
elastomers and perfluoropolymer elastomers sold under the Kalrez
and Chemraz brands by Greene, Tweed & Co. and the Perlast brand
compound sold by Precision Polymer Engineering Ltd. Although the
o-ring seal 128 is depicted as having a circular cross-section, it
will be appreciated that the o-ring seal 128 may have a different
cross-section shape, such as, for example, rectangular, triangular,
octagonal or oval.
[0023] The o-ring seal 128 includes an exterior surface 142 and a
metal coating layer 144 on the exterior surface 142. The metal
coating layer 144 is preferably prepared under the same techniques,
using the same materials described above with reference to the
metal coating layer 140 of the seal bag 118. The metal coating
layer 144 increases the durability and lowers the permeability of
the o-ring seal 128. The use of metalized o-ring seals 128
significantly decreases permeation of liquids and gasses across the
o-ring seal 128 at elevated temperatures.
[0024] Although the o-ring seals 128 have been described with
reference to the seal section 112 and shaft 116, it will be
understood that the o-ring seals 128 will also find utility in
other applications. For example, the o-ring seals 128 can be used
in other downhole and surface pumping components that include, for
example, pothead connectors, motor assemblies, pump assemblies,
sensor arrays, and logging tools.
[0025] It will be further understood that the novel use of
metalized polymers will find application in other downhole
components, including, for example, mechanical seal bellows and
pothead connectors. By way of illustration, an alternative
embodiment includes the use of a metalized bellows 150 within a
mechanical seal 152. Turning now to FIG. 5, shown therein is a
cross-sectional view of a mechanical seal 152 constructed in
accordance with a preferred embodiment. The mechanical seal 152
includes a rotating assembly 154 secured to a shaft 156 and a
stationary face 158 that remains fixed relative to the shaft 156.
The rotating assembly 154 is spring-loaded and configured to
axially expand and contract to stay in contact with the stationary
face 158 in the event the shaft 156 is axially displaced.
[0026] The bellows 148 is preferably constructed from a polymer
substrate 160 and a metalized coating 162. In preferred
embodiments, the polymer substrate 160 is fabricated from a
polymer, such as, for example PTFE, PFA, or polyvinyl chloride
(PVC). The metalized coating 162 is preferably made by deposition,
sputtering, spraying or through use of foil lamination. Preferred
metals include titanium, stainless steel, nickel, chrome, silver
and gold, and alloys for each of these metals. It will be
appreciated that the metalized coating 162 may be produced with
combinations of multiple metals and metal alloys. In alternate
preferred embodiments, the bellows 148 is provided with a
multilayered coating that includes two or more metalized coating
162. For these multilayered embodiments, it will be appreciated
that each metalized coating 162 may be prepared using different
metals and metal alloys. With the metalized coating 162, the
bellows 148 is capable of withstanding higher temperatures and is
less likely to rupture during explosive decompression.
[0027] It is to be understood that even though numerous
characteristics and advantages of various embodiments of the
present invention have been set forth in the foregoing description,
together with details of the structure and functions of various
embodiments of the invention, this disclosure is illustrative only,
and changes may be made in detail, especially in matters of
structure and arrangement of parts within the principles of the
present invention to the full extent indicated by the broad general
meaning of the terms in which the appended claims are expressed. It
will be appreciated by those skilled in the art that the teachings
of the present invention can be applied to other systems without
departing from the scope and spirit of the present invention.
* * * * *