U.S. patent application number 11/594550 was filed with the patent office on 2008-05-08 for systems and methods for underwater impressed current cathodic protection.
This patent application is currently assigned to Marine Project Management, Inc.. Invention is credited to Alan W. Bell, Steven M. Simpson.
Application Number | 20080105562 11/594550 |
Document ID | / |
Family ID | 39358819 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080105562 |
Kind Code |
A1 |
Simpson; Steven M. ; et
al. |
May 8, 2008 |
Systems and methods for underwater impressed current cathodic
protection
Abstract
An ICCPS system includes a waterproof transformer or transformer
rectifier adapted for underwater placement, an above-water source
of AC power, and one or more cables connecting the power source to
either a rectifier on the surface and underwater transformer or to
a underwater transformer rectifier to deliver high voltage/low
amperage DC power or high voltage/low amperage AC power from the
source for underwater conversion to low voltage/high amperage DC
power for delivery to on underwater anode.
Inventors: |
Simpson; Steven M.; (Ojai,
CA) ; Bell; Alan W.; (Ojai, CA) |
Correspondence
Address: |
RALPH D CHABOT
2310 E PONDEROSA DR, SUITE 4
CAMARILLO
CA
93010-4747
US
|
Assignee: |
Marine Project Management,
Inc.
|
Family ID: |
39358819 |
Appl. No.: |
11/594550 |
Filed: |
November 7, 2006 |
Current U.S.
Class: |
205/724 ;
204/196.36 |
Current CPC
Class: |
E02B 17/0026 20130101;
C23F 2213/31 20130101; C23F 13/06 20130101; C23F 13/02
20130101 |
Class at
Publication: |
205/724 ;
204/196.36 |
International
Class: |
C23F 13/02 20060101
C23F013/02 |
Claims
1. An ICCP system comprises one or more waterproof transformer
rectifiers adapted for underwater placement, an above water surface
source for AC power, and one or more AC power delivering cables
connecting the AC power source to said transformer rectifiers.
2. An ICCP method comprises delivering high voltage/low amperage AC
power from the above water portion of a facility mounted underwater
with a portion of the facility above the surface of the water, to a
waterproof transformer rectifier grounded underwater to the
facility, converting AC power to DC power in the waterproof
transformer rectifier, and delivering the DC power to an underwater
anode.
3. An ICCP system comprises one or more waterproof transformers
adapted for underwater placement, an above water source for high
voltage/low amperage DC power and one or more high voltage/low
amperage DC power carrying cables connecting said high voltage/low
amperage DC power to said transformers.
4. An ICCP method comprises delivering high voltage/low amperage DC
power from the above water portion of a facility that is mounted
underwater with a portion of the facility above the surface of the
water, to a waterproof transformer grounded underwater to the
facility, converting said high voltage/low amperage DC power to low
voltage/high amperage DC power, and delivering the low voltage/high
amperage DC power to an underwater anode.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to underwater impressed current
cathodic protection system systems and methods. More particularly,
it relates to placing components underwater which are now placed
above the water surface.
[0003] 2. Description of Related Art
[0004] Existing underwater impressed current cathodic protection
systems (ICCPS) utilize an above water transformer rectifier to
power the underwater anode(s). The transformer rectifier is
typically powered with facility high-voltage alternating current
(AC) which is converted to low voltage, high amperage direct
current (DC) at the transformer rectifier. One leg of the
transformer rectifier DC output is normally grounded to the
structure being protected via the ICCPS and the other leg is
connected to a power cable which is connected to the underwater
anode(s).
[0005] Because low voltage/high amperage is transmitted through the
power cable to the anode(s) the power cable diameter is large.
Further, the facility structure must be capable of handling the
power cable weight and accommodate the transformer rectifier weight
and footprint. The facility structure must also bear the weight of
an I-tube to protect the cable(s) through the splash zone of the
facility.
[0006] The topside engineering costs of the existing systems and
methods is high. The new methods and systems should eliminate a
majority of these costs by placing the transformer or transformer
rectifier underwater. They will also reduce the structural load to
the platform by moving the transformer or transformer rectifier
underwater. Additionally, the heavy low voltage/high amperage cable
can be replaced by a lighter high voltage/low amperage cable which
will also reduce the weight imposed on the facility. Because the
cable is smaller, the associated I-tube is also smaller, and
imposes less weight on the facility.
[0007] Placing the transformer or transformer rectifier underwater
also eliminates the need for specific gravity sleds for the anodes.
Instead, the anodes can be mounted directly onto the underwater
transformer or transformer rectifier encasement which will function
as the gravity sled for the anode.
[0008] Additionally, because the transformer or transformer
rectifier is located underwater, the effective output of the
transformer or transformer rectifier is greater, as current
requirements are reduced because of the shorter distance from the
transformer or transformer rectifier to the anode, and the
structure ground or grounded structure. Cooling constraints are
also reduced as the transformer or transformer rectifier uses water
as a heat sink rather than air.
SUMMARY OF THE INVENTION
[0009] According to the invention, an ICCP system for use with a
facility, such as an oil drilling or production platform, and
having a portion, e.g., a platform, above water, comprises one or
more waterproof transformers or transformer rectifiers adapted for
placement on or near the floor of the body of water, one or more AC
power cables for connecting these waterproof
transformers/transformer rectifiers to a generator or other high
voltage AC source above the surface of the water, a waterproof DC
ground for underwater connection between the waterproof
transformers or transformer rectifiers and the facility, and
optionally, an I-tube for the cables.
[0010] Alternatively, an ICCP system for use with such facilities
comprises one or more waterproof transformers or transformer
rectifiers adapted for placement on or near the floor of a body of
water, one or more high voltage/low amperage power cables for
connecting these waterproof transformers/transformer rectifiers to
a high voltage/low amperage DC current source. The high voltage/low
amperage DC current source may be the output from a rectifier that
converts AC power to high voltage/low amperage DC current.
[0011] The ICCP methods comprise connecting a source of high
voltage power, above the surface of the sea, e.g., on the platform
of a facility such as an oil drilling or production platform, to a
waterproof transformer or transformer rectifier placed below the
surface of the water, e.g., on or near the floor of the body of
water, delivering high voltage power on one or more power cables
from the power source to the waterproof transformer or transformer
rectifier, converting the high voltage/low amperage power to low
voltage/high amperage power in the transformer or transformer
rectifier, and delivering the high amperage power to an underwater
anode. Grounding of the underwater transformer or transformer
rectifier is made underwater to the facility.
[0012] Waterproof transformers and transformer/rectifiers may be
housed in oil filled containers. These containers are preferably
sealed from the environment and substantially watertight because of
the housing and oil within the housing.
[0013] The housing may be made of a waterproof material, e.g.,
fiberglass. The oil in the container acts as a coolant, and is
equalized to hydrostatic pressure when the container is placed in
deep water.
[0014] These systems and methods have several benefits: [0015]
Significantly reduces facility structural weight load and footprint
requirements for the ICCPS. [0016] Significantly reduces project
engineering costs and requirements. [0017] Significantly reduces
facility construction costs and requirements. [0018] Increases
effective output relative to water depth of the ICCPS. [0019]
Increases productivity and reduced operating risk.
BRIEF DESCRIPTION OF THE DRAWING
[0020] The methods and systems of this invention are illustrated in
the appended, exemplary drawing.
DETAILED DESCRIPTION OF THE DRAWING
[0021] In the drawing, generator 1 is placed on the platform 10 of
facility 9. Facility 9 is an oil drilling rig with a portion 11
located above the surface 8 of a body of water, e.g., sea 13, and a
portion 12 located below water surface 8. Atop platform 10 is
generator or other land-based high voltage AC source 1. Source 1 is
connected, through high voltage AC lines 2, to underwater
waterproof transformers or transformer rectifiers 6, which are
connected to underwater anodes 5 through anode power cables 7.
I-tube 2 protects AC lines 2 from environmental forces in the
splash zone around facility 9. DC ground 4 is connected to facility
9 underwater.
* * * * *