U.S. patent application number 14/536308 was filed with the patent office on 2015-05-14 for fpso field development system for large riser count and high pressures for harsh environments.
The applicant listed for this patent is Seahorse Equipment Corp. Invention is credited to Jos Bronneberg, Kent Davies, Randy Jordan, Oriol Rijken.
Application Number | 20150129237 14/536308 |
Document ID | / |
Family ID | 53042713 |
Filed Date | 2015-05-14 |
United States Patent
Application |
20150129237 |
Kind Code |
A1 |
Rijken; Oriol ; et
al. |
May 14, 2015 |
FPSO Field Development System for Large Riser Count and High
Pressures for Harsh Environments
Abstract
In an offshore production system, a semisubmersible supports the
risers and provides the service requirements for the wells, while
an associated FPSO provides the processing functions and storage of
the produced hydrocarbons. As a result, a greater number of risers
can be supported in a harsh environment while the turret and swivel
requirements of the system are significantly reduced.
Inventors: |
Rijken; Oriol; (Houston,
TX) ; Jordan; Randy; (Houston, TX) ; Davies;
Kent; (San Diego, CA) ; Bronneberg; Jos;
(Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Seahorse Equipment Corp |
Houston |
TX |
US |
|
|
Family ID: |
53042713 |
Appl. No.: |
14/536308 |
Filed: |
November 7, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61901794 |
Nov 8, 2013 |
|
|
|
Current U.S.
Class: |
166/354 |
Current CPC
Class: |
B63B 27/34 20130101;
B63B 2035/4473 20130101; B63B 35/44 20130101; B63B 22/021 20130101;
B63B 2035/448 20130101 |
Class at
Publication: |
166/354 |
International
Class: |
B63B 35/44 20060101
B63B035/44; B63B 22/02 20060101 B63B022/02 |
Claims
1. An offshore oilfield development system comprising: a
semisubmersible having equipment for water and/or gas injection,
chemical injection, and manifolding; a plurality of subsea risers
in fluid connection with the equipment on the semisubmersible and
wellheads on the seafloor; and a submersible mooring buoy having
means for mooring an FPSO said means including means for fluid
transfer from the mooring buoy to an FPSO moored thereto; and at
least one fluid conduit connecting the mooring buoy to the subsea
risers via the semisubmersible.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/901,794 filed on Nov. 8, 2013.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to the offshore
production of oil and gas. More particularly, it relates to surface
vessels used to receive, process and store hydrocarbons from subsea
wells.
[0005] 2. Description of the Related Art Including Information
Disclosed Under 37 CFR 1.97 and 1.98
[0006] A Floating Production Storage and Offloading system ("FPSO")
is a floating facility installed above or close to an offshore oil
and/or gas field to receive, process, store and export
hydrocarbons.
[0007] It consists of a floater, which is either a newly built or
converted tanker, [permanently] moored on site. The cargo capacity
of the vessel is used as buffer storage for the oil produced. The
process facilities (topsides) and accommodation are installed on
the floater. The mooring configuration may be of the spread mooring
type or a single point mooring system, generally a turret.
[0008] The high pressure mixture of produced fluids is delivered to
the process facilities mounted on the deck of the tanker, where the
oil, gas and water are separated. The water is discharged overboard
after treatment to eliminate hydrocarbons. The stabilized crude oil
is stored in the cargo tanks and subsequently transferred into
shuttle tankers either via a buoy or by laying side by side or in
tandem to the FPSO. The gas is used for enhancing the liquid
production through gas lift, and for energy production onboard the
vessel. The remainder is compressed and transported by pipeline to
shore or re-injected into the reservoir.
[0009] A Steel Catenary Riser ("SCR") is a steel pipe hung in a
catenary configuration from a floating vessel in deep water to
transmit fluids to or from the seafloor. A Lazy Wave Steel Catenary
Riser ("LWSCR") is an SCR having an elevated intermediate portion
that acts to minimize motion of the SCR on the seafloor when the
floating vessel is subjected to heave.
BRIEF SUMMARY OF THE INVENTION
[0010] In an offshore production system according to the invention,
a semisubmersible supports the risers and provides the service
requirements for the wells, while an FPSO provides the processing
functions and storage of the produced hydrocarbons. As a result, a
greater number of risers can be supported in a harsh environment
while the turret and swivel requirements of the system are
significantly reduced.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0011] FIG. 1 is a side schematic view of one embodiment of the
present invention shown in operating conditions.
[0012] FIG. 2 is a side schematic view of the embodiment
illustrated in FIG. 1 during extreme metocean conditions.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention relates to a field development
methodology for offshore oil and gas fields in harsh environments
(e.g. hurricane/cyclonic) using FPSO technology.
[0014] A system according to the invention comprises a
semisubmersible, a disconnectable buoy, an FPSO and a bundle of
fluid transfer lines. The system is designed to be deployed in deep
water harsh environments where riser performance (either SCR or
LWSCR) is a key performance parameter. The power and pressure
requirements for gas and/or water injection are key drivers of
having those services on the semisubmersible rather than being,
supplied by an FPSO through a swivel, yoke or equivalent
system.
[0015] The semisubmersible is used to support the risers because of
its favorable motion characteristics under harsh conditions. The
semisubmersible also supports the water injection equipment, gas
injection, the High Integrity Protection System ("HIPS") and any
chemical injection equipment. The power for this equipment may be
generated on the semisubmersible. The produced hydrocarbons may be
manifolded into a fluid transfer line. The fluid transfer line may
have a predominantly-oil line, a predominantly-gas line and a
communications line. The pressure in the fluid transfer line is
much lower than that of the producing wells. The fluid transfer
line is connected to a moored submersible buoy. The submersible
buoy is connected to an FPSO via a bow-mounted turret. All
processing and storage is performed on the FPSO. The FPSO may
disconnect from the buoy if the environmental conditions become too
extreme. The buoy drops below the water surface to a depth with
reduced hydrodynamic loading. The rotational functionality is
provided by the bow-mounted turret. The swivel is mounted onto the
FPSO; no rotating parts are on/in the buoy.
[0016] In a production system according to the invention, the
semisubmersible supports the risers and provides the service
requirements for the wells, while the FPSO provides the processing
and storage of the produced hydrocarbons. As a result, a greater
number of risers can be supported in a harsh environment while the
turret and swivel requirements are significantly reduced.
[0017] A sample schematic of a system according to the invention
under operational conditions is shown in FIG. 1. FIG. 2 is a
schematic of the methodology under extreme conditions.
[0018] The invention is intended for use in harsh environments. The
methodology is highly applicable to locations where the harsh
environments are rare but intense (a benign methodology might work
except for those rare occasions). Such locations include many of
the hurricane/cyclonic areas of the world. Competing systems
include the FPSO or semisubmersible by itself, a disconnectable
buoy similar to White Rose or Stones or the MoorSpar.TM. mooring
buoy.
[0019] The advantages of a system according to the invention
include: [0020] Support for a large number of risers under harsh
conditions, including high pressure, sour service, and high H2S
content [0021] A HIPS that is located above the water line in a
serviceable environment [0022] A water injection system that is
located above the water line in a serviceable environment [0023] A
fluid transfer system between the semisubmersible and FPSO that is
"low pressure", and is comprised of only a few lines, thereby
simplifying the design and allowing for more motion. [0024] A
disconnectable buoy which supports only a few lines and doesn't
require any rotational parts. [0025] A swivel requiring only a few
flow paths and an electronic data path [0026] A bow-mounted turret,
reducing the construction and/or modification costs of the FPSO and
enhancing storage capacity. [0027] The entire system is comprised
of field-proven hardware [0028] Ability to start producing a field
before pipeline infrastructure
[0029] Potential disadvantages of such a system include: [0030]
Requirement for two vessels--an FPSO and a semisubmersible, with
associated mooring line infrastructure; and, [0031] Operation of
two vessels in proximity to each other.
[0032] Systems or methodologies that perform similar functions
include the FPSO, the semisubmersible, the disconnectable FPSO, the
MoorSpar.TM. mooring buoy and riser tower. Each system has its own
advantages and disadvantages. Most of these systems cannot meet at
least one of the following requirements: many risers, high
pressure, sour service, high H.sub.25 content, large quantities
and/or high pressure water injection, harsh environment, storage
& offloading.
[0033] The independent innovative aspects of the invention include
the following: [0034] A system comprising at least a
semi-submersible and FPSO wherein the processing of the
hydrocarbons is not done on the semisubmersible and the water
injection and/or gas injection is not done on the FPSO; [0035] A
system that supports deep-water risers in a harsh environment
without an initial pipeline infrastructure; [0036] A system that
supports deep-water risers that will have to withstand high
H.sub.25 level and/or high temperatures and/or sour service,
without an initial pipeline infrastructure; and, [0037] Use of one
or more disconnectable FPSOs in conjunction with a
semisubmersible.
[0038] Although particular embodiments of the present invention
have been shown and described, they are not intended to limit what
this patent covers. One skilled in the art will understand that
various changes and modifications may be made without departing
from the scope of the present invention as literally and
equivalently covered by the following claims.
* * * * *