U.S. patent application number 16/472580 was filed with the patent office on 2019-10-24 for a flow base system for subsea wells.
The applicant listed for this patent is Vetco Gray Scandinavia AS. Invention is credited to Mohammad Hasan ALI, Tor Alexander FJELDLY, Steinar Lindermann HESTETUN, Craig Wilson JOHNSTONE, Kare TOLO, Paul William WHITE.
Application Number | 20190323325 16/472580 |
Document ID | / |
Family ID | 60972212 |
Filed Date | 2019-10-24 |
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United States Patent
Application |
20190323325 |
Kind Code |
A1 |
HESTETUN; Steinar Lindermann ;
et al. |
October 24, 2019 |
A FLOW BASE SYSTEM FOR SUBSEA WELLS
Abstract
A flow base system (1) for subsea wells is disclosed, the flow
base system comprising a header pipe (2) for production fluid
extended through the flow base system, wherein from opposite sides
of the header pipe (3) a set of flow base modules (2),
respectively, is connected for supply of production fluid to the
header pipe (3) via individual branch pipes (10) connecting the
header pipe (3) with a Christmas tree (XT) interface (11) arranged
for vertical connection to an XT respectively. The flow base system
(1) is installed in a well template structure (18), wherein a flow
base module (2) respectively is inserted into each well slot
(S1-S4) formed in the well template structure (18).
Inventors: |
HESTETUN; Steinar Lindermann;
(Sandvika, NO) ; TOLO; Kare; (Sandvika, NO)
; JOHNSTONE; Craig Wilson; (Aberdeen, GB) ; WHITE;
Paul William; (Aberdeen, GB) ; ALI; Mohammad
Hasan; (Sandvika, NO) ; FJELDLY; Tor Alexander;
(Sandvika, NO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vetco Gray Scandinavia AS |
Sandvika |
|
NO |
|
|
Family ID: |
60972212 |
Appl. No.: |
16/472580 |
Filed: |
December 21, 2017 |
PCT Filed: |
December 21, 2017 |
PCT NO: |
PCT/EP2017/084213 |
371 Date: |
June 21, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 41/04 20130101;
E21B 41/08 20130101; E21B 43/017 20130101 |
International
Class: |
E21B 41/08 20060101
E21B041/08; E21B 43/017 20060101 E21B043/017; E21B 41/04 20060101
E21B041/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2016 |
NO |
20162048 |
Claims
1. A flow base system (1) for subsea wells comprising a template
structure (18) with a header pipe (3) and a number of flow base
structures (2), each flow base structure comprising a XT interface
(11) connectable to a XT and wellhead, a set of flow base
structures (2) being arranged on each side of the header pipe, each
flow base structure being connected to the header pipe (3) via
individual branch pipes, the flow base structures (2) being fixed
to the well template structure (18).
2. The flow base system of claim 1, wherein the piping of the flow
base system (1) is fixed to the template structure (18).
3. The flow base system of claim 1, wherein the piping of the flow
base system is partly fixed to the flow base structures (2).
4. The flow base system of claim 1, wherein the valves of the
system are removable.
5. The flow base system of claim 1, comprising two or more header
pipes.
6. The flow base system of claim 1, wherein the flow base modules
(2) are essentially identical and the flow base modules on one side
of the at least one header pipe (3) are turned 180.degree. in
relation to the orientation of the flow base modules on the other
side of the at least one header pipe.
7. The flow base system of claim 1, wherein each flow base module
(2) comprises a well insert (14) in fixed relation to guiding means
(15) arranged for guidance of an XT during landing and
installation.
8. The flow base system of claim 4, wherein the guiding means (15)
is realized as guide posts/pillars or as funnel-equipped tubes
rising from a flow base support (13), in which the branch pipes
(10) and valves as well as XT interfaces (11, 38) are
supported.
9. The flow base system of claim 1, wherein a singular isolation
valve (12) on each branch pipe (10) is controllable for opening the
branch pipe for flow of production fluid into the one or more
header pipes (3).
10. The flow base system of claim 1, wherein coupling means (7) is
arranged in an end (4) of one or more header pipes (3) for
connecting to external subsea equipment.
11. The flow base system of claim 10, wherein an isolation valve
(6) in said end (4) of the one or more header pipes (3) is
controllable for through flow of production fluid from external
equipment.
12. The flow base system of claim 1, wherein a valve control
interface (29) is installed for intervention by a remotely operated
vehicle (ROV) or diver.
13. The flow base system of claim 1, wherein a well intervention
system (35) is installed essentially in parallel with the
production fluid pipework.
14. The flow base system of claim 13, wherein the well intervention
system (35) comprises at least one header pipe (36) with branch
pipes (37) extended to each flow base module (2).
15. The flow base system of claim 13, wherein the fluid of the well
intervention system is supplied via an umbilical (32) to an
umbilical termination assembly (33) associated with the flow base
system.
16. The flow base system of claim 1, wherein a flow base module (2)
comprises an extension (16) for connecting to an external supply of
production fluid via a jumper pipe.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a flow base system for
subsea wells.
BACKGROUND AND PRIOR ART
[0002] The infrastructure of subsea hydrocarbon production fields
typically comprises rigid and flexible piping and manifolds to
collect production fluid from subsea wells. Subsea wells can be
grouped in template solution, or spread out as standalone satellite
wells regularly/irregularly distributed over the field. If wells
can be grouped closely together, templates can be used for
controlling the spacing between the wells. For the purpose of this
disclosure, subsea wells which are closely grouped and guided in a
template will be named template wells.
[0003] In general terms, a template is a structure which is placed
on the seabed to provide guidance and support for other equipment
such as drilling and completion equipment, wellheads, Christmas
trees (XT), manifolds and pipeline connection equipment.
[0004] A production well template is a welded structure that
supports manifold piping and valves for production fluid from wells
which are grouped together at a single seabed location. The number
of wells is limited by the size of the well template, which has an
individual section or slot for each well connected to the template.
Typical sizes include 2, 4, 6 and 8 slot configurations.
[0005] Template installation typically includes landing of a
prefabricated piping deck onto the template. The piping deck
typically includes the flowlines and valves necessary to conduct
production fluid from the template, as well as the hydraulic lines
required to operate the manifold and XT valves. Since maintenance
and repairs on deep water equipment requires implementation of
ROV-assisted structures, the piping deck, e.g., may be separately
retrievable in order to avoid dismantling of the entire production
system in case of damage to the piping components.
[0006] In shallow water installations, at water depths less than
200 m, diver-assisted intervention is possible and ROV-related
structures are not necessary. However, there is a need for
structures with fewer components to simplify intervention
procedures.
[0007] There is also a constant need for more compact
configurations on subsea structures. For shallow water
installations, the production structures may be situated in fishery
zones, with e.g. trawlers towing trawls on the seabed. To minimize
conflict between oil and gas industry and fishing industry, it is
an advantage to arrange oil production modules in compact
structures and minimize the footprint on the seabed. The presented
flow base system seeks to meet this challenge by arranging
production modules that are normally spread out on the seabed into
one compact structure.
[0008] In template structures there are also challenges related to
tolerances when a large number of different structures or modules
have to be fitted to each other and connected on the seabed. The
meet the tolerance requirements, large piping spools are used to
obtain sufficient flexibility in the piping structures in the
field. As more of the production modules are assembled in one
structure, the tolerance requirements are minimized due to a
decreased need for piping.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a
non-complex, low cost flow base system for subsea wells while also
permitting tying-in of standalone wells and clusters of wells of an
existing infrastructure.
[0010] It is another object of the present invention to provide a
flexible flow base system that will fit in most common subsea field
layout architectures.
[0011] Still other objects include the provision of a versatile
flow base system which permits implementation of, e.g., pigging
modules and well intervention systems.
[0012] One or more of these objects is met in a flow base system
for subsea wells, the system comprising a header pipe for
production fluid extended through the flow base system, wherein
from opposite sides of the header pipe a set of flow base modules,
respectively, is connected for supply of production fluid to the
header pipe via individual branch pipes connecting the header pipe
with a coupling interface arranged for vertical connection to a
Christmas tree (XT) respectively. The flow base system is installed
in a frame structure similar to a well template structure, such
that a flow base module respectively is inserted into the well
slots formed in the frame structure. This flow base system permits
protection of the flow base components under a common top cover for
the frame structure. This embodiment is also a compact and cost
saving solution which combines one singular protection structure
with a non-complex piping and instrumentation diagram
(P&ID).
[0013] In other words, a flow base system for subsea wells is
disclosed that comprises a template structure with a header pipe
and a number of flow base structures, each flow base structure
comprising a XT interface connectable to a XT and wellhead, a set
of flow base structures being arranged on each side of the header
pipe, each flow base structure being connected to the header pipe
via individual branch pipes, the flow base structures being fixed
to the well template structure.
[0014] Furthermore, in preferred embodiments, the piping of the
flow base system is fixed to the template structure. The piping of
the flow base system can also be partly fixed to the flow base
structures. However, it is advantageous to enable a small float in
the piping to allow for tolerance misalignment to be adjusted. To
enable service, maintenance or replacement of elements, all valves
of the system are removable.
[0015] In some embodiments the flow base system comprises two or
more header pipes.
[0016] The described use of flow base structures facilitates
extensive use of standard components in a streamlined building
process. This benefits to reduced time for installation and testing
and thereby cost savings. The described design also facilitates
upscaling or downscaling of the system.
[0017] In some embodiments, each flow base structure comprises a
well insert in fixed relation to guiding means arranged for
guidance of an XT during landing and installation.
[0018] In some embodiments, the guiding means is realized as guide
posts or pillars or as funnel-equipped tubes rising from a flow
base support, in which the branch pipes and valves as well as XT
interfaces are supported.
[0019] In some embodiments, a singular isolation valve on each
branch pipe is controllable for opening the branch pipe for flow of
production fluid into the at least one header pipe. The concept of
providing a single barrier results in simplified piping and control
of the flow base system.
[0020] In some embodiments, coupling means is arranged in one end
of the at least one header pipe for connecting to external subsea
equipment. The arrangement of coupling means at one end of the
header pipe or pipes, makes it possible to extend the subsea field
through the flow base system. This significantly improves the
flexibility in the layout of a subsea field using the described
flow base system. By connecting a further production line to the
flow base system, a production flow can flow through the flow base
system.
[0021] The coupling means can also be used for coupling of a pig
launcher/receiver to the flow base system.
[0022] In some embodiments, an isolation valve in the same end of
the header pipe is controllable for through flow of production
fluid from connected external equipment. As the flow base system
combines flow base structures with a template structure, the
flexibility with regard to where valves are places is improved.
[0023] The described use of coupling means provides the ability for
tying-in standalone satellite wells or interconnected (daisy-chain)
wells, and permits connection of another flow base system if
appropriate. The embodiment also provides the ability of connecting
a pig launcher or receiver in the said end of the header pipe.
[0024] In some embodiments, the flow base modules are essentially
identical and the flow base modules on one side of the header pipe
are turned 180.degree. in relation to the orientation of the flow
base modules on the other side of the header pipe.
[0025] In alternative configurations, the flow base modules on a
first side of the header pipe may be mirrored layouts of the flow
base modules on a second side of the header pipe. The first and
second sides of the header pipe can advantageously be opposite
sides of the header pipe. The advantage of standardization through
the repeated use of identical components can still be enjoyed.
[0026] Operational control is distributed within the flow base
system from an umbilical termination assembly (UTA) associated with
the flow base system. This embodiment avoids control tubing since
flying leads or cables can be used for distribution of hydraulic
fluid and/or electrical power. Thus, XT control within the flow
base system is distributed from the UTA via hydraulic and electric
flying leads/cables.
[0027] In some embodiments, a valve control interface is installed
for intervention by a remotely operated vehicle (ROV) or a diver.
This feature can provide redundancy in case other operational
control fails.
[0028] The XT control in the system can be distributed within the
flow base system from an umbilical termination assembly associated
with the flow base system.
[0029] Furthermore, the XT control can be distributed from the
umbilical termination assembly via hydraulic and/or electric flying
leads.
[0030] In some embodiments, a well intervention system is installed
essentially in parallel with the production fluid pipework. The
well intervention system comprises at least one header pipe with
branch pipes extended to each flow base structure respectively. The
fluid of the well intervention system can be supplied via an
umbilical to an umbilical termination assembly associated with the
flow base system. The umbilical termination assembly (UTA) can be
coupled directly to the XTs on each flow base structure.
[0031] The well intervention system allows for supply of gas for
enhanced lift of production fluid, or for supply of injection
chemicals to the well. The flow base module may thus each comprise
two vertical connection systems for the production fluid and for
gas lift/chemicals respectively.
[0032] Each flow base module of the flow base system comprises a
well insert in fixed relation to guiding means arranged for
guidance of an XT during landing and installation.
[0033] The guiding means can be realized as guide posts/pillars or
as funnel-equipped tubes rising from a flow base support, in which
the branch pipes and valves as well as the XT interfaces are
supported.
[0034] The flow base structure may comprise an extension for
connecting to an external supply of production fluid via a jumper
pipe. This configuration extends substantially the possibility of
tying-in external singular or daisy-chain wells in an existing
production field architecture.
SHORT DESCRIPTION OF THE DRAWINGS
[0035] Embodiments of the invention will be further explained below
with reference made to the drawings. In the drawings:
[0036] FIG. 1 is a schematic view illustrating the flow base
system.
[0037] FIG. 2 is a first perspective view of a subsea well template
in which the flow base system is integrated.
[0038] FIG. 3 is a second perspective view of the subsea well
template in which the flow base system is integrated,
[0039] FIG. 4 is a partially broken away perspective view
corresponding to FIG. 2, showing details of the flow base system
installed in the subsea well template.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] With reference made primarily to FIG. 1, a flow base system
1 comprises a set of flow base modules 2 arranged on opposite sides
of a header pipe 3 for production fluid. The header pipe 3 extends
through the flow base system from a first or upstream end 4 to a
second or downstream end 5 as seen in the direction of flow F
through the header pipe. The first end 4 is optionally connectable
to external equipment for transport via the header pipe 3. The
second end is the discharge end from which production fluid is
discharged downstream.
[0041] A header isolation valve 6 is arranged in the first end of
the header pipe, which also in the same end carries coupling means
7 for connecting to an external supplier of production fluid or to
other subsea equipment. These external units can be another flow
base system, a standalone satellite well or interconnected
daisy-chain wells, or a pigging launcher/receiver e.g. In the
discharge end 5, the header pipe carries coupling means 8, such as
a flange coupling e.g., arranged for connecting the flow base
system to a pipeline, a jumper pipe or to other downstream
equipment for fluid transport. The header pipe 3 further comprises
a number of pipe joints 9, especially T-couplings 9 through which
the flow base modules 2 are connected to the header pipe 3 at
mutually spaced locations along the header pipe.
[0042] Each flow base module 2 comprises a branch pipe 10
connecting the header pipe with an XT tree interface 11. An
isolation valve 12 on the branch pipe is controllable for opening
the branch pipe for flow of production fluid into the header
pipe.
[0043] The isolation valves 6 and 12 are on/off valves, and can be
realized as gate valves e.g.
[0044] The isolation valves 6, 12 are releasably connected to the
pipe joints or T-branches 9 and branch pipes 10. If necessary, the
isolation valves 6, 12 can be removed and replaced. The piping of
the flow base system and surrounding structures is permanent and
will not be removable. This is possible, since all valves are
retrievable.
[0045] The XT interface 11 is supported on a flow base support 13
which also carries a well insert 14 in fixed relation to an array
of guides 15, the guides 15 are arranged for guidance of an XT when
lowered to the flow base module during installation. The XT
interface 11 faces upwards for vertical or upright connection to
the XT. The XT itself is not part of the invention and is omitted
from the drawings for reasons of clarity.
[0046] In the shown embodiment, the flow base modules 2 on one side
of the header pipe 3 are turned horizontally through 180.degree. in
relation to the orientation of the flow base modules 2 on the other
side of the header pipe 3.
[0047] In one embodiment the flow base module is supplementary
equipped with an extension and on/off valve for tying-in an
external well and supplier of production fluid. In this embodiment
a satellite well can e.g. be connected directly to the XT interface
11, if appropriate.
[0048] With reference to FIGS. 2-4, the flow base system 1 is
integrated in a frame structure 18 arranged to be lowered for
connecting with a foundation (not shown) that is anchored in the
seabed. The frame structure 18 comprises two side-bays 19 and 20
interconnected through a mid-section 21.
[0049] Guide funnels 22 in the ends of the side-bays provide
guidance for mating with the foundation, particularly in case
piling is required for anchoring of the frame structure 18.
[0050] Each side bay 19, 20 is a rectangular structure composed of
longitudinal beams 23 and transverse beams 24. The beams 23 and 24
define the individual slots S1-S4, which are four in the shown
embodiment, and in which a flow base module 2, respectively, is
arranged to ensure that the well insert 14 is placed in register
with a corresponding well. In mounted position the branch pipes 10
reach into the mid-section for connecting with the header pipe 3,
which is suspended in the mid-section 21 to extend substantially
through the frame structure 18. Thus, with respect to design and
function, the frame structure 18 is essentially similar to a
production well template and can be referred to as such.
[0051] In this connection it should be pointed out that the modular
design of the flow base system permits implementation in templates
of other size than the one illustrated, such as 2-, 6- or even
8-slot templates, if appropriate.
[0052] The flow base system 1 is protected under a top cover 25
which is supported by a superstructure comprising horizontal or
lying beams 26 and vertical or upright struts 27. Over the bays 19
and 20, the top cover 25 comprises hatches 28 respectively which
are installed above each slot after installation of the XTs.
[0053] The flow base components in the mid-section 21 are covered
and protected below a portion of the top cover comprising a valve
control interface 29. The valve control interface 29 is supported
by a separate superstructure 30, this way building an integrated
part of the top cover 25. The valve control interface 29 comprises
handles and connections 31 for manual control of the valves of the
flow base system by means of an ROV or a diver.
[0054] In normal operation, XTs are monitored and controlled from
topside management via an umbilical 32 connecting to the XTs via an
umbilical termination assembly (UTA) 33. The UTA 33 distributes the
control of the XTs via hydraulic and electric flying
leads/cables.
[0055] The UTA 33 further distributes well intervention fluid via a
well intervention pipework 35. The well intervention pipework 35
comprises a header pipe 36 from which a branch pipe 37 respectively
extends to each flow base module 2 for termination in a second XT
interface 38, likewise arranged for connection to the XT. In the
shown embodiment, there is a vertical or upright connection to the
XT. Isolation valves 39 on the branch pipes 37 are controllable for
regulating the supply of well intervention fluid to the wells. The
well intervention pipework 35 can be used for supply of all kinds
of well intervention fluid as is commonly known in the art and used
in hydrocarbon production from subsea wells, such as gas for
enhanced lift of the production fluid, injection water, or chemical
products for wax and hydrate prevention, etc. An isolation valve 40
may be arranged in the downstream end of the header pipe 36 to
permit supply of injection water to the well intervention pipework
from external source, such as from a subsea water well, if
appropriate.
[0056] The flow base system as disclosed provides a compact,
cost-effective and fabrication friendly solution. The main features
of the flow base modules, i.e. the flow base support, XT interfaces
and pipework, permits the use of a standard satellite XT into a
template system. In other words, the same XT can be used both as
satellite and template XT. The system also permits connecting a
step-out well from a well slot in case that is required. The
tolerance loop between the manifold piping and XT is significantly
simplified by the present flow base system since the pipework can
be non-retrievable. Thus, no fabrication jigs or precision welding
will be required, all tolerances can be taken care of by machining
of a limited number of components in the XT flow base.
[0057] In shallow water applications, the present flow base system
uses diver replaceable valves instead of fully retrievable manifold
modules. Also, the pipework is simplified as all control tubing is
removed and replaced by hydraulic flying leads (HFL) and electric
flying leads (EFL) which are connected directly from UTA, or via a
subsea distribution unit (SDU) if appropriate. The overall
simplification results in reduced total weight, which in turn
permits using a smaller installation vessel.
* * * * *