View
225
Download
0
Category
Preview:
Citation preview
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
1/10
EUR
7
THE DESIGN
ND INST LL TION OF THE UCH N
FIELD
SU SE EQUIPMENT
by
D.B.L.
Walker
P Trading
Limited
EUROPE n
OFFSHORE
PETROLEUM
conFEREnCE
EHHI ITIOn
©
Copyright 198 European Offshore Petroleum Conference and Exhibition
This paper was presented at the European Offshore Petroleum Conference
and
Exhibition held In London England October21·24 1980 The material Is subject tocorrection by the author
Permission to copy isrestricted to
an
abstract
not more than 300 words
ABSTRACT
This paper cover s
th e d es ign and
installation of
the Buohan Field subsea equipment
inoluding:
template, trees and completions, wireline
r iser
and BOP staok, subsea manifold, flowlines and
umbilioals, produotion
riser
and oontrol system.
A brief desoription
of th e
rig modifioat ions to
enable
i t
to
handle
t he produot ion
riser is also
inoluded.
INTRODUCTION
The
Buohan Field l ies in
b look 21/1 of
the
North
Sea, 160 km
eas t-north-east of
Aberdeen.
The
water
depth is between 112 and 118 m and environmental
oonditions
are similar
to those exper ienoed
in
the
Forties
Field whioh l ies
55 km further to
the
east.
With estimated
reooverable
reserves of
only
50 million bar re ls o f
oil ,
however, Buohan is a
twentieth
of
the
size of i ts
giant
neighbour.
An eoonomio evaluation indioated
that
the
Field
was too sma ll to be
exploited
along oonvent ional
l ines,
suoh
as
a
fixed
platform
tied in to
the
Forties
pipeline.
The development had
to
be on a
relatively
short
time
soale requ iring
low
oapital
investment.
The reader
is
d ireo ted to Referenoe 1
fo r a review of
the
alternative
sohemes oonsidered
by
th e Company.
Field
development is based on
produotion
from
subsea wells
to
a oentral underwater
manifold.
A semi-submersible drilling
rig,
oonverted to
oarry produotion
equipment, is
permanently
anohored ove r t he manifo ld to whioh i t
oonneots
by
a produotion
riser.
Multiple
lines in
the
riser bundle
oarry the
oil
up to
the rig for
prooessing and baok
down
to the
seabed fo r
export.
A pipeline t ies th e manifold into a C LM tanker
loading buoy.
When
bad weather
fo ro es th e
tanker
to
stop
loading,
produotion
oeases. f oonditions
oontinue
to
worsen,
then
th e
produotion
ris er is
designed to be reoovered and staoked on
board
th e
rig until
the
weather improves.
275
With this basio oonoept, BP farmed
into
the
Buohan
Field in July 1977 and with a 54 interest beoame
th e
operator.
Plans were
developed fo r
a peak
produotion
from 8
subsea
wells of 72,000
bbls
pe r
day
with
an expeo ted f ield
l i fe of
5 years. Based
on a oomputer simulation
of
f ield operation, i t was
estimated that produotion oould be maintained for
65
of
the yea r, g iv in g an average annual
produotion
rate of 48,000
bbls per day. The
rig
has 3 ,500
bbls
of
storage
whioh
improves
th e
system
performanoe.
With a
gas/oil
ratio
of 56
310
sof/bbl
exoess
gas
will
be flared
on
th e
r ig.
Provision has
been
made
to introduoe a gas l i f t
system
to boost
produotion
as reservoir
pressure
deolines.
Figure 1 i l lustrates th e Buohan
Field.
Five
of
th e
wel ls a re o lu st er ed t og et he r direotly under th e
rig to faoil i tate workover s ee F igure 2 . Two
s te l l i te wells
l ie
1. 7 km to
the south
and
provision
has
been made
fo r
a
third.
Preliminary
field development
plans were based on
an
18 month rig oonversion programme November
1977
to
May
1979 and a
oonourrent
19 month
drilling and
well oompletion
pha se . F lowline
construotion was soheduled for summer 1979
with
produotion
star ting in th e autumn of that
year.
THE SUBSEA TEMPLATE
To
meet
t hi s t ar ge t i t
was
obviously essential
to
build and insta l l
the dr i l l ing template
for
the
cluster
of
subsea wells as rapidly as possible
during
the
summer
of
1977, to
enable produot ion
dr i l l ing to
prooeed
over
th e following
months.
References and
i l lustrat ions
at end of paper.
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
2/10
The
template therefore had to be simple and
easily
fabricated. Since
th e
layout of
th e
wells had no t
been d ec ide d, t he t em pl at e had to provide a number
of d r il li n g s lo t s with th e facili ty to
support
th e
flowlines.
An 8 s l o t t em pl at e w it h a 5. 2 m spacing between
well
centres
was chosen as shown in Figure
3.
With
th e
underwater manifold occupying one
slo t, . th ere
was p ro vi si on f or 5 template wells with 2 spare
slots in case drilling was abandoned on any
location. The template rested on th e seabed on
aO.65 mwide
s k i r t
round t he base Of each
1.22 m diameter conductor
guide.
The
structure
was held in place by four 12 inch 300 mm
pi n
piles. Provision was made to jack t he t em pl at e
up on i ts
piles to
maintain i t level
in
t he e ve nt
of
a sloping or uneven seabed.
The
90
tonne template was taken ou t
to
th e field
on
a
flat
top barge and
lif ted
into
th e
water
by
a
crawler
crane
on
th e deck
of
a large supply
vessel. t was winched down to
th e
seabed where
divers confirms i ts orientation and position,
some 7 m from an existing exploration
well, later
to be tied in as a
producer.
The
piles
were
driven
using a small underwater v i b r o ~ h m m e r
No
levelling
was reqUired and
th e
template was
secured to th e piles by th e inflation of
annular
packers. Installation
time
was
4 days.
Design, fabrication and
installation
of th e
template took a to tal 01 4 months. SUbsequent
d rill in g and construction work has
validated
th e
basically
simple concept and i f
th e structure
were redesigned today, very few modifications
would be
introduced.
COMPLETIONS ND
TREES
Immediately following template installation in
August 1977, drilling commenced·on th e 4 template
wells. This extended
over the next 14
months,
which also
included
th e
setting of 90
m of 30
inch (760 mm conductor to
ac t
as a foundat ion
for the underwater manifold.
The
wells were
temporarily
suspended pending delivery
of
th e
subsea trees.
Simultaneously two satell i te wells were drilled
by a second r ig during 4 months in th e summer
of 1978. By mOdifying th e original programme
of
5
template
w el ls p lu s
one
southern
s a t e l l i t e
to
become
4 template plus
two
satellites (one
of which
was drilled
back
into
th e central
formation) th e d rill in g schedule was maintained.
The layout of t he t em pl at e
wells,
manifold and
th e off-template well is
shown
in
Figure
2.
C on tr ac ts f or
th e
trees, hangers and
associated
downhole equipment were placed in February 1978
and f irs t
deliveries
were made to
th e
rig in
December of
th e same
year. With a
closed in
wellhead pressure close to 5,000 ps i
34 MPa ,
10,000 psi (68 MPa rated equipment was specified.
The completion had to
provide
fo r
th e
introduction
of
gas l i f t a t some future date by wireline
intervention only and had to be capable of being
used
in
both
perforated
i.e.
previously
tested)
276
and unperforated wells. A nominal 4 x 2 inch
(100
mm
x 50 mm dual completion was
specified
with each string carrying a
su rf a ce c o nt r ol l ed
down-
hole
safety
valve In the case of
th e
4
production
string, this
is
a
tubing
retrievable
valve, with the facili ty in case o f f ai lu re to
be permanently locked ou t and replaced by a
wireline
retrievable unit. For the operation
of
th e
gas l i f t
t he t ub ing string
has been provided
wi th side pocket mandrels
into
which gas
l i f t
valves can be
introduced
by wireline. In
th e
case of satell i te w el ls , t he se gas l i f t valves
ar e already in place. This, i t is hoped, will
avoid th e need to bring in a workover rig to
install them d ur in g t he commissioning of th e gas
l i f t system.
Two types
of
subsea dual tUbing hangers were used.
A hydraulically se t hanger was used on the converted
production well, p ro vi di ng t he
facilities fo r
hanger
setting
and simUltaneous
wireline
access
to both bores with one
multi-purpose
hydraulic
setting tool. The hangers used on
th e
other wells
relied on
being mechanically set with
d r i l l
pipe,
using a second purpose-built aCCess
tool
fo r
wire-
line and testing purposes.
Dual bore split trees were used, shown schematically
in Fi gu re 4. Each tree weighs 52 tonnes and was
installed
as a single
unit. The
lower
tree contains
a dual manual master
v al ve b lo ck ;
th e upper
carries
a six valve block - 2
master,
2 wing, and 2 swab
all hydraulically operated and fit ted with
e x te r na l p o si t io n
indicators. A by-pass loop
carrying
a further 3 valves i s mounted on th e
lower tree and provides
th e
link between
th e
dual
4
inch
flowlines
back
to the
manifold
and the
upper
tree.
Prior
to introducing gas l i f t t he by- pas s val ve
can be
lef t
open to all ow b ot h flOWlines to carry
o il and
to
p er mi t p ig gi ng to remove wax
deposits.
In
th e
event
of major equipment failure, th e upper
tree
can be recovered leaVing th e lower half in
place.
This would r eq u ir e d iv er
intervention
to
break th e connector, flow loop flanges and.
control
circu its.
As each tree became available, th e wells were
re-entered, th e completions run and t he w el ls
perforated, using
one
.rig
a t
th e
template
location
and one
over
th e
satell i te
wells.
Total
time
spent on t he se o p er a ti on s fo r
th e
4 template and
1
off-template
wells amounted to 9 months and 3
months
fo r
th e
two
satell i te
wells.
WIRELINE
BOP ST CK
Following t he r un ni ng of th e
tree, a ll
further
wireline
work
was
conducted through a custom
b u ilt
wireline BOP
stack
mounted above
th e
tree.
This
carries
both a set o f b li nd rams, designed
to seal with or without a
wireline
in p la ce , and
a set of shear rams.
By altering
th e
position
of
a spool beneath th e rams, i t can be run
to
provide
wire line access
to
e it he r s tr in g .
The stack
is
used with
th e
dual 4 x 2 inch wireline riser and
is
operated
from a
se lf - co n ta i ne d se rv i ce control
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
3/10
system, designed to be moved with i t from one
rig
to
another.
During normal operations the tree and
down
hole
safety valves ar e
controlled
from the production
platform
through a
10 line
hydraulic umbilical.
For reasons
of
safety, however,
i t is desirable
during
a workover
to control
both
OP
stack
and tree from a
single control
panel
on the
workover
rig.
This
is achieved
by
routing the
incoming
10
line
tree
umbilical through a control
stab on the high pressure cap which seals off
the
top
of
the tree.
When the
cap is removed
to
permit t he
OP to
be run,
the circuit is
broken and a
stab
on the
OP stack
takes
the
place of
the one
on th e
cap.
The
stack functions
and tree valves ar e then controlled from a
single panel via twin 28 line
umbil ical s to
the
service control
unit on
the
workover rig.
THE SUBSEA M NIFOLD
The biggest
piece
of
subsea equipment
in
the
Field
is
the
underwater manifold which weighs
110
tonnes
See
Figure
5 . This assembly of valves and
connectors is
mounted on
the template directly
under the platform. The valves and pipework
ar e
mounted between
two
horizontal frames, th e upper
being supported 5 m above the lower
by
4
corner
posts
and a
central 30
inch column.
Passing vertically through the manifold
ar e
a
12
inch line to
carry the exported crude,
eight
4 inch production and
eight
2 inch lines
fo r
gas l i f t
11
female
riser connectors ar e
mounted
face up on
the
top frame
to
receive
the production
riser
and
projecting
below the lower frame ar e 17
stabs
and two connectors.
The
main centrally mounted
inch wellhead connector connects
on
to a
dummy
wellhead and
is the principal
means
of
securing the manifold to the
seabed.
The connector
is welded to the 30 inch column which runs
up
through the middle
of
the manifold and transmits
the
riser loads
imposed on
the
top frame down
to
the
foundation.
The second connector
is
mounted
on the 12
inch export
line.
A third horizontal frame
of
similar dimensions
and
known
as the manifold base, is mounted on the
30 inch
conductor below th e manifold i t sel f . Apart
from a
12
inch manually
operated
valve
in the
export line, there ar e no
other
valves on t he base;
i t
merely s erv es t o support the short spools
of
pipe
linking the
template
pipework
to
the female
receptacles which
receive the
manifold stabs.
By using this means i t was possible to insta l l
the manifold base
in
advance of the manifold and
to
make
up
and
install the
flanged pipework spools
between i t and
the
trees.
The
base
is
no t
designed to
be recovered
to the
surface. Components in the manifold can be
recovered fo r maintenance and in t he event of
major problems, the ent ire s tructure can be
lif ted into
th e moonpool
of
the
production platform.
As
in
the
case
of
the
trees,
this
would
require
diver intervention.
To understand
the
uses
of
the manifold i t should
be
considered in
the
l ight of the
19
separate risers
which
make up the riser
bundle see Table
1 .
By
opening
or c losing
valves
in the
manifold i t
provides the
means
to:-
a Shut in
the
flow subsea when
the risers
ar e
disconnected.
b Manifold th e
production or
gas
l i f t
flows
subsea
in the event that some of the risers
ar e not run.
c Cross connect the
service
risers
to the
crude carrying
risers to
allow flushing
with water
prior to
disconnect.
d Provide the
return
path fo r pigging the
flowlines
via the high pressure service
r iser .
e
Provide
a
link
between
the
high
pressure
r iser and the
flowlines
to create a f lowpath
fo r well
killing.
This
is
an
alternative
route
to
the normal means of
killing
a
well
through
the wireline riser.
t should be noted
that
the manifold contains
no
subsea chokes.
INSTALLATION ND HOOK UP
The manifold
base
was installed in June 1979. Prior
to
that
the
divers had jetted
out the
drill ing spoil
and installed pipe supports
on
th e template
fo r the
pipe spools which would run between the trees and
the
base. The operation was
conducted from a
semi
submersible
diving vesse l
anchored
over
the template.
Spools of pipe were fa:bricated on the deck
of
the rig
to
measurements taken. by
the
divers
using
special
j igs.
The
spools were then lowered
on
winches
over
the side to
th e seabed.
Hydraulic
bolt tensioners
were used fo r making
up
the f langed and clamped
connections
subsea. 25 m spool p ieces were laid
on the seabed at
the
edge of the template to act as
expansion
loops fo r the
incoming flowlines from th e
sate l l i te wells.
A combination of good weather and
careful
planning
by the contractors, SUb
Sea International, and th e
BP
construction
team
r esul te d i n
an exceptionally
successful
diving
operation.
This
included 22
spoolpieces
being
measured up,
fabricated, installed
and pressure tes ted in 45
days,
during which t ime
the average time in
the
water was 22 hours pe r day.
FLOWLINES
ND UMBILICALS
The second major construction job in the Field during
the 1979 summer was
the
laying and connecting
of
the
pipelines
and
the
umbilicals. Each of
the two
southern satell i te wellS had
to
be tied
in
back
to
the
manifold
by
twin 4
inch flowlines
and a
control
umbilical,
and
the 12 inch export line
had
to
be
laid to the loading buoy.
Originally
i t had been
intended
to
lay a ll the lines from the new Santa Fe
reel ship, Apache,
bu t
due
to
delays
in
he r
construction
programme, the
12
inch line
was laid
f irs t
from
the
semi-SUbmersible, Choctaw 2,
with the
Apache arriving la ter in the
Field
to la y the
flowlines
and
umbilicals.
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
4/10
The
4 inch
flowlines
were epoxy powder coated and
welded up
into 300m strings at
the
Santa Fe
base
at Leith.
Tests earlier
in the year had demonstrated
the ability
of the coating to
survive the
reeling
and unreeling process. th e
pipe
was welded up into
a
continuous
7 500 m
le ng th as
t
was
spooled
on
to
the 25 m diameter drum vertically mounted midships
on Apache.
During
the reeling process
a
supply boat was
installing dead
man
anchors
in
the
v ic in it y o f the
satelli te wells to prepare for the initiation
of
pipelaying. A submersible was
also
present during
the laying
operation
to assist in surveying the
l ine.
A pull- in technique developed by BP
was
used to
connect
the flowlines to the satel l i te trees.
After
the lines were laid, the ends of
the
flowlines
were held
off
the seabed
by
buoyancy
tanks
and
drag
chains
and were p Ul le d
in to
the lower trees
by
a
hydraulic
winch clamped
to
the
30
inch
conductor. Di ve rs t he n installed the short make-up
spool
to
complete the connection. At the template
end th e
pre-installed spoolpieces
served as
the
target
fo r the lay down operation and using
manipulator frames th e f langes
on
the spoolpieces
and pipeline were
brought
into
alignment. The
laying rate reached 440
m
pe r hour
including
the
ti me t ak en
to
t an anode
every
70
m The
best
total time
recorded
fOr initiating from the
dead
man anchor,
laying
1.7 kmof
flowline and
laying down·the
line at the template
recovering
and.adjusting
to length
required) was 14 hours.
The two control umbilicals were laid simultaneously
from reels on the stern of the Apache. Each
umbilical consists
of
ten inch
6
mm
hydraulic
hoses packed round a central 1s
inch 29
mm
steel
cable which provides
both strength
and weight.
Adequate tension was no t maintained, however during
the
abandonment of
the
two ends at the template and
entanglement
resulted.
This was picked by
the
submersible
s ur ve y and subsequently straightened
out by divers.
MANIFOLD
INSTALLATION
Only
the
manifold remained to be installed during
September. 1979 after Apache had
cleared the Field.
The
semi-submersible
rig Dundee Kingsnorth was
brought in
to
the shelter of Largo
Bay
in th e Firth
of Forth
where
the
flat
t op barge
carrying
the
manifold
was
manoeuvred between
her
twin
hulls.
Using the draw works and a string of dri l l pipe,
the
manifold was
l i fted up
into
the moonpool where
i t was secured during
the
tow
to the
Field.
After
a long wait
on
w ea th er a nd
delays
caused
by
last
minute equipment problems the
actual running of
the
manifold
was completed
in
6 hours. Extreme
care was
required
during
the
landing of
the
manifold
on
the base
to
avoid damage to the
stabs
and
connector s. A ll
went well except for the connector
on th e
export
line which would not c lo se and
has
sUbsequently had to be
replaced.
Although
in
theory
the repair could have been
carried
ou t by
recovering the
manifold
to
the
surface, in practice
subsea
replacement
of
components
is
very much
simpler
because
of
the
size
and w ei gh t
of th e
structure
which makes
handling
extremely
weather
dependent.
TH
PRODUCTION RISER
Like
the
Argyll
design, the Buchan production r iser
i s no t designed to stay connected in all
weathers,
but
must be recovered and stacked. in the derrick in
severe
conditions. I t
was
designed
to survive
12
m
maximum
waves with
the
associa
ted
rig
offset
and
current,
bu t recovery
of
the r iser will have to be
initiated at a considerably lower threshold.
Nevertheless i t is
the ability
of the
t anker to
stay
connected to
the
loading
buoy
rather
than
the
r iser
which
will
determine
the
production from
the Field.
The
r iser is shown
in
cross-section in Figure 6 and
in elevation in Figure 7. Prior to the introduction
of gas
l i f t the
bundle consi st s o f a central 12
inch
export r iser
surrounded
by ten
4
inch risers
one production r iser from each
of wel l s
and two
service risers
see Table 1).
The risers ar e
independent
of
each
other
and are run
and
tensioned
separately.
The
4
inch
r isers
are,
however constrained to deflect
with
the 12
inch
r iser by being spaced ou t from
t by
passing through
guide funnels. These ar e
supported
on arms mounted
every
7.6 m
along
t he l ength
of t he expor t
r iser .
Hence although each r iser
in the
bundle is independent
in the axial
direction, horizontally
the bundle tends
to
deflect
as
a single composite beam.
To reduce bending stresses at the b as e . of the r isers,
a universal joint is mounted in t he expor t r iser
directly
above the manifold. Fo r th e
same
reason,
the bottom 15 m joint
on
each production r iser is
made
from
extra
heavy
tubular.
With the introduction of gas l i f t
facilities
exist
to
cIampa 2 .inch gas
l i f t
r iser
to
each
production
riser
and
the
guide
funnels are
sized to accommodate
the
pair.
This r iser
concept
offers the advantage of operational
f lexibili ty. Only SUfficient risers need
to
be run
to
accommodate flow and required, individual
r isers can be p Ul le d and
replaced without
haVing to
recover the entire
bundle.
On
tpe other
hand r iser
handling time
during
the
running or
recovering
operation is increased
by
the need to
handle
individual lines sequentially.
The
r iser was th e
subject
of an immense amount
of
design analysis.
Model tests were conducted on the
bundle to establish drag and inertial coefficients
on
individual
r isers.
This
data
was
then
used
in
the
stress analysis
programme to
predict th e
bending
behaviour
of
individual
risers
as
well
as the gross
behaviour of the bundle. A
spectral
fatigue analysis
was conducted
to
determine fatigue l ife and
this
was
supported by
fatigue t es ti ng o f
a threaded
r iser
connector. In
addition,
during operation r iser
behaviour
will be continually monitored
by
instrumentation measuring parameters such
as
the
deflection
of the
universal join
and the pipe wal l
strain
at
two locations on
the r iser .
8
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
5/10
RIG MOUNTED
EQUIPMENT
As well
as
the
installation
of
production
equipment
the
rig conversion
programme incorporates several
modifications
in
t he r eg ion
of th e moonpool. These
include:-
enlargement of
the
moonpool
to
accommodate
both
production and wireline riser
provision of
four new
36
tonne
r iser tensioners
i n addition to the
eight existing 27 tonne units
installation
of
four
hose reels
to
carry the
main control umbilicals
see
below
modifications
to the
derrick
t o permi t handl ing
the
wireline
riser
through
a second
opening
in
the dril l deck floor
proVlslon
in
the
derrick fo r stacking
30
m
lengths
of
riser
provision of addi tional sheaves fo r tensioning
lines
and guide
wires. All
systems ar e
designed
to accommodate 5 m of
rig heave.
Flexible
rubber hoses ar e used to connect the
top
of the
risers
into
the moonpool pipework.
ONTROL SYSTEM
All the
subsea equipment is
controlled hydraul ical ly
via 4 hydraulic umbilicals deployed from the
production platforms.
Two
65 function umbilicals
ar e run to twin control pods mounted
on
the base
to
control
the
trees
and downhole
safety
valves
and two 62 function umbilicals
control
the
manifold
operation
through pods mounted
on
the
upper manifold
frame
see Figure
5 . Total duplication of
ll
key
subsea functions
is
provided between rig and control
pods.
A 10 line hydraulic umbilical
is
run to each tree
from the subsea tree pods.
inch
hydraulic lines
ar e used throughout.
The main umbilicals ar e deployed from 4 hose reels
situated
at
the edge of the moonpool. A guide line
system is used
to
run and recover the control pods.
9
In addition to the main control
panel
on the
r ig,
a
second smaller unit on the rill deck floor
provides
fo r
local control of the riser
connectors
on top of
the manifold.
This is
used
during running
and
recovering the production riser.
All
subsea valves ar e fail safe closed.
In
addition
the
subsea control system is ti ed in to the main rig
control panel
t o ensure
that in the
event of
a
shutdown subsea valves will be
closed.
CONCLUSIONS
The Buchan Field development can be
seen
as
the
natural successor
to
Argyll. While s im il ar i n
concept, i t
represents the extension
of
the
floating
production
principle to a field
with
more
subsea
completions,
bu t no radical departures in new
technology. In
terms of
field
size, however, i t
comes
close
to
the
l imit of
what can be
achieved
by
the
conversion
of a standard
dril l ing rig.
The next
step is
l ikely to
be custom
buil t f10ating production
platforms.
KNOWLEDGEMENTS
The author wishes
to
acknowledge BP
Trading Limited,
BP Petroleum Development
Limited
and
their
Partners
in the Buchan Development, namely St.
Joe Petroleum
Corporation, CanDel
Petroleum Limited,
Natomas
International, Gas and
Oil
Acreage
Limited,
Charterhall
Oil Limit ed, Loch ie l
Exploration UK
Limited, CCP
North Sea Associates and
City Petroleum
Corporation
fo r
permission to
produce
this
paper.
REFERENCES
1.
Darnborough
E. .
The Buchan
Field
Development . Europec Paper No.
230.
October, 1980.
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
6/10
TABLE
The
production r s r bundle
Risers
Number
Nominal
Operating Pressure
Size
Uns
psi
MFa
Produotion 8
4
5
34
Low
Pressure Servioe
4
5
1 5
High Pressure
Servioe
4
75
5
Gas Lift
8
2
325
Export
225
1 5
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
7/10
FUTURE
NORTHERN
S TELLITE
W
FLO TING
PRODUCTION
PL TFORM
SUBSE
TEMPL TE
WELLS
C LM
BUOY
SOUTHERN
S TELLITE
WELLS
Fig
Layout of the Buchan
Field
SPIDER SU RT-
PRODUCTION
RISERS
SUB SE
H R I S T M S ~ · ·
TREES
S T
W LL
FLOWLINES
SE BED
T E M P L T E ~
CONTROL
UMBILIC LS
UMBILIC LS
CENTR L EXPORT
RISER
M NIFOLD
Fig 2
Layout of
the template wel ls and
manifold
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
8/10
Fig
The template
PRODUCTION
STRING
NOM
UPPER
T I
I
LOWER
TREE
L PRODUCTION
PROPOSED
GAS
INJECTION
Fig
Schematic
of
a
subsea
tree
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
9/10
M NIFOLD
CONTROL
PODS
TREE
CONTROL
PODS
RISER
CONNECTORS
M NIFOLD
UPPER
FR ME
I I I E PORT
LINE
M NIFOLD
LOWER
FR ME
~ M N I F O L D
SE
Fig The subsea manifold
GUIDE
FUNN LS
~ E X P O R T
RIS R
S RVI
RISER
G S LIFT
RISER
PRODUCTION
RISER
Fig
6 Cross section of
th e production r is r
8/9/2019 The Design and Installation of the Buchan Field Subsea Equipment
10/10
TENSIONERS
12 EXPORT RISER
4 RISERS 1
OFF
2
RISERS
OFF
GUI E
FUNNELS
UNIVERSAL
JOINT
MANIFOLD
TEMPLATE
Fig levation
of
the product ion r i s r
Recommended