Download - Piotr Krawczyk - Article
-
8/17/2019 Piotr Krawczyk - Article
1/17
OP
1.
2.
2013
M
RoZh
Hans
bstract
This papespans onpredictingscour trenspan analobtained a
It is demorenches
spans beiand, in so
This workevolution.
ith thesusceptibl
Keywords
IntroducPipelines lis caused
seabed evhese ph
applicationcurrentsenvironme
This papeseabed scBBL pipelshelteringanalysis t
Ma
naging
Piotrmke Bijkeiwen CheBoersma,
r presentthe BBLspan evolches. Botsis methond unnec
strated hnd the sg acceptae cases,
is basedWhile theBL pipel to scour
: pipeline,
tionaid on eroby two f
olution irr nomenas, like theay resul
ntal loads.
r consideour. The dine. Theeffect ofchniques
naging Fre
Free S
rawczyk,, Wittevee, BMT Ar BBL Com
the strat pipeline.ution in ti these su
ds, whichssary rem
re that taan evolutble. This r it may eli
on fielddiscussioine, it isand dyna
free span,
dible seabctors: se
spectiveare of p North Se in the
s integritiscussionirst onecour trenwhich w
Spans on
Page 1
pans o
alny Ltd,n+Bos/ACoss, zhiwany, H.A.
egy adopThe dise and qu
bjects areften lead
ediation w
ing into aion in timeduces thinate it alt
measure is presendirectly aic seabed
scour, VI
ed are pr bed scou
f the pipelrticular ca, where tspan bei
manageollows twocuses ohes. Theuld allow
ynamic Se
Dyna
Piotr@HalRB, romkn.chen@
Boersma
ed to maussion f antifying tonly partl to overlyrk being
ccount th can res need forgether.
ents ofted in thepplicablecondition
, fatigue,
ne to dev around t
ine (i.e.: sncern in
he combig expos
ent of t parallel d improvisecond opredictin
abed
Febr
ic Sea
ny.co.uk.bijker@amtargossbblcomp
nage scocuses onhe shelteriy coveredconservatindertake
shelterinult in conoffshore i
cour trencontext oto any o.
span evol
elop longhe pipelin
nd waverelatively
ed loadind to un
e free spevelopmeg our une focuse span ev
uary 28, 201
bed
rb.nl.comny.com
r induce two sung effectby the e
ve results.
effect ofiderably ltervention
ches andthe expefshore pi
tion
ree spanse and/or
migration)shallowby wave
cceptably
ans causts made f erstandin on develolution in
3
free jects:of theistingbeing
scourongerwork
spanienceeline
. Thislobal
. Bothwaters and
high
d byor theg theopingtime.
-
8/17/2019 Piotr Krawczyk - Article
2/17
OP
3.
2013
hen co
amount ofacceptabl
This workoperation i
• Spansunaccesignificundertacceptremedi
•
Most sscourstandaundert
This papeis on-goin
Past deThe procinvestigate
developm[1], whichdespite thavailable t
The DNcompreheassessingon how trecommenhis is rat
unnecesseffect ofmethodolomissing eestimates.also appliurther red
The workdeterminepipeline s
Ma
bined, th
offshore i condition
is drivenn the 200
identifiedptable inntly reduken in ance criter tion work
cour trencrenchesd assessken to qu
describe.
elopmess of sd over t
nts can battempts tis extensi the engi
Recomsive guidthe free s address
ded for scher simpli
ry remediscour tregy. It is dtirely forIt will beable to i
uce the re
presentedthe acceplf-lowerin
naging Fre
se two d
nterventio.
y the exp, where:
duringthe as
ced in lenutumn thia for scoubeing und
hes are oeported ient methntify the s
the pres
tsabed sce last th
found ino summae researceers man
endedeline for f pans in th span evour inducstic appr
tion worknches isfined forin-line VIhown her -line VIVuirement
in ref. [4]tability of. This ca
Spans on
Page 2
evelopme
work re
erience wi
pring timfound cgth, by th same
r inducedertaken.
served a the liter ods. Thusheltering
nt status
ur arounee decad
an overvieise the vah effort, tging scou
racticeee spane as-founlution ind spans (ach and
being undonly partross-flow, whichthat the
and thatfor span r
introducescour indu be used
ynamic Se
ts resulte
uired to
h BBL pi
e surveynfiguratioe time reear. Thisree spans
consisteature and, a dedicaffect of na
of the stu
pipelinees. A val
w paper brious resehere is stir induced
105, renalysis,configur
time. Ato cater foit has be
ertaken. Fly includVIV and dtends tohelteringtaking thictification
probabiliced spansto enhanc
abed
Febr
d in signi
aintain th
eline sinc
and co had dediationsuggests
may lead
tly morebeing thed assesrrow scou
ies. Furth
s has buable su
Sumer aarch direcll little pr spans.
. [2], bis clearlytion and iominal s
r future sen conclu
urthermor d in theirect wavegovern fr effect of s effect in
.
tic analys developie to the d
uary 28, 201
icantly re
e pipeline
the start
ncluded tisappeareworks co that stato unnec
arrow th basis f ment hastrenches.
er develo
en extenmary of
nd Fredsotions. Hoctical gui
ing thegeared tot remainsfety mar an growtded to le
, the shelDNV-RP action, be span f our trenc
to accou
is techniqg as a reefault DN
3
uced
in an
of its
o be, orld bendardssary
n ther thebeen
ment
sivelythese
e, ref.ever,ance
mostards
silentin is), butad to
teringF105t it istiguees is
t can
es toult of-RP-
-
8/17/2019 Piotr Krawczyk - Article
3/17
OP
4.
2013
F105 met
number ofo governnumber ofThese aspipelines (not be aExperiencscour indstatisticalapproach i
ShelteriThe sheltadvancedThis mode
ortex Indhe use ofears in A
(horizontalIt is theref making anwo vibrati
and thecalculatedengineerinCalibrationof represeelocity le
Figure 1located inpipe diamshows vor These areigure. As
being sheand in-linestipulated
Ma
odology.
importantt all timespans, allumptionspipelinessumed t with theced spanalysis m
s therefor
g Effectering effeComputatil has beeuced Vibr mesh-def nsys CFX) and crosore capaby arbitraryon modes
vibrationfrom thg principl results pr ting expeels comm
hows a sa typicalter and witices bein the redhe flow isin an alt
VIV respy DNV-R
naging Fre
owever, it
assumpti and (2) itof whichare genelf-loweriat all scBBL projs behaveay not bedevelope
of Scoct of scoional Fluid specifical
ations (VIrmation asoftware.s-flow (vele of resolassumpti, or the r
amplitude first pries areesented inrimental r only enco
nap-shotcour trenth a width
shed bend the blaffected
ernating ponse at al
-F105 m
Spans on
Page 3
should b
ns suchis assumvolve rapirally appr g in relatiur induc
ect sugge in an ethe mostd for thes
r Trencur trench Dynamicly develop) near th
nd re-mesFurthermortical) pipeving pipens with relationship
. All thciples (i.sed toref. [6] susults at thntered in
f the CFh for theof approxihind thee oval py the proxattern, whil times (ththodology
ynamic Se
realised t
s: (1) fatid that thedly and bopriate fovely shortd spansts that stirely dif ppropriat spans.
ess is inv (CFD) med to tack seabed.
hing technre, the moline motiomotionsgards to t between
se intera.: fluidresolve flggest that
Reynoldffshore pi
model.BBL pipelimately twipeline intterns to timity of thch resultsere is no).
abed
Febr
hat the m
ue limit s pipelinehave in ar effectivetime). Hobehave ime of th
erent ma approac
stigatedodel presle large aThis is aiques intr del allows across t
ithout thee interactthe hydr
ctions ar echanicsuid-structuthe CFD
numberpeline app
he pipeline (shelte pipe diaa steadyhe right he seabed,in a com
pure in-lin
uary 28, 201
thod relie
ate is assevelops asimilar mly self-loever, it s
n this m most onner, for. An alter
here usinted in r plitude pihieved thduced infor both, ie fluid dorequiremion betwedynamic
automaand strure interaodel is cand the re
lications.
e can bering 50%eters). Thflow simuland sidethe vorticined cros
e VIV res
3
on a
umedlargenner.eringhouldnner.erouswhichative
g anf. [6].eline
roughecentn-linemain.nt forn theorces
ticallycturaltion).pableuced
seenof thee plotation.f thes are
s-flowonse
-
8/17/2019 Piotr Krawczyk - Article
4/17
OP
2013
Figure
Figure 2 sComparedseabed another conbe seen tnoted thateight-shaprench. Thi
investigat
Figure 2:
Ma
: CFD mpi
ows an e here ared in a typiitions rem experien the motied patterns sort of od trench d
ipeline
naging Fre
del – typie shelter
xample ofthe moti
cal scourain the se significn patternover flat
val motionepths and
otion pat
Spans on
Page 4
cal vorted by a na
the shelten patternrench sheme). Pipently lower has cha
seabed topattern hprofiles.
terns ove
ynamic Se
sheddinrrow sco
ring effects for theltering 50line locate vibrationged consan oval vs been c
flat seab
abed
Febr
in a stear trench
observedpipeline l of the pi
d in the samplitudeiderably, f ibration pnsistently
ed and in
uary 28, 201
dy flow fr
for the picated ovpe diametcour trenc. It can al
rom a flatttern in aobserved
a scour t
3
om
eline.r flat
er (allh canso betenedscourfor all
ench
-
8/17/2019 Piotr Krawczyk - Article
5/17
OP
2013
Figure 3pipeline. Brecordedshows a50% of thpipe diamshelteringrepresentof these s
Figure 4simulationhe pipe d
consistentIV is con
RecommeRP-F105renches f
Ma
hows twoth trenchsing Muloderatelypipe diater on the65% of
tive of soans are in
nd 5 sho for the p
iameter). Iwith thesiderablyded Pracethodolo
r in-line
Figure 3a
Figure 3b
naging Fre
of the sprofiles ar i Beamdeep, sligeter on thdownstrethe pipee of the l
the order
Figure 3
w the resipe in mot can be nNV-RP-Felayed w
tice methgy doesIV. This li
Spans on
Page 5
our trence a schemcho Soutly asym
e upstream side. Fdiameter
ngest spaof 50-60m
: Scour tr
ponse moerately d
oted that105 predien compdology. Tot incorpitation is
ynamic Se
h profilesatisationding survetric, sco side and
igure 3b s. Thesens observ long.
ench prof
dels geneep scourhe cross-tions. Hored to that is caurate thenot explai
abed
Febr
investigatf the in-sitey equipur trenchapproximows a detwo trened on the
iles
rated bastrench (slow VIV r ever, thepredictioed by th
shelteringned in the
uary 28, 201
ed for thu trench pent. Figurofile sheltely 60%p scour th profileBL pipeli
d on theeltering 5sponse isonset of is basedfact thateffect ofRecomm
3
BBLofilesre 3ateringof theench,
aree, all
CFD% offairly
n-linen theDNV-scournded
-
8/17/2019 Piotr Krawczyk - Article
6/17
OP
2013
Practice.
noted thathe time w
F
Fig
Ma
owever,
the effecten the R
igure 4: I
re 5: Cro
naging Fre
reviewing
is missingcommend
-Line VI
ss-Flow
Spans on
Page 6
the back
simply beed Practic
in scour
IV in sco
ynamic Se
round lite
ause it he was pub
rench sh
r trench
abed
Febr
rature, re
s not beelished.
ltering 5
heltering
uary 28, 201
. [3], it c
investiga
% OD
50% OD
3
n be
ted at
-
8/17/2019 Piotr Krawczyk - Article
7/17
OP
2013
Figure 6simulationdiameter).
ppreciablexcess of(Vr >4.5) isassociatedconsistentlresponseamplitudesomewhat
F
Ma
nd 7 sho for the pHere, th
e VIV a3.5. Inte
notably h with sy observeis fairlyare lowe
narrower
igure 6: I
naging Fre
w the resipe in thepure in-l
plitudesrestingly tigher than-calledfor all in
consistent. That is phan those
-Line VI
Spans on
Page 7
ponse modeep scouine VIV r re only
hough, in that predross-flowestigatedwith DN
robably thinvestigat
in scour
ynamic Se
dels gener trench (sponse ibservedline VIVicted byinduced
scour trenV-RP-F10 result ofd in ref. [
rench sh
abed
Febr
rated bashelteringessential
for reducfor higherNV-RP-F1in-line Vh profiles
5 predictiBBL scou].
ltering 6
uary 28, 201
d on the5% of thly non-exid velocitiflow vel
05. ThisIV, has. Cross-floons, albe trenches
% OD
3
CFDpipestent.es incitiesffect,been
VIVit thebeing
-
8/17/2019 Piotr Krawczyk - Article
8/17
OP
2013
Fig
The abovspans ca
effect ofmethodsobtained.
BBL Comechnique
during suintroducinof this imcomparedBBL respo
oleratedspan lengtpipeline inhave been
Ma
re 7: Cro
resultsimprove
cour trenf analysi
pany use to quantivey andcustom r rovementfor the dense mode
hen thehs translaan accep
demonstr
naging Fre
ss-Flow
uggest thconsider
ches. This, which
advancy the shelo refine tsponseis illustraault DNV-ls. It can b
trench eff te to lesstable conated not to
Spans on
Page 8
IV in sco
at fatiguebly when
effect isresults in
d Compuering effehe DNV-odels fored in TaRP-F105e noted th
ct is fullremedialition. In s require a
ynamic Se
r trench
predictiotaking in
not fullyoverly c
tational Ft of in-sitP-F105cour indule 1, wheesponseat conside
accountork beinme casey remedi
abed
Febr
heltering
s for scoo accoun
capturednservativ
luid Dyna scour trepan anal
ced free sre fatigueodels an
rably long
d for. Lo required, entire cltion at all.
uary 28, 201
65% OD
ur induce the shel
by the e results
ics simnches obssis methans. Thepredictio for the cr spans c
ger acceto maintausters of
3
freetering
istingbeing
lationervedd byresults arestom
an be
tablein thepans
-
8/17/2019 Piotr Krawczyk - Article
9/17
OP
5.
2013
Tabl
Scenari
Response→
Span Le(L/D
46
51
55
59
Span Le
(L/D46
51
55
59
The resultlength L/Dratio of 59This is modiameter).
scour trenlocated inould no
processcommenc
Span Evcceptabil
and tools,an approaeatures (
cohesivescour).
For non-stdifferent, aof the spreliable asand (2) th
Several stincluding
Ma
1: The e
o → Sfl
Model
gth ↓ )
gth ↓
)
s present= 59, as lis long e
re than thThe pipe
ch and toa very delonger coould ther .
olutionity of pipewhich arech is ade.g.: glaci
oils, whic
ationary ss the critin and th
sessmentpredictio
udies havansen et
naging Fre
fect of scpan overt seabed
NV-RP-F105
horizo
6.0 yr
0.6 yr
0.1 yr
0.0 yr
7,175 yr
57.3 yr
6.9 yr
2.4 yr
ed in Tabnger scoough to d scour tr can ther
self-remeep trench,stitute anfore ceas
line freedevelopeuate for t
er scars,
h are ge
ans on aality of the prevailimust ther s into its f
e been cal (1991),
Spans on
Page 9
our trencSpan in a mtrench, shelt
DNV-RP-F105
Fatigue ental directio
6.1 yr
0.6 yr
0.1 yr
0.0 yr
Fatigue e
vertical100,000+ yr
4,990 yr
347 yr
93 yr
le 1 arer spans ar evelop vench depthfore be e
iate theshelterinobstacle t
e and nat
pans is g assuminhe spansboulders,
erally les
ynamic s free spag enviro
efore accuture deve
rried outKlomp et
ynamic Se
on spanoderate scoering 50%
BBL
stimate for t (in-line VIV
2,699 y
872 yr
305 yr
98 yr
stimate for t
irection (cr 100,000+
89,919 y
1,830 y
124 yr
truncatede not likeltical sag(typicallypected t
pan. As t circa 80o the seaural back
enerally a stationar caused bor rocky
dynamic
abed, ho is stronglmental cunt for: (lopment.
in the paal (1995),
abed
Febr
fatigue prD
Spantrench,
DNV-F10
e free span+ Direct Wa
6.1
0.6
0.1
0.0
e free span
ss-flow VIV)yr 100,00
r 9,818
654
174
at non-di to occur.f circa 0.betweentouch th
e pipelin of the-water floilling of th
ssessedspan con
large, peoutcrops),
(i.e.: les
ever, thelinked to
nditions.) the hist
t on freeChen & B
uary 28, 201
ediction in a deep ssheltering 6
P-
B
↓ ve Action)
r 5,4
r 1,7
r 57
r 18
↓
+ yr 100,
yr 100,
r 100,
r 13,
ensional A span wi pipe dia.4 and 0. bottom
would nipe diam. The sc
e trench
sing guidfiguration.rsistent s or in ca
suscepti
situation ithe persis
A realistiory of the
span evolijker (2001
3
our% OD
BL
8 yr
00 yr
8 yr
8 yr
00+ yr
00+ yr
00+ yr
62 yr
spanh L/Deter.pipef the
w beter, ituringould
elinesSuchabedse of
le to
verytence
andspan
ution,) and
-
8/17/2019 Piotr Krawczyk - Article
10/17
OP
2013
Drago et
span evolprocess.lowering aThis washe evoluti
actually pr
This papepredictinghe formulith new
processesmanagem
The folloused forstructure i
Fi
pan celeri
qcn sn
1(
(
−
−
=
Ma
l (2007), r
tion wasodel validnd no dir
ainly duon of thedict free
reports ospan evolations der
formulatithat havnt.
ing discuodel vali presente
ure 8: O
ty is calcul
eD p
Dq n
)
)0 β
naging Fre
ef. [8], [9],
odelledation wasct validati to the a
span lengtpan devel
the first r tion in tim
ived for sns, to r been ob
sion giveation and in Figure
erall stru
lated base
Spans on
Page 10
[5] and [
s an integenerallyn of the
sence ofhs. As a r opment in
esults of ae. This tolf-lowerin
ealisticallyserved in
an over some pr 8.
ture of th
d on the fo
ynamic Se
] respecti
ral part ocarried ouree spaneliable fieesult, ther time.
n ongoingl is being pipelineaccount
recent ye
iew of thliminary r
e span e
llowing for
abed
Febr
ely. In th
the pipelit in termsevolutionld data me is still n
study to ddevelope and is f for pipe
ars of BB
approacesults. Th
olution m
mulations,
uary 28, 201
se studie
ne self-loof pipelinas carrieasureme reliable t
evelop a t on the brther upgsoil inter L pipeline
, the fiele overall
odel
ref. [8] an
3
, free
eringself-d out.ts onool to
ol forsis ofradedctionspan
dataodel
d [9]:
-
8/17/2019 Piotr Krawczyk - Article
11/17
OP
fis
f
•
•
•
•
•
r ts
itir
2013
p
q t st
1(
0
−
=
β
here:
sn = span
st = span
cn = sedi
0n = sedi
0t = sedi = poro = pipe
= pipe
= coeffi
his modelnd it is neld data iurveys an
ree spanllowing s
the 20
the 201
the 201 the 201
the 201
he wavet the K13elevant pipical wavpan of int
he wave
orth Sea,nnually inave heigspection/
me, any dequired) in
Ma
eD
D
celerity dcelerity dent transent transent transity of seauter diammbedme
cient for t
was initiaw refinedcludes: (1 (2) the
evelopmrveys:
9 spring ti
0 spring ti
0 autumn1 spring ti
2 spring ti
ata at thplatform.eline locae height vrest has b
height dis
where stowinter tim
ht rarelyaintenan
etected fr autumn,
naging Fre
e to sedie to sediort normaort normaort paralled (-)eter (m)t (m)
e length o
lly calibratusing fiel) free spaind and w
nt in time
me survey
me survey
re-surveyme survey
me survey
span locThe meastions usinariationseen detec
tribution s
rms with sie. Summexceedin
ce prograe spans aefore the
Spans on
Page 11
ent transpent transpl to pipelinl to pipelinl to pipelin
f span sup
ed using e measure length mve height
is establis
tions areured wind a dedicat a locatioed.
hown in
gnificantr time is
3m. Th, where
e assessinter stor
ynamic Se
ort normalort parallee in the coe upstreae upstrea
port area
xperimentent data
easurememeasure
hed base
derived fr and wav
ted hindcn along p
igure 9 i
ave heighenerally cis wavethe pipelid in summs could
abed
Febr
to pipelinl to pipelinrner of sp of pipelin of pipeli
-)
al laboratfor the Bts basedents at th
on the co
m the mees are trast model.ipeline rou
typical f
t of circa 6almer, witclimate dne is sur er time anffect pipel
uary 28, 201
(m/s)e (m/s)n (m3/ms)e (m3/ms)e (m
3/ms)
ry data, r L pipelin
on BBL pi K13 plat
mparison
asuremensformed
Figure 9te where
r the So
m are obsh the signictates pieyed ind remediaine integrit
3
f. [9],. Theeline
orm.
of the
t datao thehows
free
thern
ervedificantelinepring
ted (ify.
-
8/17/2019 Piotr Krawczyk - Article
12/17
OP
ssf
j
f Is
ts
2013
F
he spanelected lopans arew meters
ssumed istified an
n exampligure 10.ave heiguring pip
om the sp
can bepans deveriods theackfillingackfill mate next la
pan in-bet
0
1
2
3
4
5
6
7
8
03‐12‐2008
W a v e h e i g h t H s ( m )
Ma
igure 9:
volutioncations, wypically c per year) ref. [4].an altern
e of calibThe horizt variatioline inspe
an evoluti
oted thatlop andspans terocess is
erial consirge stormween the
03‐1
naging Fre
istorical
odel is cahere freearacteriz. Thus, th statistic
ative (dete
ration resontal axis, the blacctions an
n model.
span grorow rapidd to remanot consists of very. Thus, thtorms.
2‐2009
Spans on
Page 12
ave data
librated usspans of id by modey are neil approacrministic)
ults for sis the tim
k rectangl the red,
th is notly during lin stagnaered in c
loose san span ev
03‐12‐201
Date
ynamic Se
at the sp
ing the avnterest hrate gro
ther stagh to spanpproach
an evolute, the blus show t
dashed li
uniform inarger stor t, or mayrrent spa
d and is r olution m
abed
Febr
n of inter
ailable fielve beenth rates (iant, nor f evolutioneems mo
ion modele curve se span lee shows t
time. Thms. Durineven startn evolutiopidly wasdel predi
03‐12‐2011
uary 28, 201
est
d data foretected.n the ordest evolvi
is therefoe appropri
is providows sign
ngths obshe predic
scour ing calm w backfillin model, aed awayts a “sta
02‐12‐
3
a fewheser of ag, ase notate.
ed inificantervedtions
ucedather. Thes thisuringnant”
2012
-
8/17/2019 Piotr Krawczyk - Article
13/17
OP
f
•
•
t
2013
he calib
evelopmeredict futullowing t
Span d
survey.
Span d
xamplespical winvironme
y conside
Ma
Figur
ration a
nts at there behavio scenari
evelopme
evelopme
of such pter contal conditi
ing a 100-
naging Fre
e 10: Spa
sessment
span. Thr of the es:
t during “t
t during a
redictionsitions isons. Span
year desig
Spans on
Page 13
evolutio
present
same misting spa
ypical” wi
n extreme,
are provipredicte
evolution
n storm c
ynamic Se
n model
d abov
thodologs. This w
ter storms
or “desig
ded belo by as
during an
ndition wit
abed
Febr
alibration
consid
can howuld norm
, up to the
” storm.
. Span esumingxtreme e
h a typical
uary 28, 201
ered his
ver be ully consid
next sche
olution f reviousent is pre
build-up t
3
orical
ed toer the
duled
r theears’icted
ime.
-
8/17/2019 Piotr Krawczyk - Article
14/17
OP
2013
Figure 1
Figure
Ma
1: Predict
2: Predic
naging Fre
ed span
ted span
Spans on
Page 14
rowth as
rowth as
ynamic Se
uming th
suming t
abed
Febr
e 2011/20
e 100-ye
uary 28, 201
2 wave d
r wave d
3
ata
ta
-
8/17/2019 Piotr Krawczyk - Article
15/17
OP
it
ssst
s
•
•
•
2013
ssuming t
odel pred significa the shelt
onsiderinxpected tould reachould betorm condpan wouldus split th
lready pr cour indu
s mentioodel still
The rel
accurac
in the
uncertai
data is
with th
quality
The pr
introduc
pipeline
From th
the sch
of com
change
The m
Additioon the
trench,
conditio
mean s
urther de
ngoing.
Ma
he same
icts that tt incremeering effec
extreme remain sh 4.5m. Boted howitions coul be long ee originaldicted toed spans.
ed beforeas the foll
iability of
y of the s
span dat
nties in t
presently
specialis
f the free
cess is
ed. We al
s that the
e availabl
matizatio
actness
in the co
del is n
al functiostructural
and the
ns, the ge
abed.
velopment
naging Fre
ave cond
e span wit, yet thet of scour
storm cagnant upeyond thiever that tld occur.nough forpan into tdevelopThus long
, the spaowing limi
the mod
rvey data
a, in pa
e span p
being perf
ts of the
span surv
schematiz
ready kno
prediction
field dat
of the se
of sand
tent of silt
t yet abl
would nespan mo
scour tr
otechnical
and add
Spans on
Page 15
itions as i
ll increaseinal span lrench.
nditions,to the poi thresholhe spanhis is motthe pipe t
o shorter sufficienter spans
evolutioations:
l obviou
and the s
ticular th
edictions.
ormed. In
survey co
ys.
ed and e
form pr
of the bac
we also
abed data,
nd chan
or clay.
e to pre
ed to be idel predic
nch dept
data and
itional cal
ynamic Se
previous
in lengthength is c
it can bent where t, rapid sould self-ivated bysag dow
ones. In f ag to fare not exp
model is
ly depen
pecialist i
support
More det
addition d
mpany to
nhancem
vious stu
kfilling pro
know that
to incorp
es in co
ict self-re
troducedting pipe
predicti
the initial
ibration o
abed
Febr
years, th
y approxinsidered
noted thhe significan growtemediatethe fact th into the s
act, a 50-6ilitate selected.
under de
s on th
terpretatio
configur
ailed anal
iscussions
further i
nts are
ies of act
cess nee
more wor
rate the si
esivenes
mediation
to limit spdeflection
n based
pipe emb
f the mo
uary 28, 201
span ev
mately 7macceptabl
at the spant wave
is expecbefore theat an 80cour trenc5m long s-remediati
velopment
reliabilit
n. Uncert
tion, res
sis of th
are bein
prove the
resently
ual self-lo
s improve
k is requir
gnificant
due to
of the s
n lengthinto the
on the
edment in
el is the
3
lution
. This, due
an iseighted. Itpeaklong
h andan is
on of
. The
and
inties
ult in
field
held
data
being
ered
ment.
ed on
ffects
small
pans.
asedscour
storm
o the
refore
-
8/17/2019 Piotr Krawczyk - Article
16/17
OP
6.
2013
Conclus
It is conclcovered baccount rerequiremeeliminated
The result[3], that thlow veloci
may still b
Previoushat the tr by BBL inof scour tr Further wgeneralise
Recent aComputatigeneral, aHowever,
recommenexperimenurther co
guidance
Limiting sstationaryseabed copersistencrealistic ahe spans
evolutionsuccessfulmonitoredare emineFurther wmodel.
The newconsideratseabed, bo the pipe
Ma
ions an
ded thaty the trasults in cot for rem
.
presente presenc
ties the tr possible.
ork on thnch effecicates th
ench wasrk is howd guidelin
dvancesnal Fluidd for stufor the
ded to pts. A Joinfirmationote which
pan lengfree spanditions,
of thed reliableand (2)
model isly been cin detail f nt, the pr rk is on-
approachion theing (1) thline, and
naging Fre
recom
the shelteitional spnsiderablydial work
d in this p of a scou
ench effec
e shelteri is not set this mayobservedver requir .
in modeDynamicsying the sethod t
rform furtt Industryof the CFcould be
hs for ps. This shere the
spans anassessmethe predithereforealibratedr the lastdicted tre
going to
to manost impo develop2) the ero
Spans on
Page 16
endatio
ing effectn analysi longer fret scour in
aper confir trench dt is less p
g effect ositive to t not alwato be send, to qua
lling ofapproachheltering
be full
her validaProjectD predictised for a
ipelines aems toriticality o the pre
nt must thtions intobeing deor a numthree yeand is in gnhance t
ging scortant aspent of nar
sion of fre
ynamic Se
ns
of scour ts methode spans buced free
rm the oblays onse
ronounce
scour tree scour ts be theitive to thtify this ef
turbulentto refine offect of s accepte
ion of thill therefons and tider rang
re gener e rather
f free spaailing en
erefore actheir futeloped a
ber of fr s. Althouood agrehe reliabil
r inducects of throw scour
span su
abed
Febr
renches is. Takinging accep
spans ca
ervationt of pipelin and larg
nches, reench profiase. The
trench wect and to
flows alur understour trenc by the
CFD pr re be lau come upe of pipeli
lly calculconservatis is stronironment
count for (re develond the fie spansh limitatioment wit
ity of the
free spe erodibltrenchesports and
uary 28, 201
not suffithis effectable. Thu be reduc
resentede VIV. At
amplitud
. [3], concle. Recentshelteringidth and p come up
low foranding ofes in partiindustry,
dictionsched towith a g
e applicat
ated assve for dyly linkedl conditio1) the histpment. Ast versiohat havens of the
the fieldspan ev
ans take and dyroviding s interactio
3
ientlyt intos, theed, or
in ref.igher
e VIV
ludedworkeffectrofile.ith a
usingIV in
cular.it is
ersusbtainneric
ions.
mingamic
to thens. Aory ofspan
hasbeenodel
data.lution
intoamic
helterwith
-
8/17/2019 Piotr Krawczyk - Article
17/17
OP
7.
2013
dynamic b
methodsmanagemless reme
Present wapproachscour and
Referen
[1] A Revi
J. Fred
[2] Free S
[3] VibratiE.A. H2001,
[4] A StratFyrileivOffsho
[5] Interac
InternaResea
[6] NumeriUnsteaProceeOffsho
[7] Drago,
FatiguSixteeLisbon,
[8] HansedeveloMecha
[9] Klomp,(1995),1995
Ma
ed forms.
nd modelnt proceiation wit
ork is bascould hodynamic s
es
w of Wa
soe; Coas
anning Pi
ns of a Fr nsen, M.aper No
egy for A, H. Nese and Pol
ion of Off ional Asch (IAHR)
cal Simuldy Curredings ofe and Arc
M, M .P
Damagth (2007)Portugal,
E.A. Stment ofics and A
.H.G.,Pipeline
naging Fre
oth these
s. They aure for thout jeopar
ed on fielever be aeabed con
e/Current-
al Engine
pelines, D
ee SpanniBryndum,1-4016
ssessmen, L Sortlr Enginee
hore Pipesociationconferenc
tion of Pints; P.the ASMic Engine
igliapoco
for ScoInternationJuly 1-6,
aub C. Fcour indurctic Engin
. A. HanSeabed I
Spans on
Page 17
aspects r
re combin BBL pipdising the
measurepplied toditions.
Induced S
ring Proc
NV-RP-F1
ng PipelinK. Mork,
of Non-nd, Procring Confe
lines andfor Hyd
e, Beijing,
peline VIVBhattacha 28th Inring; OM
and T.Ci
ur Induceal Offshor 007
redsoe J.ced free seering Co
sen, Z. Cnteraction,
ynamic Se
esulted in
ed and inline, whiintegrity o
ments forny offsh
cour Arou
edings, 1
05, 2006
Located. Verley,
tationaryedings orence, 19
ynamic Sro-Enviro2001
Near therjee, K.KernationalE 2009
ffardi (20
d Freesp and Pol
and Supans of pference
hen, R.Free Sp
abed
Febr
significant
tegrated ih has alr the pipeli
the BBLre pipelin
d Pipelin
92, Chap
in the Vici. Sortland
Free Spaf the Nin9
eabed, Z.ment E
Sea-Bed. Nielsen
Confere
07), Anal
ns, Procr Enginee
mer B.ipelines P
ijker andan Devel
uary 28, 201
improvem
the freeady resule system.
ipeline.suscepti
s; B.M. S
er 217
ity of a T, H. Nes;
s, K. Moth Intern
Chen, R.gineering
for Stead, G. Stce on O
sis of Pi
edingsring Confe
. (1991)oc. of Of
M.B. Brypment. I
3
ent of
spaned in
imilarble to
umer,
ench;MEA
k, O.tional
ijker,and
andwart;
cean,
eline
f therence
Timeshore
ndumOPE