perancangan single buoy mooring system fso … · • bagaimana cara menghitung tegangan maksimum...
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PERANCANGAN SINGLE BUOY MOORING SYSTEM FSO KAKAP NATUNA
I GUSTI PUTU SUANTARA4108 100 0344108 100 034
JURUSAN TEKNIK PERKAPALANFAKULTAS TEKNOLOGI KELAUTANINSTITUT TEKNOLOGI SEPULUH NOPEMBERSURABAYA
LATAR BELAKANG
• Kegiatan eksplorasi diperairan laut dalam.
• Anjungan terpancang kurang ekonomis apabila dibandingkan
dengan anjungan terapung (floating platform) pada perairan
yang dalam.yang dalam.
• FSO mengalami gerakan yang disebabkan oleh beban
lingkungan (arus, angin dan gelombang) sehingga tali tambat
mengalami tegangan. Sehingga analisa kekuatan mooring
system perlu dilakukan.
RUMUSAN MASALAH
• Bagaimana memprediksi karakteristik motion FSO Kakap
Natuna?
• Bagaimana cara menghitung tegangan maksimum chain
pada sistem single buoy mooring FSO Kakap Natuna?pada sistem single buoy mooring FSO Kakap Natuna?
• Bagaimana cara memprediksi excursion/offset FSO Kakap
Natuna?
• Bagaimana layout single buoy mooring untuk FSO Kakap
Natuna yang paling optimum?
MAKSUD DAN TUJUAN
• Menghitung karakteristik motion FSO Kakap Natuna.
• Melakukan analisa line tension dan excursion dari mooring
system FSO Kakap Natuna pada kondisi saat ini.
• Mencari layout dari mooring system FSO Kakap Natuna• Mencari layout dari mooring system FSO Kakap Natuna
dengan line tension dan excursion yang lebih optimum.
BATASAN MASALAH
• Pembahasan hanya dilakukan untuk perairan dimana FSO
Kakap Natuna beroperasi.
• Pembahasan studi hanya mengenai pengaruh beban lingkungan
terhadap FSO Kakap Natuna.
• Jumlah rantai dalam pembahasan ini seperti pada kondisi saat ini
sebanyak 6 rantai dengan panjang rantai secara keseluruhan
454 meter.
• Kajian hanya mengikuti rule Biro Klasifikasi Indonesia & standar
API
SISTEM TAMBAT (1)
Internal Turret
Spread Mooring
SISTEM TAMBAT (2)
Single Buoy Mooring
External Turret
SISTEM TAMBAT (3)
Single Buoy Mooring dengan Yooke Arm
METODOLOGI PENELITIAN
Data FSO
Perhitungan dengan teori difraksi
Pemodelan hull FSO
RAO
Simulasi time
Variasi sistem tambat
Data sistem tambat awal
No
Yes Yes
No
Data LingkunganSimulasi time
domainSimulasi time
domain
Line tension & Excursion
Line tension & Excursion
Unity check
Unity check
Minimum line tension
Sistem tambat baru
PEMODELAN INTACT CONDITION
PEMODELAN ONE LINE DAMAGE CONDITION
SUSUNAN MOORING LINE
Mooring
Line
SpecificationLine Working
Pre-TensionSegmen A (at buoy) Segmen B (at pile)
L1 Approx. 165 m in length Approx. 289 m in length 31.9 MT
L2 Approx. 165 m in length Approx. 289 m in length 31.9MTL2 Approx. 165 m in length Approx. 289 m in length 31.9MT
L3 Approx. 165 m in length Approx. 289 m in length 31.9 MT
L4 Approx. 165 m in length Approx. 289 m in length 31.9 MT
L5 Approx. 165 m in length Approx. 289 m in length 31.9 MT
L6 Approx. 165 m in length Approx. 289 m in length 31.9 MT
RAO FSO KONDISI FULL LOAD
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0.00 0.10 0.20 0.30
Dis
tan
ce
Frequency (Hz)
Surge Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
0.00 0.10 0.20 0.30
Dis
tan
ceFrequency (Hz)
Sway Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0.00 0.10 0.20 0.30
Dis
tan
ce
Frequency (Hz)
Heave Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Roll Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Pitch Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Yaw Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
RAO FSO KONDISI BALLAST
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0.00 0.10 0.20 0.30
Dis
tan
ce
Frequency (Hz)
Surge Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
0.00 0.10 0.20 0.30
Dis
tan
ceFrequency (Hz)
Sway Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
0.00 0.10 0.20 0.30
Dis
tan
ce
Frequency (Hz)
Heave Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Roll Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Pitch Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Yaw Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
RAO BUOY
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
0.00 0.10 0.20 0.30
Dis
tan
ce
Frequency (Hz)
Surge Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
0.00 0.10 0.20 0.30D
ista
nce
Frequency (Hz)
Sway Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
0.00 0.10 0.20 0.30
Dis
tan
ce
Frequency (Hz)
Heave Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
Frequency (Hz) Frequency (Hz) Frequency (Hz)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Roll Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00
0.50
1.00
1.50
2.00
2.50
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Pitch Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
0.00000
0.00005
0.00010
0.00015
0.00020
0.00025
0.00 0.10 0.20 0.30
De
gre
e
Frequency (Hz)
Yaw Motion RAO (Response Amplitude Operators)
0 deg. Direction
45 deg. Direction
90 deg. Direction
135 deg. Direction
180 deg. Direction
ANALISA LINE TENSION PADA KONDISI SAAT INI
Full Load Condition
Computed Allowable Line
Chain Grade
Segmen
Normal ConditionAfter Corrosion
(12 years)Intact Damage
Nominal dia.
(mm)
Breaking Load(ton)
Nominal dia.
(mm)
Breaking Load(ton)
Safety Factor
Allowable Line
Tension (ton)
Safety Factor
Allowable Line
Tension (ton)
KI-R4 A 76 612.78 71.2 535.37 1.7 314.924 1.3 411.823
ORQ B 103.9 829.05 99.1 752.44 1.7 442.618 1.3 578.800
Segmen
Computed
Maximum Line
Tension
(Tonnes)
Allowable Line
Tension
(Tonnes)
Status
From “E”
A173.618
(at line #2)314.924 OK
B169.488
(at line #2)442.618 OK
Damage at Line #1
A
258.464
(at line #3)
(from “E”)
411.823 OK
B
253.692
(at line #3)
(from “E”)
578.800 OK
VARIASI ROTASI KOORDINAT PILE
1
26
15o
15o
15o
15o
5
4
3
DISTRIBUSI MAKSIMUM LINE TENSION DARI SEGALA ARAH
100
150
200
250
Lin
e T
en
sio
n (
to
nn
es)
Line Tension Distribution
N
NE
E
SE
S
SW
WSEGMENT B
0
50
0 10 20 30 40 50 60 70
Rotation (degree)
W
NW
0
50
100
150
200
250
0 10 20 30 40 50 60 70
Lin
e T
en
sio
n (
to
nn
es)
Rotation (degree)
Line Tension Distribution
N
NE
E
SE
S
SW
W
NW
SEGMENT A
SEGMENT B
DISTRIBUSI MAKSIMUM LINE TENSION DARI ARAH NORTH EAST DAN EAST
180
200
220
Lin
e T
en
sio
n (
ton
ne
s)
Line Tension Distribution
NE (segmen A)
100
120
140
160
-70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70
Lin
e T
en
sio
n (
ton
ne
s)
Rotation (degree)
NE (segmen A)
E (segmen A)
NE (segmen B)
E (segmen B)
PERBANDINGAN MAXIMUM LINE TENSION
Condition SegmenT
Computed Maximum Line
Tension (Tonnes) Difference
(tonnes)Existing pile 10o rotation
Intact
A
173.618
(at line #2)
(from “NE”)
144.514
(at line #3)
(from “E”)
29.104
Intact
B
169.488
(at line #2)
(from “NE”)
140.506
(at line #3)
(from “E”)
28.982
One line damage
A
258.464
(at line #3)
(from “E”)
246.737
(at line #2)
(from “NE”)
11.727
B
253.692
(at line #3)
(from “E”)
239.863
(at line #2)
(from “NE”)
13.829
Chain Grade
Segment
Normal ConditionAfter Corrosion
(12 years)Intact Damage
Nominal dia.
(mm)
Breaking Load(ton)
Nominal dia.
(mm)
Breaking Load(ton)
Safety Factor
Allowable Line
Tension (ton)
Safety Factor
Allowable Line
Tension (ton)
KI R4 A 60 394.19 55.2 331.119 1.7 194.776 1.3 254.707
ORQ B 68 383.44 63.2 329.306 1.7 193.710 1.3 253.312
Full Load Condition
Computed
ANALISA LINE TENSION PADA KONDISI HASIL OPTIMASI
Segmen
Computed
Maximum Line
Tension
(Tonnes)
Allowable Line
Tension
(Tonnes)
Status
From “E”
A144.514
(at line #3)194.776 OK
B140.506
(at line #3)193.710 OK
Damage at Line
#1
A
246.737
(at line #2)
(from “NE”)
254.707 OK
B
239.863
(at line #2)
(from “NE”)
253.312 OK
KESIMPULAN
1. Karakteristik motion• Gearakan surge maksimum disebabkan gelombang datang dari
arah 0o dan 180o
• Gerakan sway dan heave maksimum disebabkan gelombangdatang dari arah 90o
• Gerakan roll maksimum disebabkan gelombang datang dari arah90o
• Gerakan pitch dan yaw maksimum disebabkan gelombang datangdari arah 45o dan 135o
2. Maksimum line tension• 173.618 ton (segmen A) dan 169.488 ton (segmen B) pada kondisi
intact.• 258.464 ton (segmen A) dan 253.692 ton (segmen B) pada kondisi
one line damage
KESIMPULAN
3. ExcursionBesar excursion FSO tidak mengalami perubahan yang signifikanpada kondisi saat ini sebesar -34.002 m (sb. X) dan -25.545 m (sb. Y)sedangkan pada posisi hasil optimasi sebesar -33.74 m (sb. X) dan -25.605 m (sb. Y)
4. Maksimum line tension hasil optomasi• 144.514 ton (segmen A) dan 140.506 ton (segmen B) pada kondisi
intact.• 246.737 ton (segmen A) dan 239.863 ton (segmen B) pada kondisi
one line damage5. Didapatkan diameter yang lebih kecil dengan diameter 60 mm pada
segmen A dan 68 mm pada segmen B
SEKIAN, DAN TERIMA KASIH......SEKIAN, DAN TERIMA KASIH......