Pipeline Risk Assessment

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Metal Performance Assessment Group

Engineering Consulting and Training Services

dan

Rekayasa Pertambangan - Program Pasca Sarjana

Institut Teknologi Bandung

Pipeline Risk Assessment

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MENGAPA ADA RISK ?

1. Pipeline memiliki masalah dalam disain & konstruksi

2. Pipeline mengalirkan fluida berbahaya

3. Pipeline sudah dioperasikan untuk waktu yang cukup

lama (aging)

4. Adanya mekanisme kerusakan yang terjadi sehingga

pipa gagal (mis : akibat faktor lingkungan/korosi)

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Damage Mechanism & Failure Modes

1. Fatigue

2. Corrosion

3. Brittle Fracture

4. Buckling / Plastic Deformation

5. Stress Corrosion Cracking

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The Origin of Failure

9 Design Faulty

9 Manufacture Defect

9 Construction Defect

9 Operation Misconduct

9 Maintenance/Assembling

9 Inspections

9 Nature

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1986 1988 1990 1992 1994 1996 1998 2000 250 200 150 100 50 0 No. of Incidents Fatalities Property Damage ($MM)

DOT Gas Distribution Incidents : 1986-99

Data statistik memperlihatkan bahwa risk dari pipeline dapat

dikurangi, dikendalikan, atau diubah tetapi tidak dapat dihilangkan

menjadi nol.

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28.4 5.5 5.5 58.7 0.9 0.9 33.3 5.6 3.7 54.6 2.8 0 20.9 5.2 3.7 65.7 4.5 0

0

10

20

30

40

50

60

70 Other

Accidently Caused by

Operator

Construcion/Operating

Error

Damage from Outside

Forces

External Corrosion

Internal Corrosion

1998

1997

1996

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Risk = Probability of Failure x Consequences of Failure

Risk = LoF (t) x CoF (t)

Probability adalah peluang terjadinya sebuah kegagalan (0 ≤ p ≤ 100%).

P = 0, kegagalan tidak mungkin terjadi, jika P = 1, kegagalan pasti terjadi.

Likelihood adalah deskripsi kualitatif dari probability dan frekwensi kegagalan

Safety adalah perlindungan terhadap publik, lingkungan dan kepemilikan, sedangkan Risk

adalah ancaman terhadap pencapaian tujuan tersebut.

Hazard (“bahaya”) adalah karakteristik (atau sebuah kelompok karakteristik) yang

berpotensi menghasilkan kerugian - loss (mis : flammability, toxicity, reactivity).

Pipeline Incident hasil dari satu atau lebih kejadian dalam urutan yang menyebabkan

pipeline kehilangan integritas dan kehilangan isinya baik produk cair maupun gas.

DEFINISI

Risk adalah produk dari peluang (likelihood / probability) kegagalan dan dampak nya

(consequences) yang tidak diinginkan (accidental event).

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KARAKTERISTIK RESIKO

1. Istilah “Risk” artinya kita tidak dapat menentukan secara tepat nilai

atau besarnya sebab kedua faktor diatas (peluang kegagalan dan

dampaknya) masih memiliki unsur ketidakpastian (uncertainty).

2. Risk memiliki dimensi yang beragam :

a. Score (tanpa satuan, 344, 45, 6B, 1A, ….. )

b. Jumlah kecelakaan/kematian per tahun

c. Jumlah kerugian pertahun ($/yr), dsb.

3. Risk memiliki nilai relatif dan tidak dapat berdiri sendiri, jadi

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Define Objectives

Segment Identification

Data & Info Gathering Likelihood of Failure Consequences of Failure (Hazard) Risk Estimation Acceptable Risk? Risk Mitigation Maintaining RIsk Level Acceptable Protection - Performcance Improvement - Conditioning Monitoring Feedback Yes No

Pipeline Risk Assessment

Pipeline Risk Management

Flow Chart untuk Pipeline Risk Assessment

Risk Assessment

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Pipeline

Data

Design

Assessment

Maintenance

Inspection

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APA KEUNTUNGAN DARI

PENGELOLAAN RISK ?

9 Terjalin komunikasi yang baik antara pipeline operator,

regulator, insurer, customer, dan pihak lainnya.

9 Peningkatan safety dan reliability system pipeline.

9 Penurunan biaya operasi, inspeksi dan maintenance

pipeline.

9 Keamanan bagi lingkungan dan masyarakat sekitar

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Masukan dalam Perhitungan Risk

9 Data disain dan kondisi operasi pipa

9 Sejarah kegagalan (jika ada)

9 Rekaman temuan inspeksi

9 Data populasi dan distribusi penduduk

9 Kondisi ROW aktivitas pihak ketiga

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DATA TEKNIS YANG PERLU

MENDAPAT PERHATIAN SERIUS :

9 Review dari Fluida (minyak dan gas)

9 Product Hazard dan Faktor Dispersi

9 Sejarah Kebocoran (jika ada)

9 Data Penggalian

9 Suvey Potensial untuk Proteksi Cathodic

9 Survey Cacat Coating

9 Hasil Intelligent Pig

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Probability of Failure atau Likelihood of Failure

Peluang kegagalan merupakan komponen pertama dalam

perhitungan resiko dan harus dapat ditentukan terlebih dahulu.

Peluang kegagalan merupakan indikator utama terhadap integritas

struktur dan keandalan pipa terhadap kerusakan yang dihasilkan.

Probability of Failure dapat dihitung / ditaksir dari :

1. Teori Reliability dan Probabilistik (mis : FOSM)

2. Fault Tree Analysis

3. Sejarah / Laju Kegagalan persatuan waktu (Frekwensi of Failure)

4. Sistim score berdasarkan weighting faktor, dsb.

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Likelihood of Failure / Frequency of Failure

Accident probability

tergantung

:

kondisi pipa

,

management, human error,

dsb

.

1.

1. high

high

F > 10

-

2

2 _{per year}

_{per year}

2.

2. low

low

10

10 -

-

2

2 _{> F>10}

_{> F>10}

-

4

4 _{per year}

_{per year}

3.

3. very low

very low

10

10 -

-

4

4 _{> F>10}

_{> F>10}

-

6

6 _{per year}

_{per year}

4.

4. rare

rare

10

10 -

-

6

6 _{> F >10}

_{> F >10}

-

8

8 _{per year}

_{per year}

5.

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Failure rates untuk pipa dengan diameter ½ ”- 2”

FAILURE MODES

FAILURE RATES

Small leak

10

-9

_{per hr.m}

Break

3.10

-11

_{per hr.m}

Failure Rates 5 x 10

-4

_{(per km per yr)}

Small

x < 20 mm

87%

Medium

20 mm < x < 80 mm

10%

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Annual Failure Frequency Ranking for One pipeline

Category Description Frequency

1 (low)

So low frequency that event considered negligible. <10-5

2 Event rarely expected to occur. 10-4_>10-5

3 (medium)

Event individually not expected to happen, but when summarized over a large number of pipelines have the credibility to happen once a year.

10-3_>10-4

4 Event individually may be expected to occur during the lifetime of the

pipeline (Typically a 100 year storm) 10

-2_>10-3

5 (high)

Event individually may be expected to occur than once during lifetime.

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Consequence of Failure

Menjelaskan hasil atau akibat atau dampak (-) sebuah accidental

event. Konsekewnsi biasanya dievaluasi dari sisi i) human

savety, ii) environmental impact dan iii) economic loss atau

besaran lain yang menyebabkan kerugian material atau

non-material.

Resiko yang tidak diinginkan pada kegagalan pipeline

1. Fire

2. Explosion

3. Pollution

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Identifying Potential Consequences for Pipeline

Pipeline

Human safety

Environmental

impact

Material

Damage

Gas

Relevant

Normally not

relevant

4

Relevant

Condensate

Relevant

1

_Relevant

Oil

Relevant

Water

Normally not relevant

Relevant

5

_Relevant

Umbilical

Normally not

relevant

2

Normally not

relevant

2,3

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Safety Consequence Ranking

Description

1 (low)

No person(s) are injured

2 (not used)

3 (medium)

Serious injury, one fatality (working accident)

4 (not used)

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Spillage Ranking

Category Description Amount of

release

1 (low) Non, small or insignificant of the environment.

Either due to no release of internal medium or only insignificant release.

~ 0

2 Minor release of polluting media. The released media

will decompose or be neutralized rapidly by air or seawater.

<1000 tonnes

3 (medium) Moderate release of polluting medium. The released

media will use some time to decompose or neutralize by air or seawater, or can easily be removed.

<10000 tonnes

4 Large release of polluting medium which can be

removed, or will after some time decompose or be neutralized by air or seawater.

<100000 tonnes

5 (high) Large release of high polluting medium which can not

be removed and will use long time to decompose or be neutralized by air or seawater.

>100000 tonnes

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Economic Consequence Ranking

Description

Production delay/

Downtime

1 (low) Insignificant effect on operation, small or insignificant cost of

repair 0 days

2 Repair can be deferred until scheduled shutdown, some repair

costs will occur.

<1 month

3 (medium) Failure causes extended unscheduled loss of facility or system

and significant repair costs. Rectification requires unscheduled underwater operation with pre-qualified repair system before further production.

1-3 months

4 Failure causes indefinite shut down and significant facility of

system failure costs. Rectification requires unscheduled underwater operation without pre-qualified repair system before further production, OR Failures resulting in shorter periods of shut down of major parts of (or all of) the

hydrocarbon production for the field.

3-12 months

5 (high) Total loss of pipeline and possible also loss of other structural

parts of the platform. Large cost of repair including long time of shut down of production. OR Failures resulting in shut down of the total hydrocarbon production for a longer period.

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16-23 J06-24 JO7-24 J05-18 C513-07 WO9-23 WO6-24 WO4-24 WO6-18 W11-18 W10-07 JO4-24 JO7-24 J11-18 4" 0.48 km 12" 1 km 12" 0.5 km 12" 1.2 km 10" 1.0 km 10" 0.48 km 8"0.48 km 6" 0.48 km 3" 0.4 km 10" 0.6 km

PIPELINE SECTIONING

Pembagian seksi pipa perlu untuk mengidentifikasi bagian pipeline

yang memiliki potensi risk tertinggi.

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PRESENTASI RISK - MATRIX

Representasi grafis untuk memudahkan mengkarakterisasi

pipeline risk (merupakan rangkuman)

Consequence evaluation Human safety, Environmental Impact Economical loss Consequence vs damage Not acceptable ALARP region Acceptable Event Frequency estimation Frequency vs damage Frequency ranking 1 2 3 4 5 1 2 3 4 5 Risk matrix