Penilaian Risiko Pipa Bawah Laut akibat Instalasi dan Operasi Single Point Mooring (SPM)

Aldara, Desta Rifky (2020) Penilaian Risiko Pipa Bawah Laut akibat Instalasi dan Operasi Single Point Mooring (SPM). Masters thesis, Marine Engineering.

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Abstract

Fasilitas eksplorasi lepas pantai yang berada pada daerah terpencil memerlukan investasi dan biaya operasional yang tinggi. Sehingga aset-aset yang dimiliki tergolong menjadi aset yang sangat penting bagi perusahaan. Oleh karena itu, studi dan pemeriksaan yang cermat diperlukan untuk memastikan bahwa risiko fasilitas dapat diterima. Eksplorasi lepas pantai tidak terlepas dari penggunaan pipa bawah laut yang memiliki beberapa risiko apabila terjadi kerusakan. Berdasarkan data historis, kegagalan pipa bawah laut disebabkan oleh faktor pihak ketiga (dropped anchor, dragged anchor, dan ship sinking). Dalam kajian ini, penilaian risiko terhadap pipa bawah laut akibat dari instalasi dan operasional Single Point Mooring (SPM) dilakukan dengan menggunakan standar DNVGL RP F107 dan simulasi numerik. Frekuensi dinilai dengan membandingkan hasil dari metode Event Tree Analysis (ETA), Fault Tree Tree Analysis (FTA), dan Bayesian Network. Sedangkan penilaian konsekuensi dilakukan dengan perhitungan pada standar DNVGL RP F107, simulasi Computational Fluid Dynamics (CFD) dan Finite Element Method (FEM). Hasil frekuensi dan konsekuensi dipetakan dalam matriks risiko menurut DNVGL RP F107. Berdasarkan hasil perhitungan, semua jenis kapal memiliki nilai frekuensi kurang dari 10-5 (peringkat 1). Sedangkan peringkat konsekuensi terendah berada pada peringkat 3 dengan nilai dent 12.32% dan tertinggi berada pada peringkat 5 (>20%) yang mengakibatkan kerusakan pada pipa bawah laut. Hasil pemetaan risk matrix menunjukkan bahwa tingkat risiko berada pada kondisi acceptable dan ALARP (As Low As Reasonably Practicable). Kondisi acceptable diperoleh dari peringkat frekuensi 1 dan konsekuensi peringkat 3 dan 4. Sedangkan kondisi ALARP diperoleh dari frekuensi pada peringkat 1 dan konsekuensi pada peringkat 5. Meskipun tidak wajib untuk dilakukan mitigasi, akan tetapi tetap disarankan untuk melengkapi pipa bawah laut dengan proteksi eksternal. Proteksi eksternal berupa rock dumping disarankan untuk melindungi pipa bawah laut karena memiliki kemampuan yang baik untuk melindungi pipa bawah laut dari benturan benda dan memiliki yang lebih murah dibandingkan dengan concrete mattress. ============================================================================================= Offshore exploration facilities located in remote areas require high investment and high operational cost. The assets are classified as vital assets for the companies. The careful study and examination is therefore required to ensure that the risk of the facility is acceptable. Offshore exploration used subsea pipelines that has several risks if the accident occurs. Based on historical data, most of subsea pipelines failures are caused by third party factors (dropped anchor, dragged anchor, and ship sinking). This paper examines risk assessment of subsea pipelines due to installation and operation of Single Point Mooring (SPM) used DNVGL RP F107 standard and numerical simulations. Frequency is assessed by comparing the results of the Event Tree Analysis (ETA), Computational Fluid Dynamics (CFD), and Fault Tree Tree Analysis (FTA), and Bayesian Network methods. Whereas the consequences were assessed by using calculations on the DNVGL RP F107 standard and Finite Element Method (FEM). The results of frequency and consequences are mapped within a risk matrix according to DNVGL RP F107. Based on the calculation, the frequency of all types of vessels is less than 10-5 (rank 1). While the lowest consequence was rank 3 with a dent/diameter is 12.32% and the highest was rank 5 (>20%) which can damage the subsea pipelines. The risk matrix shows that the risk level are in acceptable and ALARP (As Low As Reasonably Practicable) condition. Acceptable obtained by frequency in rank 1 and the consequence in rank 3 and 4. While ALARP obtained by frequence rank 1 and consequence rank 5. Although it is not mandatory for mitigation, it is recommended to provide the subsea pipeline with external protection. Rock dumping is recommended as external protection for subsea pipelines due to the good ability to protect the subsea pipelines and it has lower cost compared to concrete mattress.

Item Type: Thesis (Masters)
Uncontrolled Keywords: CFD, DNVGL RP F107, FEM, Penilaian risiko, Pipa bawah laut CFD, DNVGL RP F107, FEM, Risk Analysis, Subsea Pipeline
Subjects: T Technology > T Technology (General) > T174.5 Technology--Risk assessment.
T Technology > TJ Mechanical engineering and machinery > TJ930 Pipelines (General). Underwater pipelines.
T Technology > TN Mining engineering. Metallurgy > TN879.5 Petroleum pipelines
T Technology > TN Mining engineering. Metallurgy > TN880.5 Natural gas pipelines
Divisions: Faculty of Marine Technology (MARTECH) > Marine Engineering > (S2) Master Theses
Depositing User: Aldara Desta Rifky
Date Deposited: 02 Sep 2020 03:22
Last Modified: 02 Sep 2020 03:22
URI: https://repository.its.ac.id/id/eprint/81679

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