Penilaian Risiko Terhadap Pipa Eksisting Akibat Pembongkaran Pipa Bawah Laut Pada Anjungan Lepas Pantai

Dentawyanjana, Bhre Satriavi (2023) Penilaian Risiko Terhadap Pipa Eksisting Akibat Pembongkaran Pipa Bawah Laut Pada Anjungan Lepas Pantai. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pembongkaran pipa bawah laut anjungan lepas pantai X sebagai bagian rig to reef program berpotensi berdampak pada fasilitas pipa bawah laut yang masih aktif di sekitar wilayah pembongkaran. Hal ini dikarenakan terdapat banyak fasilitas offshore yang masih aktif di sekitar lokasi pembongkaran. Maka dari itu penilaian risiko terhadap pipa eksisting perlu dilakukan akibat proses pembongkaran pipa bawah laut terhadap bahaya dropped anchor, dragged anchor, ship sinking dan dropped object. Objek kajian pada studi ini adalah pipa bawah laut dengan panjang 2310 m sebanyak dua jalur. Dikarenakan pipa yang akan dibongkar dilapisi concrete coating maka metode pembongkaran yang dilakukan berdasarkan judgement peneliti dan expert adalah cut and lift removal. Pipa akan dipotong menjadi segmen – segmen sepanjang 10 meter. Terdapat beberapa kapal yang digunakan selama proses decommissioning yaitu satu accommodation working barge, satu transportation barge, dan dua AHTS. Durasi pembongkaran pipa bawah laut membutuhkan waktu 55 hari berdasarkan work breakdown structure yang telah dibuat dengan waktu kerja selama 8 jam per hari. Potensi bahaya berdasarkan skenario pembongkaran dan DNV-RP-F107 yaitu bahaya berupa dropped anchor, dragged anchor, dropped object (pipe), dan ship sinking. Penilaian risiko pada penelitian ini mengacu pada guidelines DNV-RP-F107. Selain itu, pada bahaya dropped anchor dan dropped object (pipe) dilakukan simulasi menggunakan software ANSYS Student Version guna mendapatkan nilai deformasi pada pipa yang akan menjadi validasi hasil perhitungan konsekuensi numerik berdasarkan guidelines DNV-RP-F107. Dari hasil penilaian risiko, bahaya dropped anchors dan dropped object (pipe) berada pada level acceptable. Sedangkan bahaya dragged anchors dan ship sinking berada pada level ALARP. Berdasarkan hasil tersebut, langkah mitigasi tidak dilakukan karena tingkat risiko tertinggi berada pada posisi ALARP. Apabila akan dilakukan penelitian selanjutnya diharapkan aspek teknis pada setiap tahapan dapat dijelaskan lebih detail, dilakukan kajian metode pembongkaran pipa bawah laut yang berbeda dengan cut and lift removal, serta simulasi dropped anchor dan dropped object perlu diteliti kembali agar hasil deformasi mendapatkan selisih yang lebih kecil dari kalkulasi berdasarkan DNV-RP-F107.
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The decommissioning of offshore platform X's subsea pipeline as part of the rig to reef program has the potential to impact active subsea pipeline facilities around the decommissioning area. This is because there are many offshore facilities that are still active around the decommissioning site. Therefore, a risk assessment of the existing pipeline needs to be carried out due to the subsea pipeline decommissioning process against the hazards of dropped anchor, dragged anchor, ship sinking and dropped object. The object of study in this study is a subsea pipeline with a length of 2310 m for two lines. Since the pipe to be dismantled is coated with concrete coating, the decommissioning method based on the judgment of researchers and experts is cut and lift removal. The pipe will be cut into 10-meter segments. There are several vessels used during the decommissioning process, namely one accommodation working barge, one transportation barge, and two AHTS. The duration of the subsea pipeline decommissioning takes 55 days based on the work breakdown structure that has been made with a working time of 8 hours per day. Potential hazards based on the dismantling scenario and DNV-RP-F107 are dropped anchor, dragged anchor, dropped object (pipe), and ship sinking. The risk assessment in this study refers to the DNV-RP-F107 guidelines. In addition, the dropped anchor and dropped object (pipe) hazards are simulated using ANSYS software to obtain the deformation value of the pipe which will validate the results of numerical consequence calculations based on DNV-RP-F107 guidelines. From the risk assessment results, the dropped anchors and dropped object (pipe) hazards are at an acceptable level. While the dragged anchors and ship sinking hazards are at the ALARP level. Based on these results, mitigation measures were not taken because the highest level of risk was at the ALARP position. If further research is to be carried out, it is hoped that the technical aspects at each stage can be explained in more detail, the different subsea pipe decommissioning methods with cut and lift removal, and the simulation of dropped anchors and dropped objects need to be re-examined so that the deformation results get a smaller difference from the calculations based on DNV-RP-F107.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Subsea Pipelines, Decommissioning, DNV-RP-F107, ANSYS Simulation, Penilaian Risiko, Subsea Pipelines, Decommissioning, DNV-RP-F107, ANSYS Simulation, Risk Assessment
Subjects:	T Technology > T Technology (General) > T174.5 Technology--Risk assessment. T Technology > TJ Mechanical engineering and machinery > TJ930 Pipelines (General). Underwater pipelines.
Divisions:	Faculty of Marine Technology (MARTECH) > Marine Engineering > 36202-(S1) Undergraduate Thesis
Depositing User:	Bhre Satriavi Dentawyanjana
Date Deposited:	15 Feb 2023 10:28
Last Modified:	15 Feb 2023 10:28
URI:	http://repository.its.ac.id/id/eprint/97339

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