Analisis Umur Kelelahan Sisa pada Struktur Jacket Platform Akibat Pengaruh Subsidence

Munaf, As Achmad Daffa Dhiya'udien (2024) Analisis Umur Kelelahan Sisa pada Struktur Jacket Platform Akibat Pengaruh Subsidence. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Banyak anjungan minyak dan gas di perairan Indonesia, baik yang masih beroperasi maupun yang telah melewati batas umur operasi (expired) mengalami peristiwa subsidence, terutama pada struktur jacket platform. Subsidence di sekitar platform ini disebabkan oleh eksploitasi migas yang masif pada reservoir hidrokarbon yang sedang berproduksi. Fenomena ini menimbulkan risiko karena beban gelombang yang tidak dapat ditoleransi, di mana gelombang tersebut meningkatkan risiko kegagalan struktur, yang dapat berdampak pada operasional platform. Perubahan kondisi seabed akibat subsidence juga akan memengaruhi beban gelombang siklis yang diterima oleh struktur jacket platform. Pada Tugas Akhir ini, penulis akan menganalisis umur kelelahan sisa pada struktur jacket platform akibat subsidence. Penelitian Tugas Akhir ini bertujuan untuk menganalisis pengaruh subsidence terhadap umur kelelahan struktur jacket platform. Pengujian dilakukan dengan menggunakan metode cumulative damage dan fracture mechanics untuk memprediksi waktu kegagalan komponen yang ditinjau pada struktur jacket platform pada kondisi non-subsidence dan saat terjadinya subsidence. Hasil analisis menunjukkan bahwa umur kelelahan struktur akan berkurang ketika terjadi subsidence. Dengan metode cumulative damage, nilai umur kelelahan kondisi non-subsidence adalah 279 tahun, sedangkan umur lelah sisa struktur pada kondisi subsidence adalah 59 tahun. Sementara itu, dengan metode fracture mechanics, nilai umur kelelahan kondisi non-subsidence adalah 76 tahun, dan umur lelah sisa struktur pada kondisi subsidence yaitu 41 tahun. Hasil tersebut menunjukkan penurunan nilai umur kelelahan struktur yang cukup signifikan.
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Many oil and gas platforms in Indonesian waters, both those still operating and those that have passed the operating life limit (expired), experience subsidence events, especially in the jacket platform structure. Subsidence around these platforms is caused by massive oil and gas exploitation in producing hydrocarbon reservoirs. This phenomenon poses a risk due to intolerable wave loads, where the waves increase the risk of structural failure, which can impact platform operations. Changes in seabed conditions due to subsidence will also affect the cyclical wave loads received by the platform jacket structure. In this Final Project, the author will analyze the residual fatigue life of the jacket platform structure due to subsidence. This Final Project research aims to analyze the effect of subsidence on the fatigue life of the jacket platform structure. Tests were carried out using cumulative damage and fracture mechanics methods to predict the failure time of the components reviewed in the jacket platform structure under non-subsidence conditions and when subsidence occurs. The analysis results show that the fatigue life of the structure will be reduced when subsidence occurs. With the cumulative damage method, the fatigue life value of the non-subsidence condition is 279 years, while the residual fatigue life of the structure in the subsidence condition is 59 years. Meanwhile, using the fracture mechanics method, the value of the fatigue life of the non-subsidence condition is 76 years, and the residual fatigue life of the structure in the subsidence condition is 41 years. These results show a significant decrease in the fatigue life of the structure.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Jacket Platform, Kelelahan, Cumulative Damage, Fracture Mechanics, Subsidence; Jacket Platform, Fatigue, Cumulative Damage, Fracture Mechanics, Subsidence
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA347 Finite Element Method T Technology > TC Hydraulic engineering. Ocean engineering > TC1665 Offshore structures--Materials. T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User:	As Achmad Daffa Dhiya'udien Munaf
Date Deposited:	26 Jul 2024 01:21
Last Modified:	26 Jul 2024 01:21
URI:	http://repository.its.ac.id/id/eprint/108947

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