Analisa resiko terhadap pipa gas bawah laut kodeco akibat scouring sedimen dasar laut

Rubbyanto, Rezha (2010) Analisa resiko terhadap pipa gas bawah laut kodeco akibat scouring sedimen dasar laut. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Analisis risiko dalam penelitian Tugas Akhir ini dilakukan pada sistem perpipaan bawah laut milik Kodeco Energy Co. Ltd. dari lepas pantai Poleng Process Platform (PPP) sampai di Onshore Receiving Facilities (ORF) akibat _scouring_ sedimen dasar laut. _Scouring_ merupakan pergerakan tanah dasar laut yang disebabkan oleh aliran air laut, yakni arus dan gelombang, yang prosesnya sama seperti erosi dan secara alami juga dapat disebabkan oleh elemen struktur yang berada dekat dengan dasar laut. Fenomena _scouring_ ini dapat menyebabkan timbulnya bentangan bebas (_freespans_) yang memungkinkan terjadinya _buckling_ dan gangguan stabilitas terhadap pipa gas bawah laut sebagai akibat perubahan gaya hidrodinamis yang bekerja di lokasi _scouring_. Oleh karena itu, diperlukan suatu analisis yang dapat menentukan tingkat risiko terhadap pipa bawah laut Kodeco akibat _scouring_ berbasis keandalan. Peluang kegagalan diperoleh dengan menerapkan metode BEA untuk mendapatkan nilai indeks keandalan terhadap gaya hidrodinamis vertikal dan gaya hidrodinamis lateral. Dari hasil perhitungan, didapatkan peluang kegagalan terhadap gaya hidrodinamis vertikal untuk ketiga lokasi penelitian, yakni KP 50, KP 52, dan KP 54, adalah nol. Sedangkan peluang kegagalan terhadap gaya hidrodinamis lateral berkisar antara 0,0021–0,0070 untuk panjang _span_ yang berbeda di tiap _kilometer point_ yang ditinjau. Perhitungan konsekuensi diperoleh melalui kalkulasi kombinasi tegangan-tegangan yang bekerja pada sistem perpipaan tersebut. Penentuan tingkat risiko didasarkan pada perhitungan frekuensi tahunan dan konsekuensi kegagalan yang diberikan dalam bentuk matriks risiko. Dengan mengacu pada DNV-RP-F107, diperoleh tingkat risiko untuk ketiga lokasi penelitian terhadap gaya hidrodinamis vertikal, yakni berada di zona hijau. Sedangkan tingkat risiko terhadap gaya hidrodinamis lateral untuk masing-masing panjang _span_ yang berbeda di ketiga lokasi penelitian berada di zona ALARP.
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The risk analysis in this research is performed on a subsea piping system owned by Kodeco Energy Co. Ltd., extending from the offshore Poleng Process Platform (PPP) to the Onshore Receiving Facilities (ORF), due to subsea sediment scouring. Scouring is the movement of seabed soil caused by seawater flow, including currents and waves, in a process similar to erosion, which can also naturally occur due to structural elements located close to the seabed. The scouring phenomenon can cause the formation of free spans, which may lead to buckling and stability disturbances in the subsea gas pipeline as a result of changes in hydrodynamic forces occurring at the scouring location. Therefore, an analysis is required to determine the risk level of the Kodeco subsea pipeline due to scouring based on reliability. The probability of failure is obtained by applying the BEA method to determine the reliability index for vertical and lateral hydrodynamic forces. The calculation results show that the probability of failure due to vertical hydrodynamic forces at the three research locations, namely KP 50, KP 52, and KP 54, is zero. Meanwhile, the probability of failure due to lateral hydrodynamic forces ranges from 0.0021 to 0.0070 for different span lengths at each kilometer point reviewed. The consequence calculation is obtained through the calculation of the combination of stresses acting on the piping system. The risk level is determined based on the calculation of the annual frequency and consequences of failure, presented in the form of a risk matrix. Referring to DNV-RP-F107, the risk level for the three research locations due to vertical hydrodynamic forces is in the green zone. Meanwhile, the risk level due to lateral hydrodynamic forces for the different span lengths at the three research locations is in the ALARP zone.

Item Type:	Thesis (Other)
Additional Information:	665.744 Rub a
Uncontrolled Keywords:	Scouring, Freespans, Metode Bea, Risiko vii, Scouring, Freespans, Bea Method, Risk
Subjects:	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:	magang .
Date Deposited:	08 Oct 2026 01:59
Last Modified:	08 Oct 2026 01:59
URI:	http://repository.its.ac.id/id/eprint/145418

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