Conceptual Design and Feasibility Study of Offshore Platform Reutilization for Fish Storage Facilities

Alghozwani, Ahmad Kholis (2026) Conceptual Design and Feasibility Study of Offshore Platform Reutilization for Fish Storage Facilities. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Laut Natuna Utara merupakan salah satu kawasan perikanan paling produktif di Indonesia, namun jarak yang jauh antara kawasan penangkapan ikan lepas pantai dan pelabuhan pendaratan menyebabkan waktu pengangkutan menjadi lebih lama, konsumsi bahan bakar meningkat, serta penurunan kualitas hasil tangkapan pasca-panen. Di saat yang sama, banyak anjungan minyak dan gas lepas pantai di Indonesia yang mendekati akhir masa pakainya meskipun masih memiliki integritas struktural yang memadai untuk dimanfaatkan lebih lanjut. Penelitian ini mengusulkan pemanfaatan kembali anjungan lepas pantai yang sudah tua sebagai fasilitas penyimpanan ikan dan pengisian bahan bakar di tengah laut melalui kerangka kerja teknik terpadu yang menggabungkan analisis spasial, pengambilan keputusan multi-kriteria, perancangan ulang konsep anjungan, analisis struktural, dan evaluasi sisa masa pakai. Kernel Density Estimation (KDE) dan Hotspot Analysis Getis-Ord Gi* digunakan untuk mengidentifikasi kawasan penangkapan ikan prioritas, sedangkan Entropy Weighting dan Simple Additive Weighting (SAW) digunakan untuk mengevaluasi dua kandidat platform yang lolos tahap penyaringan teknis. Hasil penelitian menunjukkan bahwa platform North Belut WHPD–CPP merupakan kandidat yang paling sesuai, dengan skor akhir SAW tertinggi sebesar 1,0000 dibandingkan 0,7196 untuk kandidat Kerisi. Desain ulang yang diusulkan mengurangi berat operasional anjungan dari 16.000 MT pada kondisi operasi minyak dan gas semula menjadi 8.963 MT, yang hanya mewakili 56% dari beban desain semula, sekaligus mengakomodasi fasilitas penyimpanan ikan, pembekuan cepat, pengisian bahan bakar, akomodasi, dan fasilitas pendukung. Penilaian struktural menggunakan SACS menegaskan bahwa elemen penentu memenuhi kriteria penerimaan API RP 2A dengan nilai pemeriksaan kesatuan maksimum sebesar 0,97 setelah justifikasi ulang. Penilaian kelelahan berdasarkan kerusakan kumulatif Palmgren–Miner menghasilkan perkiraan umur kelelahan awal 71,59 tahun; setelah memperhitungkan laju korosi pada zona splash di sekitar elemen boat landing, sisa masa pakai terkoreksi diperoleh sebesar 15,84 tahun dari kondisi saat ini, atau setara total umur struktural 33,84 tahun, yang masih melampaui masa desain 25 tahun. Temuan ini menunjukkan bahwa pemanfaatan kembali platform lepas pantai yang sudah tua merupakan solusi yang layak secara teknis dan berkelanjutan untuk memperkuat logistik perikanan lepas pantai sekaligus memperpanjang masa pakai infrastruktur lepas pantai yang ada.
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Indonesia's North Natuna Sea is one of the country's most productive fishing regions; however, the long distance between offshore fishing grounds and landing ports increases transportation time, fuel consumption, and post-harvest quality deterioration. At the same time, many offshore oil and gas platforms in Indonesia are approaching the end of their production life despite retaining adequate structural integrity for further utilization. This study proposes the reutilization of aging offshore platforms as mid-sea fish storage and bunkering facilities through an integrated engineering framework combining spatial analysis, multi-criteria decision-making, conceptual platform redesign, structural assessment, and remaining life evaluation. Kernel Density Estimation (KDE) and Getis-Ord Gi* Hot Spot Analysis were employed to identify priority fishing areas, while Entropy Weighting and Simple Additive Weighting (SAW) were used to evaluate the two candidate platforms that passed the technical screening stage. The results indicate that the North Belut WHPD–CPP platform is the most suitable reutilization candidate, achieving the highest SAW final score of 1.0000 compared to 0.7196 for the Kerisi candidate. The proposed redesign reduces the platform operating weight from 16,000 MT under the original oil and gas operating condition to 8,963 MT, representing only 56% of the original design loading while accommodating fish storage, blast freezing, bunkering, accommodation, and supporting utility facilities. Structural assessment using SACS confirms that the governing member satisfies the API RP 2A acceptance criterion with a maximum unity check of 0.97 after rejustification. Fatigue assessment based on Palmgren–Miner cumulative damage produced an initial predicted fatigue life of 71.59 years; after accounting for splash-zone corrosion at the boat landing member, the corrosion-adjusted remaining life was estimated at 15.84 years from the platform's current condition, corresponding to a total structural life of 33.84 years, which still exceeds the 25-year design life. These findings demonstrate that reutilizing aging offshore platforms provides a technically feasible and sustainable solution for strengthening offshore fisheries logistics while extending the service life of existing offshore infrastructure.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Offshore Platform, Reutilization, Fish Storage Facility, Structural Assessment, Remaining Life
Subjects:	T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM276.A1 Fuel (Including supplies, costs, etc.) V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM485 Cold storage on ships. Marine refrigeration.
Divisions:	Faculty of Marine Technology (MARTECH) > Marine Engineering > 36202-(S1) Undergraduate Thesis
Depositing User:	Ahmad Kholis Alghozwani
Date Deposited:	04 Aug 2026 06:28
Last Modified:	04 Aug 2026 06:28
URI:	http://repository.its.ac.id/id/eprint/143370

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