OFFSHORE STRUCTURES DESIGN OF THREE-LEGGED FIXED JACKET PLATFORM IN MAHAKAM BLOCK, EAST KALIMANTAN

• Main Author: Kristian Danarko, Ignatius
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/80230
• Institution: Institut Teknologi Bandung

The decline rate of domestic oil and gas production in the last ten years occurs as a result of the production inefficiency in the existing field. Necessary effort should be held responsible by the government and oil and gas practitioner to overcome this problem – considering that oil and gas contribution to our energy main resources is as yet significant, at least until 2050. Increasing the number of production facilities to the existing field should come as a solution in addressing the problem. In this final project, offshore structures design of a fixed-jacket type production platform is carried out as a supporting production structure in Mahakam Block, East Kalimantan. Feasibility study of this structure is evaluated through in-place structural analysis, seismic analysis, and fatigue analysis, referring to API RP 2A-WSD, 21st edition. The design criteria examined in the in-place analysis and seismic analysis include the stress ratio of structural member, joint punching shear, pile axial capacity, and deflection. In the fatigue analysis, the fatigue life of the structure will be examined based on the service life requirements used in this final project (40 years). Based on in-place analysis’ results, the structure satisfies the applicable criteria with horizontal bracing being the component with the largest member stress ratio (UC=0.78). The structure also satisfies the criteria applicable to seismic analysis, with the largest member stress ratio is taken place by the secondary framing component on the main deck (UC=0.45). Results of the fatigue analysis show that the fatigue life of the joint components satisfy the service life criteria, with the minimum fatigue life occurs in the X-bracing connection (1108 years). Some adjustments have been made by modifying the jacket tubular profile, with the fatigue life result of the same connection turns out to have a lower value (107 years) compared to the initial condition.