Perpustakaan Digital ITB

The increasing demand of energy in the form of oil and gas has skyrocketed in the past few years and has become a crucial part of the automation and industrial sector. The high demand of energy has led to the exploration and exploitation of oil and gas offshore. To support the exploration and exploitation of oil and gas, a structure known as an offshore platform required. Offshore platforms are designed to withstand the extreme environmental conditions during the designated service life of the structure. This final project discusses the design of a four-legged fixed offshore platform in accordance with the API RP 2A WSD standards. In addition, an in-service analysis consisting of in-place, seismic, and fatigue analysis, as well as a jacket upending analysis is conducted. Based on the in-place analysis, the designed structure complies the API RP 2A WSD standards for member stress check, tubular connection check, deflection, and pile capacity. The structure also complies the seismic analysis requirements for member stress check, tubular connection check, and pile capacity during strength level earthquake (SLE) and ductility level earthquake (DLE) condition. The fatigue analysis of the structure shows that it has a service life of 15.41 years with a damage value of 0.973. After the structure complies all of the in-service analysis requirements, the structure undergoes a type of pre-service analysis known as upending analysis for the jacket structure. An upending analysis consists of floatation, lifting, and upending simulation of the jacket structure in accordance with GL Noble Denton 0028/ND Guidelines for Steel Jacket Transportation and Installation criteria. The combined controlled ballasting and crane assisted upending is analyzed. The use of buoyancy tank is considered to upend the structure. Based on the upending analysis, the jacket structure complies upending analysis criteria for seabed clearance, transverse GM, and longitudinal GM. Based on the maximum hook load during the upending phase, the Eka Nusantara 3000 (EN3000) Derrick Barge is selected for the installation process. The barge has a maximum main hook lifting capacity of 3000 MT and 600 MT for the auxiliary hook.