Evaluation of seismic response of topside equipment at fixed offshore platforms
Evaluation of seismic response of topside equipment at fixed offshore platforms
Dosyalar
Tarih
2022-02-02
Yazarlar
Huseynli, Ashraf
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Yayınevi
Graduate School
Özet
Nowadays, oil and gas have an enormous role in the global economy, being the most common energy source. Considering the more significant oil and gas reserves are located in subsea, particular offshore structures assist the oil and gas extraction process. Besides operational and dead loads, these structures take the risk of being subjected to high rates of seismic, wind, and wave loads. Considering the heavily-weighted vessels containing flammable materials on offshore topside structures, any damage to these vessels during a seismic event can lead to a collapse of a part, leading to a fire or blast concluding with a disaster. Hence, a study on the response of topside equipment and their connections to seismic actions is a worth approach of disaster management to be looked into. This study aims to study the response of typical topside equipment subjected to seismic events. Hence, a model of a fixed offshore structure and several types of equipment widely used in upstream operations with real-life physical parameters have been developed in finite element analysis software. In the finite element analysis, 22 historical ground motion records have been utilized. These records have been chosen based on several parameters as earthquake magnitude, peak ground acceleration, peak ground velocity, frequency content parameters, and et cetera. Firstly, the response of the fixed offshore platform has been analyzed and the topside acceleration time histories have been found. Then, these topside acceleration time histories have been applied to the bases of the equipment to capture the response of these vessels to seismic events. The probability of failure occurring at the vessels has been observed to have a direct relationship with several ground motion parameters and the seismic response of the platform structure. Damage levels on the equipment have been represented by effective plastic strain values. The ground motion parameters like the peak ground acceleration and duration have been observed to have a significant impact on the plastic strain formation at the vessels. Moreover, near-fault ground motions containing displacement and velocity pulses have been noted to form significant damages at the vessels according to the displacement and velocity pulses. Furthermore, the results show that the damage probability of the vessels demonstrated diversity according to the geometrical shape and natural period. The results obtained from the study provide a basis for several seismic design recommendations for topside equipment at fixed offshore structures.
Açıklama
Thesis (M.Sc.) -- İstanbul Technical University, Graduate School, 2022
Anahtar kelimeler
Offshore platforms,
Açık deniz platformları,
Seismic behavior,
Sismik davranış,
Pavement elements,
Üst yapı elemanları,
Tanks,
Tanklar