The Structural Analysis Of The Jacket Mooring Tower

With the exploration of offshore and deep-sea petroleum resources, the exploration and development of shallow marginal oil and gas has attracted a lot of attention, the research and fabrication of the small floating production system has become a popular topic for shallow marginal oil and gas exploration by national petroleum corporations. In this paper, the mooring structure type is studied as a part of the small floating production system of ShengLi Oil-field Engineering and Consulting Corporation.In this paper, based on the design Guidebook of Petro-offshore Engineering and the marine environment of shallow sea near Cheng Island of Shengli Oilfield, a flexible rigid arm system like tower --- mooring tower jacket structure is proposed and studied. The main contents are as follows:1. Consider the marine environment loads probably influencing the structure and calculate the external force according to the formulas of wind, wave, fluid and ice load of current codes(according to DET NORSKE VERITAS'standard) and mooring force of oil tanker caused by marine environment.2. Establish the ANSYS model of mooring tower, proceed the static analysis under the load combinations of normal condition, ultimate wave condition and ultimate ice condition, model analysis by Block Lanczos method, confirm the relationship between structure natural frequency and wave load frequency; instant analysis of static loads and instant ice loads by complete method, to further explain ice loads is the main control load.3. Summarize the main load and influence factors of mooring tower based on the calculation results, optimize the structural weight, jacket diameter and pipe thickness by Zero-order method and optimization program in ANSYS software and check the structural strength under the condition of ultimate ice load case by a set of optimization result.