Numerical Analysis of Structural Strength and Safety Characteristics for Subsea tree
Date
2023-04-23
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
asiri waleed abdullah i
Abstract
With the development of offshore oil and gas exploration, the number of Subsea trees
has increased rapidly, which has become the mainstream model of oil and gas development.
Subsea tree has been in the marine environment for a long time, which bearing complex
environmental load and working load, and the failure probability is high. What’s more, the
structure of subsea tree components is difficult to repair and replace, the damage of its
structure will not only affect the normal transmission of oil and gas, but also cause serious
marine environmental pollution and ecological disaster. Therefore, in this paper, a set of risk
analysis and evaluation method suitable for Subsea tree is proposed, which helps to find the
potential risks and weak links before operation. The main contents and innovations of this
paper are as follows:
The fault data of underwater subsea tree is difficult to statistics, the structural strength
and safety characteristics of subsea tree is analyzed by using fuzzy fault tree analysis method,
which results to the importance of fuzzy probability of subsea tree system is analyzed. Based
on the OREDA database, a fault tree is established for the above fault events of the
underwater Subsea tree. "Subsea tree fault" is selected as the top event, which is analyzed
from throttling module fault, subsea tree body fault, tubing hanger fault and hydraulic
connector fault.
In order to further determine the failure mode and its weak links, the safety risk
assessment of subsea tree is carried out on the basis of the failure mode of subsea tree and the
failure frequency of its subsystem. Analytic hierarchy process (AHP) and technique for order
preference by similarity to ideal solution (TOPSIS) are used to evaluate the multi-index risk
of underwater subsea tree leakage scenario. The weight vector of each evaluation index is
determined by AHP, and a comprehensive evaluation index system is constructed based on the
principle of TOPSIS. Then it is proposed to calculate the comprehensive advantages of
internal leakage and external leakage from three aspects: environmental safety, leakage
probability and economic loss. The example analysis shows that the risk value of external
leakage is higher than that of internal leakage, which indirectly verifies the feasibility and
III
effectiveness of the proposed comprehensive evaluation index system.
Based on the risk assessment of Subsea tree, Bayesian network method is used to
analyze the safety characteristics of fault polymorphism, fuzziness and dynamics for
underwater subsea tree system and its components. Fuzzy set theory is introduced into
Bayesian analysis, which considered the polymorphism of system and component faults and
the variation law of failure probability, and this method is applied to the safety characteristic
analysis of underwater subsea tree.
Description
Subsea tree-Structural strength- Safety characteristics-Least square method-
Index system-Analytic hierarchy process-Tubing hanger-Bayesian networks
Keywords
Subsea tree-Structural strength- Safety characteristics-Least square method- Index system-Analytic hierarchy process-Tubing hanger-Bayesian networks
Citation
Day-Ahead Generation Schedule of Wind-Thermal-Storage System Considering Prediction Error