Economical design with sufficient fracture resistance is of high importance in any offshore pipeline projects. Using an Engineering Critical Assessment (ECA), alternate acceptance criteria for pipeline girth weld inspection can significantly reduce the cost of constructing of offshore oil and gas pipeline by minimizing unnecessary repairs. Offshore pipelines consist of short pipeline segments c...

this paper presents a k- turbulence model for simulation of steady current and itsinduced vortex shedding caused by the presence of an offshore pipeline. performance of the modelaround a circular cylinder above a wall with gap to diameter ratios of 0.1, 0.35 and 0.5 underdifferent flow regimes with reynolds numbers of 1500, 2500 and 7000 is studied. the flow field iscomputed with solving the re...

In this paper, an intelligent ultrasonic inspection device for offshore pipeline inspection and a corrosion assessment of offshore pipeline software are developed to inspect the damage state of Chinese pipelines. The main function of the inspection system is ultrasonic signal pre-processing, data acquisition, de-noising and data compression in real time. The system includes a micro-computer, tr...

The traditional event tree analysis uses a single probability to represent each top event. However, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. The fuzzy set theory is universally applied to deal with this kind of phenomena. The main purpose of this study is to construct an easy metho...

offshore pipelines used for oil and gas transportation are often buried to avoid damage from fishing activities and to provide thermal insulation. thermal expansion and contraction of the pipeline during operation can lead to lateral or upheaval buckling. a safe buried pipeline design must take into account a reliable evaluation of soil uplift resistance and pipe embedment depth. while the cost...

the traditional event tree analysis uses a single probability to represent each top event. however, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. the fuzzy set theory is universally applied to deal with this kind of phenomena. the main purpose of this study is to construct an easy metho...

fault tree analysis (fta) as a probabilistic risk assessment (pra) method is used to identify basic causes leading to an undesired event, to represent logical relation of these basic causes in leading to the event, and finally to calculate the probability of occurrence of this event. to conduct a quantitative fta, one needs a fault tree along with failure data of the basic events (bes). someti...