Free-span occurs normally in a pipeline at uneven seabed, dynamic seabed and pipeline crossing. Free spanning in pipeline causes Vortex Induced Vibration (VIV) fatigue, fracture and bursting. In this paper, a pipeline located in South Pars Gas Field is assessed against local buckling and VIV fatigue using probability of failure theory based on the recommended methodology by Det Norske Veritas (...

The deepwater drilling riser is a very important and vulnerable connection between an offshore platform subsea wellhead. Under some certain complex marine environment operating conditions, the may drift beyond safe limitations or be driven away rapidly. In order to protect safety of platform, personnel equipment, it necessary implement emergency disconnection riser. Since stretched under normal...

This study proposed a novel experimental platform to conduct dynamic loading tests of truncated model steel catenary riser (SCR) within the touchdown zone (TDZ). The facilities platform, including soil tank, system, and stirring were introduced in detail. parameters test determined through simulation an situ riser. A pipe was adopted as riser, with its outer diameter equaling that prototype SCR...

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...

There is accelerating interest in composite risers for deepwater applications. Composite risers offer much higher strength to weight ratios over metallic risers but there is less experience of their behavior in deepwater environments. A general review on current developments specific to composite risers highlighting the remaining challenges and the applications, design evolution, state-of-the-a...

the steger and warming flux vector splitting implicit scheme is used to numerically solve two dimensional reynolds averaged navier–stokes (rans) equations governing the vortex induced vibration of a flexible riser laterally supported by a spring and a damper. the k–ε model is used as turbulence model to simulate the turbulent flow in the wake of the riser. to update the new position of the rise...

In this paper the influence of inlet and outlet configurations a pseudo-2D fluidized riser on hydrodynamics (i.e. flow pattern cluster characteristics) are studied. A detailed comparison between experimental data full 3D CFD-DEM simulation results is performed. Solids volume fraction mass flux characterized particle clusters detected in our simulations compared to data. It shown that correct re...

The problem of predicting the regime a two-phase flow is considered. An approach proposed that classifies using Deep Neural Networks (DNNs) operating on features extracted from Doppler ultrasonic signals Fast Fourier Transform (FFT) proposed. are categorised into one four classes: annular, churn, slug, and bubbly regimes. scheme was tested an experimental facility. To increase number samples wi...