THE ESTIMATION OF TECHNICAL STATE OF MARINE PIPELINES
Procedures of calculation of stress-deformation state of the most hazardous submarine pipeline sections are considered, an example of the calculation is given.
In the oil fields under development in the shelf of Vietnam marine pipelines for offshore pumping of high- solidification oils, gas-liquid mixtures, gas and water to maintain formation pressure are in operation. The constructive design of pipelines is performed without sea bottom penetration.
As is shown by the world practice, the main causes of failures of such pipelines in operation can be damage from ship anchors, internal and external corrosion of pipes, excessive bends in vertical and horizontal planes, wear of pipelines at the intersection points, damage resulting from metal fatigue caused by waves, currents, changes in pressure and temperature of a product being pumped, bottom deformation and sagging of pipelines, damage caused by construction work in the immediate proximity to pipelines.
To ensure reliable and trouble-free operation of marine pipelines and to make a timely decision regarding time and type of repair one should possess true information about technical condition of these pipelines. In case of impossibility of using traditional methods of checking required parameters, applied for pipelines laid on the ground, it becomes necessary to develop and to update the procedures of obtaining such parameters by theoretical methods.