الفهرس | Only 14 pages are availabe for public view |
Abstract To protect offshore pipelines from severe, environmental loads, anchor and fishing gears engmeers often trench the lines, or muunnze the effect of the above pipelines. This action will lead to near shore areas, design cover them with gravel to condition on the submarine restrict lateral movement of the pipeline which usually operates at high pressure, high temperature and also is laid on irregular seabed. Recently, at the beginning of: MAY-1990, it was first published that, there is an offshore subsea buried pipeline which was laid at 40 meters depth, and operating at internal pressure of 1000 psi and temperature of 800 C has been attacked by a new mode of failure called UPHEA VAL BUCKLING. This mode of failure led to an excessive deformation that caused a buckle wave about 2.6 meters height and about 24 meters length during seven months of service. This costed the owners a lot to substitute this part of the pipeline under 40 meters |