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...

offshore pipelines are an effective tool for transportation of oil and gas which are usually assembled by the use of girth welds. since flaws may naturally exist at such welds, fracture assessment of girth welded offshore pipelines is substantial. current fracture assessment procedures like bs 7910 consider identical material properties for the weld and the base metals. however the strength dif...

Offshore pipelines are an effective tool for transportation of oil and gas which are usually assembled by the use of girth welds. Since flaws may naturally exist at such welds, fracture assessment of girth welded offshore pipelines is substantial. Current fracture assessment procedures like BS 7910 consider identical material properties for the weld and the base metals. However the strength dif...

Girth weld cracking is one of the main failure modes in oil and gas pipelines; girth weld cracking inspection has great economic and social significance for the intrinsic safety of pipelines. This paper introduces the typical girth weld defects of oil and gas pipelines and the common nondestructive testing methods, and systematically generalizes the progress in the studies on technical principl...

In order to achieve integrated condition in the girth welding of high pressure natural gas transmission pipelines, the weld zones and its surrounding area should have good mechanical properties. Residual stresses are an important defect especially in the girth welding of the pipeline. In this study, two API X70 steel pipes (with spiral seam weld) of 56 inches outside diameter and 0.780 inch wal...

Ultrasonic phased arrays offer significant advantages over radiography for pipeline weld inspections: they have higher detection rates for critical planar defects (i.e. cracks and lack of fusion), better defined interpretation, vertical sizing capability for Engineering Critical Assessment, no safety hazards, no licensing issues, no chemical wastes, and no requirement to evacuate the area. Phas...

Automated ultrasonics is steadily becoming the standard method of inspection of pipeline girth welds throughout the world. In addition, old technology multiprobe systems are rapidly being replaced by newer phased arrays. Olympus NDT developed the first phased array system a decade ago, which proved to be much more flexible and capable than multiprobe systems, particularly for offshore special a...

Hydrogen enrichment induced by pipeline welding residual stress is a key issue affecting the safe service of hydrogen pipelines. In order to explore influence on diffusion and effect heat treatment, an X80 model with six-layer girth weld was established using ABAQUS software, coupling analysis temperature field, carried out. The distribution in area local inclusion analyzed, relationship betwee...

Welding quality control is an important parameter for safe operation of oil and gas pipes, especially for high-strength steel pipes. Size control of welding defect is a bottleneck problem for current pipe construction. As a key part of construction procedure for butt-welding of pipes, pore defects in girth weld is difficult to ignore. A three-dimensional non-linear finite element numerical mode...

Installation of new pipelines is predicted to grow at a rapid rate over the next twenty years, due in part to the increase use worldwide of combined cycle power generation plant using natural gas a fuel. The need to construct large diameter pipelines over long distances has led to an increased demand to improve the productivity of pipeline girth welding. Many novel techniques have been tried in...