Abstract The suspected circumferential weld defects found in the pipeline inspection process were tested and studied. It was that there slag inclusion girth at 9 o’clock, which had not been early stage or laboratory nondestructive testing process. are most likely due to incomplete removal between layers low welding wire energy. There a root crack 6 o’clock position of weld, length 10 mm, close ...

Steel structures continuously exposed to offshore marine environments are prone to corrosion. This can be of major economic and perhaps of environmental significance. The risk of these scenarios occurring can be assessed using good quality data, good quality corrosion and pitting models and structural reliability assessment. Recently, improved models for the prediction of longer term corrosion ...

Welding is the main method for oil/gas steel pipeline connection, and a large number of girth welds are weak part pipeline. Under extremely complex loads, undergoes significant plastic deformations eventually leads to fracture. A damage mechanics model promising approach, capable describing material fracture problems according stress states materials. In this study, an uncoupled 2D with functio...

Two-dimensional finite element modeling procedures are addressed to predict the residual stresses for multipass welds. A generalized plane strain model with a five-pass weld in a plate and an axisymmetric model with a six-pass girth weld in a pipe are considered. Element rebirth and pass-lumping techniques are employed in both models. The combined heat input using surface and body flux componen...

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...

Girth welded replica of API X70M material have been produced on NG-GMAW welding technique. The particular area interest is to develop suitable girth process parameter using NGGMAW. major aim the work was replicate welds having tensile strength between 650 and 680 MPa. Design Experiment (DoE) method by Taguchi design, some selected processes adopted. Two parameters (factors) – arc voltage wire f...

Girth weld defects in long-distance oil and gas pipelines are one of the main causes pipeline leakage failure serious accidents. Magnetic flux (MFL) is most widely used inline inspection methods for pipelines. However, it impossible to determine type girth defect via traditional manual analysis due complexity MFL signal. Therefore, an automatic image classification method based on deep convolut...

This paper presents an experimental characterisation of fatigue at welded connections for the next-generation high-strength low-alloy offshore riser steel, X100Q. An instrumented girth weld is conducted with a parallel programme physical-thermal simulation (Gleeble) to develop heat affected zone (HAZ) test specimens. X100Q shown exhibit superior performance current state art X80. Significant di...

Recently developed optical inspection tools provide images from the inside of natural gas pipelines to monitor pipeline integrity. The vast amounts of data generated prohibits human inspection of the resulting images. We designed an image processing and classification method to identify abnormal events. Non-overlapping image blocks are classified into twelve categories: normal, black line, grin...