Onshore and Offshore Inspection

Key details

  • Laser measurement of geometric features such as HiLo, penetration, concavity

  • Visual record of coloration, cracking, spatter and surface breaking porosity

  • Performs and completes a 360 degree scan of the root pass - laser and camera

  • Integration with line-up clamp (ILUC) with adjustable inspection capabilty

  • Avoids defects being detected too late in the process and consequent expense

  • Track record of more than 40,000 weld inspections completed (onshore / offshore)

  • All systems are set-up, calibrated and verified using calibration artefacts

  • Improved pipeline integrity

Weld defects identified with the OMS system

Why?

During the welding process, defects can occur for a variety of reasons. Typically, a defect will be picked up when a weld is inspected by x-ray or automatic ultrasonic testing (AUT). By this time, the weld will have passed through several sequential processes on-board a pipelay vessel. If a defect is found at this stage, problematic welds will have to be removed by cutting them out, then the entire process has to start again. By inspecting the weld for the specific type of surface defect earlier in the process, a great deal of lost time can be recovered, and costs saved. Pipelay vessels can cost $100k’s per day, so the saving is considerable. Furthermore, there are some types of defect that the later processes are less sensitive or impossible to detect, such as coloration for corrosion resistant alloy (CRA) welds, HiLo and porosity.

Solution

The basis of the solution is to use a fine laser beam in an optical triangulation system arrangement in order to gain thousands of measurements per second to build-up detailed weld geometry and an accurate 3-D map.

How?

Each system has a linear actuator which enables the system to find the weld within a region. Once found, the laser system is activated and spins around the weld collecting 3-D data as well as co-ordinated images. This information is then sent to the operator to review together with computer aided go/no-go software which aids the interpretation. Once the weld has been successfully reviewed, the operator can pass the all clear message to the pipelay vessel in order to move onto the next pipe for welding.