A natural gas leakage was detected on the unpiggable high-pressure DN 600 pipeline Kasejovice – Mikulášov in Czech Republic after 50 years of operation. The pipeline was excavated and found to suffer from extensive corrosion; corrosion of a similar extent was also found when another section of the pipeline was excavated on the same location. The operator therefore decided to carry out inspection on a representative 15 km section in order to check the actual condition of the pipeline system and, based on its result, to determine further procedure for repair or renovation. Conventional in-line inspection during operation was not feasible on this pipeline section, and therefore the inspection was carried out “off-line”. An ultrasonic inspection tool was propelled through the pipeline section with a controlled speed by water.
CEPS provides a comprehensive portfolio of pipeline services and pipeline integrity services needed during pre-commissioning, commissioning, decommissioning, shut-down, repair and rehabilitation as well as pipeline abandonment works.
In the field of internal inspections CEPS provides propelling of ULTRASONIC, MFL, TFI and any other inspection tool in the pipeline when the flow of transported medium is insufficient or medium is not available. Our company uses water or combination of water/air as the substitute propelling medium and assure constant inspection tool velocity so that the operator gets high quality inspection data. This method also enables ultrasonic inspection of gas pipelines. CEPS provides turn-key solutions of off-line inspections, design, and manufacturing of temporary launching /receiving traps.
The course of standard off-line inspection carried out by CEPS is described in the following.