Subsea pipeline cathodic protection surveys

Subsea pipeline cathodic protection surveys

Keywords: Corrintec, Cathodic protection, Marine environments,Pipelines

Corrintec Ltd has completed a series of projects during recent months in offshore oilfields as far apart as Tierra del Fuego and the Sea of Japan.

Surveys are undertaken to ensure that there is no damage to the pipeline as well as monitoring levels of corrosion and the condition of pipeline anodes.

Corrintec's latest innovation is a new software package that enables data to be logged and analysed with greater speed and flexibility. The CP PRO package is now used for all surveys and claims numerous advantages including the ability to compare historical data and identify trends in the condition of the pipeline with greater precision.

The software was recently used in the United Arab Emirates where Corrintec was commissioned by BP Amoco Shaijah to survey a 30in. condensate pipeline. The 13.2km pipeline, running from all SBM to shore, was surveyed using the trailing wire method that is considered ideally suited to buried pipelines and allows for rapid survey rates.

In Japanese waters, Corrintec has carried out a pipeline and platform inspection for Offshore Iwaki Petroleum (OIP) in conjunction with main contractors Shin Nippon Kaiji. This involved checking the level of cathodic protection on the platform using proximity readings taken at various test points.

The subsequent pipeline survey over a length of 40km used the ROV method that produces very detailed results using probes mounted directly on a remotely operated vehicle. In addition, Corrintec claims to be one of the few companies able to offer a TDS option, where data concerning temperature, depth and salinity data are provided as constant readings.

In May, the company carried out a ROV pre-trench survey on part of Europipe II, covering a 60km section from Stavanger to Emden owned by Statoil. The survey was commissioned by main contractor Stolt-Comex Seaway to confirm that the cathodic protection system was working efficiently and that no areas of damage had occurred to the coating, prior to burying the pipeline.

One of the most complex projects of recent months was undertaken in waters off Tierra del Fuego where Corrintec completed an in-field survey for main contractor Hydronav on behalf of Total Austral. This involved surveying four gas, oil and water pipelines, each 13km in length, running in parallel from a petrochemical plant at Rio Cullen to the Hidra Centro platform and SPM. In addition, the trailing wire method was used to survey three pipelines between the Hidra Centro and Hidra Norte platforms as well as two pipelines, 8km in length to the Argo underwater well head.

Further details are available from Corrintec Ltd. Tel: +44 (0) 1962 869 622;Fax: +44 (0) 1962 866 628; E-mail: enq@corrintec.co.uk