Abstract
In the Northeast Marine Region of Mexico, there are approximately 1800 km of pipelines that allow the daily transport and operation under safe conditions. So, the oil and gas production in this region and their transport to the Process, Compression and Pumping Centers is externally protected by means of a cathodic protection system with aluminum sacrificial anodes. Currently, the cathodic protection potentials have started to decrease or are below the minimum acceptable value, as the system useful life is in its final stage. This system minimizes the steel deterioration by means of its interaction with other more active material which is corroded when exposed to the aggressive environment conditions. The anodes quantity is calculated in function of the area to protect, which is calculated according to the pipelines dimensions. The anodes are distributed along the pipelines, considering their protection coverage and depending upon their mass. From their installation, the anodes react and corrode due to the environmental conditions, such as salinity, temperature, dielectric coating failures. This situation involves a protection reduction until unprotected areas are reached and the pipelines corrosion is initiated. Considering the potentials monitoring carried out along the subsea pipelines and risers, reinforcement on the cathodic protection system was necessary. This activity was carried out using sacrificial anodes, without stopping the pipelines operation and with the help of surface and saturation diving, as well as a “dynamic positioning craft”, which allows operation up to 70 m deep.
