Application of Compost Gel for Treatment of Anode Beds of Onshore Pipelines in High Resistivity Soils

Abstract

Italo Martins Gomes, Thiago Ferreira da Silva and Israel de Macedo Sousa

The construction of onshore pipelines often occurs in places that are difficult to access or in non-ideal conditions due to logistical and economic needs or due to design errors. Occasionally, the anode bed of the impressed current cathodic protection system, for protection against external soil corrosion, can be installed in high resistivity soils, making it difficult to efficiently inject enough electrical current to polarize and protect the pipeline. In the present work, soil treatments were carried out with a gel composed of copper sulfate, aluminum silicate and calcium sulfate hydrate in two anode beds with insufficient current injection. The results showed an increase of more than 80% in the current injection and considerable drops in the electrical resistance of the system, consequently, a considerable improvement in the polarization and protection potential of the pipelines to which these systems were interconnected. All this combined with a very low cost compared to other techniques.

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