Applicability of the Slope Parameter Method to the Design of Cathodic Protection Systems for Marine Pipelines

This paper reviews the generalized approach to marine cathodic protection design, as applied to petroleum production jackets and to pipelines. It is demonstrated that the existing method in the case of pipelines can be interfaced with a newly proposed attenuation equation for evaluation of the range of applicability and calculation error. Accordingly, a modification to the existing protocol for galvanic cathodic protection system design is presented that quantitatively interrelates design life; anode size, weight, and properties; pipe size, current demand, and coating quality; seawater resistivity; magnitude of polarization; and anode spacing. An example cathodic protection (CP) system design is presented, and the utility of the method is discussed.