Retrofit Cathodic Protection Software for Marine Pipelines

Description

This user-friendly software provides all necessary tools for the design of cathodic protection (CP) systems for underwater pipelines. Designing retrofit CP systems in a sound, technical fashion is complicated since one needs to take metallic pipe electrical resistance, as well as the anode, coating, and polarization resistance terms into account. This software overcomes these complications and accomplishes cathodic protection design based upon first-principles considerations. In addition, the software can process survey data from existing pipelines (if available) and use this as an input for the retrofit design. Anode configuration and sled design are executed in simple steps, and the resultant potential attenuation is calculated and displayed graphically.

Both retrofits for aging pipelines and new designs can be accomplished by using this software. Such retrofit designs differ significantly from those for new pipelines because maximization of anode (alternatively, anode groups or sleds) spacing is normally the critical issue, but is inconsequential in most new pipelines. One major producer has estimated that by using this software it was possible to extend the distance between anode sleds over what would otherwise have been done at a cost savings of over $1,500 for each additional meter of separation. Aside from this software, there is no unified, first-principles approach whereby anode spacing can be maximized.

Potential Applications

Much of the existing marine infrastructure is now over 20 years old and the CP retrofitting of thousands of miles of pipeline will be required in the next decade. This software package provides the first unified, first-principles based approach to optimize the design of CP systems leading to major cost savings for the offshore industry.

Background of Invention

Cathodic protection is a technology that protects buried and submerged steel from corrosion. Marine pipelines that transport crude oil and gas from offshore production facilities constitute a specific example. Such pipelines have now been in place worldwide for as long as 50 years. However, cathodic protection systems for these pipelines are normally designed for 25-30 years and many are beginning to expire. CP technology is very different for retrofit systems when compared to initial designs. Retrofit systems are based upon “bracelet” anodes that are attached to the pipe with about 200m in spacing upon deployment from a lay barge. Retrofit systems, on the other hand, have widely spaced anode groups that are installed by divers. Thus, the guiding parameter for retrofits is maximization of anode spacing, which can be on the order of several miles.

Supporting Agencies

This project was funded by ChevronTexaco, ExxonMobil, the Minerals Management Service, and Shell.

Pictured above is a form included in software package

Inventors
Wei Chu, Ph.D.
Post-Doctoral Associate
Ocean Engineering

Diane Lysogorski
Graduate Student
Ocean Engineering

Keith Bethune
Former Graduate Student
Ocean Engineering

IP Status
Copyright

Contact Information
Office of Technology Transfer
777 Glades Road, ADM 218
Boca Raton, FL 33431-0991

Kurt R. Moore
Assistant V.P. & Director
Ph: 561-297-1165
Fax: 561-297-2141
kmoore34@fau.edu

Michelle Webb
Assistant Director
Ph: 561-297-0673
Fax: 561-297-2141
mwebb18@fau.edu

Case Number
2003-09