International journal of advanced scientific and technical research Issue 4 volume 1, January-February 2014 Available online on http://www.rspublication.com/ijst/index.html ISSN 2249-9954 R S. Publication, rspublicationhouse@gmail.com Page 47 MONITORING AND EVALUATION OF CATHODIC PROTECTION PERFORMANCE FOR OIL AND GAS PIPELINES: A NIGERIA SITUATION Onyechi, Pius C 1 ., Obuka, Nnaemeka S.P 2* ., Agbo, Cornelius O 3 ., and Igwegbe, Chinenye A 4 . 1 Department of Industrial and Production Engineering, Nnamdi Azikiwe University, Awka, Nigeria. 2 Department of Mechanical and Production Engineering, Enugu State University of Science and Technology, Enugu, Nigeria. 3 Department of Mechanical Engineering, University of Nigeria, Nsukka, Nigeria. 4 Department of Chemical Engineering, Nnamdi Azikiwe University, Awka, Nigeria. Abstract Pipeline integrity is maintained by simultaneous application of protective coating and Cathodic Protection (CP). This study was carried out to monitor and evaluate the extent of cathodic protection performance on the Trans-Niger Pipelines (TNP) onshore Nigeria. The scopes of assessment for the evaluation were mainly; the „On‟ potential measurements, and „On/Off‟ potential measurements. These potential measurements were carried out in accordance with the NACE SP-0169-2007 standard practice of reference electrode potential at -850mv criterion. The readings recorded for the distance of 21km of the pipeline; starting from Rumuekpe manifold, were used as the benchmark in evaluating the CP performance on the TNP. Some of the results (20inch and 28inch pipelines) showed very high deviation from the potential criterion indicating poor CP performance, while mostly those of the 36inch pipeline were satisfactory. Findings of this study show that the CP performance on these pipelines is dependent on the physical state (coating disbandment) of the pipes and their years under operation. Keywords Cathodic Protection, Trans-Niger Pipelines, Potential Measurement, Reference Electrode, Pipe Coating *Corresponding Author email: silvermeks7777@yahoo.com (Obuka Nnaemeka S.P.) INTRODUCTION Pipelines play an extremely important role throughout the world as a means of transporting gases and liquids over long distances from their sources to the ultimate consumers. The general public is not aware of the number of pipelines that are continually in service as a primary means of transportation. A buried operating pipeline is rather unobtrusive and rarely makes its presence known except at valves, pumping or compressor stations or terminals. Pipelines are exposed to aggressive soil, varying climatic conditions, microorganism and stray currents that initiate corrosion processes. The research carried out in the last several decades