ENSURE THE INTEGRITY OF OFFSHORE RISERS AT THE SPLASH ZONE AREA & OPTIMIZE THEIR EXTERNAL INSPECTION REGIME

At present time with oil prices continuing to fall, most operators work hard to enforce the cost reduction philosophy and the synergy operations in their maintenance regimes to reduce their daily operational expense (OPEX), This starts from decreasing the gap between the maintenance costs and the applicability of this in the industry this led to a rapid development in the unconventional technologies and produced new advanced inspection technology. In light of the above, the use of the traditionally inspection techniques applied at the splash zone area such as general visual inspection (GVI) and local thickness measurement (UTM) are not practical as they require the removals of the marine growth, armwrap, concrete coating and in some cases the marine painting system. This require a massive preparations activities prior completion till reach the final acceptable conditions and risers reinstatements are reached. Some of the inspection areas where most of the current developments in offshore risers are being seen are in splash zone area that poses some of the biggest challenges to smooth operation in harsh environment. Where the corrosion at splash zones of offshore risers can be severe reading corrosion rates up to 1mm/Year, due to the lack of effectiveness of cathodic protection and coating damages caused either by disbandment or object impact. So it’s highly recommended that this zone have a specific inspection plan combined with a special inspection program for preventing the occurrence of failure as well as following up the evaluation of any failure mechanism which eventually might be present. This paper highlights the challenges to overcome these maintenance costs related to the periodical external inspection of insulated offshore risers at splash zone area. Also the objective of this paper is optimizing the offshore riser’s inspection regimes via evaluating the effectiveness of the unconventional non-destructive testing (NDT) methods for in-service inspection of insulated offshore risers at the splash zone area. The assessment will be completed using two unconventional advanced inspection techniques these are the Ultrasonic Guided Wave Technique (wavemaker GW) and the Pulsed Eddy Current – (PEC). Subsea PEC and GW have been already achieved with considerable success and encouraging results during inspections carried out in the Mediterranean Sea, This technology allows complete mapping of the pipeline corrosion status without production interruptions since no destruction or pre-treatment of the protective coatings is required. The state of the art of these nonintrusive technological solutions for inspecting the corroded areas of splash zones of offshore risers using the two inspection techniques (PEC & GW) are demonstrated through an actual case study. Keywords— offshore riser, splash zone, External corrosion, Pulsed eddy current (PEC),Guided wave (GW),Armawrapm, General visual inspection (GVI).