INTEGRITY OF OLD PIPELINES BURIED IN PETROLEUM PRODUCTS STORAGE TERMINALS

摘要

This work aims to present the results obtained from the experience gained through the accomplishment of the inspection with the ultrasonic umbilical pig in a non-piggable internal pipe buried in the Transpetro Storage Terminal in Sao Caetano do Sul, in Sao Paulo, Brazil. The pipeline considered in this work is a line for marine fuel oil, which, because of its high viscosity, must be heated in order to flow. The oil is heated in the terminal by the steam produced in boilers. The heat transfer may occur in a heat exchanger or inside the storage tank, and the pipeline referred is thermally isolated. So that the line could be inspected, it was divided in two parts, one upstream of the pumps (suction), which is a 12-inch line, and the other downstream of the same pumps (discharge), which is a 14-inch line. This work has been developed by Transpetro's Pipeline Operation, Maintenance, Inspection and Safety Departments together, since the planning phase, passing by the job execution and getting to the conclusion. To begin with, the operational liberation of the line had to be agreed between all the departments involved with the PIG inspection, which were mentioned before, and Transpetro's Logistics Department. Once the PIG passage was scheduled, an initial cleaning had to be performed by the Operation Activity. Since this line is non-piggable, the installation of adaptations was necessary. After that, the passage of cleaning PIGs was possible, and the line sections could be enabled. The next step was the inspection of the pipeline with umbilical ultrasonic PIGs. After the passage of these PIGs, the adaptations had to be removed and the pipeline had to be conditioned for the operational return. After this part of the inspection was finished, the verification of the results issued was necessary. Once the theoretical results were available, ditches were opened for correlation inspection and temporary repairs in the most critical points for the operation were applied. The last part of the work consists in an analysis study of technical and economical viability for rehabilitation of the lines.