A Smart Location System

This paper describes the technology used in the Intelligent Location System developed by PIPEWAY and includes some of the results already obtained optimizing repair time and logistic costs during the location of anomalies detected by intelligent pigs, a joint operation within the scope of the contract for Subsea Pipeline Recovery in the Guanabara Bay with Petrobras/Transpetro and GDK Engenharia. The system uses the ELF (Extra Low Frequency) transmission and reception technology at points near a pipe, with or without concrete coating, whose signals are recorded in the inspection tool memory to accurately establish reference points, thus preventing excessive dig work or dredging when human and operational risks tend to be high. By recording the frequencies transmitted by the Smart Location System in the inspection tool memory, this extremely serviceable technology for approaching anomalies in onshore or offshore pipelines has proved to be a powerful tool, with centimetric precision and low costs when facing adverse conditions, where a slight difference of meters or the difficulty to visualize the anomaly from the outside may represent significant savings. This system provides a solution for the lack of fixed reference points such as valves, magnets and other equipments that could help to locate the anomalies. The idea of finding an engineering solution that would provide a faster and efficient method for identifying those anomalies was started in 2002, after some inspections were made with geometric and/or thickness loss instrumented pigs in an attempt to approach anomalies detected in offshore pipelines in the Guanabara Bay, whose bottom is intensely silted up, offering poor visibility, and where no physical references were installed in less than a one-kilometer distance from the target features. The main purpose of using this technology is the improvement in pipeline and operational reliability so that the operator is able to quickly relate the severity of the situation to the actual operating conditions. A short analysis of the main costs involved in the application of this localization system, including the mobilization of a geometry inspection tool, would show that investments could benefit from this technique. This becomes clear when considering diving, dragging or digging costs required by traditional methods whose intrinsic high costs and risks may represent non-anticipated costs when new exploitations are required to identify anomalies.