INSTRUMENTATION IMPROVEMENTS FOR THE LEAK DETECTION AND BATCH TRACKING SYSTEMS OF THE SAO PAULO BRASILIA PIPELINE (OSBRA)

摘要

OSBRA is the 964 Km pipeline which supplies over 6.500.000 m3/year of gasoline, diesel oil and LPG to the Brazilian Midwestern region. Products on OSBRA pipeline are pumped 24 hours a day and 365 days a year on a scheduled basis from Planalto Paulista Refinery - REPLAN to 5 midsize cities through 6 remote operated pumping stations located along the pipeline. The pipeline operation, including pumping and valve actuations and tank farm monitoring, is done remotely from PETROBRAS Transporte S/A - TRANSPETRO National Pipeline Control Center (CNCO). A real time leak detection system (LDS) was supplied and installed at the CNCO. The LDS is based on measurements of flow and pressure as well as pump and valve status along the pipeline. An actual field leak test was done in order to validate and verify the LDS performance. The LDS performance was considered satisfactory at the first time, but after a few months an excessive number of false leak alarms started to occur. A detailed investigation was conducted both on operational procedures and field instrument installation. This report shows how this investigation was conducted and the main recommendations that were agreed in order to avoid the LDS to detract from credibility and the creation of complacency. It is presented the existing limitations on the flow measurements and the improvements that are planned to field instrumentation, operational/maintenance procedures and the OSBRA LDS and Batch Tracking models so it could reach a higher performance level.