DISTRIBUTED AUTOMATION SYSTEMS PROVIDE INFORMATION AND SUPPORT TO DECISION

摘要

Transpetro - the transportation division of Petrobras -operates approximately 10.000 kilometers of pipelines and 43 oil terminals. It is the main oil and gas logistic company in Brazil and one of the top companies in Latin America. This work presents a concise description of Transpetro's project to integrate these distributed sites. Most of the pipelines are remotely operated by the Operational Control Center (OCC), located in Rio de Janeiro, but there are also a number of pipelines and specific operations that are under the responsibility of the terminals, and these operations are called "distributed operations". These operations include pump and compressors control, valves alignment, products quality monitoring, and even some pipelines control not integrated to the OCC yet, such as the ones that are used to deliver final products to the distribution companies. Each of the Terminals has, or is receiving, an automation system including instrumentation, programmable logic controllers, communication and supervisory systems. Pressure, density, flow and level are some of the variables collected by the automation system and made available to the terminal operator. The system also allows the remote control of valves, bombs, compressors and other equipment. All this information gathered by the automation system becomes digitally available on the level of the terminals supervisory systems, which in Transpetro are mainly based on Intellution iFIX and Telvent OASyS. Therefore, other systems can access the supervisory systems and use its digital information for the benefit of the company. On the Operational side, there are some specialist systems that refine and sophisticate the level of information available in the supervisory system. One of these is the Leak Detection System, which interfaces with the supervisory system using data transfer protocols such as DDE and OPC, receiving the process data and applying a computational model that allows the operator to identify a potential leak. In a Logistic Company such as Transpetro, it is important to keep all the information concerned to storage (in tanks or pipelines), both current and scheduled operations, in a set of systems functioning in an integrated way. One of these systems is the homemade one called BDEMQ (Storage, Transportation and Quality Data Base). Transpetro is now implementing the interface between the automation systems and BDEMQ in all terminals. The technology used is a C and Java language-based interface through an Ethernet TCP/IP network. Hence, once Transpetro has all the data digitalized in its terminals' automation systems, it is possible to improve the level of control and information, increasing the support to the operators' and managers' decision taking processes.