No abstract

Most pipeline codes, do not stipulate any requirement for block valve spacing nor for remote pipeline valve operations along transmission pipelines carrying low vapor pressure petroleum products. This requirement is generally industry driven for their desire to proactively control hazards and mitigation of environmental impacts in the event of pipeline ruptures or failures causing hydrocarbon spills. This paper will highlight a summary of pipeline codes for valve spacing requirements and spill limitation in high consequence areas along with a criteria for an acceptable spill volume that could be caused by pipeline leak/full rupture. A technique for deciding economically and technically effective pipeline block valve automation for remote operation to reduce oil spill and thus control of hazards is also provided. The criteria for maximum permissible oil spill volume, is based on industry’s best practice. The application of the technique for deciding valve automation as applied to three initially selected pipelines (ORSUB, OSPAR and ORBEL) is discussed. These pipeline represent about 14% of the total (6,800 kilometers, varying between 6” to 42”) liquid petroleum transmission lines operated by Petobras Transporte S.A. (Transpetro) in Brazil. Results of the application of the technique is provided for two of the pipelines: OSPAR (117 Km, 30” line) and ORBEL II (358 Km 24” line), both carrying large volumes of crude oil.

The objective of this paper is to describe the process used by TRANSPETRO to select and implement a leak detection system. The process consists of three steps: selection of a leak detection system, evaluation on a trial basis, and project implementation, which includes the negotiation of the contract and project implementation strategies. PETROBRAS Transportation Company — TRANSPETRO — operates several networks of pipelines in Brazil, with a total length of 6,500 km transporting petroleum products and crude, and 3,500 km transporting natural gas. Over the last two years, two large leaks occurred in the pipelines operated by TRANSPETRO. After analyzing these incidents, TRANSPETRO came to the conclusion that the consequences of leaks could be minimized with a reliable leak detection system and a proper emergency response procedure. To ensure that the leak detection system was fit to purpose and represented the best fit of technology to requirements, TRANSPETRO used a plan that involved three steps. First, based on the leak detection system criteria, TRANSPETRO and PETROBRAS R&D Center engineers selected a software based leak detection system with a hydraulic model (CPM, according to the API 1155 [1]) from among various leak detection techniques and products commercially available in the international market. Second, the selected leak detection system was implemented on two pipeline segments on a trial basis to evaluate it against TRANPETRO’s selection criteria for oil pipelines under real world conditions. Finally, after the successful completion of the trial, the implementation project, including up to 150 pipeline segments, was contracted.