Desenvolvimento de metodologias para medição de vazão em dutos de petróleo e derivados usando o radiotraçador 123I

Abstract

To ensure the credibility of commodity transfer operations in the oil and gas industry, calibrated flow meters are used to quantify fluid movement in pipelines. The use of the Time Transient Method with radiotracers can add logistical and financial advantages to the flow measurement as a function of the properties of the interaction of radiation with matter. Traditionally, as proposed by the ISO 2975-7: 1977 standard for tests in aqueous media, the Time Transient Method is used by placing two detectors separated by distances that, in industrial plants, it is not always possible to install them in positions recommended by this standard. As there is no specific standard for measuring the flow of oil and its liquid derivatives using radiotracers, the objective of this work is to propose a methodology in which the Time Transient Method is applied, using the 123Ilabelled oil as a radiotracer, with a set of four NaI(Tl) scintillating detectors to measure the flow of oil and its liquid derivatives in pipelines, pipelines installed in industrial plants or plants with restricted space, typically found on offshore platforms. The method proposed in this work uses scintillator detectors separated from each other by 0.30 m and three injections containing 5.0 ml of 123I-labelled oil. The experiments were carried out in a transport line that allowed the production of flows with velocity profiles characteristic of laminar, transition and turbulent regimes. the results reached uncertainties lower than 1.0% for flows with a Reynolds number in the order of 104.