Predicting the Decrease in the Metrological Reliability of Ultrasonic Flow Meters in Conditions of Wax Deposition

Commercial accounting is carried out at all stages of delivery of the produced and prepared oil to the final consumer. The most common are dynamic methods, direct (mass) and indirect (volume-mass). As a rule, accounting is carried out by systems for measuring the quantity and quality of oil (SIQO). In the process of accounting, the work of SIQO is influenced by a large number of external factors that cause the appearance of additional errors. When accounting for crude oil, wax deposition on the inner surfaces of meter lines and flow meters becomes significant. The influence of this factor in practice is not taken into account due to the immeasurability of the thickness of the paraffin layer. The article discusses the effect of paraffin on the metrological reliability of an ultrasonic flow meter. It is proposed to automatically estimate the current value of the thickness of the paraffin layer by the model and determine the value of the additional error. This allows, when approaching the limits of metrological reliability, to timely carry out maintenance of the flow meter and extraordinary control of its metrological characteristics and, in general, to increase the accuracy of accounting.