English

Vol. 10 6, 2020 p 610-619

Pages

Article name, authors, abstract and keyword

610-619

Study of the causes for wax deposition under the operating conditions of main oil pipelines

Rustam Z. Sunagatullin a, Rinat M. Karimov b, Radmir R. Tashbulatov b, Boris N. Mastobaev b

a Pipeline Transport Institute, LLC (Transneft R&D, LLC), 47a Sevastopolsky Prospect, Moscow, 117186, Russian Federation
b Ufa State Petroleum Technological University, 1 Kosmonavtov Str., Ufa, 450062, Russian Federation

DOI: 10.28999/2541-9595-2020-10-6-610-619

Abstract: The results of investigations of the main causes and the most significant factors of intensification of paraffin deposition in main oil pipelines are presented. A comprehensive analysis of the composition and properties of commercial oils and their sediments was carried out, according to which phase diagrams of equilibrium of oil dispersed systems were obtained using the example of commercial oils from Bashkir fields. Based on the phase diagrams, a curve of wax oil saturation was constructed, the analysis of which confirms that the existing thermobaric conditions during the operation of main oil pipelines do not allow transporting oil without the risk of waxing. It was noted a special influence of the value of the temperature gradient in the near-wall zone and the imbalance of the ratio of high-molecular oil components in commercial batches formed in the process of joint pumping on the intensity of waxing of sections of oil pipelines complicated by deposits, which was confirmed by statistical data on the frequency of pigging. The regularities obtained in this way are proposed to be used as an express method for predicting complications associated with intensive waxing of main oil pipelines. In order to quickly assess the risks of waxing of sections of main oil pipelines, an indicator is introduced that characterizes the ratio of the content of solid paraffins to the total content of resins and asphaltenes of oil, called the criterion of instability of a commercial oil batch.

Keywords: wax deposition, oil, main pipeline, thermobaric conditions, phase diagram, temperature gradient, frequency of pigging, criterion of instability.

For citation:
Sunagatullin R. Z., Karimov R. M., Tashbulatov R. R., Mastobaev B. N. Study of the causes for wax deposition under the operating conditions of main oil pipelines. Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktovScience & Technologies: Oil and Oil Products Pipeline Transportation. 2020;10(6):610619.

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