Abstract
The article presents a review and analytical assessment of modern methods for regulating the rheological properties of high-paraffin and highly viscous crude oils. The main problems arising during the production, transportation, and processing of heavy oils associated with high viscosity, elevated pour point, and the formation of asphalt-resin-paraffin deposits are considered. It was established that the deterioration of crude oil flowability at low temperatures is caused by the crystallization of paraffin hydrocarbons and the formation of a spatial structure within the oil system. The paper analyzes modern technologies for improving the flowability of highly viscous oils, including thermal treatment, the use of pour point depressants, dilution with light oils, application of emulsion systems, and nanomaterials. Particular attention is paid to the influence of depressant additives on reducing the pour point and viscosity of crude oils. It is shown that the use of modifying reagents contributes to the destruction of paraffin structures, reduction of hydraulic resistance, and improvement of oil transportation efficiency. Modern studies related to nanotechnologies and intelligent flow control systems are also reviewed. It was found that the implementation of digital technologies, automated monitoring, and mathematical modeling makes it possible to optimize transportation regimes, improve the reliability of pipeline systems, and reduce operating costs. The conducted review confirms the prospects of the integrated application of depressant additives, nanomaterials, and intelligent technologies for improving the rheological properties of high-paraffin oils and increasing the efficiency of oil transportation processes under complex operating conditions.