The pipeline transportation of naphthene-base crude from the Russkoye field is complicated by the abnormally high viscosity and density of wellstream. For this oil gathering and trouble-free inter-field transport, it is necessary to use special methods that ensure a decrease in viscosity. The pipeline transport of naphthene-base crude from the Russkoye field is also complicated by climatic conditions (low temperatures), especially in case of above ground pipelining. When the temperature of viscous oil transport decreases to the temperatures of the beginning of paraffin crystallization, a solid phase begins to appear in the pumped liquid - crystals of paraffin-like conglomerates adhering to the inner surface of the pipeline. On oil pipelines pumping rheologically complex oil, special pumping technologies are traditionally used. To reduce oil viscosity and pour point, additives of various types or crude mixture with light oil and/or gas condensates produced in nearby regions are used.
The article considers the viscosity-temperature features of oil and gas condensate mixtures produced by the wells of the Russkoye field. The regulation of phase transitions is carried out by the introducing into the oil system gas condensate, which is produced in large volumes at the Russkoye field. The study of the rheological characteristics of the initial oil and gas condensate, and their blends were allowed to determine the optimal ratio of the pumped-over fluids for the safe pipeline transport. The results of studying the differential pressure in the dynamic mode of modeling the pumping of oil and its mixtures with gas condensate under conditions of a gradual decrease in temperature confirmed the data of the rheological determination of the temperature of the onset of paraffin crystallization in a mixture with a naphthenic-oil fraction. The effectiveness of inhibiting the formation of asphalten-resin-paraffin deposits in the pumped liquid stream has also been confirmed by the Cold Finger test.
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