At the late stages of field development, the issues of optimizing well oil production become topical. Artificial oil lift is the most energy-intensive process in an oil field. On the territory of the Perm region a significant part of the production fund is operated by electric submersible pumps, and the main complication in oil production is the formation of asphalt-resin-paraffin deposits. The authors proposed a technological justification for changing the diameter of the tubing string to reduce the intensity of organic deposits formation. This justification includes determining the change in the following parameters: friction pressure losses, energy consumption of oilfield equipment, oil flow rate and temperature distribution along the wellbore. Changing the last parameters has a significant impact on the intensity of paraffin deposits on the inner surface of the tubing. Evaluation calculations for the target well showed that a decrease in the diameter of the lifting string leads to an increase in the temperature of its inner surface, the flow rate in the lifting string, friction pressure losses and, accordingly, the energy consumption of oilfield equipment. For correct modeling of changes in the intensity of paraffin formation, laboratory studies were carried out on the WaxFlowLoop installation under various thermobaric and kinetic conditions. It has been shown that an increase in the flow rate and temperature in the lifting string can significantly reduce the rate of paraffin formation and, accordingly, increase the time interval between cleaning the well from organic deposits. An assessment of the inter-cleaning period of the well was carried out, and a clean-up operation for different diameters of the production string is supposed to be carried out when the same residual flow area is reached. As a result of the calculations, it was found that by reducing the diameter of the production string from the standard size from 73 to 42 mm it is possible to reduce the well cleanup period by 96.2%. At the same time, the increase in the cost of electricity for changing the operating mode of the downhole pumping equipment is insignificant.
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