Reducing the formation of asphaltene deposits and increasing the flow rates of oil wells

Abstract

Purpose. Reducing the formation of asphaltene deposits in the bottom-hole zone of wells and increasing their flow rate. Methodology. The purpose of the work is achieved by conducting theoretical and experimental studies on the formation of asphaltene and paraffin deposits in the bottom-hole zone of the oil reservoir and identifying patterns of their dissolution by pumping heated low-boiling oil components containing carbon atoms C6–C9 in molecules into the well. Findings. The experimental studies conducted under laboratory conditions showed high solubility of asphalt-resin and paraffin compounds in low-boiling oil components. To prevent the deposition of asphaltene deposits in the bottom-hole zone of wells, the turbulent nature of oil movement is necessary, which is achieved by increasing reservoir pressure when water or gas is injected into the oil reservoir. It is also necessary to have a reservoir pressure above the saturation pressure of oil with gas. Effective methods are recommended to reduce the formation of asphaltene deposits in the oil reservoir in the bottom-hole zone and to restore the production rates of producing wells by pumping heated low-boiling oil components containing carbon atoms C6–C9 in molecules into the well. It has been experimentally established that when the temperature of the specified solvent changes from 20 to 800 °C, the time of complete dissolution of the asphalt-resin compound (bitumen) in the form of balls with a diameter of 5 mm is within 0.20–3.0 hours, and in reservoir conditions with a temperature of 60–80 °C – significantly less for 0.2–0.25 hours. This indicates that before pumping low-boiling oil components containing C6–C9 carbon atoms in the molecules, they must be preheated to reservoir temperature. A method is also proposed for treating the bottom-hole zone of an oil reservoir with a complex solution including low-boiling oil components containing carbon atoms C6–C9 in molecules, hydrochloric and fluoric acids. Originality. Effective methods are proposed to reduce the formation of asphaltene and paraffin deposits in the bottom-hole zone of the oil reservoir and to restore the production rates of producing wells by pumping heated low-boiling oil components into the well, as well as a complex solution with the inclusion of acids. Practical value. A technique has been developed to improve technological processes to reduce the formation of asphalt-resin-paraffin deposits and to establish rational parameters of the installation for producing low-boiling oil components containing carbon atoms C6–C9 in industrial conditions. Using the results of research in oil fields allows you to restore the initial permeability and thereby increase the flow rate of oil wells by 20–30 %.