DEVICE FOR CLEANING WELLS OF TAR-RESIN-PARAFFIN SEDIMENTS Russian patent published in 2014 - IPC E21B37/06 

FIELD: oil-and-gas industry.

SUBSTANCE: invention can be used for well cleaning. Pipe string is lowered in the well to 1-10 m from wellhead. Pressure line is connected to first pipe shutter and with pump unit and tank-trucks with reagents and process fluid. Pump unit force the solvent in annulus to displace well fluid via said string in oil line without exceeding the tolerable operating pressure. Tank-truck is disconnected from pump unit to connected tank-truck with process fluid thereto. Pump unit feeds process fluid into injection like in amount of 1.0 m³ to force it from pressure line into well annulus. Well is held for 6 hours to close the shutter and to connect first annulus shutter with tank-truck with solvent. Well borehole is flushed in three cycles in closed cycle. Second annulus shutter is opened, oil line shutter is opened and tank-truck is disconnected from pump unit to connect thereto the tank-truck with process fluid. Borehole is flushed from solvent by process fluid by displacing it into oil line without exceeding the pressure permissible for flow string and oil line.

EFFECT: higher efficiency of cleaning, accelerated process.

2 dwg