METHOD FOR COMPLETION OF METHANE-COAL WELL Russian patent published in 2006 - IPC E21B43/00 

FIELD: mining industry, namely, final construction stage of wells for extracting methane from coal beds.

SUBSTANCE: in accordance to invention, lifting column is lowered, on lower end of which down-pump is positioned, into operation column, perforated in interval of productive coal bed. Well mouth is tightened. Influx of bed fluid is caused due to decrease of column of liquid in behind-pipe space of well caused by down-pump. Excessive pressure is released from behind-pipe space of well with simultaneous preservation of calculated value of counter-pressure on productive bed at well mouth. Level of liquid in behind-pipe space of well is decreased to mark, positioned below perforation interval of operation column, and aforementioned level is maintained further. Gas is forced into behind-pipe space of well during period of descent of liquid column in it, under excessive pressure. Forcing of gas into behind-pipe space is stopped after level of liquid inside it reaches mark, positioned below perforation interval of operation column.

EFFECT: increased methane-coal well finalization process efficiency, shorter time needed for it to reach optimal operation mode due to improved conditions for draining bed fluid by means of down-pump.