PROCEDURE OF TREATMENT OF WELL BOTTOMHOLE ZONE Russian patent published in 2009 - IPC E21B43/16 

FIELD: mining.

SUBSTANCE: invention refers to mining and can be implemented for development and recovery of producing wells yield reduced because of bottomhole mudding with asphaltic-resinous-paraffin formations and mechanical impurities. The object of the invention is generating periodic pulses of pressure in the bottomhole zone of a reservoir with regulated amplitude and frequency characteristics for each alternating stage of well treatment. The essence of the invention is as follows: the procedure consists in pumping fluid into the cavity of the well, in creating depressive drop of pressure between the bottomhole zone and the cavity of the well by means of generating periodic pulses of pressure in the bottomhole zone in form of a shock wave moving along the cavity of the well; the shock wave is formed, when the cavity of the well at the well head is periodically opened to let well fluid under pressure drain and then it is shut off with valves. One of the valves is a drain valve. It communicates the well cavity with a drainage capacity. The second valve is a fluid filling valve. It facilitates connection with a fluid source under pressure. The fluid drain valve performs opening and shutting off the well cavity at the well head for draining well fluid under pressure. Periodically pressure in the well is raised connecting the well head with the fluid source under pressure by means of opening the fluid filling valve. According to the invention at the stage of removing mechanical and hydrocarbon formations there is performed quick drain valve opening and comparatively slow shutting off to create depression, facilitating implosion extraction of mud out of botomhole thickness, and to create repression preventing mud reverse moving. At the stage of working agent supply into an interval of perforation there is performed drain fluid opening and quick shutting off for creating repressive pulses of pressure facilitating expansion of fractures when working agent penetrates them. At the stage of removing working agent and products of chemical reaction from the bottomhole zone again there is performed drain valve quick opening and slow shutting off for implosion extraction of residual mud out of bottomhole zone thickness. Also frequency of pulses at mud removal is chosen providing resonant swinging of well fluid column and maximum value of depression amplitude, and during fractures expanding - also providing working agent moving in fractures to flush off rock of the bottomhole zone from hydrocarbon film.

EFFECT: new procedure of well bottomhole zone treatment.