PROCEDURE FOR TREATMENT OF FILTRATION ZONE OF HORIZONTAL WELL WITH ABNORMALLY LOW RESERVOIR PRESSURE Russian patent published in 2011 - IPC E21B43/25 E21B37/00 

FIELD: gas and oil production.

SUBSTANCE: procedure consists in lowering production string - PS- into well to depth of beginning of filter in horizontal section of borehole and in lowering flexible pipe into PS. Liquid and gas are pumped into the well through this flexible pipe. According to the invention a level of well fluid is determined in the well before flexible pipe lowering. Upon flexible pipe lowering under the level of fluid and before its coming out from the PS gas in form of air-nitrogen mixture is pumped through the flexible pipe to complete replacement of well fluid with gas in the PS. Further, the flexible pipe is lowered to its coming out for not over one metre from the PS and the flexible pipe is lowered to bottomhole with interval-by-interval stops every 50-100 m. Liquid in form of water solution of surface-active substance - SAS with air-nitrogen mixture is pumped till mechanical impurities emerge on surface in each interval.

EFFECT: raised efficiency of treatment of filtration section of horizontal well borehole due to high evacuation of clay material.

1 ex, 1 dwg