ISOLATION METHOD OF BRINE WATER INFLUX IN WELL Russian patent published in 2012 - IPC E21B33/138 E21B43/32 

FIELD: oil and gas industry.

SUBSTANCE: isolation method of brine water influx in the well flooded with bottom formation waters with rise of water-gas contact (WGC) above lower holes of perforation interval, at which cement bridge from hydrophobisating cement compound is installed after the well killing and removal from it of tubing string at interval from working face to upper perforation holes. After the waiting period of cement curing ends, it is drilled in non-flooded part of productive formation and below current WGC by 3-5 m so that cement ring remains on walls of production string. In wall of production string, at interval of 2-3 m above and 2-3 m below current WGC there made are process openings, through which waterproof composition, for example plasticised cement solution or gel with increased flowability and penetrating capacity, is pumped to the formation depth. Make-up cement bridge from cement grouting on the basis of cement of normal density, which covers the process openings, is installed in well shaft at interval of 3-4 m above and 3-5 m below current WGC. After waiting on cement there partially drilled is make-up cement bridge at the distance of 2-3 m above current WGC. Repeated perforation of the current perforation interval covered with cement ring is performed at the most effective gas-saturated part of cross section, with formation of new perforation interval. Methanol is pumped through newly formed perforation openings; then, acid treatment of newly opened perforation interval is performed. Production tubing is lowered into the well to the depth of upper holes of new perforation interval and the well is developed.

EFFECT: improving isolation efficiency of brine water influx in the well.

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