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 brine water cone, at which isolating cement bridge from hydrophobisating cement compound is installed after removal of tubing string from well at perforation of non-flooded part of productive formation. After waiting on cement period is completed, it is drilled so that cement ring remains on walls of production string, which covers the perforation interval of non-flooded part of productive formation. To interval of flooded part of productive formation there pumped under pressure through lower perforation holes is water isolating composition, for example plasticised cement grouting or gel with increased flowability and permeability so that make-up cement bridge from cement solution on the basis of cement of normal density remains in well shaft, which covers lower perforation holes made in flooded part of productive formation. After wait-on-cement time (WOC) is over and strength and leakage test of cement bridge is completed, repeated perforation of the perforation interval of non-flooded part of productive formation covered with cement ring is performed in the most effective gas-saturated part of the section. Methanol is pumped through newly formed perforation holes to remove aqueous component of filtrate of hydrophobisating cement compound; then, acid treatment of newly opened perforation interval is performed to destruct cement ring, tubing string is lowered to the well to the depth of upper holes of new perforation interval and the well is developed.

EFFECT: increasing brine water influx isolation efficiency.

6 dwg