ISOLATION METHOD OF BRINE WATER INFLUX IN WELL Russian patent published in 2013 - IPC E21B43/32 

FIELD: oil and gas industry.

SUBSTANCE: according to the proposed method, after a tubing string is removed from the well to the interval of flooded part of productive formation, a sand plug is inwashed. Above it at the interval of the non-flooded part of productive formation there installed is an insulating cement bridge from hydrophobisating cement composition. After completion of waiting-on-cement period (WOC), it is drilled and a cement ring is left on walls of the production string. The sand plug is removed below the cement ring in flooded part of the productive formation. An insulating packer lowered on a string of process pipes is installed on the roof of productive formation. At the interval of the flushed sand plug there pumped under pressure through existing perforation holes of flooded part of productive formation or through newly created process openings for waterproofing is waterproofing composition; waterproofing composition is reinforced with a reinforcement cement bridge from cement mortar based on cement of normal density, which is installed on the well shaft. After the reinforcement cement bridge is installed, the insulating packer is unpacked, and the string of process pipes is lifted. After wait-on-cement time (WOC) is over and strength and leakage test of cement bridge is completed, the pipe string with the packer is removed from the well, repeated perforation of the non-flooded part of productive formation covered with cement ring is performed in the most effective gas-saturated part of the section. Acid treatment of newly developed perforation interval is performed to destruct the cement ring; a new tubing string is lowered to the well and the well is developed. After stable influx of gas is obtained from the formation to the well there pumped and forced through to the bottom-hole zone of the formation is mixture of methanol with non-ionogenic surface-active substance to remove water component of the filtrate of hydrophobisating cement compound, the well flaring is performed till the well reaches the working mode and then it is put into operation.

EFFECT: improving insulation efficiency of influx of formation water without contamination of high-permeability non-flooded gas-saturated intervals of productive formation.

3 ex, 7 dwg