INJECTION WELL REPAIR METHOD Russian patent published in 2008 - IPC E21B33/134 

FIELD: oil production, particularly methods or devices for cementing, for plugging holes, crevices, or the like.

SUBSTANCE: method involves creating sand bridge within perforation interval. Sand with 0.6-0.8 mm particle dimensions is used and sand bridge is installed up to level spaced at least 1.5 m over perforation interval. Sand is supplied via production string having lower end arranged in well and spaced 30-35 cm over upper level of sand bridge to be created. Then liquid circulation with flow rate of 1.5-2.0 dm³/s via production string is provided. After that sand in amount of 45-55 kg/m³ is poured in production string. Liquid circulation rate is increased to 2.8-3.4 dm³/s along with sand amount increase up to 90-110 kg/m³ for production strings having diameters of 2.5" and up to 140-160 kg/m³ for production strings of 3" diameters. After calculated amount of sand pouring liquid with volume of not less than one production string volume is injected and technological time-delay is carried out for not less than 4 hours to provide sand subsidence. After than liquid circulation in well is recommenced. Finally upper level of sand bridge is determined.

EFFECT: increased reliability of perforation interval isolation during remedial cementing.

1 cl, 1 ex