METHOD FOR REPAIR AND INSULATION WORKS IN WELL Russian patent published in 2016 - IPC E21B33/138 C09K8/50 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, in particular, to methods of sealing defects of production string, liquidation of leakiness of cement sheath in tight formations and restrict water influx in well. Method provides repair insulation works in well and includes injection into the zone of isolation of water shutoff composition consisting of silicon dioxide hydrosol of density 1196-1220 kg/m and sodium chloride solution of density 1012-1030 kg/m, which are mixed on the surface and is pumped into the fault in the following ratio of components, vol. parts: silicon dioxide hydrosol 200-400, gelling agent 100, when specific injectivity of isolated interval is more than 0.8 m³/(h·MPa) sequential injection of water shutoff composition is made followed by buffer of fresh water, and formation of mineralised water with density of 1180-1190 kg/m³ with the following ratio of components in vol. parts: silicon dioxide hydrosol 200-400, gelling agent 100, formation mineralized water 100.

EFFECT: technical result consists in improvement of efficiency of remedial cementing works in well due to increase quality of repair works.

1 cl, 2 tbl