METHOD OF REPAIR AND INSULATION OPERATIONS IN A WELL Russian patent published in 2017 - IPC E21B33/138 C09K8/46 C09K8/467 

FIELD: oil and gas industry.

SUBSTANCE: method comprises preparing and cyclic injection of gel-forming agent and liquid glass in the deformation interval. A slurry of ground anhydrite is used as gel-forming agent. The injectability of the insulated interval is pre-determined, and a ground anhydrite slurry is prepared in fresh water at the water-solid ratio of 0.8-1. Depending on the injectability of the insulated interval, from 1 to 15 cycles of ground anhydrite and liquid glass slurry in the volume ratio of 1:1 is pumped into the isolated borehole. Each cycle includes a 1-5 m³of anhydrite ground slurry with addition of synthetic or basalt fiber in an amount 1-6 kg per1 m³ anhydrite slurry, 0.5-1 m³ buffer from fresh water,1-5 m³ liquid glass. Next, cement solution is pumped, dissolved from 2-5 tons of plugging portland cement. The well is left to respond for 24 hours. The diameter of the synthetic or basalt fiber is 10-35 mcm, and its length is 3-18 mm. Fiber is added during preparing or pumping of ground anhydrite slurry.

EFFECT: improved efficiency of the repair and insulation operations method, improved plugging capability and hardening of the obtained plugging stone with the use of a gel-forming agent.

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