METHOD FOR REPAIR AND INSULATION WORK IN WELL (OPTIONS) Russian patent published in 2021 - IPC C09K8/467 E21B33/138 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, in particular to the restriction of water flows in producing wells. The method for repair and insulation work in the well includes the preparation of a grouting solution containing Portland cement, mineral additive “Penetronadmix”, a water recovery reducing agent, a plasticizer, water, and its injection into the well. For the preparation of the grouting solution, magnesium oxide and nitrilotrimethylphosphonic acid are additionally used, a composition of synthetic sulfonated polymers with a bulk density of at least 0.5 g/cm³ is used as a water recovery reducing agent, and a plasticizer is used: the composition of carboxylates and mixtures of sodium salts of polymethylenephthalene sulfonic acids of various molecular weights with a bulk density of at least 0.4 g / cm³, the mixing liquid is pre-prepared by dissolving in fresh water in a given quantitative ratio of nitrilotrimethylphosphonic acid, a water reduction agent, a plasticizer, and then in the process of mixing the solution, Portland cement, a mineral additive, and magnesium oxide are added at a certain ratio of components. A variant of the method is also described.

EFFECT: proposed method for repair and insulation work in the well makes it possible to restore the integrity of the cement ring in the annulus of wells with the formation of microcracks and micro-gaps in it both in the reservoir water and in the hydrocarbon liquid, increases the efficiency of repair and insulation work in the well, and the resulting grouting stone has high strength.

2 cl, 1 tbl