METHOD FOR PREPARATION OF GROUTING MORTAR FOR INSULATION AND PREVENTION OF EARTHFALLS IN CAVERNOUS PART OF SHAFT OF WELLS, AND MAINLY GENTLY SLOPING AND HORIZONTAL ONES Russian patent published in 2013 - IPC C09K8/467 

FIELD: oil and gas industry.

SUBSTANCE: in preparation method of grouting mortar for insulation and prevention of earthfalls in cavernous part of the shaft of wells, and mainly gently sloping and horizontal ones, by mixing Portland cement, clay powder, water and additives, which differs by the fact that as additives there used are silicates of alkali metals and derivatives of higher fatty acids, which are obtained at processing of wood or oil resins and tar oils. First, water solution of silicates of alkali metals is prepared by introducing the latter to water. Then, derivatives of higher fatty acids, which are obtained at processing of wood or oil resins and tar oils, are introduced to the above water solution. Mixture is mixed during at least 40 minutes. Then, while stirring, clay powder is added and mixed during 10-20 minutes, and then Portland cement is added, and the mixture is stirred during not less than 30 minutes. Clay powder providing the yield of clay mud with viscosity of 20 mPa*s of not less than 16 m³/t is used as clay powder at the following component ratio, wt %: silicates of alkali metals 10-20, Portland cement 20-70, the above derivatives of higher fatty acids 2-5, the above clay powder 10-25, and water 100.

EFFECT: excluding sedimentation phenomena, diffusion and sagging of an insulating or fixing bridge, including at construction of wells with big deviation of the well shaft from vertical plane; providing complete filling of an inclined shaft of the well, possibility of forming the structure and hardening of the mortar immediately in the zone of earthfalls; providing hydrophobisation and inhibition of the formation rocks.

2 cl, 3 tbl, 3 dwg