FIELD: oil and gas production. SUBSTANCE: composition includes homogeneous phase containing hydrophobic liquid, emulsifier, and cross-linking agent for polysaccharide and disperse phase containing water and polysaccharide. Composition may also contain a heaving up disperse- phase material. A method of preparing sealing liquid is described as well as a method of tamping underground formation zone which is pierced by borehole. According to this method, sealing liquid is pumped in into this zone through borehole and, there, it is subjected to high-shear force. As a result, polysaccharide and cross-linking agent come into contact with each other and cross linking of polysaccharide is initiated resulting in hardening of sealing liquid. EFFECT: improved sealing characteristics. 28 cl
