COMPOSITION FOR SHUTOFF OF WATER INFLOWS TO WELL Russian patent published in 2003 - IPC

FIELD: oil and gas producing industry, particularly, compositions for shutoff of water inflows to wells. SUBSTANCE: composition includes polymer, sodium silicate aqueous solution of 40%-concentration, calcium chloride aqueous solution of 30%-concentration. Polymer is used in form of polyvinyl alcohol. Composition has the following amounts of ingredients, wt.%: polyvinyl alcohol 2-4; said solution of sodium silicate 40-50; said solution of calcium chloride 46-58; with ratio of weight parts between said solution of calcium chloride and polyvinyl alcohol amounting up to 1.00:(0.03-0.09), respectively, and between said solutions of sodium silicate and calcium chloride of 1.00: (0.92-1.45), respectively. EFFECT: higher efficiency of work involved in shutoff of water inflows to wells due to reduced permeability of water-saturated reservoirs, provided reliable and durable shutoff barrier with improved elastoplastic characteristics with concurrent preservation of high strength properties, resulting in increased overhaul periods.