COMPOSITION AND METHOD OF PREPARING HYDROPHOBIC EMULSION IN INTEGRATED WELL-KILLING TECHNOLOGY Russian patent published in 2000 - IPC

FIELD: oil and gas production. SUBSTANCE: invention aims at widening application area of well- killing compositions and enhancing efficiency of integrated well-killing technology owing to composition proposed and method of preparing high-stability, low-viscosity, hydrophobic, heavy (density at least 1200 kg/cu.m) emulsion and offering formulas for calculation of volume required for injecting composition into well, provided that most economically advantageous setting saline fluid is used, including use of ordinary formation water, subquality water, and Cenomanian water. Composition contains: 4.5-7.5 volumes of special oil-production reagent (emulsifying component); mixture of kerosene-gas oil petroleum fraction with heavy solvent Ц amyl phenyl ketone at volume ratio ensuring density of mixture at least 1200 kg/cu. m and 30-50 vol % (in total) of special oil- production reagent dissolved therein; and 70-50 vol % of disperse phase: aqueous calcium chloride or nitrate solution with density not below 1200 kg/cu.m. Composition is used as bottom part of column. Its economically advantageous volume is calculated from formula: V_ea = [V_sum*(ρ_dic-ρ_dw)]/(ρ_he-ρ_dw), cu.m, wherein V_sum is summary volume of integrated column; cu.m; ρ_dic weighted mean density of integrated column, kg/cu.m; ρ_dw density of fresh or mineralized water, kg/cu.m; and ρ_he density of hydrophobic emulsion, kg/cu.m. Top part of column consists of fresh or mineralized water. When preparing composition, specified amount of emulsifying component is first dissolved in specified amount of heavy solvent using "vessel-pump" circulation-type stirring of system for 10-15 min. Then, specified volume of above-indicated kerosene-gas oil fraction is added and, after stirring of system for further 10-15 min and determination of its density, specified volume of above-indicated disperse phase is gradually added. EFFECT: improved well-killing technology. 4 cl, 3 tbl