GAS-LIBERATING FOAMING COMPOSITION Russian patent published in 2003 - IPC

FIELD: oil producing industry; applicable in foam treatment of wells and bottom-hole formation zones. SUBSTANCE: gas-liberating foaming composition including water, sodium nitrite, sulfamic acid and foaming agent contains additionally reagent neutralizing sulfamic acid, with the following ratio of components, wt.%: sodium nitrite, 0.9-20.9; sulfamic acid, 0.9-16.4; reagent neutralizing sulfamic acid, 0.2-7.9; foaming agent, 0.1-2.5; water the balance. Reagent neutralizing sulfamic acid is used in the form of aqua ammonia, ammonium carbonate or hydrocarbonate or their mixture. Said neutralizing reagent is sufficient for neutralization of sulfamic acid up to 50-97%. Gas-liberating foaming composition has foam stabilizer in amount of 0.05-0.2 wt. % for 100% of composition. Foam stabilizer is used in the form of water-soluble polymer, for instance, polyacrylamide. EFFECT: higher gas-liberating foaming ability of composition, reduced corrosiveness and extended assortment of chemical substance for production of foaming composition. 5 cl, 2 tbl