HIGH TEMPERATURE LUBRICATING AGENT FOR UPDATING VISCOSITY OF LOW- AND HIGH-DENSITY BRINES Russian patent published in 2012 - IPC C09K8/04 C09K8/62 E21B43/22 E21B43/26 

FIELD: mining.

SUBSTANCE: viscoelastic composition for the use in underground formations includes, at least, one quaternary alkylamidoamine of the given formula and at least one indicated sub-additive when the ratio by weight is within 1000:1 and 5:1. Water-base fluid for the use in oil deposit includes indicated composition. Composition of high-density brine for oil deposit includes within 30-70 wt % of organic and/or inorganic salt and the composition mentioned above. Fluid of oil deposit termination in the form of high-density brine contains within 30-70 wt % of, at least, one organic or inorganic acid, within 0.1-4 wt % of, at least, one cationic surfactant from the modified group and, at least, one sub-additive from the modified group. The method of cracking underground formation includes provision of thickened fluid for water-base hydraulic fracturing, which includes water environment and effective amount of the above mentioned composition and injection of aqueous fluid through the well bore into the underground formation at a pressure, sufficient to break the formation. The invention is developed in the formula subclaims.

EFFECT: improvement of efficiency in upgrading permeability of underground formations.

24 cl, 4 ex