METHOD FOR IMPROVEMENT OF TREATMENT OF UNDERGROUND FORMATION THROUGH WELL, AND METHOD FOR HYDRAULIC FRACTURING OF FORMATION THROUGH WELL Russian patent published in 2013 - IPC E21B43/22 E21B43/267 

FIELD: oil and gas industry.

SUBSTANCE: treatment method of an underground formation involves introduction to the formation of the first liquid containing the first thickening agent (TA), pumping of the second liquid thickened with the second TA; after being pumped, liquids contact on their boundary surface; one liquid contains activated chemical decomposer (CD), decomposing TA of the other liquid only, and the other one contains activator of the same CD, and/or the first liquid contains CD, agent for adjustment of pH or complexing agent (CA), which destabilises only the second liquid, and/or the second liquid contains CD, agent for adjustment of or CA, which destabilise only the first liquid; liquids react at their contact boundary and create a sliding layer at the same boundary, which has viscosity of less than 15 mPa·s - considerably lower than viscosities of liquids. The formation hydraulic fracturing method involves pumping to the formation of fracturing liquid containing the first TA, carrier liquid thickened with the second TA and containing a proppant suspension; after being pumped, liquids contact on their boundary surface; one of them contains activated CD destructing TA of only the other one, and the other one contains activator of the same CD, and/or the first liquid contains CD, agent for adjustment of pH or CA, which destabilise only the second liquid, and/or the second liquid contains CD, agent for adjustment of pH or CA, which destabilise only the first liquid; liquids react at their contact boundary and create a sliding layer at the same boundary, which has viscosity of less than 15 mPa·s.

EFFECT: increasing well productivity.

36 cl, 2 ex, 7 dwg