Method for exerting a combined effect on the near-wellbore region of a producing formation

A method for exerting a combined effect on a near-wellbore region of a producing formation, comprising:

• filling at least one section of a perforation located in the near-wellbore region with water or a killing fluid,
• through a tubing installed to a bottom hole, providing a first composition having a density of 1.3-1.4 g/cm3, after which said tubing is installed at a height of 20-25 m above an upper section of the perforation, after which
• a second composition having a density of 1.6-1.8 g/cm3 is provided through said tubing into a region of interaction of said first and second compositions, said first and second compositions interacting through the perforation in the near-wellbore region of the producing formation,
• said first and second compositions interacting resulting in an exothermic reaction forming heat and gas with increasing temperature and pressure respectively, in the near-wellbore region of the producing formation, which in turn leads to a heating of the producing formation,
• said forming of heat and gas in the near-wellbore region of the producing formation leading to a formation of microcracks in the producing formation and an improvement in one or more filtration characteristics of the producing formation,
• after a completion of providing said first and second compositions, said tubing being installed in the at least one section of the perforation of the near-wellbore region, providing a third composition through said tubing, said third composition being an acidic solution containing hydrochloric acid with a concentration of 2-5% in an amount of 0.4-1.5 m3 per each meter of a thickness of the producing formation,
• wherein said first composition comprises:
• ammonium nitrate, NH4NO3—44.0-54.0 mass percent (mass %);
• sodium hydride, NaH—2.8-3.2 mass %;
• powder nanoaluminum, Al—5.6-15.6 mass %;
• hydrazine nitrate, N2H5NO3—3.0-5.0 wt. %;
• oxamide nitrate, C2O2(NH2)2—HNO3—1.0-3.0 mass %;
• 1,2-bis(hydroxymethyl)-o-carborane, C4B10H16O2(99.9%)—3.0-5.0 mass %;
• hydrocarbon fuel—8.0-13.0 mass %;
• sodium chloride, NaCl, and/or potassium chloride, KCl—4.5-5.5 mass %;
• nitric acid, HNO3—7.0-9.0 mass %;
• emulsifier—0.5-3.0 mass %;
• and
• water—10.0-15.0 mass %,
• wherein said second composition comprises:
• sodium nitrite, NaNO2—18.0-23.0 mass %;
• hydrocarbon fuel—8.0-13.0 mass %;
• urea, CO(NH2)2—22.0-28.0 mass %;
• 9-BBN, C16H30B2—0-3.0 mass %;
• Carborane, C2B10H12(99.9%)—3.0-6.0 mass %;
• sodium chloride, NaCl, and/or potassium chloride, KCl—4.5-5.5 mass %;
• emulsifier—0.5-3.0 mass %;
• and
• water—24.0-27.0 mass %.