METHOD OF THERMAL GAS-CHEMICAL AND IMPACT-WAVE TREATMENT OF OIL-BEARING STRATA Russian patent published in 2020 - IPC E21B43/22 E21B43/24 C09K8/60 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to the field of oil industry, in particular, to increase of extraction degree of oil from mined deposits. Method involves pumping to a bottomhole of a reducing composition containing ammonium nitrate, formaldehyde, a catalyst for oxidation of the simplest aliphatic alcohols methanol, or ethanol, or isopropanol and hydrogen peroxide containing a decomposition inhibitor. Oxidation products contain only gaseous nitrogen or carbon dioxide and water. Initiator of oxidation of aliphatic alcohols of methanol, or ethanol, or isopropapol used is aqueous solutions of salts of metals with variable valence: FeCl₃, Fe(NO₃)₃, K₂CrO₄, KMnO₄. Hydrogen peroxide decomposition inhibitor used is oxalic acid added to the reducing composition, or 40–60 % hydrogen peroxide in amount of 0.5–5.0 %. Content of ammonium nitrate in the reducing composition is 40–66 %. Used is hydrogen peroxide with concentration of 20–60 %. Reducing composition is prepared by dissolving ammonium nitrate in 37–40 % formalin, while adding hydrogen peroxide for at least 2 hours. Initiator of oxidation of organic alcohols contains salts of metals with variable valency with concentration of 3–6 %. To ensure impact-wave action on oil-bearing stratum, partial neutralization of reducing solution with soda or ammonium water till pH = 5.0–7.0 is performed.

EFFECT: ensuring safety of the process, increasing efficiency of using the energy potential of all chemical reagents.

3 cl, 3 tbl, 8 ex