METHOD FOR DECARBONIZATION OF HYDROCARBON-CONTAINING FORMATIONS Russian patent published in 2007 - IPC E21B43/27 C09K8/74 

FIELD: oil and gas extractive industry, namely, methods for restoring penetrability of hydrocarbon-containing formations, possible use during major repairs of oil and gas wells for increasing debit thereof.

SUBSTANCE: method for decarbonization of hydrocarbon-containing formations and behind-column concrete includes converting calcium carbonate to non-soluble calcium sulfate, then perforated zone of given formations is performed firstly with technological solution, containing, in percents of mass: ammonium persulfate 5-15, surfactant 0,2-1,5, water the rest, then with technological solution, containing acidic agents based on hydrofluoric and hydrochloric acid or their salts with addition of surfactant, then well is cured for some time and then drained by creating 10-14 depression-repression cycles in it during time of 8-12 hours, while amount of technological solutions is selected equal to 1-1,2 of volume of pores of processed zone.

EFFECT: prevented dissolution of calcium carbonates during restoration of penetrability of collector of hydrocarbon-containing formation, and also prevented destruction of behind-column concrete due to transfer of calcium carbonate, soluble in acidic substances, to non-soluble calcium sulfate.

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