METHOD TO STIMULATE HYDROCARBON INFLOW FROM WELL CHARACTERIZED BY ABNORMALLY HIGH RESERVOIR PRESSURE Russian patent published in 2008 - IPC E21B43/22 

FIELD: oil production, particularly enhanced recovery methods for obtaining hydrocarbons with the use of chemicals or bacterial activity.

SUBSTANCE: method involves preparing 6% aqueous soda ash solution Na₂CO₃, wherein solution volume is equal to that of drilling mud filtrate, which has penetrated in reservoir, but is not less 0.5 m³ per one meter of exposed efficient reservoir thickness; forcing thereof via flow string in reservoir; holding solution inside reservoir under injection pressure for 1 hour; injecting 8.0% hydrochloric acid solution HCl having volume equal to that of aqueous soda ash solution Na₂CO₃, but not less than 0.5 m³ per one meter of exposed efficient reservoir thickness; forcing the solution in reservoir via flow string and holding thereof inside reservoir under injection pressure for 1.0 hours; developing well; performing direct well flushing; injecting aqueous 10.0% calcium hypocloride solution Ca(ClO)₂·2H₂O in reservoir under pressure not exceeding reservoir fracturing pressure, wherein calcium hypocloride solution volume is equal to that of 8.0% hydrochloric acid solution, but is not less than 0.5 m³ per one meter of exposed efficient reservoir thickness; holding said calcium hypocloride solution in reservoir under injection pressure within 10.0 hours; developing well by one of known methods; performing direct well flushing; preparing clay-acid mixture solution, including 10.0% aqueous HCl, HF with 5% by volume concentration and ascorbic acid C₆H₈O₆ with 0.2% by volume, wherein said clay-acid mixture solution has volume equal to that of 10.0% calcium hypocloride solution, but not less than 0.5 m³ per one meter of exposed efficient reservoir thickness. Said mixture is injected in reservoir via flow string under injection pressure for 10.0 hours. Then well is developed by one of well-known methods and hydrodynamical study is carried out.

EFFECT: increased efficiency of chemical well bore zone treatment in the case of barite-loaded polymeric or polymeric-clay mud usage.

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