Method of treating bottom zone of low-permeable oil reservoirs. RU patent 2244111.

FIELD: oil and gas production.

SUBSTANCE: invention aims at increasing productivity of oil- and gas-producing and injecting wells exposing high-temperature low-permeable oil reservoirs. In the treatment method according to invention including forcing enzyme substrate and separate enzyme into formation and creating conditions to enzymatically convert substrate into acid, geologic and productive characteristics for each interval of bottom zone are determined in order to pick out low-permeable intervals of oil reservoir for treatment, whereupon properties of enzyme substrate and separate enzyme as well as conditions for their pumping are chosen. Substrate utilized in the method is head fraction of methyl- and/or ethyl-, and/or butyl acetate production, to which aliphatic alcohols are added, and enzyme is an acid solution. Substrate is pumped simultaneously and/or before, and/or after pumping of enzyme, after which well is closed for some time and then opened and placed under predetermined operational conditions.

EFFECT: enhanced efficiency of acid treatment due to increased phase permeability for oil and deepness of active acid-treated zone of low-permeable oil reservoirs.

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IPC classes for russian patent Method of treating bottom zone of low-permeable oil reservoirs. RU patent 2244111. (RU 2244111):

E21B43/27 - by use of eroding chemicals, e.g. acids

E21B43/22 - Use of chemicals or bacterial activity (E21B0043270000 takes precedence;chemical or bacterial compositions therefor C09K0008580000; chemical features in extracting oils from oil sands or shales C10G)

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