ACID TREATMENT METHOD FOR BOTTOMHOLE ZONE OF FORMATION HAVING CARBONATE RESERVOIR Russian patent published in 2007 - IPC E21B43/27 

FIELD: oil production, particularly methods for stimulating production by forming crevices or fractures by use of eroding chemicals.

SUBSTANCE: method involves drilling branch bores in well; lowering ejector plant provided with packer; injecting 10-15% hydrochloric acid solution having predetermined volume; holding the process under bath conditions; performing 4-6-fold pulsed solution forcing in reservoir under specified conditions; executing time delay; terminating injection in continuous mode; performing time delay; extracting injected solution in amount of up to 2.5 of injected solution volume; injecting the second portion in reservoir in pulsed regime in the beginning of said portion injection; executing time delay and performing continuous solution injection; performing time delay; extracting injected solution in amount of up to 2.5 of injected solution volume; injecting the third solution in reservoir in pulsed regime in the beginning of said portion injection; executing time delay and performing continuous solution injection; extracting injected solution in amount of up to 2.5 of injected solution volume by means of injection plant or by swabbing operation.

EFFECT: increased efficiency.

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