ELECTROCHEMICAL TREATMENT METHOD FOR PRODUCTIVE RESERVOIR OF OIL-AND-GAS WELLS Russian patent published in 2007 - IPC E21B43/25 C09K8/42 

FIELD: oil production industry, particularly development of drilled wells and to stimulate oil production from existent cased or uncased walls due to inorganic and organic deposit dissolving in well bore and in bottomhole reservoir zone.

SUBSTANCE: method involves killing well with liquid, namely with mineralized water; removing bottomhole equipment from well; installing electrodes electrically linked to power source in well; switching-on constant current source and treating productive reservoir with electric field by passing electric current through the reservoir. Electrodes linked with power source are installed in well below liquid level in well. Graphite anode and cathode provided with non-conductive centrators are used as the electrodes. The anode and cathode are spaced apart along well height. Anode is arranged within productive reservoir zone. Cathode is installed 10-100 m below anode. Mineralized water with alkaline surfactant taken in amount of 0.25-1.0% by weight is used for well killing. The invention is disclosed in dependent claims.

EFFECT: increased efficiency of productive reservoir zone cleaning of drill products, including polymer-based ones, and possibility to remove inorganic deposits accumulated in well and bottomhole reservoir zone during well operation due to creation of stable acid medium with low pH values within productive reservoir interval and prevention of acid medium neutralizing during well treatment, as well as sulfate-reducing bacterium growth suppression.

4 cl, 4 tbl, 5 dwg