WELL BOTTOMHOLE ZONE TREATMENT METHOD Russian patent published in 2016 - IPC E21B43/16 E21B43/27 E21B43/12 E21B34/06 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil production and, in particular, to methods of acid treatment of a bottomhole formation zone with subsequent well introduction into service. Method can also be used at wells workover and, in particular, when cleaning channels of the productive formation. Method involves the treated formation separation from the annular space of the well. Injection of an oxygen composition into the treated formation interval is performed. Process exposure is performed. Reaction products are swabbed and extracted from the formation. Well killing is carried out. Pump unit is lowered and the well operation is started. Herewith, before separation of the treated formation from the annular space a tubing string is lowered into the well with an open end provided with a check valve and with two packers for separation of the treated formation interval from the annular space and from the bottom or from another formation in the well. Tubing string above the lower packer is equipped with a setting tool - ST. Well circulating valve is set above the upper packer. After the process holding both packers are reset above the interval of the treated formation. Well killing is carried out through the borehole circulation valve by replacement of fluid in the annular space of the well and in the tubing string with a killing fluid. Then the upper packer is removed. Prior to lowering into the well the pump unit by means of the ST the tubing string is disconnected from the lower packer and the above said tubing string is removed from the well.

EFFECT: provided is maintaining of collection properties of the bottomhole zone of a productive formation at the use at the killing stage of any types of killing fluids.

8 cl, 2 dwg