TREATMENT METHOD OF BOTTOMHOLE ZONE Russian patent published in 2014 - IPC E21B43/27 E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry. Treatment method of bottomhole zone includes running tubing string to the interval of stratum perforation, pulsed pumping of 10-15% water solution of hydrochloric acid through the tubing string, process holdout within 3 hours for the purpose of reacting and extracting of reaction products. Before running the tubing string is equipped bottom-up with device for pulsed fluid pumping, breakable valve, tube with perforated holes and sleeve inside and packer. In running process tube with perforated holes is installed 2 meters below the lower interval of stratum perforation. Hydrocarbon solvent is pumped through the tubing string in continuous mode with unseated packer; then process holdout is maintained. In process holdout process fluid is pumped in volume of 0.5 m³ to the tubing string and annular space alternately in 4 cycles each 20 minutes; thereafter hydrocarbon solution and reaction products are washed by backwash from the well. Then the tubing string is elevated so that the device for pulsed fluid pumping is set opposite bottom of the stratum; the packer is seated, sleeve is moved down relative to the tube with perforated holes, and holes of the perforated tube are sealed by sleeve fixing in regard to the tube with perforated holes; the tubing string is filled with process fluid and by created excessive pressure the breakable valve is cut thus allowing fluid communication in the piping string and stratum through the device for pulse fluid pumping. Then through the tubing string pumping ad squeezing of 10-15% water solution of hydrochloric acid is made in pulsed mode in volume based on calculation of 0.8 m³ per 1 m of stratum thickness with gradual flow rise of 10-15% water solution of hydrochloric acid pumping from 0.5 m³/h up to 0.8 m³/h; process holdout is maintained within 3 hours and reaction products are extracted by swabbing.

EFFECT: increasing efficiency of stratum treatment due to preliminary cleaning and washing of bottomhole zone by hydrocarbon solvent with further treatment by hydrochloric acid solution in pulsed mode with short pulses and flow increase thus allowing yield increase at further development of stratum, simplifying production process, reducing costs and duration of stratum treatment.

1 ex, 2 dwg