TREATMENT METHOD OF BOREHOLE ZONE OF LOW-PERMEABLE BED AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2019 - IPC E21B43/22 E21B28/00 E21B34/06 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used for borehole formation processing (BFP) with low permeability. Method includes complex hydro shock and wave and chemical impact on formation. Chemical reagent is pumped into sub-packer zone of well. Hydraulic percussion pressure pulses are created with direct hydraulic shock by falling liquid column, by filtering chemical reagent into formation under pressure and by reverse hydraulic impact by dropping pressure. When pickup is achieved 0.2-0.5 m³/h alternating pressure waves are created. They contain multi-cycle filtration components – depression/repression combined with direct and reverse hydraulic shocks when switching modes. Amplitude of hydraulic shocks of not more than permissible pressure is provided for the formation. Synergetic effect of chemical action of solvents and acids with dynamic treatment mode and mechanical action of hydraulic shocks, with pumping of reaction products enables efficient dissolving and flushing out organic and mineral components of borehole of formation. To accelerate the BFP process under the packer, creating a buffer tank of 1–2 m³ in the well bore in the zone of the packer for delivery of the chemical into it. Product is pumped to the formation by small volumes from the annular space of the shank, and pumping out along the shank. Operations are repeated with circular circulation under the packer until the entire volume of the chemical is generated. Formation parameters are measured and, if the required intake capacity or influx is not achieved, the operations are repeated with a new volume of the chemical reagent delivered into the sub-packer zone. Also disclosed is the method implementing device.

EFFECT: increased efficiency of treatment of borehole formation zone.

4 cl, 4 dwg