METHOD FOR PERFORMING PULSE HYDRAULIC FRACTURING OF CARBONATE FORMATION Russian patent published in 2012 - IPC E21B43/26 E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: method involves lowering to the well of tubing string, pumping of fracturing fluid with a pump unit via discharge line to tubing string, formation of pressure drops between annular space, bottom-hole zone and cavity of tubing string by means of periodic pressure pulses in bottom-hole zone in the form of moving fluid mass wave. Annular space of well is sealed with packer installed above roof of formation subject to hydraulic fracturing, and on the end of tubing string there arranged is pulse generator. Drain valve is installed above pulse generator, but below packer as a part of tubing string. Hydropulsation compensator is installed on the well head for protection of pump unit against high pressure surges in its discharge line. Hydraulic fracturing of formation is performed by pulse pumping of fracturing fluid at the pressure exceeding crack opening pressure by 20-25% during 20-30 minutes. After that, pumping of acid solution is performed in pulse mode. For that purpose, chlorhydric acid solution (10-15%) in quantity equal to 1.3-2 m³ per 1 m of perforated formation thickness, but not less than 10 m³ is used. After that, well is closed and pressure reduction and acid reaction is awaited; drain valve is destructed and well is developed by swabbing via tubing string. Then, packer is released and tubing string is removed from the well.

EFFECT: simpler and more effective method due to increasing the duration of formation productivity.

8 ex, 1 dwg