CAVITATION DEVICE FOR STIMULATION OF OIL RECOVERY OF FORMATIONS Russian patent published in 2020 - IPC E21B43/18 F04F5/02 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of oil and gas industry and is intended for solution of tasks on recovery of reservoir properties of borehole zone of wells and involvement in development of hard-to-recover and unprofitable reserves of hydrocarbons. Proposed device comprises centralizer, hollow case and bottom with outer flanges. They are interconnected by screws. There is an inlet cylindrical hole for injection of working fluid into it through filter-separator. In housing there is flow swirler, annular vortex chamber with annular confusor, and also multichannel jet device. This device is made in the form of two circular flat rings coaxially rigidly installed between flanges. Main of the rings has arc-like grooves facing the auxiliary ring of the end surface, made along the circumference with the specified pitch for connection of the vortex ring chamber to the annular diffuser located on the periphery between the flanges. According to the invention, the auxiliary ring is identical to the main one and has arched and equally oriented arc grooves. Jet device is equipped with annular gasket. It overlaps arc grooves and forms two-row exhaust channels with critical section of outlet holes shifted in one row relative to the other one by half of pitch. At the same time annular gasket is made with wedge-shaped sides separating confusor and diffuser into two interconnected circular sections.

EFFECT: increasing efficiency of treatment of bottomhole zone of wells.

1 cl, 2 dwg