WELL BOTTOM ZONE CLEANING DEVICE Russian patent published in 2006 - IPC E21B37/00 

FIELD: oil industry, particularly devices for hydrodynamic well treatment.

SUBSTANCE: device comprises power source and energy converter linked to the power source and made as multiplicatory pulse generator. The energy converter is made as pre-cavitator and main cavitator. One of the cavitators is formed as cylindrical bush. Outer side bush surface has annular recesses so that annular Venturi pipes are created between inner casing pipe surface and cylindrical bush surface. The main cavitator has body in which guiding means with tail, as well as bush with conical orifice, disk spring assembly and disk spring fixing means are arranged. Annular cap is put on guiding means tail. The disk spring fixing means is formed so that the cap is spring-loaded against the bush having conical orifice. Through channels are defined by the guiding means and the body. The guiding means is secured in the body by cylindrical bush of pre-cavitator and by bush having conical orifice. The bush and spring-loaded annular cap may form conical annular channel on outer side and adjacent end surfaces of conical annular channel. The channel is adapted for working liquid circulation from power source so that annular jet is created and directed to inner surface of casing pipe and working liquid enters into annular grooves of pre-cavitator bush.

EFFECT: increased well productivity due to improved well bottom zone treatment.

8 cl, 2 dwg