FACILITY FOR HYDRAULIC SAND BLAST PERFORATION OF WELLS Russian patent published in 2009 - IPC E21B43/114 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil industry and can be implemented at development of oil fields with hydraulic breakage of horizon. The facility for hydraulic sand blast perforation of wells consists of a case of a perforator with an axial channel and side holes wherein head pieces are rigidly fixed. At the top a double-step bushing is rigidly secured to the case; the bushing is installed in a double-step coupling. By means of the coupling the facility is attached to the flow string. A circular pressure tight cavity filled with oil is created between the steps of the bushing and coupling. A unit of centering elements is fastened to the case from beneath. The unit includes an axial channel with a saddle for a working ball and doubled vertical ribs wherein vertical slots are made. Flexible arc-shaped plates permanently contacting with a casing string of the well are installed between each pair of ribs on axes. Bushings assembled in the slots are secured on the ends of the axes; the slots are of length facilitating travel of bushings in them at a distance of flow string elongation caused by pulsation of working fluid pressure.

EFFECT: increased reliability an efficiency of facility operation.

2 dwg