SECTIONAL SAND JET PERFORATOR Russian patent published in 2017 - IPC E21B43/114 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to devices for directed opening of a production formation in a horizontal well with a casing string and for performing hydraulic fracturing of the formation. A sectional hydro-sandblasted perforator contains a hollow bod and consists of a coupling, separate sections with radial holes and jet nozzles installed therein, centralisers, the separate sections are interconnected by spacers. The radial holes in the sections are formed at a predetermined angle with respect to the axis of the body. The holes in the sections are offset from the axis of the body. The diameter of the holes in the sections is less than the diameter of the holes in the coupling and in the spacers provided with rigid centralisers outside. The coupling, the sections and the spacers are separated by a bearing and pulled together by a shaft with nuts screwed onto it from both sides. The shaft is installed eccentrically relative to the axis of the body and rigidly connected to individual sections, and the nuts are contacted with the coupling and the last section that has been killed by the bearings. The coupling, the individual sections and the spacers are sealed together by the sealing elements, and the individual sections are configured to co-rotate with the shaft with respect to the fixed couplings and spacers. The jet nozzles are pressed into separate sections made of hard-alloy material in the form of a cone and equipped with external and internal conical surfaces tapering outward from a separate section of the hollow body. The radius of the jet nozzle pressed into a separate section is less than the radial extension of the coupling centralisers and the spacer, and the diameter of the jet nozzle corresponds to six grain diameters of the proppant fraction.

EFFECT: invention anables to perform hydro-sandblasting perforation in the well casing string in the direction of minimum formation stress, regardless of the device cposition in the borehole, increase the efficiency and reliability of operation, and prevent the proppant hole from plugging the jet nozzle opening.

4 dwg, 1 tbl