METHOD OF HYDRAULIC JET PERFORATION OF WELLS AND DEVICE FOR ITS EMBODIMENT Russian patent published in 2002 - IPC

FIELD: oil and gas producing industry. SUBSTANCE: method may be used in production of underground waters by water-supply wells, and in hydraulic jet perforation of cased wells and opening-up of rocks in recovery of oil, gas and water. Method includes running into well on pipe string of erosion perforator provided with jet nozzles, movable bushing and valve in its body. Well perforation is performed by supply under pressure of abrasive fluid by pumping unit through pipe string and jet nozzles of erosion perforator. Prior to lowering of erosion perforator, immovable bushing is coaxially installed in perforator body lower end. Movable bushing-barrel is installed on immovable bushing outlet end. Upon completion of hydraulic perforation of well, jet nozzles are closed in body of erosion perforator. Valve is opened by lowering of pipe string down to stop of external supporting disc of movable bushing-barrel against sand bridge in boreholes. After completion of abrasive fluid supply, washing fluid is supplied with valve opened. Sand bridge is washed-out and simultaneously lifted to surface. Device for the method embodiment includes erosion perforator secured to pipe string end. Jet nozzles are installed in erosion perforator side walls. Erosion perforator internal through channel accommodates movable bushing and valve. Coaxially secured in perforator lower end is immovable bushing whose outlet end carries movable bushing. Installed on outlet end of movable bushing is movable bushing-barrel with inclined channels in bottom and with external supporting disc. Locking rod is located inside of immovable bushing and movable bushing-barrel along their longitudinal axes. Upper end of locking rod is connected with valve and movable bushing. Lower end of locking rod is secured in bottom of movable bushing-barrel. Made in lower part of movable bushing above valve, in its side walls are through radial channels. Circular bore closed by movable bushing is made inside body above valve. Socket for valve is made in upper end face of immovable bushing. Locking rod is embraced by spring in compressed state. Upper end of said spring rests on internal shoulder of immovable bushing. Spring lower end rests on bottom of movable bushing-barrel. Movable and immovable bushings, movable bushing-barrel and circular bore above valve in body are made with such height that movable bushing with opened valve ensures in body internal through channel, closing of jet nozzles in its side walls and communication of internal space of pipe string with borehole space. EFFECT: reduced time, material and labor resources due to exclusion of additional means for elimination of sand bridges. 2 cl, 1 dwg