BLASTING CARTRIDGE Russian patent published in 1997 - IPC

FIELD: shooting-through and blasting operations in oil-gas and water wells. SUBSTANCE: blasting cartridge uses sealed case 1, electric lead-in, initiation assembly and high explosive 51; the initiation assembly has electric primer 6, cartridge of elastic mixed powder 7 that is non-ignitable from electric primer 6 at atmospheric pressure. Low-density high-explosive charge 8 is protected against the effect of external pressure by the thickened part of case 1 and end washers. Low- density high-explosive charge 8 may have a diameter equal to 2 to 4 critical diameters of the explosive, and a length not exceeding 20 diameters. Sealing plug 4 and electric primer 6 may be installed in case 1 for axial movement; installed on case 1 on the side of electric lead-in may be thin-walled metal cap 3 hermetically closing bore 11 on case 1 and self-fixed on it at a preset ambient pressure. EFFECT: enhanced efficiency. 3 cl, 1 dwg