RU2071029C1 - Unit of primary initiation - Google Patents

Abstract

FIELD: detonators. SUBSTANCE: invention is meant for initiation of explosive charges in detonators. Unit of primary initiation incorporates case 1 housing pulse transformer 2 with primary 3 and secondary 4 windings, heating bridge 5 connected to secondary winding 4 applied on core 6, charge 7 of primary explosive. Secondary winding 4 has number of turns exceeding 10 which relates to number of turns of primary winding 3 as 1:10-1:30. Heating bridge 5 has resistance within limits 0.2-1.0 Ohm. Primary winding 3 and secondary winding 4 with core 6 may be manufactured in the form of individual and interconnected elements. Element with primary winding 3 is fitted with unit 10 for connection with main line. Element of secondary winding 4 may be positioned into leak-tight elastic shell 11. EFFECT: increased operational reliability. 3 cl, 3 dwg

Description

 The invention relates to techniques for explosive perforation of oil and gas wells, and more particularly to nodes for initiating a charge of explosives in explosives.

 Known sites for initiating a charge of explosives containing a pulse transformer with primary and secondary windings, an incandescent bridge, a charge of a primary explosive (for example, author certificate. USSR N 1700896; UK patent N 2040612).

 Known initiation nodes increase the safety of work, however, an alternating or pulsating current of high voltage (over 380 V) is dangerous, as it can cause unauthorized detonation of explosives.

 This disadvantage is eliminated in another known primary initiation unit, adopted as a prototype (see, for example, US patent N 4414901, 1983). The primary initiation unit comprises a pulse transformer with primary and secondary windings located in the housing, an incandescent bridge connected to the secondary winding, wound around the core, and a primary explosive charge.

 The disadvantages of the prototype is that the boundary of the safe voltage is not defined, which, based on practical data, should be at least 600 V; the design of the primary and secondary windings, the incandescent bridge are not designed to limit voltages of 600 V or more; transformer coupling of the primary and secondary windings also does not have limit voltage limits; the issues of sealing the primary initiation unit have not been resolved.

 The aim of the invention is to remedy these disadvantages and create a primary initiation site, the design of which allows to achieve the goal.

 This is achieved by the fact that in the known primary initiation unit containing a pulse transformer with primary and secondary windings located in the housing, an incandescent bridge connected to the secondary winding wound on the core, and a primary explosive charge, the secondary winding is made with more than 10 turns and correlates with the number of turns of the primary winding as 1:10 1:30, while the glow bridge is made with a resistance in the range from 0.2 to 1.0 Ohm; the primary winding and the secondary winding with the core are made in the form of separate and interconnected elements, moreover, the element with the primary winding is equipped with a connection unit with a trunk line; the secondary winding element is housed in a sealed elastic sheath.

 A positive effect is achieved in the proposed device due to the fact that based on the experimental data, the number of turns of the windings given in the formula, their ratio, the resistance of the incandescent bridge, the design of the primary and secondary windings, and the sealing element of the assembly, which practically confirmed the achievement of the goal, are selected.

 The proposed assembly is shown in the drawing, where in FIG. 1 shows a transformer primary winding assembly; figure 2 - node of the secondary winding of the transformer; in FIG. 3 primary initiation assembly, which contains a housing 1, a pulse transformer 2; primary winding 3 of the transformer; secondary winding 4 of the transformer; a filament bridge 5 connected to the secondary winding 4; the core 6 of the secondary winding; charge 7 of the primary explosive; separate and interconnected elements 8 of the primary winding 3; separate and interconnected elements 9 of the secondary winding 4; node 10 connecting the primary winding 3 to the main line; a tight elastic shell 11, in which the element of the secondary winding 4 is placed.

 The device operates as follows. A current impulse is fed from the explosive machine through a geophysical cable, assembly 10, element 8 to the primary winding of the transformer 3. The current passing through the transformer excites an electromagnetic field, which, crossing the turn of the secondary winding of the transformer 4, induces an EMF in it. Induced in the secondary winding, the current passes through the glow bridge 5, which, by heating, excites the detonation of the primary explosive. The resulting high temperatures and pressures initiate the detonation of the main charge.

 The primary initiation unit proved to be sealed, reliable, and does not work at voltages less than 600 V.

Claims (3)

 1. The primary initiation assembly, comprising a pulsed transformer with primary and secondary windings located in the housing, an incandescent bridge connected to the secondary winding wound around the core, and a primary explosive charge, characterized in that the secondary winding is made with more than 10 turns and correlates with the number of turns of the primary winding as 1 10 1 30, while the glow bridge is made with a resistance in the range of 0.2 1.0 Ohms.  2. The node according to claim 1, characterized in that the primary winding and the secondary winding with the core are made in the form of separate and interconnected elements, and the element with the primary winding is equipped with a node connecting to the main line.  3. The node according to claim 2, characterized in that the element of the secondary winding is placed in a sealed elastic shell.

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