Downhole perforating method and apparatus using secondary explosive detonators
US4762067A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1987 |
| Grant date | Aug 9, 1988 |
| Priority date | — |
| Expiry date | Nov 13, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42D1/05
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
For use in a perforating gun assembly, a perforating gun detonator is disclosed. One embodiment is hermetically sealed while the other has openings therein to admit well fluids. In both embodiments, a narrow conductive metal foil is provided with a current to vaporize the narrow foil, explode the foil and propel a flyer driven by a shock wave for detonation of a spaced secondary explosive. The explosive then couples explosion into a detonating cord against a shoulder in a housing adjacent to the secondary explosive. The current is formed by means of an AC voltage multiplier circuit providing a charge on a capacitor which is discharged through a spark gap. Charging circuitry includes a blocking capacitor to prevent DC and a resistor for bleeding a small current from the capacitor to ground which prevents static or stray current accumulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.