High voltage explosive assembly for downhole detonations

Patent metadata

Field	Value
Publication number	US-10557693-B2
Application number	US-201515506202-A
Country	US
Kind code	B2
Filing date	Aug 28, 2015
Priority date	Aug 29, 2014
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A downhole explosive detonation assembly with a high voltage electro-explosive initiator having an input high voltage power supply with a low impedance shunting fuse, a flexible electrical link and a capacitor discharge unit. The explosive detonation assembly is adapted to detonate detonating cord from the side.

First claim

What is claimed is:

1. A downhole explosive tool firing assembly comprising two rigid support structures connected by a flexible link comprising:
a first support structure for a first circuitry that increases an input voltage;
a second support structure for an electrically active second circuitry charged by said increased input voltage, said second circuitry including a capacitor, switch and an electro-explosive initiator, a barrel for an electro-explosive initiator driven flyer and a secondary explosive, wherein the switch is adapted to cause electrical power to flow from the capacitor to the electro-explosive initiator; and
a flexible, electrically conductive link between said first and second circuitry, wherein the electro-explosive initiator comprises an explosive pellet, a stripper washer, and a flyer, the flyer being initially located between the explosive pellet and the stripper washer, and is adapted to detonate a detonating cord by propelling the flyer into the side of the detonating cord.

2. A downhole explosive tool firing assembly as described by claim 1 wherein said electro-explosive initiator is of the class comprising a semiconductor bridge (SCB), an exploding bridge wire (EBW) and an exploding foil initiator (EFI).

3. A downhole explosive tool firing assembly as described by claim 1 wherein said first circuitry that increases the input voltage is a flyback transformer followed by a diode rectifier.

4. A downhole explosive tool firing assembly as described by claim 1 wherein said flexible link comprises an electrically conductive, high voltage flexible ribbon cable.

5. A downhole explosive tool firing assembly as described by claim 1 further comprising a surface positioned computer and surface positioned controller operatively connected to said tool firing assembly by a cable extending into a wellbore; a control unit adapted for downlink communication with said surface positioned computer and said surface positioned controller over said cable, wherein the controller comprises a receiver and microprocessor that recognizes a low-voltage activation signal and allows power to said first circuitry.

6. A downhole explosive tool firing assembly as described by claim 1 wherein the flyer is a metallic plate.

7. A downhole explosive tool firing assembly as described by claim 6 wherein the flyer is an aluminum plate.

8. A downhole explosive tool firing assembly as described by claim 7 wherein the flyer is an aluminum plate approximately 0.010 inch thick.

9. A downhole explosive tool firing assembly as described by claim 7 wherein the detonating cord is located within approximately 0.4 inch of the flyer.

Assignees

• Hunting Titan Inc

Inventors

• Lerche Nolan C
• Brooks James E

Classifications

• E21B43/11855

  mechanically actuated, e.g. by movement of a wireline or a drop-bar (E21B43/11852 takes precedence) · CPC title

• F42B3/13

  with semiconductive bridge · CPC title

• F42D1/043

  Connectors for detonating cords and ignition tubes, e.g. Nonel tubes (mounting of detonators in blasting cartridges F42B3/26) · CPC title

• F42B3/125 Primary

  characterised by the configuration of the bridge initiator case (F42B3/11 takes precedence) · CPC title

• F42B3/00 Primary

  Blasting cartridges, i.e. case and explosive (fuse cords, e.g. detonating fuse cords C06C5/00; chemical aspects of detonators, blasting caps or primers C06C7/00) · CPC title