Firing device, explosive charge, method, and system, for seismic exploration

Claim 2

A firing device for initiating electrically initiatable seismic charges assemblies having a delay period intermediate initiation and detonation of same, and then delivering the initiated charge assemblies for detonation outside the system, which comprises means for sequentially directing said charge assemblies along a path of continuous forward travel for electrical initiation of same; contact means, at a forward point on said path of travel, for receiving electric current for electrically initiating said charge assemblies and disposed in a stationary position for intercepting contact with said charge assemblies as they travel along said path to transfer said current to said assemblies for initiation of same; and means in response to contact of said charge assemblies with said contact means for directing the thus initiated charge assemblies from said firing device during said delay period.

Claim 3

In a firing device of claim 1, open means for sequentially guiding said charge assemblies along said path of forward travel; means for conveying said charge assemblies sequentially to said guiding means and then into said path of forward travel; and said contact means supported at a forward point on said guiding means.

Claim 4

In a firing device of claim 2, said contact means spaced in a central portion of said path of forward travel, and stationary means forward of said contact means for impact with the forwardly moving initiated charge assemblies to direct travel of each said initiated assembly from said firing device, through an open side of said guide means.

Claim 5

In a device of claim 3, a conduit as said conveying means; and a tray member as said open guide means, at one end of said conduit.

Claim 6

In a firing device of claim 4, said conduit and said tray member constituting an integral unit of construction.

Claim 7

In a firing device of claim 3, said contact means comprising a rigidly supported dielectric body having at least one pair of electrical conductor surfaces electrically insulated from the other and facing said conduit; means for respectively connecting the member surfaces of said pair(s) with opposite poles of a source of firing current; and said pair(s) of conductor surfaces being positioned to engage said seismic charge in said contact.

Claim 8

A firing device of claim 6, wherein said dielectric body is attached to said tray member and is elongated and disposed substantially coaxially with said conduit; two separate pairs of said electrical conductor surfaces, and each said conductor surface disposed in a separate quadrant on the end of said dielectric body facing said conduit.

Claim 9

In a firing device of claim 7, each said conductor surface supported on a central portion of, but spaced apart from the boundary radii forming, the dielectric quadrant surface containing same.

Claim 10

In a firing device of claim 8, said dielectric body being substantially cylindrical, and the dielectric surface of each said quadrant extending as a trough from the center of the diametric cross section forwardly of said dielectric body through the perimeter thereof.

Claim 11

In a firing device of claim 9, said dielectric surface of said body, in each said quadrant, being of V-shape having the crest formed by the boundary radii forming same and a valley extending from the quadrant center toward the forward end of said dielectric body and through the quadrant side; a layer of an electrically conductive material supported on each quadrant surface, spaced from the boundary radii of said quadrant surface, and covering substantially the remainder thereof, whereby each electrically conductive layer is electrically insulated from the other; and an electrically conductive lead forwardly extending through said dielectric body from electrical contact with each conductor surface; and means for respectively connecting any pair of said leads with opposite poles of a firing current source external to said firing device.

Claim 12

A firing device of claim 10, wherein each said valley extends from the quadrant center at an angle of from 20° to 30° with the longitudinal axis of said dielectric body, and each conductor surface is spaced from its boundary radii so as to form a resulting continuous strip of said dielectric surface free from said conductive material, to thereby electrically insulate each said surface from the others.

Claim 13

A firing device for sequentially initiating delay type electrically initiatable end-recessed elongated seismic charge assemblies in an underwater siesmic test area, and then directing the thus initiated charges from the firing device during the delay period, and said charge assemblies having electrical conductor leads extending from the interior into the recessed end thereof, for carrying the requisite firing current, said firing device comprising a conduit for sequentially conveying said charge assemblies, recessed end first, into a path of forward travel in the underwater test zone, and an elongated tray shape member connecting with the forward end of said conduit in substantially coplanar relationship with a wall portion of said conduit for guiding said charge assemblies along said path; a rigidly secured arm member extending from said guide member across a central portion of the forward end thereof and across the extended longitudinal axis of said conduit in a plane substantially normal to said axis, at a distance from said conduit of at least 1.1 times the length of each said charge assembly, but so extending from said guide member a distance less than the diametric distance across said conduit; a cylindrical dielectric body disposed at one end of said guide member substantially coaxially with said conduit, and supported at its forward end in said arm member and within the confines of same, thereby providing; together with said arm, an open area on said path adjacent said arm and dielectric body supported therein; a layer of an electrically conductive material supported on each quadrant surface of said dielectric body facing said conduit, and spaced from the boundary radii of said quadrant surface but covering substantially the remainder thereof, whereby each electric conductive layer is electrically insulated from the other; an electrically conductive lead forwardly extending through said dielectric body from electrical contact with each conductor surface; means for respectively connecting any pair of said leads with opposite poles of a firing current source external to said firing device; and said cylindrical dielectric member rearwardly extending from said arm member a distance not greater than the depth of said recess portion of said charge.

Claim 14

A firing device for sequentially initiating delay type electrically initiatable end-recessed elongated seismic charge assemblies in an underwater siesmic test area, and then directing the thus initiated charges from the firing device during the delay period, and said charge assemblies having electrical conductor leads extending from the interior into the recessed end thereof, for carrying the requisite firing current, said firing device comprising a conduit for sequentially conveying said charge assemblies, recessed end first, into a path of forward travel in the underwater test zone, and an elongated tray shape member connecting with the forward end of said conduit in substantially coplanar relationship with a wall portion of said conduit for guiding said charge assemblies along said path; a rigidly secured arm member extending from said guide member across a central portion of the forward end thereof and across the extended longitudinal axis of said conduit in a plane substantially normal to said axis, at a distance from said conduit of at least 1.1 times the length of each said charge assembly, but so extending from said guide member a distance less than the diametric distance across said conduit; a cylindrical dielectric body disposed at one end of said guide member substantially coaxially with said conduit, and supported at its forward end in said arm member and within the confines of same, thereby providing; together with said arm, an open area on said path adjacent said arm and dielectric body supported therein; a layer of an electrically conductive material supported on each quadrant surface of said dielectric body facing said conduit, and spaced from the boundary radii of said quadrant surface but covering substantially the remainder thereof, whereby each electric conductive layer is electrically insulated from the other; an electrically conductive lead forwardly extending through said dielectric body from electrical contact with each conductor surface; means for respectively connecting any pair of said leads with opposite poles of a firing current source external to said firing device; and said cylindrical dielectric member rearwardly extending from said arm member a distance not greater than the depth of said recess portion of said charge.

Claim 15

An explosive charge assembly for underwater seismic exploration, adapted to be electrically initiated upon traveling in the seismic shooting zone into contact with opposite poles of an electric firing current source and then directed away from said contact for subsequent detonation, comprising an elongated shell having a closed interior along a portion of its length, and an open end section adjacent the shell interior; a small seismic explosive charge, as the main explosive charge, within said shell interior, and an electrically initiatable primer device for said main charge supported in said main charge and containing electrical conductor leads extending into said open end shell section for conveying electrical firing current from said source for initiation of said primer; said conductor leads extending into said end section in substantially parallel and rigid relationship, and spaced apart at an angle greater than 90° having its vertex on the longitudinal axis of said shell and measured in a plane normal to said axis.

Claim 16

An explosive charge assembly for underwater seismic exploration, adapted to be electrically initiated upon traveling in the seismic shooting zone into contact with opposite poles of an electric firing current source and then directed away from said contact for subsequent detonation, comprising an elongated shell having a closed interior along a portion of its length, and an open end section adjacent the shell interior; a small seismic explosive charge, as the main explosive charge, within said shell interior, and an electrically initiatable primer device for said main charge supported in said main charge and containing electrical conductor leads extending into said open end shell section for conveying electrical firing current from said source for initiation of said primer; said conductor leads extending into said end section in substantially parallel and rigid relationship, and spaced apart at an angle greater than 90° having its vertex on the longitudinal axis of said shell and measured in a plane normal to said axis.

Claim 17

An explosive charge assembly of claim 13 wherein said primer comprises a closed elongated shell, said pair of conductor leads extending into, and terminating in, said primer shell, through one end thereof, and a resistance wire within said primer shell connecting the terminating ends of said conductor leads; an ignition charge within said primer shell disposed in operative communication with said resistance wire to ignite in response to heat developed by passage of electric current through said bridge wire via said conductor leads; a high explosive within said primer shell, as a base charge spaced from said ignition charge; a primer charge intermediate said ignition charge and said base charge; a slow burning composition, as a delay fuse, intermediate said primer charge and said ignition charge, and ignitable in response to ignition of said ignition charge and spaced in ignition relationship therewith; said primer charge being detonatable in response to ignition of said delay fuse composition and spaced in detonating relationship therewith; and said base charge being detonatable in response to detonation of said primer charge and spaced in detonating relationship therewith.

Claim 18

A seismic charge assembly of claim 14 in which said seismic explosive charge is a nitrocarbonitrate.

Claim 19

A seismic charge assembly of claim 15 containing from 1/8 to 3 lbs. of said nitrocarbonitrate charge.

Claim 20

An explosive charge assembly of claim 16 in which the total length of the cartridge shell is within the range of from 13/4 to 3 inches.

Claim 21

A complete seismic charge assembly of claim 17 wherein said primer charge of said primer device comprises a combination of (1) a diazodinitrophenol wafer, in direct open communication with said delay fuse, and of sufficiently high density to ignite in response to ignition of said delay fuse, and (2) a mass of diazodinitrophenol intermediate said wafer and said base charge, and of sufficiently low density to detonate in response to ignition of said wafer.

Claim 24

A system of claim 19 in which said firing device comprises (1) open means for sequentially guiding said charge assemblies along said path of continuous forward travel, and (2) means for conveying said charge assemblies sequentially to said guiding means and then into said path of continuous forward travel.

Claim 25

A seismic exploration method wherein complete delayed electrically initiatable seismic charge assemblies are emplaced and fired in an underwater zone to provide energy for a seismic record, said method comprising sequentially conveying a plurality of said charge assemblies into, and along, a path of forward travel in said underwater zone; sequentially contacting said assemblies while they travel with a contact means disposed across said path of travel and including opposite poles of a firing current source so as to electrically initiate said charge assemblies concurrently with said contacting; and during the period of delay, sequentially directing travel of the thus initiated charge assemblies from the zone of said initiation into an adjacent area in said underwater zone for detonation.

Claim 26

A seismic exploration method wherein complete delayed electrically initiatable seismic charge assemblies are emplaced and fired in an underwater zone to provide energy for a seismic record, said method comprising sequentially conveying a plurality of said charge assemblies into, and along, a path of forward travel in said underwater zone; sequentially contacting said assemblies while they travel with a contact means disposed across said path of travel and including opposite poles of a firing current source so as to electrically initiate said charge assemblies concurrently with said contacting; and during the period of delay, sequentially directing travel of the thus initiated charge assemblies from the zone of said initiation into an adjacent area in said underwater zone for detonation.

Claim 27

A seismic exploration method wherein complete delayed electrically initiatable seismic charge assemblies are emplaced and fired in an underwater zone to provide energy for a seismic record, said method comprising sequentially conveying a plurality of said charge assemblies into, and along, a path of forward travel in said underwater zone; sequentially contacting said assemblies while they travel with a contact means disposed across said path of travel and including opposite poles of a firing current source so as to electrically initiate said charge assemblies concurrently with said contacting; and during the period of delay, sequentially directing the travel of the thus initiated charge assemblies pivotally about said contact means as a pivot point.

Claim 28

A seismic exploration method wherein complete delayed electrically initiatable seismic charge assemblies are emplaced and fired in an underwater zone to provide energy for a seismic record, said method comprising sequentially conveying a plurality of said charge assemblies into, and along, a path of forward travel in said underwater zone; sequentially contacting said assemblies while they travel with a contact means disposed across said path of travel and including opposite poles of a firing current source so as to electrically initiate said charge assemblies concurrently with said contacting; and during the period of delay, sequentially directing the travel of the thus initiated charge assemblies pivotally about said contact means as a pivot point.