Firing device, explosive charge, method, and system, for seismic exploration
AssigneeHercules Incorporated
InventorRichard R. Larson
Life of this patent
Estimating the term…
Abstract
A firing device is provided for initiation of delay type seismic charge assemblies, which comprises means for conveying and guiding the charge assemblies, in the seismic test zone, into electrical initiation contact with one of any number of available pairs of electrical conductor surfaces, insulated from the other and adapted to connect with opposite poles of an external firing current source; and means for directing the thus initiated assemblies from the initiation zone, during the delay period, for subsequent detonation. Also provided are elongated end-recessed seismic charge assemblies initiated in the above device; and seismic exploration system, and method, utilizing said device.
Claims22
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.
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.
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.degree. having its vertex on the longitudinal axis of said shell and measured in a plane normal to said axis.
A system for generating seismic disturbances in a body of water which comprises:
- a movable platform;
- means on said platform for storage of electrically initiatable seismic delay type explosive charge assemblies;
- a firing device, as a submersed firing station comprising (1) means for sequentially directing said charge assemblies along a path of continuous forward travel for electrical initiation of same;
- (2) means, at a forward point on said path of travel, for receiving electric current for electrically initiating said charge assemblies and for contacting said charge assemblies as they travel along said path to transfer said current to said charge assemblies for initiation of same;
- and (3) means for directing the thus initiated charge assemblies from said firing device during the delay period;
- a delivery conduit connecting said platform with said directing means of said submersed firing station;
- fluid pressure generating means on said platform connecting with said delivery conduit for sequentially moving said charge assemblies from said platform through said delivery conduit to said directing means, and then into and along said forward path of travel for said initiation.
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.
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.
Dependencies are inferred from the claim text.