David L Coursen

US Patent:

50997637, Mar 31, 1992

Filed:

Jun 13, 1991

Appl. No.:

7/714846

Inventors:

David L. Coursen - Sedona AZ
Rufus E. Flinchum - Christianberg VA

Assignee:

ETI Explosive Technologies International - Mississauga

International Classification:

F42G 300

US Classification:

102313

Abstract:

A blasting agent is disclosed for use in a borehole having a pressure resistant closure. The blasting agent is used in combination with a primary initiating system comprised of a detonator and an initiator for the detonator. The blasting agent is preferably a semi-fluid explosive material having a predetermined sensitivity. The sensitivity is related to the borehole diameter and the initiating system's strength, wherein the blasting agent upon initiation is transformed into explosive products by means of reaction front which consumes substantially all the blasting agent as the reaction front passes through the blasting agent. The reaction front has an average velocity of propagation of beween 200 meters/second and 1,000 meters/second for at least 30% of the total length of blasting agent located in the borehole. Another aspect of the invention is a method of blasting wherein the average velocity of propagation of the explosive front in the blasting agent is in a range of between 200 m/sec and 1,000 m/sec.

US Patent:

53885210, Feb 14, 1995

Filed:

Oct 18, 1993

Appl. No.:

8/137562

Inventors:

David L. Coursen - Espanola NM

Assignee:

Coursen Family Trust - Espanola NM

International Classification:

F42B 300

US Classification:

102311

Abstract:

A formation is blasted with one or more arrays of elongated, chemical, explosive charges so as to produce relatively low levels of ground vibration. The orientation and velocity of propagation of explosion in each charge and the velocity of propagation of vibration in the formation are such that, at a selected outlying location, the onset of vibration from explosion of the first negligably small increment of the charge arrives a finite time before that from explosion of the last negligably small increment. The charges of each array are fired in accurately-timed sequence, with the times between initiations chosen so that, at the outlying location, the onset of vibration from explosion of the last small increment of each charge, except the last charge, arrives a negligably small increment of time before the onset of vibration from explosion of the first small increment of the succeeding charge. All arrays ape designed to give equal times between onsets of vibration from the first and last charge increments to explode. Arrays are initiated in accurately-timed succession such that, at the outlying location, the onsets of vibration from the first small increment of charge to detonate in each of the arrays arrive separately at time intervals approximately equal to zero to four complete periods of a major Fourier component of the vibration from a single array, plus one period divided by the number of arrays.

US Patent:

50714961, Dec 10, 1991

Filed:

May 16, 1990

Appl. No.:

7/524375

Inventors:

David L. Coursen - Sedona AZ
Rufus Flinchman - Christianberg VA

Assignee:

ETI Explosive Technologies International (Canada) - Mississauga

International Classification:

C06B 4502

US Classification:

149 21

Abstract:

A blasting agent is disclosed for use in a borehole having a pressure resistant closure. The blasting agent is used in combination with a primary initiating system comprised of a detonator and an initiator for the detonator. The blasting agent is preferably a semi-fluid explosive material having a predetermined sensitivity. The sensitivity is related to the borehole diameter and the initiating system's strength, wherein the blasting agent upon initiation is transformed into explosive products by means of reaction front which consumes substantially all the blasting agent as the reaction front passes through the blasting agent. The reaction front has an average velocity of propagation of between 200 meters/second and 1,000 meters/second for at least 30% of the total length of blasting agent located in the borehole. Another aspect of the invention is a method of blasting wherein the average velocity of propagation of the explosive front in the blasting agent is in a range of between 200 m/sec and 1,000 m/sec.