Method and apparatus for generating a long sequence of seismic pulses

Abstract

Within the stationary, upstanding cylindrical housing of a rapid fire seismic gas exploder an expansible detonation chamber is formed between a base resting on the earth and a piston adapted to move reciprocally. A plurality of separate external gas entry conduits communicate with the detonation chamber at spaced apart inlets in the wall of the housing. Each conduit is supplied from its own separate gas mixer which in turn is interconnected with sources of fuel gas and oxidizing gas through a pair of remotely operable flow control valves. As the pairs of control valves are actuated in timed sequence at a desired rate of fire, successive charges of combustible gas mixture are injected into the detonation chamber, utilizing one mixer and its associated gas entry conduit at a time. Correspondingly timed spark ignition is provided in or adjacent each mixer, resulting in a series of gas explosions in the chamber which coordinates with the reciprocal movement of the piston. By increasing the number of these separate mixer-conduit combinations, a rapid-fire shot sequence of any practical length can be achieved without preignition.

Dependencies are inferred from the claim text.