Seismic methods having extended energy release

A seismic method, comprising:

• providing an explosive device comprising a housing enclosing a plurality of explosive elements, the explosive elements separated from each other by at least one barrier element;
• generating seismic waves by detonating the explosive device in a subterranean formation,
• wherein the plurality of explosive elements explode at differing times;
• and
• detecting at least one of the seismic waves or reflections of the seismic waves with seismic detectors.

A geophysical survey system, comprising:

• a seismic energy source comprising an explosive device that comprises a plurality of explosive elements separated by barrier elements, the explosive elements capable of being detonated at differing times;
• a detonation control device that is capable of detonating different explosive elements at different times;
• and
• a plurality of seismic detectors, adapted to detect seismic waves and/or reflections thereof generated when the seismic energy source explodes.

A downhole seismic source for generating an energy pulse comprising:

• a housing;
• a detonator;
• and
• a shaped charge device located within the housing and comprising an explosive element and a plurality of shaped charges arranged to focus the energy pulse in a predetermined orientation.

A seismic method comprising:

• providing an explosive device comprising a housing enclosing a plurality of shaped charges;
• detonating the explosive element;
• collapsing the plurality of shaped charges;
• whereby an extended directed force is imparted onto a subterranean formation, creating seismic waves within the subterranean formation;
• and
• detecting at least one of the seismic waves or reflections of the seismic waves with seismic detectors.

An apparatus for generating seismic impulses comprising:

• a housing;
• an explosive element located within the housing;
• a detonator operably connected to the explosive element;
• and
• a mass flyer element located within the housing and capable of moving from an upper position to a lower position.

A method for generating seismic impulses comprising:

• providing an apparatus comprising an explosive element and a mass flyer element located within a housing, the mass flyer capable of moving from an upper position to a lower position;
• accelerating the mass flyer from an upper position towards a lower position;
• impacting the mass flyer onto the bottom of the housing creating a force and imparting the force onto a subterranean formation thereby creating seismic waves;
• and
• detecting at least one of the seismic waves or reflections of the seismic waves with seismic detectors.