System and Method for Reducing the Effects of Ghosts From the Air-Water Interface in Marine Seismic Exploration

Abstract

A system mechanically alters the geometry of the surface of the water by breaking the water surface with a mechanical device. The mechanical device may comprise a plurality of propellers, a plurality of aquafoils in the shape of plows, a wire whip, or other mechanical device to reduce the coefficient of reflectivity of the air-water interface.

1 . A method of reducing ghost effects at an air/water interface in a marine seismic exploration system including a vessel towing a seismic system at sea, the method comprising the step of mechanically altering the geometry of the surface of the sea by means of a mechanism extending through the air/water interface. 
     
     
         2 . The method of  claim 1 , wherein the step of mechanically altering the geometry of the surface of the sea comprises towing a plurality of aquafoils behind the vessel, the plurality of aquafoils extending through the air/water interface. 
     
     
         3 . The method of  claim 1 , wherein the step of mechanically altering the geometry of the surface of the sea comprises towing a plurality of passive propellers behind the vessel, the plurality of passive propellers extending at least part way into the surface of the sea. 
     
     
         4 . The method of  claim 1 , wherein the step of mechanically altering the geometry of the surface of the sea comprises towing a plurality of wire whips behind the vessel, the plurality of wire whips extending at least part way into the surface of the sea. 
     
     
         5 . A system for reducing the ghost effects at an air/water interface in a marine seismic exploration system including a plurality of seismic signal support floats towed behind a vessel at sea, the system comprising plurality of mechanical agitators supported between a plurality of the floats, the mechanical agitators extending through the air/water interface. 
     
     
         6 . The system of  claim 5 , wherein the mechanical agitators comprise aquafoils. 
     
     
         7 . The system of  claim 5 , wherein the mechanical agitators comprise passive propellers. 
     
     
         8 - 11 . (canceled)