Method and apparatus for detecting shallow water flow sands using converted shear waves

A method of detecting drilling hazards depths between zero and at least about 3,500 feet below a sea floor, comprising:

• (a) conducting a seismic survey above said sea floor to obtain seismic data corresponding to geophysical structures below said sea floor;
• (b) processing said seismic data to detect shear waves and compression waves reflected off of said geophysical structures;
• and
• (c) displaying said seismic data such that any of said drilling hazards are detectable based on the appearance of said displayed seismic data.

An apparatus for detecting shallow waterflow sands, comprising:

• at least one source for directing seismic energy toward a seismic objective;
• at least one detector of seismic energy disposed in the vicinity of said seismic objective and adapted to generate seismic data corresponding to reflected seismic waves reflected off of subterranean seismic impedance boundaries at said objective;
• a seismic data processor for deriving from said seismic data at least one shear seismic data trace in which shear wave reflection events are observable and for deriving from said seismic data at least one compression seismic data trace in which compression wave reflection events are observable;
• such that a shallow waterflow sand region in said objective is detectable through a correlation between said at least one shear seismic data trace and said at least one compression seismic data trace.