Method for shallow water flow detection

A computerized method for determining shallow water flow risk using seismic data comprising:

• processing reflected P-wave seismic data to enhance its stratigraphic resolution, wherein the reflected P-wave seismic data are obtained from marine towed streamers;
• selecting a control location comprising:
• performing a stratigraphic analysis on the reflected P-wave seismic data;
• and
• evaluating the seismic attributes of the reflected P-wave seismic data;
• applying a pre-stack full waveform inversion on the reflected P-wave seismic data at the control location to provide an elastic earth model of shallow water flow risk areas, wherein the elastic earth model is determined by matching the reflected P-wave seismic data with synthetic seismic data of the geologic model and the elastic earth model comprises P-wave velocity and S-wave velocity;
• applying a post-stack inversion on the reflected P-wave seismic data using the elastic earth model to map a ratio between the P-wave velocity and the S-wave velocity in a three dimensional (3D) volume;
• and
• determining multiple shallow water flow risk areas using the relationship of the ratio between the P-wave velocity and the S-wave velocity with respect to seismic travel time.

A method for determining a shallow water flow risk area, comprising:

• developing a geologic model of the shallow water flow risk area;
• performing a stratigraphic analysis on reflected P-wave seismic data of the geologic model to determine a control location within the reflected P-wave seismic data;
• applying a pre-stack full waveform inversion on the reflected P-wave seismic data at the control location to provide P-wave velocity (Vp) and Poisson's ratio;
• computing for S-wave velocity (Vs) using the P-wave velocity (Vp) and the Poisson's ratio;
• computing for a ratio (Vp/Vs) between the P-wave velocity (Vp) and the S-wave velocity (Vs);
• and
• identifying multiple shallow water flow risk areas using the relationship of the ratio (Vp/Vs) with respect to seismic travel time.