System and method for forming a seismic velocity model and imaging a subterranean region

A non-transitory computer readable medium storing instructions executable by a computer processor, the instructions comprising functionality for:

• obtaining an observed seismic dataset for a subterranean region of interest, wherein the observed seismic dataset comprises a plurality of seismic source locations, a plurality of receiver locations, and an observed seismic trace for each pair of seismic source location and seismic receiver location;
• obtaining a seismic velocity model for the subterranean region of interest;
• simulating, using a computer processor, a simulated seismic dataset wherein the simulated seismic dataset comprises a simulated seismic trace for each pair of seismic source location and seismic receiver location based, at least in part, on the seismic velocity model;
• forming, using the computer processor, a plurality of trace pairs from the simulated seismic dataset and the observed seismic dataset, wherein each of the plurality of trace pairs comprises an observed seismic trace and a simulated seismic trace;
• forming, using the computer processor, an objective function based, at least in part, on a penalty function and a cross-correlation between the observed seismic trace and the simulated seismic trace of each of the plurality of trace pairs;
• finding, using the computer processor, an extremum of the objective function;
• determining, using the computer processor, a seismic velocity increment based, at least in part, on the extremum;
• forming, using the computer processor, an updated seismic velocity model by combining the seismic velocity increment and the seismic velocity model;
• and
• forming, using the computer processor, an image of the subterranean region of interest based, at least in part, on the updated seismic velocity model.

A system for forming an image of a subterranean region of interest, comprising:

• a seismic source to emit a radiated seismic wave;
• a plurality of seismic receivers for detecting and recording an observed seismic dataset generated by the radiated seismic wave;
• and
• a seismic processor configured to:
• obtain an observed seismic dataset for the subterranean region of interest, wherein the observed seismic dataset comprises a plurality of seismic source locations, a plurality of receiver locations, and an observed seismic trace for each pair of seismic source location and seismic receiver location;
• obtain a seismic velocity model for the subterranean region of interest;
• simulate a simulated seismic dataset wherein the simulated seismic dataset comprises a simulated seismic dataset wherein the simulated seismic dataset comprises a simulated seismic trace for each pair of seismic source location and seismic receiver location based, at least in part, on the seismic velocity model;
• form a plurality of trace pairs from the simulated seismic dataset and the observed seismic dataset, wherein each of the plurality of trace pairs comprises an observed seismic trace and a simulated seismic trace;
• form an objective function based, at least in part, on a penalty function and a cross-correlation between the observed seismic trace and the simulated seismic trace of each of the plurality of trace pairs;
• find an extremum of the objective function;
• determine a seismic velocity increment based, at least in part, on the extremum;
• form an updated seismic velocity model by combining the seismic velocity increment and the seismic velocity model;
• and
• form the image of the subterranean region of interest based, at least in part, on the updated seismic velocity model.