Multicomponent seismic inversion of VSP data

A system for seismic inversion of vertical seismic profile (VSP) data in an oilfield having a subterranean formation penetrated by a wellbore therein, the system comprising:

• a seismic wave source device configured to perform a seismic survey;
• a plurality of receivers disposed inside the wellbore and configured to obtain the VSP data during the seismic survey;
• a VSP data inversion tool configured to:
• identify a portion of the subterranean formation in proximity to the wellbore based on a pre-determined criterion;
• process the VSP data to generate a depth/time dependent angle model comprising an incidence angle of wave propagation in the portion of the subterranean formation;
• and
• perform the seismic inversion of the VSP data using the depth/time dependent angle model to generate an elastic model of the subterranean formation;
• and
• a surface unit comprising a controller configured to adjust the operations of the oilfield based on the elastic model.

A computer readable medium storing instructions for seismic inversion of vertical seismic profile (VSP) data in an oilfield having a subterranean formation penetrated by a wellbore, the instructions when executed causing a processor to:

• obtain an initial velocity model of the subterranean formation, the initial velocity model comprising acoustic velocities of wave propagation in proximity to the wellbore;
• determine an acquisition geometry for obtaining the VSP data, the acquisition geometry comprising a plurality of receiver locations within the wellbore and a source location;
• perform a seismic survey to obtain the VSP data based on the acquisition geometry;
• analyze, using a central processing unit (CPU) of a computer system, direct arrival signals of the VSP data to generate transit time data for wave propagation from the source location to the plurality of receiver locations;
• modify, using the CPU, the initial velocity model to generate an updated velocity model by performing a tomographic inversion of the transit time data;
• generate, using the CPU, an elastic model of the subterranean formation by performing the seismic inversion of the VSP data using the updated velocity model;
• and
• adjust the operations of the oilfield based on the elastic model.