Method and system of imaging hydrocarbon reservoirs using adaptive aperture tapering in kirchhoff depth migration
A method ( 600 ) and a system ( 1000 ) for generating an adaptive migration taper for a pre-stack seismic dataset are disclosed. The method ( 600 ) includes obtaining the pre-stack seismic dataset ( 602 ) and a seismic velocity model of a subterranean region ( 604 ). The method ( 600 ) also includes generating the adaptive migration taper based, at least in part, on the pre-stack seismic dataset ( 606 ), and forming a migrated seismic image using a migration function, the seismic velocity model, the pre-stack seismic dataset, and the adaptive migration taper ( 608 ). The method ( 600 ) further includes determining a location of a hydrocarbon reservoir based, at least in part, on the migrated seismic image ( 610 ).
1 . A method comprising:
obtaining a pre-stack seismic dataset of a subterranean region;
obtaining a seismic velocity model of the subterranean region;
generating an adaptive migration taper based on the pre-stack seismic dataset comprising:
generating a dip-constrained weight function based on a maximum dip for a depth and a first taper length,
generating an adaptive weight function based on a depth index and a second taper length, and
combining the dip-constrained weight function and the adaptive weight function;
forming a migrated seismic image using a migration function, the seismic velocity model, the pre-stack seismic dataset, and the adaptive migration taper;
determining a location of a hydrocarbon reservoir based on the migrated seismic image;
planning a wellbore path to intersect the hydrocarbon reservoir; and
drilling a wellbore guided by the wellbore path.
2 . The method of claim 1 , wherein the depth index is determined from a migration impulse response.
3 . The method of claim 1 , wherein the first taper length and the second taper length are identical taper lengths.
4 . The method of claim 1 , wherein the adaptive migration taper comprises a vertical taper.
5 . The method of claim 1 , wherein the migration function is a Kirchhoff migration function based on an integral form of a wave equation that corresponds to pressure wave displacement and a pressure wave velocity as function of three-dimensional space and time.
6 . The method of claim 1 , wherein obtaining the seismic velocity model comprises performing velocity analysis on the pre-stack seismic dataset.
7 . A system comprising:
a seismic acquisition system configured to obtain a pre-stack seismic dataset of a subterranean region;
a seismic processing system configured to:
receive the pre-stack seismic dataset,
receive a seismic velocity model of the subterranean region,
generate an adaptive migration taper based on the pre-stack seismic dataset comprising:
generate a dip-constrained weight function based on a maximum dip for a depth and a first taper length;
generate an adaptive weight function based on a depth index and a second taper length; and
combine the dip-constrained weight function and the adaptive weight function, and
form a migrated seismic image using a migration function, the seismic velocity model, the pre-stack seismic dataset, and the adaptive migration taper;
a seismic interpretation workstation configured to determine a location of a hydrocarbon reservoir based on the migrated seismic image;
a wellbore planning system configured to plan a wellbore path to intersect the hydrocarbon reservoir; and
a drilling system configured to drill a wellbore guided by the wellbore path.
8 . The system of claim 7 , wherein the depth index is determined from a migration impulse response.
9 . The system of claim 7 , wherein the migration function is a Kirchhoff migration function based on an integral form of a wave equation that corresponds to pressure wave displacement and a pressure wave velocity as function of three-dimensional space and time.