Landmark Graphics Corporation

Yiqing Ren

Shengwen Jin

Fan Xia

Fan Jiang

Shiyong Xu

Richard Ottolini

Systems and methods for simulating an effect of multiple seismic sources concurrently on a geologic formation are provided. Data is read from a seismic source file that describes at least two seismic source types. The concurrent propagation of acoustic energy from the at least two seismic sources types through the geologic formation is modeled. A seismic output file is then generated.

Methods and systems for seismic modeling using multiple seismic source types

An example method for tomographic migration velocity analysis may include collecting seismographic traces from a subterranean formation and using an initial velocity model to generate common image gathers and a depth image volume based, at least in part, on the seismographic traces. A structure tensor may be computed with the depth image volume for automated structural dip and azimuth estimation. A semblance may be generated using said plurality of common image gathers and said structure tensor. Image depth residuals may be automatically picked from said semblance. A ray tracing computation may be performed on said initial velocity models using said structure tensor. An updated velocity model may be generated with a tomographic inversion computation, wherein said tomographic inversion computation uses said plurality of image depth residuals and said ray tracing computation.

Structure tensor constrained tomographic velocity analysis

Seismic imaging systems and methods that employ sensitivity kernel-based migration velocity analysis in 3D anisotropic media may demonstrate increased stability and accuracy. Survey data analysts employing the disclosed systems and methods are expected to provide better images of the subsurface and be better able to identify reservoirs and deposits for commercial exploitation. Certain embodiments migrate seismic survey data with an anisotropic velocity model to obtain common angle image gathers. These gathers are processed to obtain depth residuals along one or more horizons. Angle-domain sensitivity kernels are used to convert the depth residuals into velocity errors, which are then used to refine the velocity model. A user is then able to view a representation of the subsurface structure determined in part from the refined velocity model. Multiple iterations may be needed for the velocity model to converge. The velocity model may be a layered to have constant velocity values between formation boundaries.

Sensitivity kernal-based migration velocity analysis in 3D anisotropic media

In at least some embodiments, the system obtains shot gathers for a survey region and migrates the shot gather data with an initial velocity model to obtain angle-domain common image gathers. The system processes the common image gathers to determine depth residuals and corresponding angle-dependent time deviations throughout a seismic survey region. The system solves a set of tomographic equations which employ ray theory to establish a relationship between a travel time deviation and the depth residual of a reflector in the depth-offset ray parameter (z,p) domain. The resulting updates are applied to the velocity model and can be used to re-migrate the shot gather data. The system generates a representation of the survey region that can be displayed to a user.

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Sugar Land, TX, United States of America

Yiqing Ren