Inversion-based reflector dip estimation
AssigneeExxonMobil Upstream Research Company
InventorsHongchuan Sun, Feng Deng, Carey M. Marcinkovich
Life of this patent
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Abstract
Method for estimating reflector dips in a window of post stack image traces (51) of seismic data for use in velocity tomography (57). The method iteratively (56) flattens (55) the image traces against a specified reference trace through the application of conjugate-gradient least-squares inversion (53). Different from other dip estimation methods which emphasize on strong-amplitude reflectors, the inventive method automatically inverts for the reflector dip for every grid point in the image window.
Claims14
An automated method for estimating reflector dips in an image window of post-stack image traces of seismic data, comprising:
- flattening the post-stack image traces against a reference trace in the post-stack image traces using reflector dips to adjust depths of image points for the post-stack image traces, wherein the reflector dips are obtained from horizontal and vertical gradients of the image points in the image window of the post-stack image made up of the post-stack image traces through computer-implemented iterative inversion that inverts for the reflector dips of every grid point in the image window;
- constructing a model of seismic wave velocity in a subsurface region from the reflector dips;
- migrating the seismic data with the model of seismic wave velocity;
- and
- producing an image from the migrated seismic data showing structural features of the subsurface region and prospecting for hydrocarbons according to the structural features of the subsurface region.
A computer-implemented method for transforming seismic data into a post-stack image showing structural features of a subsurface region, comprising:
- building an initial seismic wave velocity model in the subsurface region;
- applying a depth imaging algorithm to the seismic data to generate a post-stack image made up of image traces;
- estimating reflector dips in an image window of the seismic image traces, the estimating including flattening the image traces against a reference trace in the image traces using reflector dips to adjust depths of image points for the image traces, wherein the reflector dips are obtained from horizontal and vertical gradients of the image points in the image window of the post-stack image made up of the post-stack image traces through computer-implemented iterative inversion that inverts for the reflector dips of every grid point in the image window;
- constructing a model of seismic wave velocity in the subsurface region from the reflector dips;
- migrating the seismic data with the model of seismic wave velocity and producing an image showing structural features of the subsurface region;
- and
- prospecting for hydrocarbons according to the structural features of the subsurface region.
Dependencies are inferred from the claim text.