Subsalt velocity analysis by target-oriented wavefield tomography: A 3-D field-data example |

**Yaxun Tang and Biondo Biondi**

We apply target-oriented wavefield tomography
to a 3-D field data set acquired from the Gulf of Mexico.
Instead of using the original surface-recorded data set,
we use a new data set synthesized specifically for velocity analysis
to update subsalt velocities.
The new data set is generated based on an initial
unfocused target image and by a novel application of 3-D generalized Born
wavefield modeling, which correctly preserves velocity kinematics by
modeling non-zero subsurface-offset-domain images.
We show that the target-oriented inversion strategy drastically reduces the
data size and the computation domain for 3-D wavefield tomography, greatly improving its efficiency
and flexibility.
We apply differential semblance optimization (DSO) using the synthesized new data
set to optimize subsalt velocities. The updated velocity model significantly
improves the continuity of subsalt reflectors and yields flattened angle-domain common-image gathers.

- introduction
- Theory
- 3-D field-data examples
- Generating initial image gathers
- 3-D Born wavefield modeling
- Tomographic inversion
- Migrating the original data set using the updated velocity model

- conclusions
- acknowledgements
- Bibliography
- About this document ...

Subsalt velocity analysis by target-oriented wavefield tomography: A 3-D field-data example |

2011-05-24