Time Processing Services

Interactive Velocity Analysis

An interpretive and interactive approach to velocity optimization

Velocity Analysis in Structurally Complex Onshore Data

Velocity analysis on structured land seismic data is an interpretive process. The data are often sparsely sampled and contain considerable near-surface and subsurface complexity, resulting in poor signal quality, particularly on prestack data. This makes it difficult to use traditional semblance-first velocity analysis that relies on good quality CDP gathers.

At Thrust Belt Imaging, we take an interpretive and interactive approach to velocity analysis. Using Techco Geophysical’s Velanal (developed with input from TBI), we scan constant velocity stacks for the optimal image, with gathers and semblance plots available as secondary displays.

We use this method for both stacking velocities (input to reflection statics, a key step in our TWS workflow) and PSTM velocities (to optimize the migrated image).

Interpretive Collaboration

The first is its interpretive nature. By viewing the entire stack while scanning through different velocities, you build the image while picking velocities. This is key collaboration step, where we work closely with the interpreter to incorporate geologic understanding into the process.

Stack Preconditioning

The second advantage is the preconditioning of the stack data. In addition to the power of stack, we can improve the signal quality by refining the stacking mute, filter, gain and coherency filter to produce a better-quality, more interpretable image.

Integrated with Techco Geophysical

In conjunction with Techco Geophysical, we have streamlined the process to get interpreters picking prestack time migration using Velanal with data pre-loaded by a TBI processor.