Land Wide Azimuth Processing Workflow

Audience

This course is designed for geophysicists with moderate processing experience and wanting to extend their knowledge to include land wide azimuth.

Content

To begin, the course looks at the reason for acquiring wide azimuth (WAZ) and the complexities it helps address.

Acquisition is reviewed and the difference between more traditional 2D and narrow azimuth (NAZ) acquisitions is seen. The differences between modern high density land WAZ and conventional land are highlighted. Through examples the benefits are WAZ data are visualized. The processing workflow is then spotlighted and the use of offset vector tiles (OVT) and common offset vectors (COV) is explained. True 3D noise and multiple suppression is focused on followed by COV binning and regularization. The benefits of applying reciprocity are discussed as is the methodology for 3D velocity model building and imaging. A typical WAZ production flow chart concludes the course.

The main topics covered are:

• Why we need WAZ, sampling, the seismic wave-field and illumination
• WAZ acquisition, its characteristics and how it compares to other acquisition type
• True 3D WAZ processing steps
• Understanding cross-spread, offset vector tiles (OVT), common offset vector cubes (COV)
• Overview of COV binning, regularization and the benefits of reciprocity
• Review the COV bin size, number of COV bins and the fold calculation based on the geometry
• The WAZ production flow
• Displaying the WAZ data using the interactive tools, building and QC of acquisition geometries, inline and crossline fold, generating spider display and ROSE diagrams.
• QC cross-spread and COV using the interactive applications
• How is random and coherent noise attenuation in cross-spread or receiver domain carried out using the software modules? The key parameters and method of quality control
• Understanding the azimuthal velocity workflow, how to apply, the skeleton, the snail sort and the key parameters in the modules

Learning Objectives

• Be able to describe WAZ and list the advantages it have over NAZ
• Know what a cross-spread is and why it is used in WAZ processing
• Be capable of defining an OVT and COV and determine the fold
• Know the key step in a WAZ processing workflow
• Be aware of how noise attenuation is applied
• Understand binning, reciprocity and regularization
• Know the methodology used to build the 3D velocity model