Near-surface Interferometry

Sherif M. Hanafy

The course covers the basics and field practices of interferometry, super-virtual interferometry, and parsimonious interferometry for near-surface seismic applications.

Duration

8 hours

Intended Audience

Intermediate Level

Pre-requisites (Knowledge/Experience/Education Required)

Geoscientists and engineers, especially those who process seismic data, and anyone who needs to understand the basic theory and field applications of near-surface interferometry including refraction and reflection super-virtual interferometry and parsimonious interferometry. 

Detailed Course Description

Near-surface interferometry is commonely used to enhance the far-offset traces that suffers from low signal-to-noise ratio. The techniqe has been, successfully, used in many field examples. There are two main advantages of enhancing the far-offset traces, (1) Enhance the refraction events, which will increase the accuracy of refraction picking, and (2) increase the maximum penetration depth of the final velocity model. On th eother hand, parsemonious interferometry has been used to decrease the number of shotgathers recorded in the field, which saves a lot of field time, then generate virtual first break traveltimes to fill the missing traveltimes due to the skipped shot gathers. The accuracy of the virtual traveltimes are very high and the time saved in the field is more than 80% of the original acquisition time.

In this course, the basics of the interferometry, super-refraction and parsimonious interferometry will be explained in case of refraction, reflection, and surface waves. Then the techniques will be discussed using synthetic and field examples. The advantages and limitations of each technique will, also, be discussed. The comon applications are shallow geology, engineering, and environmental applications. It is also used to generate better velocity model for static corrections.     

Learner Outcomes

  • Increase the signal-to-noise ratio of refraction waves at far-offset traces
  • Generate virtual refraction traveltimes using parsimonious interferometry technique
  • Apply super-virtual and parsimonious interferometry on synthetic and field data
  • Distinguish between sucessful and failer application of near-surface interferometry 

Instructor Biography

Sherif M. Hanafy