Kjartansson's results

The primary reference for Kjartanson's results is his doctoral dissertation available as SEP report 23. Electronically, this thesis is at

http://sepwww.stanford.edu/theses/sep23/

A ``digested'' version of the thesis is in chapter 4 of my textbook IEI at

http://sepwww.stanford.edu/oldreports/sep40/

The particular section is available in html at

http://sepwww.stanford.edu/sep/prof/iei/ofs/paper_html/node6.html

 

kjcmg
Figure 1 Top left is shot point 210; top right is shot point 220. No processing has been applied to the data except for a display gain proportional to time. Bottom shows shot points 305 and 315. The AVO is too large for realistic layered media models and it changes rapidly from one midpoint to another one nearby.

 

kjidea
Figure 2 Kjartansson's model. The model on the top produces the disturbed data space sketched below it. Anomalous material in pods A, B, and C may be detected by its effect on reflections from a deeper layer. Midpoint is y. Offset is h.

 

kjcos
Figure 3 A constant-offset section across the Grand Isle gas field. The offset shown is the fifth from the near trace. (Kjartansson, Gulf) Notice that anomalous amplitudes are not limited to thin ``reservoir thickness'' zones. They tend to expand over the time axis. Notice a missing trace.

 

kja
Figure 4 (a) amplitude (h,y), (b) timing (h,y) (c) amplitude (z,y), (d) timing (d,y) The missing trace anomaly shows up exactly at a 45 degree angle. Other anomalies are at lessor angles indicating their nonzero depth.