Geop 397 - Coherence

Question 1

In coherence cube imaging what is generated from the input 3D seismic data volume ?

Answer 1

cube of coherence coefficients

Question 2

List structural and stratigraphical features visible on coherence cube images

Answer 2

structural - faults

stratigraphical - delta, river channels, reefs

Question 3

What does coherence measurements in 3D represent and produce?

Answer 3

trace to trace similarity and produce interpretable changes

Question 4

State criterion used to assign coherence coefficients

Answer 4

similar traces mapped with high coherence coefficient

dissimilar traces mapped with low coherence coefficient

Question 5

How are the seismic traces (interrupted by faults), detected in a coherence cube?

Answer 5

sharp discontinuities of trace to trace coherence producing delineation of low coherence along fault planes

Question 6

Is coherence computation dependent on the fault or fracture orientation?

Answer 6

No. The coherence computation is not dependent on the fault or fracture orientation

Question 7

List 3 complex trace attributes

Answer 7

amplitude, frequence, phase

Question 8

Define acoustic impedence

Answer 8

AI = Rho X V

Question 9

Which 2 logs are used to generate acoustic impedence log?

Answer 9

density log and sonic log

Question 10

What does acoustic impedence represent

Answer 10

Acoustic impedence - layer properties

Question 11

What does seismic amplitude represent?

Answer 11

attributes of layer boundaries

Question 12

List 4 applications of inversion

Answer 12

seismic interpretation
reservoir characterization
time lapse seismic
pressure predictions