Podcast
Questions and Answers
What does 'A' represent in the linearized AVO equation?
What does 'A' represent in the linearized AVO equation?
- Change in amplitude with respect to sine squared of the angle
- Reflector's depth
- Amplitude at zero offset or angle (correct)
- Gradient of the line
Which term of the AVO approximations is often termed Curvature?
Which term of the AVO approximations is often termed Curvature?
- Intercept
- B
- Higher order term (correct)
- A
What is the basic function of 'B' in the linearized AVO equation?
What is the basic function of 'B' in the linearized AVO equation?
- Amplitude at zero offset or angle
- Change in amplitude with respect to sine squared of the angle
- Reflector's depth
- Gradient of the line (correct)
How are reflection coefficients represented by the first order approximation of the linearized AVO equation?
How are reflection coefficients represented by the first order approximation of the linearized AVO equation?
What are extracted and plotted on a graph as a function of sin^2(theta)?
What are extracted and plotted on a graph as a function of sin^2(theta)?
Which term from the linearized AVO equation provides information about the amplitude at zero offset or angle?
Which term from the linearized AVO equation provides information about the amplitude at zero offset or angle?
What is the main purpose of AVO crossplotting?
What is the main purpose of AVO crossplotting?
How does partial gas saturation affect the intercept and gradient on an intercept-versus-gradient crossplot?
How does partial gas saturation affect the intercept and gradient on an intercept-versus-gradient crossplot?
What would happen if the interval chosen for crossplotting is too wide?
What would happen if the interval chosen for crossplotting is too wide?
Which rocks exhibit a well-defined background trend in the intercept-gradient crossplot over a limited depth range?
Which rocks exhibit a well-defined background trend in the intercept-gradient crossplot over a limited depth range?
Why might it be challenging to identify background trends when working with large data volumes?
Why might it be challenging to identify background trends when working with large data volumes?
What determines the slope of the background trend on an intercept-gradient crossplot?
What determines the slope of the background trend on an intercept-gradient crossplot?
What characterizes AVO Class 1 gas sands in terms of reflection amplitude?
What characterizes AVO Class 1 gas sands in terms of reflection amplitude?
Which type of gas sands can be associated with the classic 'bright spot' anomaly?
Which type of gas sands can be associated with the classic 'bright spot' anomaly?
What distinguishes a Class 2p anomaly from a Class 2n anomaly according to Ross and Kinman (1995)?
What distinguishes a Class 2p anomaly from a Class 2n anomaly according to Ross and Kinman (1995)?
Which type of gas sands exhibits a Strong trough at near offset that becomes more negative with increasing offsets?
Which type of gas sands exhibits a Strong trough at near offset that becomes more negative with increasing offsets?
What is the primary distinguishing factor of AVO Class 4 gas sands among the AVO classes mentioned?
What is the primary distinguishing factor of AVO Class 4 gas sands among the AVO classes mentioned?
What is the main relationship between AVO Class and compaction trend?
What is the main relationship between AVO Class and compaction trend?
What is the main characteristic of AVO Class 2 gas sands in terms of impedance contrast?
What is the main characteristic of AVO Class 2 gas sands in terms of impedance contrast?
Which type of sand has a specific example given in the text as being mature highly compacted with relatively low Vp/Vs compared to surrounding rocks?
Which type of sand has a specific example given in the text as being mature highly compacted with relatively low Vp/Vs compared to surrounding rocks?
'The magnitude of reflection decreases with increasing offset' is a characteristic of which AVO class?
'The magnitude of reflection decreases with increasing offset' is a characteristic of which AVO class?
What causes the lower impedance of hydrocarbon sand compared to water sand?
What causes the lower impedance of hydrocarbon sand compared to water sand?
In which zone do we expect to see the AVO response for gas sand as Class 3?
In which zone do we expect to see the AVO response for gas sand as Class 3?
How does increasing the porosity of the sand affect the Intercept-Gradient values on the crossplot?
How does increasing the porosity of the sand affect the Intercept-Gradient values on the crossplot?
What is the significance of a separate data cluster falling to the left of points for brine-saturated sands when fluid substitution is considered?
What is the significance of a separate data cluster falling to the left of points for brine-saturated sands when fluid substitution is considered?
How can a change in lithology be modeled on the Intercept-Gradient crossplot?
How can a change in lithology be modeled on the Intercept-Gradient crossplot?
What type of AVO response is expected for gas sand in Zone 2?
What type of AVO response is expected for gas sand in Zone 2?
What does a point represent on the Intercept-Gradient crossplot for a single reflecting interface?
What does a point represent on the Intercept-Gradient crossplot for a single reflecting interface?
How does increasing shale content influence the Intercept-Gradient values on the crossplot compared to increasing porosity?
How does increasing shale content influence the Intercept-Gradient values on the crossplot compared to increasing porosity?
What trend appears on the crossplot signature when random noise is added to data points?
What trend appears on the crossplot signature when random noise is added to data points?
Where are all AVO class points from anomalous hydrocarbon zones expected to fall on an AVO crossplot?
Where are all AVO class points from anomalous hydrocarbon zones expected to fall on an AVO crossplot?
What does the Intercept term A represent in seismic data analysis?
What does the Intercept term A represent in seismic data analysis?
Why do brine-saturated sandstones and shales plot along a well-defined linear trend in AVO analysis?
Why do brine-saturated sandstones and shales plot along a well-defined linear trend in AVO analysis?
How are gas-saturated sand responses different from fully brine-saturated sand responses in terms of Intercept and Gradient?
How are gas-saturated sand responses different from fully brine-saturated sand responses in terms of Intercept and Gradient?
Which quadrant on the Intercept-Gradient crossplot do Class 3 sands fall into?
Which quadrant on the Intercept-Gradient crossplot do Class 3 sands fall into?
According to Castagna et al., what do deviations from the AVO background trend indicate?
According to Castagna et al., what do deviations from the AVO background trend indicate?
In seismic data analysis, what can be used as an interpretation tool when plotting R(0) against Gradient for every time sample in every CMP gather?
In seismic data analysis, what can be used as an interpretation tool when plotting R(0) against Gradient for every time sample in every CMP gather?
What is the significance of the Roman numbers I-IV on the Intercept-Gradient crossplot?
What is the significance of the Roman numbers I-IV on the Intercept-Gradient crossplot?
What is the relationship between A and B in 'background' rocks according to the text?
What is the relationship between A and B in 'background' rocks according to the text?
'Class 1 sands are high impedance relative to overlying shales.' In which quadrant on the Intercept-Gradient crossplot would you expect Class 1 sands to fall?
'Class 1 sands are high impedance relative to overlying shales.' In which quadrant on the Intercept-Gradient crossplot would you expect Class 1 sands to fall?
