Model Based Inversion: Low Frequency Model Importance

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What does the reflection coefficient R describe in the context of acoustic inversion?

The frequency of the reflected wave

The amount of wave energy reflected at the interface between layers (correct)

The speed of the incident wave

The angle of incidence

Which parameter affects the reflection amplitude of a normal-incident P-wave at the interface between elastic half-spaces?

Wave frequency

Incident wave speed

Reflection angle

Impedance difference between the half-spaces (correct)

What can full stack seismic data, assumed to represent zero-offset traces, allow us to estimate through inversion?

Layer thickness

Acoustic impedance (correct)

Wave frequency

Wave velocity

What should be considered when choosing a deterministic inversion method for full stack seismic data?

Level of well control available and desired answer detail Signup and view all the answers

Which method, also known as Bandlimited Inversion, is considered as a simple form of deterministic inversion?

Recursive Inversion Signup and view all the answers

What determines the amount of fine-scale detail needed in the answer when choosing an inversion method?

Amount of uncertainty quantification required Signup and view all the answers

What does the Simplicity term Fcontrast aim to achieve in the objective function?

Create an inverted impedance log with as few reflection coefficients as possible Signup and view all the answers

How does the Spatial Term Fspatial contribute to the solution?

Stabilizes the low frequencies Signup and view all the answers

What effect does a higher S/N ratio have on the inversion solution according to the text?

Drives the solution by the fit of the synthetic to the seismic data Signup and view all the answers

Why is it mentioned that increasing all user weights by a similar amount will not change the solution?

Due to non-uniqueness of the solution Signup and view all the answers

What does the Trend Term Ftrend primarily stabilize in the inversion process?

Low frequencies Signup and view all the answers

How does changing one weight or including an extra misfit function affect the balance of misfit functions?

Alters the balance and potentially changes the contributions of all functions Signup and view all the answers

What type of data records both lower and higher frequency than seismic data?

Well logs Signup and view all the answers

Which technique can be used for interpolating well logs to create a low frequency model?

Inverse distance interpolation Signup and view all the answers

What guides the interpolation process away from wells when well logs are missing?

RMS velocities Signup and view all the answers

What is the primary objective of model-based inversion?

To minimize the misfit between the synthetic model and seismic data Signup and view all the answers

What is emphasized as important to understand in the context of inversion techniques?

Quality of the input seismic data Signup and view all the answers

Which term refers to minimizing the fit between the seismic and the synthetic generated from inverted impedance?

Cost function Signup and view all the answers

What is a key factor in evaluating the final result of model-based inversion after multiple iterations?

'Complications' in seismic data like noise Signup and view all the answers

Which technique involves updating the elastic attributes of the model iteratively to reduce differences with seismic data?

'Model based inversion' Signup and view all the answers

'External drift kriging' is an example of what in relation to creating a low frequency model?

'Interpolation technique' Signup and view all the answers

'Sparse Spike inversion algorithm' is associated with which software?

'Jason' Signup and view all the answers

What is the purpose of applying the inverse wavelet to a seismic trace?

To convert it to a reflectivity trace Signup and view all the answers

What is the main challenge faced when converting reflectivity to impedance?

Possible phase errors and noise contamination Signup and view all the answers

What is the purpose of Colored Inversion compared to Recursive Inversion?

To transform seismic trace into impedance faster Signup and view all the answers

What is the key assumption made by Sparse Spike Inversion?

Only large spikes in reflectivity are meaningful Signup and view all the answers

How does Model Based Inversion differ from Sparse Spike Inversion?

It solves for reflectivity iteratively based on known seismic data and wavelets Signup and view all the answers

In the context of the text, why is the low frequency model important for seismic inversion?

It reconstructs important velocity structure absent in seismic data Signup and view all the answers

What does Sparse Spike Inversion aim to achieve by finding large spikes in the reflectivity?

Reproduce the seismic trace with minimum number of reflections Signup and view all the answers

How does Colored Inversion differ from Bandlimited method?

Is faster and does not need a good initial model Signup and view all the answers

What is the main difference between Recursive Inversion and Colored Inversion methodology?

It is faster and does not require a good initial model Signup and view all the answers

How does Model Based Inversion tackle random noise in seismic data?

It solves for reflectivity iteratively by minimizing misfit Signup and view all the answers

What is a key assumption made in acoustic inversion?

Stable wavelet that does not change with time Signup and view all the answers

What do the seismic data show according to the text?

Interfaces between rock layers Signup and view all the answers

Why is interpretation challenging in the southeast Asia clastic example?

Interference due to close vertical positioning of layers Signup and view all the answers

What is a benefit of acoustic inversion for improved horizon interpretation?

Attenuation of wavelet sidelobes Signup and view all the answers

Which data type provides easier analysis of lateral continuity in rock layers?

Inverted data Signup and view all the answers

What is a characteristic of the Yellow horizon in the improved horizon interpretation example?

Valley fill interpretation Signup and view all the answers

Why is the completion of the Yellow horizon easier in the improved horizon interpretation example?

Wavelet sidelobes are attenuated Signup and view all the answers

How does acoustic inversion assist in better prospect identification?

Enhances contrast between sand layers Signup and view all the answers

What complicates interpretation in the southeast Asia clastic example?

Close vertical positioning of contrasting layers within half of a wavelet length. Signup and view all the answers

What does seismic tuning cause in the lower sand layer according to the text?

Bright appearance compared to upper sand. Signup and view all the answers