Seismic Attributes & AVO Processing, Interpretation & Application (MAR 2021)

Module IV: AVO Processing, Modeling, Analysis and Interpretation

Instructor:                    Dr. Mangat R. Thapar

Course Length:            5 Days

Course CEUs:   4.0

Course Description:

The understanding and application of AVO analysis is valuable to any seismically driven exploration or development program. Learn from one of the industry's top geophysicists - Dr. Mangat Thapar. This course is a MUST for all geoscientists who utilize seismic data in their interpretations. Using Microsoft's Excel, Mathcad and VISTA software, Dr. Thapar will demonstrate key principles and pitfalls related to AVO analysis including the suitability of seismic data for analysis, preserving amplitudes, how to properly model AVO/AVA response, and matching the predicted response with seismic data, and avoiding pitfalls. These principles control the success or failure of AVO, and with it the potential success of an exploration program. Other key aspects of the course include:

• How to select appropriate acquisition parameters and processing flow to properly record and preserve AVO anomalies.
• Blocking logs using zonation, mean and variance methods to develop AVO/AVA models. How to extract interval velocities from stacking velocities through ray-tracing in the presence of dip. Discussion on how to select appropriate wavelet for modeling.
• Prediction of AVO/AVA responses using properly generated models and comparison with AVO/AVA extracted from seismic data.
• Extensive discussion throughout the course of pitfalls in AVO and how to avoid them.

Exercises:

The course concepts are reinforced with a number of real world exercises conducted throughout the course to enhance understanding of the principles presented. These exercises include:

• Amplitude corrections and scaling
• Estimation of V_s from V_p
• AVO modeling and extraction from seismic amplitudes
• AVO/AVA response from gas-sand thicknesses ranging from 300 ft to 10 ft
• Interference effects due to NMO on far offsets for reservoir thicknesses ranging from 300 ft to 10 ft
• Exercises on the tuning thickness effect on AVO, extraction of rock properties (λ μ ρ), AVO interpretation and cross plotting techniques
• Group exercise on selection of acquisition parameters and processing flow for AVO.
• Group exercise to develop a risk analysis spreadsheet for AVO which encompasses all factors in acquisition, processing, modeling, and interpretation.

Learning Outcomes:

·         Analyze and apply AVO correctly and appropriately

·         Determine when AVO is applicable using risk analysis

·         Resolve the effect of processing on AVO

·         Modeling and predicting AVO.

·         Extracting AVO response from correctly processed data.

·         Comparing extracted AVO from seism data with predicted AVO response

·         Recognize pros and cons of AVO

·         Know and avoid AVO pitfalls

Who Should Attend?

Interpreters, geophysicists, geologists, technical support personnel, seismic processors, exploration and data processing managers and data acquisition managers

Prerequisites:

It is recommended that participants take Seismic Survey Design, Acquisition and Processing or equivalent courses.

Course Content

• AVO Concept and related factors
• AVO pitfalls and assumptions
• Petrophysics and AVO
• Rock properties and wave propagation
• Hydrocarbon detection using AVO
• AVO modeling and processing
• Impact of processing on AVO analysis
• Techniques for interpretation of AVO
• AVO Cross-plotting techniques
• Case studies of AVO
• AVO risk analysis spreadsheet

Participants are encouraged to bring data examples related to this course.