Oil and Gas

Participants will learn to:

1. Consider the critical questions that need to be answered by the seismic interpretation.
2. Evaluate phase, polarity, bandwidth, and other factors affecting seismic resolution and interpretability.
3. Use color and other display parameters to extract maximum structural and stratigraphic detail from 3D data.
4. Investigate the use of various workstation tools to perform jump-correlations, seismic well-ties using synthetic seismograms, construct structural and stratal slices, and perform horizon flattening, auto-tracking and auto-extraction for efficient interpretation of horizons and faults. Consider structural attributes to aid interpretation.
5. Utilize all available velocity data to build an appropriate velocity model for depth conversion including synthetic seismograms, VSPs, seismic velocities and geological models.
6. Compare seismic time-to-depth conversion techniques and recognize the advantages and disadvantages of different methods. Discuss the appropriate stage of the project to depth convert data, horizons, faults and/or maps, and consider how to manage uncertainty in depth conversion.
7. Differentiate the various types of seismic attributes available and select appropriate attributes for a given project. Consider the advantages and limitations of various attributes and think about constructing fit for purpose custom attributes.
8. Understand the uses of rock physics within the seismic interpretation workflow including assessing the trend of data with depth, cross-plotting various seismic and petrophysical properties.
9. Review prestack interpretation techniques including the modelling and interpretation of gathers and partial angle stacks (near, mid, far, etc.).  Consider the various uses and challenges of a variety of approaches to amplitude variation with offset (AVO) methodologies. 
10. Design interpretation workflows to assist in estimating reservoir properties.
11. Export / transfer data from one package to another and have an awareness of pitfalls (e.g. datums, polygons, maps, data qc).
12. Demonstrate the importance of geophysics and consciously communicate the value, necessity and limitations to the team.

Recent advances in seismic technology now provide seismic interpreters with advanced tools for risk and resource assessment, and for characterizing reservoirs. The materials covered in this class are designed to help practicing interpreters construct interpretation workflows to extract the information necessary to make good business decisions and to convey their ideas to others.

Session 01 - Introduction

• Project goals including determining the critical question to ask when working on an interpretation
• Seismic data assessment including review of the acquisition and processing of the seismic volumes, data loading parameters, phase, polarity, bandwidth, horizontal and vertical resolution.

Session 02 – Seismic Set-up, Navigation and Initial Interpretation

•  Reconnaissance workflow for use when first loading a seismic dataset. Scanning through seismic, noting initial FLTs (“funny looking things”), identifying the phase and polarity, picking key horizons, planning an interpretation strategy, correcting for velocity pushdown, identify seabed multiples, cataloguing FLTs.
•  Use color and other display parameters to help extract maximum structural and stratigraphic detail from 3D data.

Session 03 - Visualisation and Presentation 

• Conveying ideas to others
• Integrating the key elements
• Blending, draping, incorporating
• Perspective, map, and elevation views

Session 04 - Interpretation Skills

• Horizon and fault interpretation using various workstation tools to perform jump-correlations, perform horizon flattening, auto-tracking, auto-extraction.
• Construct efficient interpretation workflows to answer the critical questions.

Session 05 - Seismic Well Ties

• Create synthetic seismograms and critically evaluate the well-seismic tie.
• Understand the geometries and uses of vertical seismic profiles (VSPs).

Session 06 - Depth Conversion 

• Compare seismic time-depth conversion and processing techniques and recognise the advantages and disadvantages of different methods.
• Discuss the appropriate stage of the project to depth convert data, horizons, faults and/or maps.
• Design a velocity model with appropriate input data.
• Review best practices for managing uncertainty in depth conversions and consider multiple scenario maps.

Session 07 - Post Stack Seismic Attributes

• Differentiate the various types of seismic attributes available including structural, stratigraphic, post-stack, pre-stack, trace-based, horizon, volume, etc. and select appropriate attributes for a given project.
• Consider the advantages and limitations of various attributes.
• Create customised seismic attributes tailored to your project.
• Spectral decomposition.
• Geobody extraction based on seismic attributes.

Session 08 - Rock Physics and Quantitative Interpretation 

• Review the relationship between physical and elastic properties of rock, discuss the use of various rock physics models / templates, plot depth trends and use fluid substitution to help understand potential fluids within the reservoir. Consider the assumptions behind the models and develop an awareness of the uncertainty.
• Use offset synthetic modelling to aid AVO analysis and interpretation of partial angle stack.
• Discuss various forms of both post-stack and pre-stack inversion.

Session 09 - Direct Hydrocarbon Indicators (DHIs)

• Review criteria for potential DHIs considering phase, polarity, seismic character and time anomalies. Consider bright spots, polarity reversals, dim spots, flat spots, chimneys, bottom simulating reflectors and reflection sag within the context of the rock physics model and sand / shale depth trends.

Session 10 - Finale

• Recent advances and keeping up with developments
• Archiving, exporting and/or transferring data with an awareness of pitfalls.
• Fit for purpose reports and presentations for the team, management and/or external parties. How to present a key concept effectively and efficiently.
• Wrapping up

Practicing seismic interpreters who wish to improve their interpretation skills and gain awareness of interpretation workflows.