Oil and Gas
Oil and Gas | Geophysics and Seismic Interpretation
Business Impact: Rock physics has numerous applications for adding reserves and growing production within the business cycle; from recognition of diagnostic seismic signatures in prospect identification to reservoir characterisation and volumetric uncertainty estimation in field evaluation as well as enhanced oil recovery through time lapse techniques in field development. Moreover, a cross discipline understanding of rock physics is central to the effective integration of geology, petrophysics, geophysics, engineering.
This course presents the physical basis for quantitative seismic interpretation within the context of hydrocarbon exploration and production. Key technologies are explained in a straightforward manner; with topics including rock physics analysis of log data, well ties, 1D and 2D seismic modelling, amplitude and AVO analysis, seismic inversion to rock properties and the use of seismic amplitude information in prospect risking. Practical exercises utilise Excel based applets to aid understanding and the lessons learnt are of general application.
Duration and Training Method
This is a classroom or virtual classroom course comprising a mixture of lectures, discussion, case studies, and practical exercises.
Participants will learn to:
- Make a basic AVO model and use it to determine expectations in seismic interpretation in a variety of AVO scenarios.
- Understand the principal characteristics of seismic wavelets and appreciate how the interference phenomenon can be used in the thickness prediction problem.
- Tie a well using the well seismic matching and adaptive techniques and appreciate the importance of well tie information in the construction of forward models and seismic inversions.
- Understand Gassmann fluid substitution and how rock physics models in general can be used in log conditioning and interpretation.
- Understand different approaches to AVO analysis, how AVO projections work and the importance of data quality in the successful application of AVO analysis.
- Understand bandlimited impedance and how it can be used in an AVO context for interpretation of net pay thickness.
- Appreciate the differences between classical ‘best estimate’ seismic inversion and modern rock physics based techniques such as JiFi and ODiSI.
- Understand the basics of Bayes theorem and how it can be applied in probabilistic approaches to seismic inversion and prospect risking.
Course content is evenly split between lectures that review the basics of how seismic relates to rock properties and PC-based practicals utilizing real data. Through the use of commercially available PC-based software, the basics of rock physics interpretation of seismic data are understood. By the end of the course, students will not only be able to create first order reflectivity models and understand the basics behind the buzzwords (AVO, EI etc), but also be able to ask pertinent questions that relate to the use of seismic data in prospect risking.
Lecture review topics include:
- Basic rock properties and reflectivity
- The mechanics of seismic data processing (Geometry, Stacking and Migration)
- An introduction to key processing issues
- Seismic bandwidth and the convolutional model
- Wavelets – shape, phase and polarity
- Resolution and non-uniqueness
- Fit and accuracy in seismic well ties
- Rock physics - where to get the numbers for modelling
- 1D and 2D seismic modelling
- AVO Analysis in reflectivity and impedance domains
- Seismic inversion to impedance, facies and rock properties
- Seismic amplitudes and the risking problem
Practical exercises include:
- Creating models of various AVO scenarios
- Net thickness prediction in thin beds
- Well tie using RokDoc (White and Adaptive methods)
- Fluid substitution on logs and AVO modelling
- Appreciating the amplitude scaling problem
- Understanding AVO projections
- AVO in the impedance domain
- Reflectivity and bandlimited impedance
- Simple net pay analysis
- The low frequency problem in inversion
- The role of the AVO gradient in determining Vs from P-wave seismic
- Risking case study
Who Should Attend and Prerequisites
The course is designed to be an introduction to practical rock physics application in seismic interpretation and would be of interest to all working Geoscientists, Petrophysicists, and Reservoir Engineers. For experienced Geophysicists who are regularly involved in seismic modelling, the course can be used as a refresher.
Eleanor is a geophysicist specialising in quantitative seismic interpretation, from rock physics to depth conversion. She has an MSc in Exploration Geophysics from the University of Leeds and has been working in the oil and gas industry since 2009. Eleanor has been with G&G consultancy Merlin Energy Resources since graduating, during which time she has worked on a wide variety of exploration and development projects from around the world. Eleanor is a member of the Society of Exploration Geophysicists, European Association of Geoscientists and Engineers and the Petroleum Exploration Society of Great Britain.
Affiliations and Accreditation
MSc University of Leeds - Exploration Geophysics
SEG - Member
PESGB - Member
EAGE - Member
N004: The Essentials of Rock Physics for Seismic Amplitude Interpretation
Rob is a seismic interpreter who specializes in applying rock physics in oil and gas exploration and production. He has worked in oil and gas exploration and development since1985, spending his early career with operating oil companies (notably Britoil, Tricentrol and Enterprise Oil). In 1999, he established his own consultancy company, Rock Physics Associates Ltd, to provide project and training services. From 2010 to 2019, Rob worked for small North Sea oil companies and latterly was Chief Geophysicist at DNO Norge AS. In 2014 Rob (with co-author Mike Bacon) published the textbook ‘Seismic Amplitude: An Interpreter’s Handbook’ (Cambridge University Press).
Affiliations and Accreditation
PhD University of London
SEG - Member
PESGB - Member
The Geological Society of London - Fellow Member and Chartered Geologist
N004:The Essentials of Rock Physics for Seismic Amplitude Interpretation
N032:Professional Level Rock Physics for Seismic Amplitude Interpretation (AVO & Seismic Inversion)