Oil and Gas
Oil and Gas | Geophysics and Seismic Interpretation
Methods for Quantifying and Communicating Uncertainty in Depth Conversion and Volumetrics
Format and Duration:
3 days
5 sessions
This advanced course takes an in-depth, quantitative look at the sources of error and uncertainty in the construction of depth maps from seismic data, and the resulting impact on reservoir volumetrics. Worked examples will illustrate the key issues encountered at various stages of the asset life-cycle, from data-sparse exploration settings to the relatively data-rich appraisal and development phases. The course will start from basic geostatistical theory and work through the depth conversion elements toward a stochastic simulation and probabilistic volumetric maps.
Feedback
Very good course and well presented by the Instructor.
Schedule
Duration and Training Method
A classroom or virtual classroom course comprising lectures, discussion, demonstrations, and practical exercises.
Course Overview
Learning Outcomes
Participants will learn to:
- Construct depth maps that include accompanying uncertainty measures.
- Perform geostatistical workflows, with the ultimate goal of providing a more tightly-constrained volumetrics calculation.
- Integrate well-constraints into the process of depth conversion.
- Validate and rate objectively depth maps and volumetric estimates generated by others.
Course Content
The course content is divided broadly into the following topics:
1. Introduction
- Simple depth grid / 2D and 3D seismic problems
- Accuracy, precision, error, and uncertainty
- GRV basics
2. Velocity, time, and depth
- Interval or average velocity
- Velocity functions
- Error propagation
- Single layer depth and time practical
3. Statistics
4. Stochastic theory and variograms
5. Estimation with kriging
6. Stochastic simulation
- Depth estimation vs. volume estimation
- Closure & isoprobability closure maps
- Volumes proved up by well
- Multiple closures and merging volumes
- Partial contact information – water-up-to (WUT) and oil-down-to (ODT)
7. Multivariate geostatistics
- Stationarity and trends
- External drift, colocated methods, and Markov-Bayes
- Stacking velocities
- Combining depth and time uncertainty
8. Deviated wells and multilayer depth conversion
- Multi-layer depth conversion practical
- Kriging with inequalities
9. DHI and amplitude constraints
- Amplitude maps and tuning
- Amplitude conformance with structure
Who Should Attend and Prerequisites
This course should be of interest to all geophysicists and interpreters working in areas with demanding depth conversion challenges and complex imaging problems.
Instructors
Ashley Francis
Background
Ashley is Managing Director for Wessex Geoscience Ltd, having co-founded this company with Julie Francis in 2022. He is a geophysicist and geostatistician whose career has encompassed over 30 years worldwide oil industry experience of exploration, development, and production geophysics. Ashley has also consulted to the nuclear and engineering sectors on subsurface definition and uncertainty.
Ashley has worked in or on behalf of service companies, consultancies and oil companies in North and South America, Europe, Africa, the Middle East, the Far East, and Australia. He spent 5 years with LASMO plc in Technical Services assisting and advising asset teams worldwide in geophysics (particularly inversion), geostatistics, risk and uncertainty. After leaving LASMO in 2001, Ashley co-founded Earthworks, a consultancy specialising in subsurface geoscience. In addition to services and training, Ashley also developed ultra-fast stochastic seismic inversion software at Earthworks.
Ashley lectured in Borehole Geophysics to Honours Graduates at the University of the Witwatersrand, South Africa in 1989-90 and was a Visiting Research Fellow at the Post Graduate Institute in Sedimentology, University of Reading, UK in 1995-97. Ashley has presented regularly at EAGE conferences and workshops and was author of the ‘Understanding Stochastic Inversion’ tutorial series in First Break. Ashley is a committee member and regular attendee at the SEG Development and Production Forum and chaired the 2000 and 2003 D&P Forum conferences. He was an SPE Distinguished Lecturer for 2006–2007, presenting worldwide to reservoir engineers on the benefits and pitfalls of seismic inversion data in reservoir modelling. In 2001, the EAGE presented him with the Anstey Award for his ‘very substantial, original and diverse contribution to seismic inversion and geostatistics, and to the quantifying of uncertainty and risk’.
Affiliations and Accreditation
SEG, EAGE, IAMG, BSSS, IPSS, and PESGB - Member
Fellow of the Royal Astronomical Society
Courses Taught
N031: Prospect Evaluation & Volumetric Methods (Dorset, England)
N045: Seismic Inversion and Applications to Stochastic Reservoir Modelling
N216: Geostatistics and Advanced Property Modelling in Petrel
N224: Methods for Quantifying and Communicating Uncertainty in Depth Conversion and Volumetrics
Accreditation and Certification
CEU: 2.1 Continuing Education Units
PDH: 21 Professional Development Hours
Certificate: Certificate Issued Upon Completion
RPS is accredited by the International Association for Continuing Education and Training (IACET) and is authorized to issue the IACET CEU. We comply with the ANSI/IACET Standard, which is recognised internationally as a standard of excellence in instructional practices.
We issue a Certificate of Attendance which verifies the number of training hours attended. Our courses are generally accepted by most professional licensing boards/associations towards continuing education credits. Please check with your licensing board to determine if the courses and certificate of attendance meet their specific criteria.