Oil and Gas
Oil and Gas | Reservoir Development
Geostatistics and Advanced Property Modelling in Petrel
The course gives an essential grounding in geostatistical theory, including stochastic theory, variogram analysis and stationarity. Practical use of geostatistics is examined in the context of Kriging (mapping) and stochastic simulation using a volumetric estimation example. More advanced topics include problems associated with change of scale of measurements (support) and multivariate geostatistics including co-kriging, collocated methods and Markov-Bayes.
Schedule
Duration and Training Method
A classroom course comprising of a mix of teaching and hands-on exercises using Petrel. The proportion of lecture and computer modelling time is approximately 60/40.
Course Overview
Learning Outcomes
Participants will learn to:
- Appraise the role of geostatistical methods in 3D geomodelling and reservoir characterisation.
- Rate the geostatistical approach against more classical deterministic methodologies.
- Evaluate the importance concepts of stochastic theory, variogram analysis and stationarity to geostatistical thinking.
- Assess univariate and multivariate (co-kriging, collocation, entropy and Markov-Bayes) statistical methods and their most effective implementation.
- Propose appropriate geostatistical data quality control and analysis strategies.
- Construct variograms as spatial analysis tools for geoscience data mapping.
- Perform univariate kriging for reservoir extrapolation within the Petrel Advanced Property Modelling package.
- Compare the range of pixel-based facies simulation options available (SIS, SGS, TGS etc) within Petrel’s geomodelling tool-kit.
- Formulate a multivariate co-kriging strategy within Petrel to provide a most-likely reservoir model estimate.
- Evaluate reservoir heterogeneity and define upscaling criteria that capture its role within the 3D geomodelling framework.
- Execute the geological and petrophysical steps within the Petrel Advanced Property Modelling workflow to construct a static 3D reservoir geo-model ready for use in dynamic simulation.
- Judge the Petrel Advanced Property Modelling module’s strengths and pitfalls.
Course Content
The course gives an essential grounding in geostatistical theory including; stochastic theory, variogram analysis and stationarity. Practical use of geostatistics is examined in the context of Kriging (mapping) and stochastic simulation using a volumetric estimation example. More advanced topics include problems associated with change of scale of measurements (support) and multivariate geostatistics including co-kriging, collocated methods and Markov-Bayes.
The theoretical work is complemented by a thorough examination of advanced property modelling in Petrel. The practical sessions in the course are hands on in Petrel and utilise a small 3D seismic and well log data set. The property modelling exercises cover the scale-up from logs to cells, data analysis, facies modelling, variogram modelling, facies simulation (including a comparison of SIS indicator and object methods) and petrophysical modelling, including porosity estimation and permeability transforms. The final theoretical and practical topic looks at the limitations and practicalities of constraining the reservoir model and its properties using seismic inversion outputs.
At all times, the course emphasises the Petrel workflow and attempts to highlight potential problems, pitfalls and their workarounds.
Theory
- Statistics
- Stochastic Theory
- Stationarity
- Estimation and Kriging
- Stochastic Simulation
- Deterministic, Stochastic and Best Estimate
- Support
- Entropy and Bayes’ Theorem
- Cokriging
Advanced Property Modelling
- Introduction and Framework
- Stratton Field Introduction
- Scale Up of Well Logs
- Data Analysis
- Facies Modelling
- Variograms in Petrel
- Stratton Field Facies Variogram Modelling
- Seismic Variograms
- Facies Simulation
- Petrophysical Modelling
- Seismic Inversion Constraints
Who Should Attend and Prerequisites
The course should be attended by anyone requiring knowledge of how geostatistics can play a role in geoscience mapping. The course will be of particular benefit to those conducting geomodelling and advanced property modelling within Petrel. Seismic mapping considerations will also be considered, in the form of inversion constraints. The course should, therefore, be of interest to a wide range of experienced geoscientists: geological modellers, petrophysicists, and seismic interpreters.
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