Geologica provides the following update on upcoming online courses:
Subsurface Pressures for Injection of Fluids and Gases
- 20 - 24 Sep 2021, Online
- 06 - 10 Dec 2021, Online
Tutor: Professor Richard Swarbrick: Manager, Swarbrick GeoPressure Consultancy
This course covers all aspects of subsurface pressures with particular emphasis on pre-drill estimates and the conditions for injection and storage of fluids and gas, including hydrogen and CO2. Methods for estimating pressures from rock and fluid properties will be reviewed, as well as the processes which determine them in the subsurface prior to drilling. The impact of rock strength relative to fluid pressure at depth will also be discussed, in relation to injection rate limitations and storage volumes.
Duration and Logistics
Five 3.5-hour interactive online sessions presented over 5 days (mornings in North America and afternoons in Europe). A digital manual and exercise materials will be distributed to participants before the course. Some reading and exercises are to be completed by participants off-line.
Level and Audience
Intermediate to advanced. Intended for geoscientists and engineers who are involved in drilling into reservoirs for the purpose of injecting, storing and producing fluid. Some knowledge of subsurface geology and the basics of drilling wells would be an advantage.
You will learn to:
- Understand how subsurface pressures determine safe injection, storage and production from deep reservoirs.
- Appreciate the processes which govern safe drilling with particular emphasis on pore fluid and fracture pressures.
- Describe how to analyze subsurface pressure data and calibrate to estimate pore pressures from a variety of drilling and logging data.
- Relate regional and local rock stress magnitudes to failure of seals.
- Evaluate how to assess volumes which can be safely sequestered in underground storage.
- Interpret typical pressure profiles in terms of subsurface fluid processes, such as lateral drainage (open aquifers) and lateral transfer (enhanced pressures and a drilling surprise).
- Perform basic pressure prediction calculations and estimate storage volumes.
- Review and critique relevant case study material.
- Components of evaluation for drilling, injection and storage of fluids
- Pressure plots. Exercises
- Typical pressure profiles and relationship with reservoir/storage and overburden
- Generating an overburden (Sv) curve. Exercise
- Overpressure generating mechanisms and recognition using velocity-density plots
- Basics of pore pressure prediction. Exercise
- Relationship between shale and reservoir pressures
- Fluid pressure compartments and rock seals
- Membrane leakage – relationship between fluid and rock properties
- Fracture pressure and its prediction
- Hydraulic seal failure and assessing seal breach risk. Exercise
- Determination of volumes and safe for storage below failure pressure
Open aquifers vs closed traps for underground storage
Depleted reservoirs – advantages and disadvantages
Hydrodynamics in open aquifers and influence on storage. Exercise
- Production and associated depletion
Holistic Exploration Workflow for Critical Mineral Exploration
27 - 30 Sep 2021, Online
Tutors: Graham Banks, Founder and Principal Geologist, Route To Reserves; Associate Principal Geologist in the Americas, Southern Geoscience Consultants and Steve Fehr, President of Orca Global GeoConsulting.
This course presents a recommended workflow for critical minerals explorers: from province to prospect scales. During the exercises, you will apply concepts and skills that are fundamental for all exploration geoscience activities – in industry and research – including: the mineral system framework, exploration as a predictive activity, chance of geological success, uncertainty, risk, value of information and respectful teamwork. The examples will be for rare earth elements (REE) and nickel. The mineral system approach for critical minerals is still at a nascent stage. This course presents some of the progress to date. However, your ideas and contributions could shape a global exploration process.
Duration and Logistics
There will be four 3.5-hour interactive, online sessions presented over 4 days (mornings in North America and afternoons in Europe). A digital manual and exercise materials will be distributed to participants before the workshop. Extra reading and exercise time can be conducted outside workshop hours. Participants are encouraged to bring a standard deck of playing cards, 2 dice and 2 small cups to the workshop.
Level and Audience
Fundamental to Intermediate. The workshop is designed for participants with: (a) a bachelor’s degree level of understanding in igneous, sedimentary and erosion processes, tectonics, structure, geophysics and geochemistry; (b) a passion to go out and discover critical minerals ore deposits. Experienced mineral and petroleum explorers are welcome to share, and expand, their range of insights and techniques.
You will learn to:
- Understand some of the techniques and tasks of an industry exploration geoscientist.
- Put a mineral exploration project into province, mineral system and play context.
- Regard mineral exploration as a high-risk game of chance, that requires a probability of success estimate and approach.
- Adapt best-practice exploration techniques from other commodities to the critical minerals sector.
- Create and efficiently communicate maps and cross sections to estimate the migration pathways and deposition locations of commodities.
- Design a mineral system framework and translate it into the data types that would improve confidence in an exploration project.
- Recognise the value of collaboration, multiple working hypotheses and a team’s range of experiences in geoscience activities.
- Identify and mitigate the (often detrimental) biases that geoscientists could bring to projects.
The transition into a low-carbon world needs critical metals explorers who can efficiently generate and rank exploration prospects in a manner that is systematic across teams, organisations and national boundaries. This is to improve the entire sector’s decision quality, ability to compare and rank projects, geoscience efficiency and investor confidence. This course will operate as a workshop with much dialogue and seminar-style presentations only as context for the group exercises.
Introduction to the course, the workshop and the teams.
- Exercise 1. Review information about an REE exploration project and a nickel exploration project.
- Exercise 2. Predict the outcome of testing a subsurface exploration concept.
- Exercise 3. Assess the value, cost, risk and uncertainty of acquiring new information.
- Exercise 4. When multiple components must coincide to create a successful outcome.
Introduction to regional context and screening provinces.
- Exercise 5. Compare and rank the REE and the nickel project.
- Exercise 6. Regional-scale screening of a metallogenic province in Greenland.
Introduction to the best-practice methods of play-based exploration and petroleum system evaluation. How they are being applied f or copper exploration.
- Exercise 7. Sketch a petroleum system in 4-D – its essential ingredients, name it, state its known size, state its possible undiscovered extension.
Introduction to petroleum play analysis and geological chance factors.
- Exercise 8. Sketch a petroleum play in 4-D – its essential ingredients, name it, state its known size, state its possible undiscovered extension.
Introduction to petroleum prospect generation and geological chance factors.
- Exercise 9: Determine a prospect’s local chance factors and its probability of geological success.
Consider exercises 7–9 for a critical minerals framework.
Introduction to the mineral system framework – how to map it and how to use it for an exploration data acquisition program.
- Exercise 10: Determine the geological chance factors of an REE mineral system.
Continue exercise 10. Translate the geological chance factors into data types.
- Exercise 11: Repeat exercise 1 with skills and techniques gained in the workshop.
Workflows for Seismic Reservoir Characterization
04 - 14 Oct 2021
Tutor: Patrick Connolly: Director, Patrick Connolly Associates; Visiting Lecturer, University of Leeds
This course will provide participants with the skills needed to design and implement workflows for seismic reservoir characterization using established best-practice and emerging technology. The course covers seismic conditioning, colored inversion, AVO theory including elastic and extended elastic impedance, DHIs, seismic net pay, well ties, rock physics, and deterministic and probabilistic inversion including the application ODiSI.
Duration and Logistics
Eight 4-hour interactive online sessions presented over 8 days (mornings in North America and afternoons in Europe). A digital manual and exercise materials will be distributed to participants before the course. Some reading and several exercises are to be completed by participants off-line.
Level and Audience
Advanced. Intended for practicing seismic interpreters. Participants should have a basic knowledge of the seismic method, including acquisition and processing, with a minimum of three years working with seismic data. However, the subject matter of this course, AVO and inversion, is covered from basic principles.
You will learn to:
- Appreciate the benefits of colored inversion – how and why it works and how to get the best results from a colored inversion application.
- Understand the relationships between reflectivity and impedance, and between time and frequency.
- Understand the model for AVO measurements and the difficulties in making accurate AVO measurements.
- Understand the concepts behind AVO analysis, including intercept-gradient crossplots and the theoretical relationship between elastic and AVO properties.
- Optimize AVO products for subsequent characterization work and create seismic products that correlate with specific reservoir properties.
- Appreciate the risks of using attributes with no physical relationship with desired objective.
- Appreciate the limitations of the seismic net pay method and to know when it is, and is not, applicable.
- Understand the principles and pros and cons of deterministic and probabilistic inversion and how to select the appropriate inversion strategy for any given problem.
Sessions 1 and 2 – Introduction and colored inversion
- Technical and learning objectives
- Bed thickness distributions
- Impedance and reflectivity spectra
- Band-limited impedance and band-limited reflectivity
- Colored inversion and blueing
- Wavelet optimization, amplitude and phase spectra
- Well ties and wavelet estimation
- Frequency slice filtering and structurally conformable filtering
- Stratigraphic filtering (O’Doherty-Anstey)
- Q and ghosts
- 1-D geological modeling with different bed-thickness distributions
- Fourier transforms
- Wavelet modeling
Sessions 3 and 4– AVO measurement
- Zoeppritz equations and linearisations – Aki and Richards, Wiggins and Shuey
- Intercept, gradient and curvature
- Background AVO trends
- Angle stacks and angle estimation
- Sources of measurement errors
- Seismic conditioning – scaling, spectral balancing etc.
- 2-term and 3-term measurements
- Maximum angle and truncation error
- Anisotropy – the Rüger equation
- Fatti equation
- Half-space modeling with the Wiggins equation
- Modeling gradient measurement errors
- 3-term curve fitting
- Modeling the effects of VTI anisotropy
Sessions 5 – AVO crossplots
- Background trends on intercept-gradient crossplots
- AVO classes
- The effect of moveout errors on the AVO classes
- Fluid substitution – the Dong equation
- Fluid changes on intercept-gradient crossplots
- Intercept-gradient coordinate rotations
- AVO properties and elastic properties
- Elastic property reflectivity vectors
- Theoretical chi relationships
- Modeling the structure of intercept-gradient crossplots
- Modeling the effect of moveout errors on AVO measurements
- Modeling the effects on AVO of fluid substitution and anisotropy
Session 6 - AVO analysis
- Transforming AVO from reflectivity to impedance
- Elastic impedance and extended elastic impedance (EEI)
- AIGI crossplots
- Empirical EEI correlations with reservoir properties
- Non-zero offset and deviated well ties
- AVO facies analysis
- Optimized χ-angles from well log analysis
- The effect of gradient errors and noise on χ-angles
- Optimum χ-angles from seismic data
- Rock physics modeling and rock physics templates
- DHIs, Bayes theorem and exploration risking
- Modeling EEI correlations
- Optimizing chi-angle stacks for different scenarios
- Modeling a seismic optimization workflow
- The effect of rock physics parameters on optimal χ-angle
- Exploration risking using Bayes theorem
Session 7– Attribute maps
- Importance of net-rock volume estimation
- Spectral decomposition
- Multi-attributes and the risks of spurious correlation
- Binary systems and EEI
- Band-limited impedance and reflectivity tuning
- Detuning and calibration
- The seismic net pay method
- Application to unconventional shale plays
- Lateral resolution and map calibration uncertainties
- Demonstration of spurious correlation from multi-attributes
- Modeling how bandwidth affects tuning
- Manual estimation of net pay from synthetic attributes
Session 8– Seismic inversion
- Sources of inversion uncertainty
- Facies probability curves
- Bayes theorem for continuous random variables
- Uncertainty quantification
- Deterministic and probabilistic inversion
- Inversion algorithms
- Lateral correlation – geostatistical inversion
- The inversion landscape – categorization
- Comparison of inversion methods and algorithms
- Manual inversion
- Deterministic gradient descent inversion
- Estimating values with uncertainty