ench week01
TRANSCRIPT
Basin Analysis and Petroleum
Exploration
ENCH
Dr. Barry McNamara
Sept 14 to Dec 7 2005
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Topics for Week 1
Course overviewo scope, expectations, format, grades, projects, exams
Instructor and students: background
Basin analysiso sedimentary basins
o what is basin analysis
Tools of the geoscientisto plate tectonics, sequence stratigraphy, seismic stratigraphy
Petroleum systemo petroleum charge, migration, entrapment
Exploration engineers and basin analysis
Reading material
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Course Schedule and ContentClass Topic
Sept 14
Week 1
Introduction to Course and Material
Review and discussion of concepts
Sept 21
Week 2
Example of basin analysis: Gulf of Suez Rift Basin
Basins I: description of basins, plate tectonics, basin classification and
tectonic setting
Sept 28
Week 3
Basins II: basin classification (continued), basin models of subsidence
and sedimentation
Oct 5
Week 4
Basin Fill I: Stratigraphy and sedimentology; tools used, dating and
correlation
Oct 12
Week 5
Basin Fill II: Facies models, basin mapping; sequence s tratigraphy
Oct 19
Week 6
Basin Fill III: Sequence stratigraphy (continued), seismic stratigraphy
Oct 26
Week 7
Due Today: Selection of basin/petroleum system for main class
project
Basins III: Regional and global stratigraphic cycles
Nov 2
Week 8
Mid Term Exam (tentative)
Review selected basin example
Nov 9
Week 9
Petroleum System I: The petroleum system
Nov 16
Week 10
Student seminars
Petroleum System II: Field size distribution, play concepts
Nov 23
Week 11
Student seminars
Selected geologic topic: Carbonate models: basin fill and sequence
stratigraphy
Nov 30
Week 12
Student seminars
Carbonate models (continued): sequence stratigraphy, reservoir
development
Dec 7
Week 13
Student seminars
Basin modeling software demonstration
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Format of Course
Lecture to cover most material you will see in Basin
Analysis: will review material from textbook (Miall,
2000) as well as selected reading material from
reference texts and assigned reading.
Cover some basin examples to illustrate concepts you
will see and report on in your research project.
Students may be asked to discuss some of their work
on their research paper as it pertains to lecture
material.
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Course Description
The course is designed to provide a framework for
understanding the geologic description of sedimentary basins,
within the context of petroleum systems, with application to
exploration for petroleum reservoirs. Course lectures and
reading material will cover: classification of sedimentary basins
and their plate tectonic settings; mechanism of subsidence and
thermal history of sedimentary basins; geological and
geophysical methods of basin mapping; depositional systems,
basin fill and facies models; thermal maturity of source rocks;
generation and migration of hydrocarbons; controls on reservoir
quality in clastic and carbonate rocks; petroleum resource
assessment and play concepts on basin scale.
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Course Objectives
to present the concepts of Basin Analysis to
exploration engineers
to place Basin Analysis within the framework of tools
and concepts for petroleum exploration that are in use
by exploration geoscientists
to prepare exploration engineers to communicate with
geoscientists to improve the decision making process
in evaluating basins for petroleum exploration
Independent study of selected basins to become more
familiar with basin analysis
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Level of Detail
Topics covered at a level sufficient to:
introduce or review geoscience subjects at a level
appropriate for exploration engineers
increase awareness of types of geoscience
information available to describe the exploration
potential of petroleum systems within a sedimentary
basin
emphasize the role of the exploration engineer in
contributing to the exploration process of Basin
Analysis
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Grading of Work
Examinations:
There will be one mid-term examination. The examination will be closed book. Late October/early November.
Final Grades:
The final grade will be determined on the basis of:
Mid term exam 30%
Basin analysis project 50%
presentation: 10%
written report 40%
Classroom work 20%
Project due on Dec 14; no late projects accepted
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Independent Work
A written research report (including references), and presentation of report to class by each student, will be required on a specific basin. Basin will be selected by student with approval of instructor. Reports and presentations will be marked for final grades. Format of report will follow a “basin analysis”.
Students will be expected to participate in class discussions, to discuss the basin project they are working on as it relates to topics being covered in class, and to present interim reports on their basin analysis project as required.
Readings (books, journal articles) will be assigned each week as required.
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Other MaterialsReference Material
Allen, P.A., and Allen, J.R., 1990. Basin Analysis: Principles and Applications,
Blackwell Scientific Publications, Oxford, 451p
C. J. Busby and R. V. Ingersoll, editors, 1995. Tectonics of Sedimentary Basins,
Blackwell Science, Cambridge, MA, 579 p.
Einsele, G., 2000. Sedimentary Basins: Evolution, Facies, and Sediment Budget,
792 p.
Tissot, B.P. and Welte, D.H., 1984. Petroleum Formation and Occurrence
Useful Websites
USGS: This Dynamic Earth: the Story of Plate Tectonics
http://pubs.usgs.gov/publications/text/dynamic.html
USC Sequence Stratigraphy Web
http://strata.geol.sc.edu/index.html
USGS: The Earth’s Crust
http://quake.wr.usgs.gov/research/structure/CrustalStructure
USGS World Petroleum Assessment 2000.
http://pubs.usgs.gov/dds/dds-060/index.html
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Instructor
Dr. Barry McNamara
Education:o BSc (‘84) St Francis Xavier University, Antigonish, Nova Scotia
o MSc (‘89), PhD (‘95), Reservoir Geology, University of Calgary
Senior exploration geologist, Innova Explorationo Actively working to find oil and gas
Work experience: Chevron, Gulf Canada, Santos,
Baytex, Vintage Petroleum, Innova Exploration;
Canada and Australia
Work experience as geologist and reservoir engineer
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What is Basin Analysis
Basin analysis involves making an interpretation of the formation, evolution, architecture and fill of a sedimentary basin by examining geological variables associated with the basin.
Basin analysis provides a foundation for extrapolating known information into unknown regions in order to predict the nature of the basin where evidence is not available.
A basin model is built on a framework of geological surfaces that are correlated within the basin. This stratigraphic framework can be expressed in terms of rock type (lithostratigraphy), fossil content (biostratigraphy), age (chronostratigraphy), or rock properties such as seismic velocity (seismic stratigraphy).
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Sedimentary Basins
Sedimentary Basin: A depression in the crust of the
Earth in which sediments accumulate. Formed by
plate tectonic activity. Continued deposition can cause
further depression or subsidence.
If rich hydrocarbon source rocks occur in combination
with appropriate depth and duration of burial,
hydrocarbon generation can occur within the basin.
approx 575 sedimentary basins identified worldwide
approx 215 known productive
approx 360 non-productive
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onshore (green) and offshore (purple)
Worldwide distribution of sedimentary basins
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USGS World Petroleum Assessment 2000
Assessed 76 geologic provinces containing
95% of non-US known petroleum reserves
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Importance of Basin Analysis
Oil and gas exploration is all about finding economically
productive hydrocarbons. Better understanding of
sedimentary basins through Basin Analysis will improve
decision making for exploration projects
New (immature, undrilled) basins can have a systematic
treatment for assessment of exploration potential
Re-look at mature basins to provide new exploration targets
Required integration of geoscientists and engineers can
produce new ideas, better decisions
“The classification of basins does little to improve our
hydrocarbon volume forecasting ability.” (Bally and
Snelson, 1980)
18(Mann et al, 2001)
Classification of
tectonic setting
of giant oil fields
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Remaining Reserves of Crude Oil by Basin
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World Endowment of Crude Oil, Natural Gas and NGL Liquids
(Source: USGS World Petroleum Assessment 2000)
Note significant reserves to be added through reserve growth in
established play areas and petroleum systems.
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Geoscience Effort in Basin Analysis
Basin analysis for exploration can be described as the integration of the following 3 components
Controls on development of the sedimentary basinplate tectonic and paleogeographic history
Stratigraphy and sedimentology of the basinbasin fill
The petroleum systemsource, maturity, migration, trap, seal
Significant geoscience effort is required to prepare each of these components of the basin analysis; multidisciplinary approach
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Controls on Development of the Sedimentary Basin
plate tectonic settings of basin formation
basin morphology over time
latitude of the basin
geothermal gradients and heat flow profiles
tools in use:o geophysical tools: seismic, gravity and magnetics
o interpretation of seismic data
o palinspastic restoration of balanced restored cross sections
o surface geology
o depositional and erosional analysis
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Plate Tectonics: Review of Earth Structure
(from USGS website)
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Convection Engine Driving Plate Tectonics
(http://www.glossary.oilfield.slb.com/DisplayImage.cfm?ID=154)
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Thickness of Crust
(http://quake.wr.usgs.gov/research/structure/CrustalStructure/)
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Lithospheric Plates
(http://pubs.usgs.gov/publications/text/slabs.html)
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Convergent Boundary
(http://pubs.usgs.gov/publications/text/understanding.html#anchor6715825)
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Specifics of Basin Fill
sequence stratigraphy
stratigraphic interpretation, geologic time
megasequences, major unconformities
facies models
basin wide chronostratigraphic framework
tie to seismic markers
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Seismic Facies and Reservoir Architecture
(Fugelli and Olsen, 2005)
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Global Sea Level Fluctuations
(Vail et al, 1977)
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Geologic Time Scale
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Numerical Modeling of Basin History
Decompaction and “Backstripping”
Account for subsidence, thermal history, uplift
Example: North Sea
o Backstrip from present to near syn-rift
o Acknowledge two rift events
o Allow for Palaeocene uplift by Iceland plume
Java Stretch and Flex Decomp
Worked examples from the
Northern North Sea
multiple-rift basin
An Example of Basin
Modeling
http://www.badleys.co.uk
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Flex Decomp: Present-day cross-section
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Flex Decomp: Layers 1 and 2 removed
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Flex Decomp: Layers 3 and 4 removed460m Iceland Plume support applied at 55Ma
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Flex Decomp: Layers 5 and 6 removed
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Flex Decomp: Layer 7 removedBase Cretaceous at 140Ma close to syn-rift
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Petroleum System
appraisal of petroleum generating kitchen
source rocks, kerogen types
source rock maturity over time
fluid flow and pressure systems
migration path from source to trap
volume of generated hydrocarbons
reservoir quality and fairway assessment
porosity destruction and formation in subsurface
seal effectiveness
prediction of hydrocarbon composition
geochemical modeling/thermal maturity
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Petroleum System
Geologic components and processes necessary to generate and store
hydrocarbons, including a mature source rock, migration pathway,
reservoir rock, trap and seal. Appropriate relative timing of
formation of these elements and the processes of generation,
migration and accumulation are necessary for hydrocarbons to
accumulate and be preserved. The components and critical timing
relationships of a petroleum system can be displayed in a chart that
shows geologic time along the horizontal axis and the petroleum
system elements along the vertical axis. Exploration plays and
prospects are typically developed in basins or regions in which a
complete petroleum system has some likelihood of existing.
http://www.glossary.oilfield.slb.com/default.cfm
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The Petroleum System
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Petroleum Generation: Kitchen
maturation of organic matter hydrocarbon generation
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Kerogen
The naturally occurring, solid, insoluble organic matter that
occurs in source rocks and can yield oil upon heating. Typical
organic constituents of kerogen are algae and woody plant
material. Kerogens have a high molecular weight relative to
bitumen, or soluble organic matter. Bitumen forms from
kerogen during petroleum generation. Kerogens are described
as Type I, consisting of mainly algal and amorphous (but
presumably algal) kerogen and highly likely to generate oil;
Type II, mixed terrestrial and marine source material that can
generate waxy oil; and Type III, woody terrestrial source
material that typically generates gas.
Modeling thermal maturity of kerogen is important to
understand oil and gas generation
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Need for Engineering Component
There are significant hydrocarbons to be discovered
and produced in known basins and petroleum
systems; using existing infrastructure and re-
examining mature basins will continue to be
important
Provide reality check; subsurface pressure regime,
flow rates, risked reserve estimates
Apply additional tools: economics, fracture
stimulation, alternative development and sales
scenarios
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Basin Analysis and Petroleum Exploration
“... it is not implied that engineering concepts can replace geological methods in the search for oil and gas, or that the exploration geologist should become an expert in reservoir engineering. It is believed, however, that some reservoir engineering concepts may be used to implement geological methods and that a close cooperation between engineering and geological talent may contribute substantially to an exploration program.” (Arps, 1963)