Download Lithology Reference Standards

Lithology Reference Standards
Houston 22 May 2006
Paul Maton (POSC)
© Copyright 2006 POSC
Outline
• Introduction
• Practical Taxonomy of Lithologies for E&P
• Conclusions
© Copyright 2006 POSC
Introduction
• An initial Lithology Reference Data Standard
(Phase 1) was defined to support Mud Logging.
This was published with WITSML 1.3 in early
2005.
• A plan to define a more comprehensive Lithology
Reference Data Standard (Phase 2) during 2005
was deferred in favour of other priorities.
• We propose to form a Lithology Work Group to
move this work forward.
• We seek participants with subject knowledge who
support the premise that increased usage of
industry reference standards, such as for
Lithology, can improve data quality “at the
source.” This can reduce ambiguity and the need
for future remedial data clean-up efforts.
© Copyright 2006 POSC
Introduction
• The Work Group membership already includes
resources from HRH, ONGC, Shell, Statoil.
– Interested parties should contact Paul Maton
– Work Group Deliverables
• Review and contribute to draft specifications of lithological
names, abbreviations, classifications.
• Conduct wider review among subject experts leading to
publication as an industry reference standard.
• Encourage usage and participate in deployment activities.
• Please participate in this collaborative effort.
• Contribute your experience and expertise.
• Position your organization to obtain value from
the resulting industry standards and best
practices.
© Copyright 2006 POSC
Practical Taxonomy
of Lithologies for E&P
• Geological reference sources contains many
classification systems for the rocks encountered
while exploring for hydrocarbons.
• Common practice is to use relevant portions of
these sources.
• Seeking an industry standard
– requires agreeing on one or more levels of
“practicality”.
• Mud loggers tend to use a less extensive vocabulary than is
used for later petrographic analysis
– And defining mappings between vocabularies in use
and the emerging industry standard
© Copyright 2006 POSC
Business Drivers
• Operator Point of View
– Standard vocabulary and semantics for lithologies will
improve the following processes
•
•
•
•
Assimilating results of outsourced work
Information exchanges with partners, regulators
Reduction of ambiguity and uncertainty in data
Common nomenclature used for mudlog, core and other rock
sample descriptions
• Service Company Point of View
– Enable use of same nomenclature and classifications in
services and software for many customers
• Cost savings in software engineering and maintenance
• Cost savings and consistency in information produced
© Copyright 2006 POSC
Case in Point
• Consider a large producing field
– Over time, many wells may be drilled that probably
intersect a fairly consistent sequence of rock formations
• If different vocabularies are used by the same or,
more likely, different geologists, problems may
result
– Similarities may appear to be differences
– Real differences, for example, in mineral composition,
may not be recognized
• Corollary Objective: Unify the vocabulary used by
geologists and data managers
© Copyright 2006 POSC
Lithological Reference Sources
• Landmark Graphics
– List of Lithology Classes with Qualifiers and Symbol Codes
• Norwegian Petroleum Directorate
– Reporting requirements for Digital Well Data: Lithological
Codes
• Shell
– 1995 Standard Legend
• Clastic Rock Classification: Pettijohn, Potter, and Siever (1987)
• Carbonate Classification: Dunham (1962)
• Statoil
– Current Listing of Lithological codes
© Copyright 2006 POSC
Common Lithological Descriptors
Used in Phase 1
• Primary and secondary lithologies
• Use of the following characteristics as Qualifiers
•Mineral content
•Fossil content
•Cement
•Grain size
•Sorting
•…~ 10 others
© Copyright 2006 POSC
Phase 1 Lithology types
Andesite
Coal
Granite
Anhydrite
Conglomerate
Gravel
Arkose
Diabase
Greenstones
Basalt
Diorite
Greywacke
Breccia
Dolerite
Gumbo
Calcarenite
Dolomite
Gypsum
Calcilutite
Dolomite,
Calcareous
Halite
Calcisiltite
Chalk
Chert
Clay
Claystone
Extrusive Rock
(Volcanic)
Feldspar
Gabbro
Glauconite
Gneiss
© Copyright 2006 POSC
Igneous
Intrusvie Rock
(Plutonic)
Lignite
Limestone
Limestone,
Argillaceous
Phase 1 Lithology types
Limestone,
Dolomitic
Potassium and
Magnesium Salts
Siltstone
Limestone, Sandy
Quartzite
Syenite
Marble
Rhyolite
Tillite (Diamictite)
Marl
Salt
Trachyte
Metamorphic Rocks
Sand
Tuff
Mudstone
Sandstone
Ultrabasic
No Description
Schist
No Sample
Serpentine
Ophiolites
Shale
Peat
Silicilyte
Phosphate
Silt
© Copyright 2006 POSC
Slate
Phase 1 Qualifiers
Anhydrite
Chalky
Dolomitic
Argillaceous
Chamosite
Feldspar
Barite
Chert
Ferruginous/Illite
Belemnitic
Chlorite
Fissile
Bioturbated
Concretions
Forams gen
Bituminous
Conglomeratic
Fossil Frags
Bryozoans
Conglomeritic
Fossils gen
Burrowed
Coral
Glauconite
Calcareous
Crinoids
Glauconitic
Calcite concr
Diatoms
Gravelly
Calcitic
Dolomite concr
Gypsiferous
Carbonaceous
Dolomite Stringer
Halite
© Copyright 2006 POSC
Phase 1 Qualifiers
Kaolinite
Pelletal
Siderite
Lignite
Pellets
Siderite concr
Limestone stringer
Peloidal
Silty
Lithic frags
Phosphates
Spicular
Marly
Plant Remains
Stylolitic
Mica
Potassium salt
Tuffaceous
Microfossils
Pyrite
Tuffite
No Description
Quartz
None
Radiolaria
Oolithic
Salty
Ostrocods
Sandy
Pebbly
Shells
© Copyright 2006 POSC
Plans for Phase 2 Lithological Classification
• Approach
– Base Phase 2 on Shell ’95 standard legend
– Add sedimentary rock types with names, descriptions,
abbreviations and adjectives
– Add mineral types, names, abbreviations and adjectives
– Use consistent capitalization and appropriate granularity
– Possibly provide images of rocks as go-bys
– Avoid over-complication
• Validation by practicing geologists
– Work Group
– From Industry
© Copyright 2006 POSC
Material Classification
Material
Property
Mineral
Sedimentary
Rock
Composition
Fossil
Igneous
Fluid
Metamorphic
Property and Composition are attribute sets inherited by Minerals and Rocks etc,
but the sets have additional attributes in, and appropriate to, each sub-class
(simplified from Epicentre data model)
© Copyright 2006 POSC
Scope of Definitions
• Consolidated Rock Types
– Lithology type, e.g. sandstone, limestone, shale
– Definitions addressing mineral composition and other
pertinent characteristics
– Abbreviation, e.g. sst, lst, sh
– Adjective form, where appropriate, e.g. sandy,
calcareous, shaly
– (possibly) typical specimen images
• Unconsolidated Rock Types
– Name, abbreviation, and adjective form, where
appropriate, e.g. sand, gravel, mud
© Copyright 2006 POSC
Scope of Definitions
• Minerals
– Family name and individual name, e.g. feldspar,
plagioclase
– Abbreviation, e.g. fld
– Adjective form, where appropriate, e.g. feldspathic
• Fossils
– Name as used in E&P, e.g. foraminifera
• Usually at a high level in the Linnean classification system
– Abbreviation, foram
– Adjective form, where appropriate, foraminiferal
© Copyright 2006 POSC
Common Attributes of Sedimentary
Rocks - 1
• Textural & Compositional
– Grain size
• Modified Wentworth scale
–
–
–
–
–
Sorting
Roundness
Sphericity
Compaction
Non-skeletal particles
(lithic fragments)
– Pellets and grains
– Skeletal particles, parts
and fragments of fossil
material
© Copyright 2006 POSC
• Porosity & Permeability
– Qualitative and
quantitative
– Fabric and non-fabric
selective
– Archie classification and
types
• Color
– Names, abbreviations &
qualifiers
• Based on Munsell system
Examples
• Sorting
–
–
–
–
–
–
–
–
–
unsorted
[((srt))]
very poorly sorted
[((srt))]
poorly sorted
[(srt)]
poorly to moderately well
sorted
[(srt)-srt]
moderately well sorted [srt]
well sorted
[srt]
very well sorted
[srt]
unimodally sorted
[unimod srt]
bimodally sorted
[bimod srt]
• Compaction
–
–
–
–
–
–
–
not compacted
[not cmp]
slightly compacted [(cmp)]
compacted
[ cmp ]
strongly compacted [cmp]
friable
[ fri ]
indurated
[ ind ]
hard
[ hd ]
• Color
– green [ gn ], dark [ dk ]
[Note: Entire abbreviations, including parentheses, are in Square Brackets]
© Copyright 2006 POSC
Common Attributes of Sedimentary
Rocks - 2
• Accessory Minerals
– References extensible list and abbreviations of mineral
class names
– e.g.: Feldspar (Fld)
• Fossil content
– References extensible list and abbreviations of fossil
class names
– e.g.: Bryozoa (Bry)
© Copyright 2006 POSC
Common Attributes of Sedimentary
Rocks - 3
• Stratification and Sedimentary Features
–
–
–
–
–
–
–
–
–
Bedding thickness and appearance
Character of base of bed
Large non-bedded features: lens, bioherm etc
Cross bedding and lamination
Ripplemarks
Planar laminations
Graded bedding
Soft sediment deformation
Syn-depositional features
© Copyright 2006 POSC
Common Attributes of Sedimentary
Rocks - 4
• Post-depositional features
–
–
–
–
–
Consolidation, cementation,
Joints, fracturing and slickensiding
Weathering and oxidation
Diagenetic structures
Nodules and concretions
• Note: Values may be either or both qualitative and
quantitative
– To be practical, qualitative values will be proposed in most
cases with quantative values or ranges for important
characteristics, e.g. grain size, density, porosity, and
permeability, using recognized classifications
© Copyright 2006 POSC
Igneous and Metamorphic Rocks
• Minimal treatment given that these are not often
of primary interest in E&P
• Names, descriptions, abbreviations and adjectival
forms of ~12 types in each category
– Examples
– Granite, (Gr), granitic
– Schist, (Sch or sch???), schistose
© Copyright 2006 POSC
Outline
• Introduction
• Practical Taxonomy of Lithologies for E&P.
• Conclusions
© Copyright 2006 POSC
Phase 2: Next Steps
• Form Work Group of practising geologists from
US, Europe, India (Volunteers sought) - 2Q2006
• Produce, review and revise specifications,
including WITSML format XML enumeration file
- 3Q2006
• Submit to WITSML TT as change request for
Version 1.3.n
- 3Q2006
• Conduct public review
• Publish as POSC Reference Data Standard
- 3Q2006
© Copyright 2006 POSC
Thank you!
More information from
Paul Maton
Alan Doniger
Gary Masters
© Copyright 2006 POSC
[email protected]
[email protected]
[email protected]
+44 1932 828794
+1 713 267 5124
+1 713 267 5111