A Practical Lithology Reference Standard

1
A Practical Lithology Reference Standard

• Paul Maton (POSC)and Gary Masters (POSC)

2
Outline

• Introduction
• Business Objectives, Motivation and Work flows
• Resources
• Lithology in WITSML 1.3
• Enhanced Lithological Classification
• Conclusions

3
Objectives and Requirements

• Provide evolving dictionary in XML of
  lithological terminology for use in
• end-2004 WITSML Version 1.3 Mudlog and Core
  specifications
• revised lithological classification, 2Q05
• next WITSML Mudlog version 1.3.1, late 2005?
• Improve or simplify existing specification(s)
• Lithological terminology needed for POSC exchange
  standards
• Easy maintenance and extensibility

4
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

5
Use Cases

• Mudlog
• Rapid wellsite description of rock cuttings
• Core analysis
• Full description of petrographic and quantitative
  properties (porosity, permeability, density,
  etc.)
• Detailed Rock description and analysis
• Optical and electron microscopy analysis

6
Outline

• Introduction
• Business Objectives, Motivation and Work flows
• Resources
• Lithology in WITSML 1.3
• Enhanced Lithological Classification
• Conclusions

7
Available Resources

• 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
• Statoil
• Current Listing of Lithological codes
• Geological Literature

8
Outline

• Introduction
• Business Objectives, Motivation and Work flows
• Resources
• Lithology in WITSML 1.3
• Enhanced Lithological Classification
• Conclusions

9
Common Descriptors for WITSML Mud-Log

• Primary and secondary lithologies
• Use of the following characteristics as Qualifiers

• Mineral content
• Fossil content
• Cement
• Grain size
• Sorting
• 10 others

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Lithology types in WITSML v1.3used by Mudlog and
Core - 1
Andesite Anhydrite Arkose Basalt Breccia Calcareni
te Calcilutite Calcisiltite Chalk Chert Clay Clays
tone
Coal Conglomerate Diabase Diorite Dolerite Dolomit
e Dolomite, Calcareous Extrusive Rock
(Volcanic) Feldspar Gabbro Glauconite Gneiss
Granite Gravel Greenstones Greywacke Gumbo Gypsum
Halite Igneous Intrusvie Rock (Plutonic) Lignite L
imestone Limestone, Argillaceous
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Lithology types in WITSML v1.3used by Mudlog and
Core - 2
Quartzite Rhyolite Salt Sand Sandstone Schist Serp
entine Shale Silicilyte Silt Siltstone Slate
Limestone, Dolomitic Limestone,
Sandy Marble Marl Metamorphic Rocks Mudstone No
Description No Sample Ophiolites Peat Phosphate Po
tassium and Magnesium Salts
Syenite Tillite (Diamictite) Trachyte Tuff Ultraba
sic
12
Qualifiers in WITSML v1.3used by Mudlog and Core
- 1
Anhydrite Argillaceous Barite Belemnitic Bioturbat
ed Bituminous Bryozoans Burrowed Calcareous Calcit
e concr Calcitic Carbonaceous
Chalky Chamosite Chert Chlorite Concretions Conglo
meratic Coral Crinoids Diatoms Dolomite
concr Dolomite Stringer
Dolomitic Feldspar Ferruginous Fissile Forams
gen Fossil Frags Fossils gen Glauconite Glauconiti
c Gravelly Gypsiferous Halite
13
Qualifiers in WITSML v1.3used by Mudlog and Core
- 2
Kaolinite Lignite Limestone stringer Lithic
frags Marly Mica Microfossils No
Description None Oolithic Ostrocods Pebbly
Pelletal Pellets Peloidal Phosphates Plant
Remains Potassium salt Pyrite Quartz Radiolaria Sa
lty Sandy Shells
Siderite Siderite concr Silty Spicular Stylolitic
Tuffaceous Tuffite
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Outline

• Introduction
• Business Objectives, Motivation and Work flows
• Resources
• Lithology in WITSML 1.3
• Enhanced Lithological Classification
• Conclusions

15
Enhanced Lithological Classification

• Current approaches
• Base on Shell 95 standard legend
• Add sedimentary rock types with names,
  descriptions, abbreviations and adjectives
• Add mineral types, names, abbreviations and
  adjectives
• Possibly provide images of rocks as go-bys
• Avoid over-complication
• Produce draft classification and taxonomy from
  available resources
• Validation by practising geologists

16
Material Classification
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
17
Common attributes of Sedimentary Rocks - 1

• Textural Compositional
• Grain size
• Sorting
• Roundness
• Sphericity
• Compaction
• Non-skeletal particles(lithic fragments)
• Pellets and grains

• Porosity Permeability
• Qualitative and quantitative
• Fabric and non-fabric selective
• Archie classification and types
• Color
• Names, abbreviations qualifiers

18
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
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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)

20
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

21
Common attributes of Sedimentary Rocks - 4

• Post-depositional features
• Consolidation, cementation, weathering
• Diagenetic structures
• Nodules and concretions

22
Igneous and Metamorphic Rocks

• Minimal treatment given that these are not often
  of primary interest in EP
• Names, descriptions, abbreviations and adjectival
  forms of 12 types in each category
• Examples
• Granite, (Gr), granitic
• Schist, (Sch or sch???), schistose

23
Outline

• Introduction
• Business Objectives, Motivation and Work flows
• Resources
• Lithology in WITSML 1.3
• Enhanced Lithological Classification
• Conclusions

24
Issues to be addressed

• Aliases
• Abbreviations
• Capitalisation
• Granularity, particularly of qualitative
  descriptors
• Images
• Validation input needed from Geologists in Oil,
  Service and Software companies
• Pilot implementation

25
Next steps

• Collect feedback from April informal SIGs
• Requirements, use cases, and availability of
  specialists
• Review meetings with SIG member specialists in
  May
• Revise and publish Standard by end June
• Promote and assist pilot implementations in
  2H2005

26
Conclusions

• XML based Lithologic vocabulary is under
  development and will be partially implemented for
  Mud logging part of WITSML 1.3
• Design is for usage in wider rock description and
  analysis, including wellsite and laboratory work
• Draft specification will be posted in 2Q2005,
  reviewed by SIG Member geological experts, then
  revised and published by POSC

27
Thank you for your attention

• More information from
• Paul Maton maton_at_posc.org 44 1932 828794
• Alan Doniger doniger_at_posc.org 1 713 267 5124
• Gary Masters masters_at_posc.org 1 713 267 5111