Lithology Reference Standards

1
Lithology Reference Standards

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

2
Outline

• Introduction
• Business Drivers
• Use cases
• Resources
• Current status
• Future requirements
• Conclusions

3
Motivation and Background

• WITSML Mud Log revision
• Lithology classification sought to enhance mud
  log data transfers
• Resources identified and available
• Shell standard legend (1996, rev 2002) widely
  respected
• 2004 sub-set produced as part of global
  standardization process
• Reports, logs, maps, geological cross-sections
  etc. from both wellsite, laboratory, and office
  work sites
• NPD Blue Book
• Uniformity of geological terminology within
  Regulatory Area

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
• Use same nomenclature and classifications in
  services and software for many customers
• Cost savings in software engineering and
  maintenance

5
Use Cases

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

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Requirements

• Three phases
• Use in end-2004 WITSML Version 1.3 Mudlog
  specification
• Revised lithological classification
• Next WITSML Mudlog version 1.3.1, late 2005?
• Improve or simplify existing specification(s)

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Available Resources

• Landmark Graphics
• List of Lithologies with
• Norwegian Petroleum Directorate
• Reporting requirements for Digital Well Data
  Lithological Codes
• Shell
• 1995 Standard Legend
• 2004 Revision
• Statoil
• Current Listing of Lithological codes

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Common Descriptors

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

• Mineral content
• Cement
• Grain size
• Sorting

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Qualifiers in WITSML Mudlog v1.3

• lithName
• lithCode
• lithPC
• lithClass
• grainType
• grainSize
• dunhamClass (limestones)

• color
• texture
• hardness
• roundness
• Sorting
• Visible porosity
• Permeability
• density

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Lithology types in WITSML Mudlog v1.3

• Anhydrite
• Arkose
• Breccia
• Chalk
• Chert
• Clay
• Coal
• Conglomerate
• Dolomite
• Dolomite, calcareous

• Extrusive rock (volcanic)
• Feldspar
• Glauconite
• Gravel
• Greywacke
• Gypsum
• Intrusive rock (igneous)
• limestone

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Lithology types in WITSML Mudlog v1.3 - continued

• Limestone, argillacous
• Limestone, dolomitic
• Limestone, sandy
• Marl
• Metamorhic rock
• Ophiolites
• Peat
• Phosphate
• Potassium magnesium salts

• Salt
• Sand
• Sandstone
• Schist
• Shale
• Silicilyte
• Silt
• Tillite
• Tuff

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Revised lithological classification

• Seeking requirements from geologists
• Possible approaches
• Extensive use of Shell 95
• More sedimentary rock types with names,
  abbreviations and adjectives
• More mineral types, names, abbreviations and
  adjectives
• Provide descriptions of rock types
• Possibly provide images of rocks as go-bys

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WITSML Mudlog version 1.3.1

• Seeking requirements from geologists
• Possible approaches
• Extend use of Shell 95, improve current
  lithology list
• More sedimentary rock types with names, but test
  need for abbreviations and adjectives
• More mineral types, names, but test need for
  abbreviations and adjectives
• Keep specification simple, within bounds of
  observational capabilities

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Participant discussion

• Comments and suggestions re-
• Business case?
• Resources needed reviewers,
• Proposed approaches?
• Recommendations, Next steps?
• Any other aspects?

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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