Practical Well Log Standards

1
Practical Well Log Standards

• Paul Maton, POSCJim Theriot, POSC

2
Outline

• Business Drivers, Challenges
• Phase 1 outcomes
• Phase 2 approaches, results, examples
• Next Steps

3
Well Logs Business Issues

• Huge numbers of curves (information overload)
• Most oil company customers only load a small
  sub-set of
• curves into their data stores

• Complex naming at BOTH Curve and Tool level
• Confusing even to petrophysicists
• Others got lost years ago!

• Hard to find up to date information in public
  domain
• Isolated lists, complex language

Expert (petrophysicist) and generalist users have
different requirements
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Information Overload - Business Value
Note Business Value does not take account of
usage. It deals with the average case
Load Frequency
High Business Value Most oil company customers
only load a small sub-set of curves into their
data stores
Most Commonly Loaded
Medium Business Value Loaded for specialist
applications
Rarely Loaded
Loaded Curve Names
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Log Data Management Challenges

• Nomenclature
• Logging companies Vocabularies
• Oil companies Dictionaries
• Classification
• Tool types
• Curve types
• Value
• Who uses ...
• Which logs...
• How often ...
• For what ...

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PWLS Version 1

• Classified 2500 curves for 100 tools from 3
  logging companies
• Defined business value high, medium, low
• Classifications published at www.posc.org/technica
  l/PWLS/pwls_10.htm

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PWLS Version 2 Objectives

• Clarify Curve Class and Classification
• Emphasize two primary use cases
• Classify curve instances based on logging company
  mnemonics
• Use curve classifications to search for relevant
  curve instances

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Users and Usage Patterns - General

• Geologist, Geophysicist, Engineer
• Get log(s) by Field, Block, Well, Log type
• Store interpreted work
• Petrophysicist
• Get Curve set for editing, processing, analysis
• Log Data Manager
• QC and load old, and/or new logs
• Classify logs and compile log catalogue

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Users and Usage Patterns PWLS V2

• Geoscientist, Engineer, Log Data Manager
• Understand and classify log curves in industry
  terms starting from mnemonics on log header
• Logging Company Dictionary Administrator
• Submit company catalogue (initial or replacement)
  to POSC
• Submit incremental change or addition to POSC
• POSC
• Maintain company and industry (classification)
  data
• Accept new and revised data from logging companies

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Approach

• Understand nomenclatures
• Identify, share and adopt good practices
• Never change original document or its data
• Produce and maintain the standards
• Logical, generic, high-level classification
• Map logging and oil companies dictionaries to
  the generic classification
• Make it easily understood and available
• Keep it up-to-date this needs Oil Co. support

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Company, Industry Data
Company nomenclature
Industry nomenclature
Company-defined codes, mnemonics
Industry-agreed classes
?
common name common definition (definition
exists) stable (managed)
company-specific dynamic cryptic (?)
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Channel, Curve and Property
Industry nomenclature
Companynomenclature
Maps to
Maps to
13
Curve Type Queries

• What is the object (or thing) whose properties we
  are measuring?
• Formation, casing, cement, wellbore, acquisition,
  etc.
• What (pure) property of the object are we
  measuring?
• Density, porosity, velocity, etc.
• What technique are we using to make the
  measurement (with the tool)?
• Neutron, acoustic, etc.
• Modifiers (or qualifiers) qualifying the (pure)
  Property
• Deep / shallow maximum / average / minimum, etc.
• Function
• Mathematical derivation / calculation, e.g.
  ratio, std. deviation

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Some Company Curve Classes
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More Company Curve Classes
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Channel, Curve Example 1
Industry nomenclature
Companynomenclature
Company Channel Class
Well Log Curve Class
Maps to
Name Gamma_Ray Object Formation
Property Gamma Ray
Technique (Spectrometry)Modifier(s) -Function
-
RP66 Org code 150Co.
Mnemonic GRDescription
Gamma RayClassification Gamma_Ray
Units Class API_Gamma_Ray
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Channel, Curve Example 2
Company nomenclature
Industry nomenclature
Company Channel Class
Well Log Curve Class
Maps to
Name Electromagnetic_Caliper Object Borehole
Property Caliper
Technique Electromagnetic Modifier(s) -
Function -
RP66 Org code 440Co.
Mnemonic PCALDescription
Caliper from Phase Shift
Imbalance Business Value
HighClassification Electromagnetic
_Caliper Units Class
Cylinder_Diameter
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Links

• Property Type Browser
• Company Data Views
• Industry Data Views
• Schema for PWLS Reference Data

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Current Focus Usage

• Users
• Oil companies
• Log analysts, Consultants
• Data management repositories, companies
• Suppliers
• Logging contractors (Acquisition, Processing )
• Software developers and vendors
• Evolve
• User communities use PWLS and provide feedback
• Revise specifications and implementations
• Maintain Property, Curve and Tool catalogues

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Conclusions

• Version 2 published at http//www.posc.org/technic
  al/PWLS/pwls_20.htm
• Active usage encouraged
• Future direction and evolution through PWLS SIG
• Version 2.1 planned for release by year-end 2004
• PWLS SIG meetings
• Stavanger 15-16 June
• Houston 23-24 June
• Additional info from www.posc.org or contact
  theriot_at_posc.org or maton_at_posc.org