Practical Well Log Standards Paul Maton, POSC Jim Theriot, POSC

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

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 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! 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 Hard to find up to date information in public domain Isolated lists, complex language Expert (petrophysicist) and generalist users have different requirements

Information Overload - Business Value Most Commonly Loaded Rarely Loaded Loaded Curve Names Load Frequency High Business Value Most oil company customers only load a small sub-set of curves into their data stores Medium Business Value Loaded for specialist applications Note: Business Value does not take account of usage. It deals with the ‘average’ case

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...

PWLS Version 1 Classified ~2500 curves for ~100 tools from 3 logging companies Defined business value – high, medium, low Classifications published at

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

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

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

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

Company, Industry Data ‘Company’ nomenclature ? Company-defined codes, mnemonics company-specific dynamic cryptic (?) ‘Industry’ nomenclature Industry-agreed classes common name common definition (definition exists) stable (managed)

Channel, Curve and Property ‘Company’ nomenclature Maps to Company Channel Class RP66 Org code Co. Mnemonic Description Business value Classification Quantity & UoM ‘Industry’ nomenclature Well Log Curve Class Name Object Property Technique Modifier(s) Function Property Class Name Parent Class Description Maps to

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

Some Company Curve Classes RP66 Org. code MnemonicDescriptionValueClassificationUnits Class 150GRGamma RayHIGHGamma_RayAPI_Gamma_Ray 440SPSpontaneous PotentialHIGHSpontaneous_ Potential Low_Electric_ Potential 150CALCaliperHIGHCaliperCylinder_ Diameter 150RDDeep resistivityMEDDeep_ Laterolog_ Resistivity Resistivity 150RSShallow resistivityMEDShallow_ Laterolog_ Resistivity Resistivity 150RMLLMicro-laterolog resistivityHIGHMicro_ Laterolog_ Resistivity Resistivity

More Company Curve Classes RP66 Org. code MnemonicDescriptionValueClassificationUnits Class 150RMLLMicro-laterolog resistivityHIGHMicro_ Laterolog_ Resistivity Resistivity 150CNCBorehole Corrected Compensated Neutron Porosity HIGHNeutron_ Porosity Porosity 150ZDENCompensated Bulk Density HIGHBulk_DensityDensity 150ZCORBulk Density CorrectionHIGHBulk_Density_ Correction Density 150PEPhoto-electric cross section HIGHPhotoelectric_ Factor

Channel, Curve Example 1 ‘Company’ nomenclature Maps to Company Channel Class RP66 Org code: 150 Co. Mnemonic: GR Description: Gamma Ray Classification: Gamma_Ray Units Class: API_Gamma_Ray ‘Industry’ nomenclature Well Log Curve Class Name:Gamma_Ray Object:Formation Property:Gamma Ray Technique:(Spectrometry) Modifier(s):- Function:-

Channel, Curve Example 2 ‘Company’ nomenclature Maps to Company Channel Class RP66 Org code: 440 Co. Mnemonic: PCAL Description: Caliper from Phase Shift Imbalance Business Value: High Classification: Electromagnetic _Caliper Units Class: Cylinder_Diameter ‘Industry’ nomenclature Well Log Curve Class Name:Electromagnetic_Caliper Object:Borehole Property:Caliper Technique:Electromagnetic Modifier(s):- Function:-

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

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

Conclusions Version 2 published at Active usage encouraged Future direction and evolution through PWLS SIG –Version 2.1 planned for release by year-end 2004 PWLS SIG meetings: –Stavanger June –Houston June Additional info from or contact or