Practical Well Log Standards for Acquisition Curves Paul Maton, POSC Jim Theriot, POSC Alan Doniger, POSC April 2005

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 for –Tools –Curves 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

PWLS Version 2 Objectives Clarify and refine Version 1 results Initial focus on two primary use cases: –Classify acquisition curve instances based on logging company mnemonics –Use curve classifications to search for relevant acquisition curve instances Additional areas of work –Recommended mnemonics for oil company generated curves: joined and interpreted –Classification of well log services and tools, e.g. for log header classification

Company: Service Class: Tool Series: Service-Channel Xref: Company Channel: Generic Service/Tool Class: Generic Curve Class:

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 Generic Name Object Property Technique Modifier(s) Function Property Class Name Parent Class Description Subset of

Curve Class Attributes 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 Generic Curve Name –Composite “tag” based the most important attribute value used only for the small subset of highest value types of curves, e.g. neutron, resistivity

Some Company Curve Classes RP66 Org. code MnemonicDescriptionValueCurve Class ( Property Type ) Units 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 MnemonicDescriptionValueCurve Class ( Property Type ) Units 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 Curve Class Generic Name:Gamma_Ray Object:Formation Property:Gamma Ray Technique:- 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 Curve Class Generic Name: Electromagnetic_Caliper Object:Borehole Property:Caliper Technique:Electromagnetic Modifier(s):- Function:-

Links PWLS General Web Link Property Type Browser Company Data Views Industry Data Views –Channel to Curve Class BrowserChannel to Curve Class Browser 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