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. 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

7. 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

8. Lithology types in WITSML v1.3used by Mudlog and Core - 1 Andesite Anhydrite Arkose Basalt Breccia Calcarenite Calcilutite Calcisiltite Chalk Chert Clay Claystone Coal Conglomerate Diabase Diorite Dolerite Dolomite Dolomite, Calcareous Extrusive Rock (Volcanic) Feldspar Gabbro Glauconite Gneiss Granite Gravel Greenstones Greywacke Gumbo Gypsum Halite Igneous Intrusvie Rock (Plutonic) Lignite Limestone Limestone, Argillaceous

9. Qualifiers in WITSML v1.3used by Mudlog and Core - 1 Anhydrite Argillaceous Barite Belemnitic Bioturbated Bituminous Bryozoans Burrowed Calcareous Calcite concr Calcitic Carbonaceous Chalky Chamosite Chert Chlorite Concretions Conglomeratic Coral Crinoids Diatoms Dolomite concr Dolomite Stringer Dolomitic Feldspar Ferruginous Fissile Forams gen Fossil Frags Fossils gen Glauconite Glauconitic Gravelly Gypsiferous Halite

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

11. 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

12. Material Composition Property Mineral Rock Fossil Fluid Igneous Metamorphic Sedimentary 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

13. 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 Common attributes of Sedimentary Rocks - 1

14. 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 ] Examples [Note: Entire abbreviations, including parentheses, are in Square Brackets]

15. 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)

16. 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

17. Common attributes of Sedimentary Rocks - 4 • Post-depositional features • Consolidation, cementation, weathering • Diagenetic structures • Nodules and concretions

18. Igneous and Metamorphic Rocks • Minimal treatment given that these are not often of primary interest in E&P • Names, descriptions, abbreviations and adjectival forms of ~12 types in each category • Examples • Granite, (Gr), granitic • Schist, (Sch or sch???), schistose

19. 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

20. 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

21. Thank you for your attention More information from Paul Maton maton@posc.org +44 1932 828794 Alan Doniger doniger@posc.org +1 713 267 5124 Gary Masters masters@posc.org +1 713 267 5111