© copyright 2006 posc lithology reference standards houston 22 may 2006 paul maton (posc)

© Copyright 2006 POSC

Lithology Reference Standards

Houston 22 May 2006

Paul Maton (POSC)


Outline

• Introduction• Practical Taxonomy of Lithologies for E&P• Conclusions


Introduction• An initial Lithology Reference Data Standard

(Phase 1) was defined to support Mud Logging. This was published with WITSML 1.3 in early 2005.

• A plan to define a more comprehensive Lithology Reference Data Standard (Phase 2) during 2005 was deferred in favour of other priorities.

• We propose to form a Lithology Work Group to move this work forward.

• We seek participants with subject knowledge who support the premise that increased usage of industry reference standards, such as for Lithology, can improve data quality “at the source.” This can reduce ambiguity and the need for future remedial data clean-up efforts.


Introduction• The Work Group membership already

includes resources from HRH, ONGC, Shell, Statoil.– Interested parties should contact Paul Maton– Work Group Deliverables

• Review and contribute to draft specifications of lithological names, abbreviations, classifications.

• Conduct wider review among subject experts leading to publication as an industry reference standard.

• Encourage usage and participate in deployment activities.

• Please participate in this collaborative effort. • Contribute your experience and expertise. • Position your organization to obtain value

from the resulting industry standards and best practices.


Practical Taxonomy of Lithologies for E&P

• Geological reference sources contains many classification systems for the rocks encountered while exploring for hydrocarbons.

• Common practice is to use relevant portions of these sources.

• Seeking an industry standard – requires agreeing on one or more levels of

“practicality”.• Mud loggers tend to use a less extensive vocabulary than

is used for later petrographic analysis– And defining mappings between vocabularies in

use and the emerging industry standard


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


Case in Point

• Consider a large producing field– Over time, many wells may be drilled that

probably intersect a fairly consistent sequence of rock formations

• If different vocabularies are used by the same or, more likely, different geologists, problems may result– Similarities may appear to be differences– Real differences, for example, in mineral

composition, may not be recognized

• Corollary Objective: Unify the vocabulary used by geologists and data managers


Lithological Reference Sources

• 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

• Clastic Rock Classification: Pettijohn, Potter, and Siever (1987)• Carbonate Classification: Dunham (1962)

• Statoil– Current Listing of Lithological codes


Common Lithological Descriptors Used in Phase 1

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

Qualifiers

•Mineral content

•Fossil content

•Cement

•Grain size

•Sorting

•…~ 10 others


Phase 1 Lithology typesAndesite

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


Phase 1 Lithology typesLimestone, Dolomitic

Limestone, Sandy

Marble

Marl

Metamorphic Rocks

Mudstone

No Description

No Sample

Ophiolites

Peat

Phosphate

Potassium and Magnesium Salts

Quartzite

Rhyolite

Salt

Sand

Sandstone

Schist

Serpentine

Shale

Silicilyte

Silt

Siltstone

Slate

Syenite

Tillite (Diamictite)

Trachyte

Tuff

Ultrabasic


Phase 1 QualifiersAnhydrite

Argillaceous

Barite

Belemnitic

Bioturbated

Bituminous

Bryozoans

Burrowed

Calcareous

Calcite concr

Calcitic

Carbonaceous

Chalky

Chamosite

Chert

Chlorite

Concretions

Conglomeratic

Conglomeritic

Coral

Crinoids

Diatoms

Dolomite concr

Dolomite Stringer

Dolomitic

Feldspar

Ferruginous/Illite

Fissile

Forams gen

Fossil Frags

Fossils gen

Glauconite

Glauconitic

Gravelly

Gypsiferous

Halite


Phase 1 QualifiersKaolinite

Lignite

Limestone stringer

Lithic frags

Marly

Mica

Microfossils

No Description

None

Oolithic

Ostrocods

Pebbly

Pelletal

Pellets

Peloidal

Phosphates

Plant Remains

Potassium salt

Pyrite

Quartz

Radiolaria

Salty

Sandy

Shells

Siderite

Siderite concr

Silty

Spicular

Stylolitic

Tuffaceous

Tuffite


Plans for Phase 2 Lithological Classification

• Approach – Base Phase 2 on Shell ’95 standard legend– Add sedimentary rock types with names,

descriptions, abbreviations and adjectives– Add mineral types, names, abbreviations and

adjectives– Use consistent capitalization and appropriate

granularity– Possibly provide images of rocks as go-bys– Avoid over-complication

• Validation by practicing geologists– Work Group– From Industry


Material Classification

Material Composition

FluidRockMineral

MetamorphicIgneousSedimentary

Fossil

Property

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

(simplified from Epicentre data model)


Scope of Definitions

• Consolidated Rock Types– Lithology type, e.g. sandstone, limestone, shale– Definitions addressing mineral composition and

other pertinent characteristics– Abbreviation, e.g. sst, lst, sh– Adjective form, where appropriate, e.g. sandy,

calcareous, shaly– (possibly) typical specimen images

• Unconsolidated Rock Types – Name, abbreviation, and adjective form, where

appropriate, e.g. sand, gravel, mud


Scope of Definitions

• Minerals– Family name and individual name, e.g. feldspar,

plagioclase– Abbreviation, e.g. fld– Adjective form, where appropriate, e.g.

feldspathic

• Fossils– Name as used in E&P, e.g. foraminifera

• Usually at a high level in the Linnean classification system

– Abbreviation, foram– Adjective form, where appropriate, foraminiferal


Common Attributes of Sedimentary Rocks - 1

• Textural & Compositional– Grain size

• Modified Wentworth scale

– Sorting– Roundness– Sphericity– Compaction– Non-skeletal particles

(lithic fragments)– Pellets and grains– Skeletal particles,

parts and fragments of fossil material

• Porosity & Permeability– Qualitative and

quantitative– Fabric and non-fabric

selective– Archie classification

and types

• Color – Names, abbreviations

& qualifiers• Based on Munsell

system


Examples

• 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 ]

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



• 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)



• 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



• Post-depositional features– Consolidation, cementation, – Joints, fracturing and slickensiding– Weathering and oxidation– Diagenetic structures– Nodules and concretions

• Note: Values may be either or both qualitative and quantitative– To be practical, qualitative values will be proposed

in most cases with quantative values or ranges for important characteristics, e.g. grain size, density, porosity, and permeability, using recognized classifications


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


Outline

• Introduction• Practical Taxonomy of Lithologies for

E&P.• Conclusions


Phase 2: Next Steps

• Form Work Group of practising geologists from US, Europe, India (Volunteers sought) - 2Q2006

• Produce, review and revise specifications, including WITSML format XML enumeration file

- 3Q2006• Submit to WITSML TT as change request for

Version 1.3.n - 3Q2006• Conduct public review• Publish as POSC Reference Data Standard

- 3Q2006


Thank you!

More information fromPaul Maton [email protected] +44 1932 828794Alan Doniger [email protected] +1 713 267 5124Gary Masters [email protected] +1 713 267 5111

© copyright 2006 posc lithology reference standards houston 22 may 2006 paul maton (posc)

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