1、Designation:D821521Standard Practice forStatistical Modeling of Uncertainty in Assessment of In-place Coal Resources1This standard is issued under the fixed designation D8215;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year o
2、f last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONAssessment of coal tonnage in-place is a fundamental factor in evaluating the commercial feasibilityof any deposit.Equal
3、ly important is an appraisal of the reliability that can be placed in the drilling dataavailable for an estimation.Traditional methods for quantitatively expressing uncertainty usereliability categories based simply on the distance between drill-hole data within the boundaries of acoal bed.A signifi
4、cant limitation of the distance approach is the inability to express uncertainty interms of how close a resource estimate is to the true value.This practice provides a geostatistical methodology to calculate the uncertainty of an in-place,coalresource estimate,both at the deposit and block level.In
5、addition to examining the drilling pattern bothwithin and outside the coal bed,other factors influencing the complexity in the geology are alsoconsidered,resulting in realistic estimates of uncertainty.Most importantly,the uncertainty isexpressed directly in tons of coal.Like other coal properties,u
6、ncertainty can be used to rank theresources in classes.1.Scope*1.1 This practice covers a procedure for quantitativelydetermining in-place tonnage uncertainty in a coal resourceassessment.The practice uses a database on coal occurrenceand applies geostatistical methods to model the uncertaintyassoci
7、ated with a tonnage estimated for one or more coalseams.The practice includes instruction for the preparation ofresults in graphical form.1.2 This document does not include a detailed presentationof the basic theory behind the formulation of the standard,which can be found in numerous publications,w
8、ith a selectionbeing given in the references(1-3).21.3 This practice should be used in conjunction with pro-fessional judgment of the many unique aspects of a coaldeposit.1.4 UnitsThe values stated in SI units are to be regardedas standard.The values given in parentheses after SI units areprovided f
9、or information only and are not considered standard.NOTE1All values given in parentheses after SI units are stated ininch-pound units.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establi
10、sh appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for
11、theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D621 Test Methods for Deformation of Plastics Under Load(Withdrawn 1994)4D653 Terminology Relating to Soil,R
12、ock,and ContainedFluidsD5549 Guide for Contents of Geostatistical Site Investiga-tion Report1This practice is under the jurisdiction of ASTM Committee D05 on Coal andCoke and is the direct responsibility of Subcommittee D05.07 on PhysicalCharacteristics of Coal.Current edition approved Oct.1,2021.Pu
13、blished October 2021.Originallyapproved in 2018.Last previous edition approved in 2020 as D8215 20.DOI:10.1520/D8215-21.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Cu
14、stomer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardC
15、opyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Internation
16、al Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1D5922 Guide for Analysis,Interpretation,and Modeling ofSpatial Variation in Geostatistical Site InvestigationsD5923 Guide for Selection of Kriging Methods in Geostatis-tical Site InvestigationsD5924 Guide for Selection of Simulation Approaches inGeostatistical Site Investigations2.2 ASTM Manuals,Monographs,and Data Series:5MNL11 Manual on Drilling,Sampling,andAnalysis of Coal