Coal Exploration SCI Rev1

COAL EXPLORATIONCOAL EXPLORATION

SBU MineralSBU MineralPT SUCOFINDO (PERSERO)PT SUCOFINDO (PERSERO)

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EXPLORATION STAGESEXPLORATION STAGES


Relationship Relationship –– Exploration Results, Exploration Results, Resources, ReservesResources, Reserves


Coal Resources and Coal ReservesCoal Resources and Coal Reserves

A Coal ResourceA Coal Resource is that part of a deposit with is that part of a deposit with reasonable prospects for eventual economic extraction. reasonable prospects for eventual economic extraction. The location, quantity, quality, geological characteristics The location, quantity, quality, geological characteristics and continuity of a Coal Resource are known, estimated and continuity of a Coal Resource are known, estimated or interpreted, from Points of Observation.or interpreted, from Points of Observation.

A Coal ReserveA Coal Reserve is the economically mineable part of a is the economically mineable part of a Measured or Indicated Coal Resource.Measured or Indicated Coal Resource.


StageStage ofof Coal ExplorationCoal Exploration

Exploration proceeds in stages. There is a “decision point” Exploration proceeds in stages. There is a “decision point” between each stage: results are evaluated and a decision made between each stage: results are evaluated and a decision made whether or not to continue. For example early reconnaissance maywhether or not to continue. For example early reconnaissance mayshow the area is too folded, with very steep dips; or that the rshow the area is too folded, with very steep dips; or that the rank ank of the coal is too low.of the coal is too low.

The early stage is low cost, covering large areasThe early stage is low cost, covering large areas

If exploration results are good, the target area becomes more If exploration results are good, the target area becomes more focussed and more expensive exploration methods are used.focussed and more expensive exploration methods are used.

Advanced coal exploration is costly, using drilling; but at thisAdvanced coal exploration is costly, using drilling; but at this stage stage the chances of success should be high, so risks are low.the chances of success should be high, so risks are low.


Research Research StageStageBase map of digital regional geology (1:250,000)Base map of digital regional geology (1:250,000)Petroleum exploration wellsPetroleum exploration wellsLocation of coal outcropsLocation of coal outcropsLocation of previous coal boreholes if any; with drilling resultLocation of previous coal boreholes if any; with drilling resultssTopographic data; digital terrain model if availableTopographic data; digital terrain model if availableRemote sensing imageryRemote sensing imageryRegional geophysicsRegional geophysicsInfrastructure (roads; ports)Infrastructure (roads; ports)National parks or nature reserves;National parks or nature reserves;Coal Tenements (KP, Coal COWCoal Tenements (KP, Coal COW, IUP, IUP))


Research Research –– GIS ModelGIS Model

Look for trends of coal quality or Look for trends of coal quality or thicknessthicknessLook for errors in regional mappingLook for errors in regional mappingLook for areas that are open (not held Look for areas that are open (not held by other companies) for the wrong by other companies) for the wrong reasons; ereasons; e..g because there has been g because there has been an error in the regional mapping.an error in the regional mapping.There will then be a list of questions to There will then be a list of questions to be solved by field workbe solved by field work


Location of Coal BasinLocation of Coal Basin

1.1. Meulaboh BasinMeulaboh Basin2.2. Central Sumatera BasinCentral Sumatera Basin3.3. South Sumatera BasinSouth Sumatera Basin4.4. Tarakan BasinTarakan Basin

5.5. Kutai BasinKutai Basin6.6. Barito BasinBarito Basin7.7. Pasir BasinPasir Basin


Sumatera Sumatera -- Coal Bearing FormationCoal Bearing Formation

Meulaboh Basin:Meulaboh Basin: Fm. Fm. TututTututCentral Sumatera Central Sumatera Basin:Basin: Fm. Sawahlunto Fm. Sawahlunto & Fm. Sihapas& Fm. SihapasSouth Sumatera South Sumatera Basin:Basin: Fm. Kasai, Fm. Fm. Kasai, Fm. Muara Enim, Fm. Air Muara Enim, Fm. Air Benakat, Fm. Talang Benakat, Fm. Talang Akar, Fm. LahatAkar, Fm. Lahat


Reconnaissance and Mapping StagesReconnaissance and Mapping Stages

to confirm the regional geology; to confirm the regional geology;

to locate and sample known coal to locate and sample known coal outcrops to determine the coal outcrops to determine the coal rank and some aspects of the rank and some aspects of the quality; in some cases coal quality; in some cases coal thickness may be assessed. The thickness may be assessed. The dips can be measured, so for dips can be measured, so for example if the area is too strongly example if the area is too strongly folded, that can be determined folded, that can be determined immediately, without going into a immediately, without going into a more detailed program.more detailed program.


REMOTE SENSING before the mappingREMOTE SENSING before the mapping

Remote sensing Remote sensing interpretation is done by interpretation is done by specialized consultantsspecialized consultants

Results are used to guide the Results are used to guide the location and focus of field location and focus of field mappingmapping

The interpretation will usually The interpretation will usually give more focussed detail in give more focussed detail in the areas of interest, than the the areas of interest, than the regional geological maps.regional geological maps.


Field MappingField Mapping

In Indonesia, with heavy rainfall In Indonesia, with heavy rainfall and the typical coal measure and the typical coal measure topography, reconnaissance & topography, reconnaissance & field mapping will provide a lot of field mapping will provide a lot of detail on the local geology, and detail on the local geology, and coal outcrops may be located & coal outcrops may be located & sampled. sampled.

In drier areas, outcrop may be In drier areas, outcrop may be limited to occasional road limited to occasional road cuttings. In these situations, cuttings. In these situations, regional oil & gas drilling, or regional oil & gas drilling, or stratigraphic boreholes, may be stratigraphic boreholes, may be initial regional sources of data initial regional sources of data


SamplingSampling

Systematic channel sampling is done on good outcropsSystematic channel sampling is done on good outcropsThe channel should be cut back into fresh coalThe channel should be cut back into fresh coal“Ply by ply” sampling“Ply by ply” sampling


Detailed Field MappingDetailed Field Mapping

Detailed mapping is done over the main Detailed mapping is done over the main target area; etarget area; e..g at 1:10,000 or 1:5000 g at 1:10,000 or 1:5000

This mapping may use a remote sensing This mapping may use a remote sensing interpretation as a guide.interpretation as a guide.

Locations determined using GPS.Locations determined using GPS.

Coal outcrops should be recorded in Coal outcrops should be recorded in detail. Attempts should be made to follow detail. Attempts should be made to follow coal along strike if possible to check coal along strike if possible to check continuity.continuity.

Measure coal thickness; strike; dip; take Measure coal thickness; strike; dip; take samples samples

Record coal lithotypes; partings;Record coal lithotypes; partings;


Detailed Field MappingDetailed Field MappingMapping gives an initial Mapping gives an initial estimate of seam thickness; estimate of seam thickness; seam correlation; and a seam correlation; and a preliminary estimate of the coal preliminary estimate of the coal quality. However coking quality. However coking properties may be unreliable. properties may be unreliable. Calorific value may be too low Calorific value may be too low and moisture too high. Vitrinite and moisture too high. Vitrinite reflectance is reliable.reflectance is reliable.

There may be recognizable There may be recognizable marker beds such as limestone; marker beds such as limestone; basalt; or even the top of basalt; or even the top of basement, that will be useful in basement, that will be useful in assessing the overall assessing the overall correlation. correlation.

GEOLOGICAL REPORT with all GEOLOGICAL REPORT with all results and maps. results and maps.


Test PitsTest Pits


TrenchingTrenching

In some areas trenching may be done, where the topography and In some areas trenching may be done, where the topography and depth of weathering are suitable.depth of weathering are suitable.


End of the Mapping Phase End of the Mapping Phase –– Scout DrillingScout Drilling

The mapping phase often ends with The mapping phase often ends with a scout drilling program. The rig is a scout drilling program. The rig is typically light weight and portable, typically light weight and portable, as access is difficult at this stage, as access is difficult at this stage, and the drilling is typically shallow and the drilling is typically shallow drilling near outcrops.drilling near outcrops.

Several widely spaced boreholes Several widely spaced boreholes are drilled. They will:are drilled. They will:

1.1. Confirm the coal qualityConfirm the coal quality2.2. Confirm seam thickness and the dipConfirm seam thickness and the dip3.3. Provide good information on drilling Provide good information on drilling

conditions and costs, to help plan conditions and costs, to help plan the next phase, drilling.the next phase, drilling.


The Report The Report

MAPS are prepared showing all the exploration results MAPS are prepared showing all the exploration results –– outcrops, strikes, dips, coal outcrops, strikes, dips, coal sample points; coal thickness; etc, and any revised interpretatisample points; coal thickness; etc, and any revised interpretations on the regional ons on the regional geology. A database is needed, in GIS format. A logical scale shgeology. A database is needed, in GIS format. A logical scale should be used. The ould be used. The map should include the KP boundaries.map should include the KP boundaries.

A REPORT is prepared. A checklist should be used, to ensure all A REPORT is prepared. A checklist should be used, to ensure all points are covered. A points are covered. A suitable check list is provided later in this report. It starts suitable check list is provided later in this report. It starts with previous work and with previous work and regional geology, and ends with the recommendations and work proregional geology, and ends with the recommendations and work program for the gram for the next phase.next phase.

Management needs to be aware of the most likely size and qualityManagement needs to be aware of the most likely size and quality of the resource of the resource target or the Base Case. However a potential range should also btarget or the Base Case. However a potential range should also be provided e provided –– a a Worst Case and Best Case, for the potential Worst Case and Best Case, for the potential tonnestonnes of coal and for the coal quality. of coal and for the coal quality. Things like distance to a barge port are also important.Things like distance to a barge port are also important.

Exploration results including coal thickness, dips and quality, Exploration results including coal thickness, dips and quality, should be presented in should be presented in tables. All data and ranges should be provided tables. All data and ranges should be provided –– not just the good results, this will be not just the good results, this will be a biased report. a biased report.

Management also needs to be aware of the likely Work Program andManagement also needs to be aware of the likely Work Program and Budget for the Budget for the next phase, so that an informed “YES/NO” decision can be made atnext phase, so that an informed “YES/NO” decision can be made at this point.this point.


Drilling PhaseDrilling PhasePlan the program. It should continue to be staged, with initial Plan the program. It should continue to be staged, with initial widewide--spaced drilling; followed by a YES/NO decision point; Surveying spaced drilling; followed by a YES/NO decision point; Surveying and and topographic mapping; for large scale surface mining, reliable topographic mapping; for large scale surface mining, reliable topographic maps are needed for estimates of overburden volumes.topographic maps are needed for estimates of overburden volumes.

Drilling, on a grid or traverse pattern. Drilling, on a grid or traverse pattern.

Good core recovery in coal is very important.Good core recovery in coal is very important.


Drilling PhaseDrilling Phase

Determine coal thickness and depth; Determine coal thickness and depth; core the coal seam, whichcore the coal seam, which will be will be sampled for analysis.sampled for analysis.

Downhole geophysical logging of all Downhole geophysical logging of all boreholes boreholes

Determine the location of the coal Determine the location of the coal subcropsubcrop by oxidation line drillingby oxidation line drilling

GEOLOGICAL REPORT with all results GEOLOGICAL REPORT with all results and maps. and maps.


Drilling PhaseDrilling Phase


Cutting DescriptionCutting Description


Core DescriptionCore Description


Core HandlingCore Handling


Core RecoveryCore Recovery

Good core recovery is essential for reliable quality dataGood core recovery is essential for reliable quality data

Use downhole geophysical logs to determine the location & amounUse downhole geophysical logs to determine the location & amount of core t of core loss.loss.

The Australian Guidelines to the JORC Code advise normally > 95The Australian Guidelines to the JORC Code advise normally > 95% core % core recoveryrecovery

It starts with the selection of the drilling contractor; and wiIt starts with the selection of the drilling contractor; and with the drilling th the drilling contract itself.contract itself.

Consistent high core recovery can be difficult in higher rank cConsistent high core recovery can be difficult in higher rank coals, which oals, which can be more friable.can be more friable.

Consider moving to PQ core if recovery is poor with HQ / HMLC. Consider moving to PQ core if recovery is poor with HQ / HMLC. This size This size may be needed anyway for the volume and size needed for float / may be needed anyway for the volume and size needed for float / sink sink testing of higher ash coals.testing of higher ash coals.

Triple tube core barrel for better undisturbed coreTriple tube core barrel for better undisturbed core


Core PhotographyCore Photography

Core should be photographed while in the core box or in split tuCore should be photographed while in the core box or in split tubes bes before sampling. This gives a permanent record of the appearancebefore sampling. This gives a permanent record of the appearanceof the coal and partings, and of fractures , cleats and dip planof the coal and partings, and of fractures , cleats and dip planes, es, and will be used by the Mining Engineer and geotechnical specialand will be used by the Mining Engineer and geotechnical specialists ists during the assessment of the resource.during the assessment of the resource.


Sampling Sampling -- PrecautionsPrecautions

Coal should be sampled as soon as possible after logging the coaCoal should be sampled as soon as possible after logging the coal.l.

For low rank coals, great care must be taken to avoid the coal dFor low rank coals, great care must be taken to avoid the coal drying at all rying at all before it gets to the laboratory. The coal must be stored in doubefore it gets to the laboratory. The coal must be stored in double sealed ble sealed plastic as soon as possible, and kept out of direct sunlight. Ifplastic as soon as possible, and kept out of direct sunlight. If the coal is the coal is allowed to dry, the asallowed to dry, the as--received moisture will be too low; and the asreceived moisture will be too low; and the as--received heating values will be too high. This can result in majreceived heating values will be too high. This can result in major errors or errors when estimating quality and therefore the likely sales price of when estimating quality and therefore the likely sales price of the coal.the coal.

Coking coals can lose some coking properties quickly (especiallyCoking coals can lose some coking properties quickly (especially fluidity). fluidity). Again coal with likely coking properties should be sampled as soAgain coal with likely coking properties should be sampled as soon as on as possible, and if there is a delay in transport to a laboratory fpossible, and if there is a delay in transport to a laboratory for analysis, or analysis, should be stored on site in a freezer. should be stored on site in a freezer.

The Report on the drilling program should mention precautions taThe Report on the drilling program should mention precautions taken to ken to ensure that the analysis is reliable, including the treatment ofensure that the analysis is reliable, including the treatment of samples and samples and precautions taken to ensure against coal drying.precautions taken to ensure against coal drying.


Ply samplingPly sampling

Coal properties tend to follow laterally Coal properties tend to follow laterally along strike.along strike.There will typically be significant There will typically be significant quality differences within the seam.quality differences within the seam.After the initial drilling phase, the After the initial drilling phase, the project geologist will typically correlate project geologist will typically correlate and name the seams; and will decide and name the seams; and will decide a typical ply naming system also.a typical ply naming system also.Later sampling will then follow these Later sampling will then follow these plies.plies.This depends on accurate correlation This depends on accurate correlation of the plies.of the plies.If plies are thick then subIf plies are thick then sub--ply samples ply samples can also be taken; but these should can also be taken; but these should also follow stratigraphic boundaries so also follow stratigraphic boundaries so that they are consistent.that they are consistent.

PlyGeological roof

1

2 Mining Bench Roof

3

6Mining Bench Floor

6

Geological Floor

Mining Bench

Mudstone

4 Non‐coal Parting

7

5Parting

PlyGeological roof

1

2 Mining Bench Roof

3

6Mining Bench Floor

6

Geological Floor

Mining Bench

Mudstone

4 Non‐coal Parting

7

5Parting


Core SamplingCore Sampling


Reconciliation with downhole Reconciliation with downhole geophysical logsgeophysical logs

The coal sample intervals must be reconciled The coal sample intervals must be reconciled with the downhole geophysical logs. Before with the downhole geophysical logs. Before doing this, we must be sure that the doing this, we must be sure that the geophysical depths are correct and that geophysical depths are correct and that there is no systematic depth error. there is no systematic depth error.

The geologists log is adjusted so that the The geologists log is adjusted so that the roof, floor and internal stone bands, match roof, floor and internal stone bands, match the geophysical log anomalies.the geophysical log anomalies.

The amount of core recovery is then The amount of core recovery is then determined; and the location of the core loss determined; and the location of the core loss can be decided.can be decided.

Core recovery should be estimated as soon Core recovery should be estimated as soon as possible. Most drilling contracts require a as possible. Most drilling contracts require a rere--drill if the core recovery is less than 95% drill if the core recovery is less than 95% within the major coal seams.within the major coal seams.


DatabaseDatabase

Data must be entered into a reliable database. Data must be entered into a reliable database.

As the project advances and becomes larger, As the project advances and becomes larger, with more data, it will be necessary to assign with more data, it will be necessary to assign responsibilities for database management eresponsibilities for database management e..g g the right to enter data; the right to make the right to enter data; the right to make changes. changes.

As noted, original data is kept. This includes As noted, original data is kept. This includes original paper data entry sheets, as these can original paper data entry sheets, as these can be used to check for data entry errors later. be used to check for data entry errors later. Original survey data and surveyors notes must Original survey data and surveyors notes must also be retained, and may be needed for an also be retained, and may be needed for an audit of the survey.audit of the survey.

Database validation will be neededDatabase validation will be needed


Geological Geological ModellingModelling

Geological modelling is done within a Geological modelling is done within a computerized modelling system such as computerized modelling system such as the Stratmodel system within the the Stratmodel system within the Minescape software (Mincom).Minescape software (Mincom).

The software allows the user to define The software allows the user to define the seam names and seam relationships the seam names and seam relationships (e(e..g splitting); minimum parting g splitting); minimum parting thickness; location and orientation of thickness; location and orientation of faults; depth of weathering.faults; depth of weathering.

The model can then be used as input to The model can then be used as input to a mineable reserve and quality a mineable reserve and quality estimation.estimation.


Mine Engineering ProcessMine Engineering Process


Thank YouThank You


Coal UtilizationCoal Utilization


PeatPeat


LigniteLignite


SubSub--bituminous bituminous --AnthraciteAnthracite

Coal Exploration SCI Rev1

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