Geological Modeling of Stratified Deposits · Modeling Operations – Parameters Splitting –...

Copyright © Gemcom Software International Inc.

The mining solutions you expect. From the people you trust.

Geological Modeling of Stratified DepositsDamian Baranowski – Principal Consultant (Asia)


Grid Model vs Block Model2

Grid Model Block Model


Grid ModelModel generated directly from data source (borehole and geometry)Grids honour data and follow trends smoothlyQuick model updateMaintain seam sequence

Block ModelManual digitising of points on sections Generate surface from strings (DTM or Wireframing) Block assigningProblem with seam overlapping and cross-overs

3

Grid Model vs Block Model

Cross sectionSeam A

Surfaces are fitted automatically to data

Grids are regularised surface incorporatng trending (smooth) They are NOT triangles.

Seam B


Grid ModelAdequately represents thin seamsMore accurate modelsBetter handle variation of seam thicknessDesign for deposit large in lateral extentBetter represents faulted and folded structureMore accurate volume reporting Quicker validation

Block ModelLess accurate modelsSub-blocking is memory intensiveMuch higher storage capacity required Long processing time (impractical)Not suitable for faultingInaccurate modeling leads to incorrect assessment of project value

4

Grid Model vs Block Model


5

Modeling Operations – Ply Splitting

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

SS SS SSSS

SS

MD

MD

MD

MD

MD

MD

MD

MD

MD

MD

MD

BS BS BS BS BS

A

A1

A2

A11

A12

A21

A22

A111

A112

A12 A12

A112

A111

A21

A22

A2

BH1 BH2 BH3 BH4 BH5


6

Modeling Operations – Ply Splitting

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

SS SS SSSS

SS

MD

MD

MD

MD

MD

MD

MD

MD

MD

MD

MD

BS BS BS BS BS

A111(E)

A12

A21

A22

A111

A112

A12 A12

A112

A111

A21

A22

A112(E)A111(E)

A112(E)

A111(E)

A112(E)

A12(E)

A21(E)

A22(E)

A12(E)

A21(E)

A22(E)

A21(E)

A22(E)

BH1 BH2 BH3 BH4 BH5


7

Modeling Operations – Father/Son

CO

CO

CO

CO

CO

CO

CO

CO

CO

SSSS SS SS SS

MDMD

MD

MD

MDBS

BS BS

BS

BS

B BU

BH1 BH2 BH3 BH4 BH5

BB

BU

B

BL

B

BU

BL

CO

CO

SS


8

Modeling Operations – Father/Son

CO

CO

CO

CO

CO

CO

CO

CO

CO

CO

SSSS SS SS SS

MDMD

MD

MD

MDBS

BS BS

BS

BS

B BU

BH1 BH2 BH3 BH4 BH5

BL

BB

BU

B

BL

B

BU

BL

SS

CO

BU(E)

BU(E)

BL(E)BL(E)


9

Modeling Operations – Interpolator

CO

SS

CL

BS

A

BH1

BH2

B

C

D

CL

CO

CO

MD

CO

CO

SS

CL

BS

A

B

C

D

CL

CO

CO

MD

CO

BH3

CO

SS

A

CCO

CO

SS

A

BH4

CCO

MD

CL

CL

BS

BH5

B

C

CL

CO

CO

MD

CL

BH6

B

C

D

CL

CO

CO

MD

CO

MD

CL


10

Modeling Operations – Interpolator

CO

SS

CL

BS

A

BH1

BH2

B

C

D

CL

CO

CO

MD

CO

CO

SS

CL

BS

A

B

C

D

CL

CO

CO

MD

CO

BH3

CO

SS

A

B(I)

C

D(I)

CO

SS

A

BH4

B(I)

C

D(I)

CO

MD

CL

BS

BH5

B

C

CL

CO

CO

MD

CL

A(I)

BH6

B

C

D

CL

CO

CO

MD

CO

MD

A(I)

D(I)

CO

CLCL


11

Modeling Operations – Parameters

Splitting– validation– average or area factors – borehole & seam selection– data classification

Interpolator – searching parameters (scan distance, sectors, max. points)– borehole & seam selection– seam priority– setting seam thickness to zero– data classification

Father/Son– validation – area selection – borehole & seam selection– data classification


12

Modeling Operations – User input

User’s interpretation is required (important factor)The results cannot be more accurate than input dataGood visualisation – helps with the interpretationCheck result graphically and numerically


Fault Modeling13

Coal deposits are subject of complex faultingCritical aspect of modelingModeling of inclined or curved faults in normal or reverse environmentInput data: fault strings (or fault surface) with dip and throw


14

Fault ModelingUn-faulting boreholes in chronological sequenceModeling operations, generating modelRe-faulting the model to its current faulted position.


Growth Technique Features

Best suited for Structural modelling (Seam roofs and floors)May be used for quality attributes (thickness, ash etc)Honours the data pointsExtrapolated values (estimates outside data value range)Expansion outside data area (by distance or “Fill Area”)Declusters data (Averaging and redistribution)Produces accurate and smooth displays (Contour maps etc)Various data type support (spots, break lines, faults, trends)

15


Growth Technique – Interpolation Methods

Growth Technique uses a combination of interpolation methods1. Inverse Distance estimation,2. Secant plane estimation and3. Tangent plane estimations at each mesh point

Stage 1 (Regional grid generation) uses methods 1 and 2Stage 3 (Final gridding) uses methods 2 and 3.**

The Secant Plane is determined using a least squares fit using data from the surrounding 8 sectorsThe Tangent Plane is determined from a first order differential equation from immediate “known” points

** Where there is lack of data (< 5 sectors) Stage 3 will resort to Methods 1 and 2.

16


Growth Technique – Interpolation Methods17

Previously Estimated points

Tangent Plane Estimations

Secant Plane Estimation

Tangent Planes

Estimation Point

Secant Plane

Actual Surface


Growth Technique – Input data18


Growth Technique – Initial Gridding 19


Growth Technique – Final Gridding 20


Growth Technique – Final Grid21


Thank you for your attention 22

To learn more, visit www.gemcomsoftware.com

http://www.gemcomsoftware.com/

Geological Modeling of Stratified Deposits · Modeling Operations – Parameters Splitting –...

Documents

Transcript of Geological Modeling of Stratified Deposits · Modeling Operations – Parameters Splitting –...