Application of Three-Dimensional Direct Least Square Method for Ellipsoid Anisotropy Fitting Model of Highly Irregular Drill Hole Patterns
-
Published:2022-08-04
Issue:15
Volume:12
Page:7848
-
ISSN:2076-3417
-
Container-title:Applied Sciences
-
language:en
-
Short-container-title:Applied Sciences
Author:
Muchtadi-Alamsyah Intan,Heriawan Mohamad Nur,Rachmaputri Gantina,Rahmadiantri Elvira,Lawiyuniarti Made Putri
Abstract
Ellipsoid or geometric anisotropy is a widely used method in geostatistical analysis to obtain variograms with different ranges in different directions (azimuth) and relatively similar sill variance. Ellipsoid anisotropy is indispensable in mining when a resource geologist intends to understand the spatial continuity of variables related to any geological controls of the mineralization. For example, when dealing with mineralization related to tabular deposits, a porphyritic deposit with an irregular drill hole pattern (fan drilling), three-dimensional ellipsoid anisotropy is quite challenging to model. We assume that the variables’ spatial continuity is isotropic, and we model it using a three-dimensional omnidirectional variogram. However, if the actual spatial continuity of the variables has a three-dimensional anisotropy, then assuming a three-dimensional omnidirectional variogram will generate imprecise resource estimations. This study presents a new practical three-dimensional ellipsoid model-fitting method using a three-dimensional direct least square method. We investigated a zinc (Zn) dataset from thousands of irregular drill hole patterns from a porphyritic system associated with skarn orebodies for the case study.
Funder
Institut Teknologi Bandung
Subject
Fluid Flow and Transfer Processes,Computer Science Applications,Process Chemistry and Technology,General Engineering,Instrumentation,General Materials Science
Reference11 articles.
1. Bayesian modeling and inference for geometrically anisotropic spatial data;Ecker;Math. Geol.,1999
2. Modelling of geometric anisotropic spatial variation;Budrikaite;Proceedings of the 10th International Conference MMA2005&CMAM2,2006
3. Anisotropy Models for Spatial Data
4. Determination of anisotropy of spatial correlation structure in a three-dimensional permeability field accompanied by shallow faults