In cooperation with the Iranian Nuclear Society

Document Type : Research Paper

Authors

Abstract

Accurate modeling of omni-directional assay variograms for a deposit, plays a very significant role in the results of 3-D assay estimation and therefore its distribution within the estimation blocks. The high grade variations in uranium deposits render the significance of accurate variogram modeling. By this research, some models have been fitted to the experimental variograms with 0.5 meter composited uranium assay data, resulted from chemical analysis of drill core samples, from a uranium deposit. Reciprocal validation test has been applied for selection and evaluating the effect of suitable results, from multi-structural models in compare with other proper types of models. Validity study of the models is conducted through the reciprocal validation test, based on a series of criteria such as the average of differences and the difference of estimated values and raw data, in order to determine the validity accuracy of the fitted model. It is concluded that the dual-structure spherical model has a higher validity and furthermore reveals the significance of minor structures in variogram modeling, specifically for uranium deposits.

Highlights

 

  1. 1.    J. Caers and T. Zhang, “Multiple-point geostatistic: a quantitative vehicle for integrating geologic analogs into reservoir models,” AAPG Memoir (2002).

 

  1. 2.    A.A. Hasani Pak and M. Sharafodin, “Exploration data analysis,” Tehran University Press (2002).

 

  1. 3.    M.T. Tahmaseb Nezami, D. Jamali, M.R. Ghaderi, F. Mahdavi, H. Noroozi, M. Najafi, “Final estimation and evaluation report of block-i from anomaly-6 khoshoumi uranium deposit at the detailed stage,” (2007).

 

  1. 4.    A.A. Hasani Pak, “Geostatistics,” (1998).

 

  1. 5.    D.G. Krige, “The use of the principal component technique to define anisotropy details for spatial structures,” AAMP, Colorado School Mines, Colorado (1999).

 

  1. 6.    C.V. Deutsch, A.G. Journel, “GSLIB: geostatistical software library and user’s guide,” Oxford University Press, New York, 369 (1992).

 

  1. 7.    M. Masoudi, “Khoshoumi (central iran) mountain structural research,” M.Sc. Thesis (2006).

 

  1. 8.    R. Kerry, M.A. Oliver, “Determining the effect of asymmetric data on the variogram,” I. Underlying Asymmetry. Computers and Geosciences, Doi: 10. 1016/j. Cageo. 2007. 05. 008 (2007).

 

  1. 9.    R.M. Lark, “A comparison of some robust estimators of the variogram for use in soil survey,” European Journal of Soil Science 51(1), 137–157 (2000).


 


Keywords

  1.  

    1. 1.    J. Caers and T. Zhang, “Multiple-point geostatistic: a quantitative vehicle for integrating geologic analogs into reservoir models,” AAPG Memoir (2002).

     

    1. 2.    A.A. Hasani Pak and M. Sharafodin, “Exploration data analysis,” Tehran University Press (2002).

     

    1. 3.    M.T. Tahmaseb Nezami, D. Jamali, M.R. Ghaderi, F. Mahdavi, H. Noroozi, M. Najafi, “Final estimation and evaluation report of block-i from anomaly-6 khoshoumi uranium deposit at the detailed stage,” (2007).

     

    1. 4.    A.A. Hasani Pak, “Geostatistics,” (1998).

     

    1. 5.    D.G. Krige, “The use of the principal component technique to define anisotropy details for spatial structures,” AAMP, Colorado School Mines, Colorado (1999).

     

    1. 6.    C.V. Deutsch, A.G. Journel, “GSLIB: geostatistical software library and user’s guide,” Oxford University Press, New York, 369 (1992).

     

    1. 7.    M. Masoudi, “Khoshoumi (central iran) mountain structural research,” M.Sc. Thesis (2006).

     

    1. 8.    R. Kerry, M.A. Oliver, “Determining the effect of asymmetric data on the variogram,” I. Underlying Asymmetry. Computers and Geosciences, Doi: 10. 1016/j. Cageo. 2007. 05. 008 (2007).

     

    1. 9.    R.M. Lark, “A comparison of some robust estimators of the variogram for use in soil survey,” European Journal of Soil Science 51(1), 137–157 (2000).