HR: 0830h
AN: H21E-0893 [PDF]
TI: Improvements in Groundwater Flow Modeling Through the Integration of Resistivity Logs and Hydraulic
Conductivity
AU: Rahman, A
AF: Dept. of Civil and Environmental Engineering, Louisiana State University
3418D CEBA, Baton Rouge, LA 70803 United States
AU: White, C D
EM: cdwhite@lsu.edu
AF: Dept of Petroleum Engineering, Louisiana State University, Baton Rouge, LA 70803 United States
AU: * Willson, C S
EM: cwillson@lsu.edu
AF: Dept. of Civil and Environmental Engineering, Louisiana State University
3418D CEBA, Baton Rouge, LA 70803 United States
AB:
In this study cokriging is used to estimate hydraulic conductivity by using spatial cross correlation between hydraulic
conductivity and borehole geophysical data (a transform of the formation factor). Experimental pseudo cross variograms are
used instead of a crossvariogram because there are few locations where conductivity and formation data are both measured.
Uncertainty in the estimates of the experimental variogram is investigated using unconditional sequential Gaussian
realizations. Confidence intervals for the experimental variogram values have been calculated assuming variogram sills are
either normally, lognormally, or $chi^{2}$ distributed. Variogram models that show highest and lowest continuity within the
95% confidence limit are used for cokriging. The generated hydraulic conductivity field is then used in a high-resolution
groundwater model created using telescopic mesh refinement (TMR) from a regional flow model of the Chicot Aquifer in
southwestern Louisiana. Results are analyzed to assess variogram uncertainty on the groundwater flow model. Spatial images
and flow predictions using univariate models based on sparse conductivity data are compared with coregionalized models using
both conductivity and resistivity data, and the effects on model accuracy and robustness are discussed.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2003 Fall Meeting