Recharge systems for protecting and enhancing groundwate

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TOPIC 3
Modelling aspects and groundwater hydraulics
Invasion profile
The mud filtrate invasion phenomena is utilized to predict the permeable intervals, and to calculate the unaltered
formation resistivity which is used to determine the aquifer water salinity.
Figure 4. Invasion profile from the different depth
of investigation resistivity measurements indicate conductive intervals
Hydraulic conductivity
Nuclear Magnetic Resonance logging
Nuclear Magnetic Resonance logging (CMR)* relies on a strong permanent magnetic field that is applied to the
formation and aligns the hydrogen nuclei parellel to its direction; a radio frequency antenna is then used to measure
the time it takes for the nuclei to return back to their initial condition.
This relaxation time constant is decomposed in to its individual components and the distribution of the time
constant T2 is plotted. The strength of the signal depends on the amount of hydrogen nuclei in the formation, and
since hydrogen is present primarily in water, the strength of the signal, or the area under the T2 distribution curve
is a representation of the total porosity.
ISMAR 2005 ■ AQUIFER RECHARGE ■ 5th International Symposium ■ 10 –16 June 2005, Berlin