Page 177 - Petrophysics
P. 177

1 50   PETROPHYSICS: RESERVOIR ROCK PROPERTIES



                           10000

                            1000
                               I
                                   I   I   11lllll
                            100

                               1
                             10
                              c
                             1

                            0.1
                              1              10             100            1000
                                          Mean Hydraulic Radius, (kH/+)”*
                 Figure  3.35. Relationship  between  mean  hydraulic  radius d  m  and  vertical
                permeability in lower Devonian sandstone  from Illizi Basin, Algeria.





                 Relationship Between KH and K,

                   Clean Sandstone Formations
                   Tiab et al. correlated horizontal permeability and vertical permeability
                 for the lower Devonian sandstone from Illizi Basin, Algeria, as shown in
                 Figure 3.35, and obtained the following correlation [44,46] :
                 kv = 0.0429 (E)                                              (3.97)
                                    2.4855





                 where:


                       k,  = vertical permeability, mD.
                       kH = horizontal permeability, mD.
                          = effective porosity, fraction.


                 This equation indicates a strong relationship detween the mean ..ydraulic
                 radius  and  vertical  permeability.  Figure  3.36  indicates  an  excellent
                 correlation between the calculated values of  kv, using Equation 3.97,
                 and core-measured kv .

                   Figure 3.37 shows a plot of  core vertical permeability values versus
                 the  product of  the  mean  grain  diameter and mean  hydraulic  radius.
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