Page 138 - Open-Hole Log Analysis and Formation Evaluation
P. 138

Formation

                                                                        10
                                                                                     Factor
                                                                                      Liitit      100   t   mee   i   1000   124
                   A
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                                                 1
              the
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                                   6.18).
                                     where
                                          FIGURE
                           do
                produce
                                     7
                               only
                             mations;
          constant.
                   proper
                                          6.17
                                     is
                                 Because
            and thus.  at
                           not
                     PRACTICAL
                                                                                                                     METHODS
                             but
                some
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              observation
                             in
                           work
                                 Archie’s
          Variations
                           as
                   marriage
              that
                               conductive
                             shal
                          See
                                                 :  100  10   P   Tom  T   = 4   Intercept       :           Increasing  m  (Hard  Rock)       OF   RESULTS   OF  ANALYSIS  AND  APPLICATION
                           well.
                                     saturation
              when
                                                          -
                                 model
                spectacular
              a
                                          Generalized  F-to-¢
                     PETROPHYSICS
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                  between
                                               Porosity
                                               ¢
                             ons
                             formations
                                               %
          of  porosity  ate
                results.
                                     exponent
                                                          Decreasing
                                 considers
                                                          a
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                                     and
                One
                                          Relationship.
                                 the
              is
          normal
                                     is

            irreducible  water saturation, the
                               relationships
                  petrophysics
                of
                             and where
                                                          (Clastics)
                the
              above

                  and
                               work
                                     usually
              the
            product
                                 electrolyte
          on  a local
                most
                  log
                                     set
                               well
                                 in
            of  ¢
                                     to
                               in
          scale,
                                 the
                                     2
                             connate water
            and
                             is
              transition
                  analysis
                               clean
                                     (see
            S,,
                           “So
          owing
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                interesting
              zone,
                               for-
                                     fig.
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            isa
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                   water
                             water
                         @
                                              figure
                                                                                                                     THE
                                                                         FIGURE
                                                      This
                                                  of
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                                                                   changes
          60%,
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                                                    analyzed
                                                             are
                                            saturation
                                                                 laid  down
                                                                         6.18
                                                zone.
                                                               a
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                                              6.19,
               production
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                                                    on
                     surprisingly
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                                                                                    qT
                                    Reservoirs
                         X S,,
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                 permeability,
                           (Ru bo/ Row)
                                                                         S,,
                                                                                      .  1  -   n   decreasing   (clastics)       %  Sw   wet)  10  —  n   =  (oil   100  =   OF   ROCK/FLUID   SYSTEMS   125
                                        Points.in
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             by
                                                                                                                     PHYSICS
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                                                Figure
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                                                6.19
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                                                                                  0.01
                           particular
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                                                      practical
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                                                illustrates
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                                                  the
                             expected
                     saturations
                                                    for
                                                             throats.
                                   characterized
                                                           more
                               at
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          no
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              This
                                                               of  the
                         irreducible
                                                the
                                            Figure
                                        plot
                           fluids
                       low-porosity,
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                                                                   environment  at
                                              linear  scales
                                   by
                                                                         Of Ro/R,  and
                                 basis
                                        to
                                          irreducible
                                                                        n.
                                                               pore
                                                        product.
          more
                     be
                                                           water
                                            6.20
            taught
                                                                   the
                                              and
                                   the
                                 for
                                        the
                                                    porosity
                                                  presence
              salient
                                                      application.
                                                          can
                                   @
                             depending
                                                                 and  owing  to  subsequent  diagenesis.
            (1)
                moderate
                                                  or
                                                             Either  way,
                           present.
                         saturation
                               irreducible
                                                    and
                   formations  with
                                        right
                                   X
                                                                 If,
                                                                                    I
                                                               throats
                             on
              fact
                                                                                  0.1
                                            shows
                                                          be
                                                             the
                                                      After
          troubles
                                                                   time  the
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                                                                                  °
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              is
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                                                               are
                             the
                                   S,,;
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                values
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                   good
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                           Figure
                                                          held
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                                       of  the
          and
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                                                  absence
              all
                                                             mean
                of
            less
                                                          in
                                                      zone
                                                Note
                                                  of
                                            similar
                                                               small
          (2)
                           6.21
                                                  a
                     without
                               saturation,
              too
                S,,,
                                                      has
                                                          the
                                   product,
            than
          do
                                                             radius
                                            plot
                         number
                                                               ones
                     fear
                                                    saturation,
              often
          not
                                            on
                                          saturation  plot  ona  straight
                                       irreducible
                                                  transi-
                                                that,.on
                                              irreducible
                                 production
                             mobility  ratio
                               some
                       low-permeability  formation,
                           shows
                                   and
                                                      been
                water
                                                            ris
                                                          pore
            50%
                  porosity  and
                                                                   sediments  were
                                                    a
                                                               or
                                                                 locally,  porosity  is
                         of
                                                                                    4
                                                                                  1

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