Page 320 - Reservoir Formation Damage
P. 320

300   Reservoir Formation Damage

                where  h is  the  formation  thickness.  Thus,  invoking  Eq.  12-125  into
                Eq.  12-124  yields



                           M-  (q
                                                                         (12-126)
                         2nhk(r

                The  pressure  differences  over  the  filter  cake  and  porous  media  can  be
                expressed  by  integrating Eq.  12-126,  respectively,  as  (Civan,  1999b):


                                                  1   1
                                                                         (12-127)
                                               2
                                          (2nh)   r.  r,.,



                                  In  *  I                               (12-128)
                                          (2nh) 2
                           2nhk f

                The  densities  and  instantaneous flow  rates  of  the  suspensions  of  fine
                particles  flowing  through  the  cake  matrix  and  porous  formation  are
                assumed  the  same.  Then,  adding  Eqs.  12-127  and  12-128,  and  rear-
                ranging  and  solving, yields  (Civan,  1999b) for  Darcy  flow  \fo f  =p c =0j:


                                                                        (12-129a)


                and  for  non-Darcy  flow:


                             = —-£— =       Mslurr
                               2nrji
                                                                       (12-129b)

                            2a


                in  which


                  ^-    P                    J__l                        (12-130)
                                 £.  r,,     r,..  r.
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