Page 217 - Reservoir Formation Damage
P. 217

198   Reservoir Formation Damage

                  Substituting Eqs.  10-66  and  67,  and rearranging  Eq.  10-65  becomes:


                                                                          (10-68)

                subject  to  the  initial  condition  given  by:


                                        •
                         = 4UW = 1, 2, •-, n, t = 0                       (10-69)
                  (<!>Pp/) y
                and  the  boundary  condition  given  by:


                                                                          (10-70)

                  The  mass  balance  of particles  captured  at the  pore  throats  is given by:


                  dm p /dt  = r r                                        (10-71)


               subject  to

                     = 0, t = 0                                          (10-72)
                  m p
                  The  mass  balance  of  indigeneous  particles  remaining  on  pore  surfaces is


                  dm* p/dt  = -r e                                        (10-73)

               subject  to

                  rn p=m po,t =                                          (10-74)

               where  m po  is  the  mass  of  particles  initially  available  on  pore  surface.
                  The  rate  of particle  entrainment by  the flowing phase  is  assumed both
               colloidally  and  hydrodynamically  induced.

                  r=oc  m l +oc,  |T — T  Ifl                            (10-75)
                           T
                   e   c  ' p  h  V  c )  s
               T  is  shear  stress.  a s  is  the  specific  pore  surface  area.  <*£,  is  the  colloidally
               induced  release  coefficient  given  by  (Khilar  and  Fogler,  1983):

                                                                         (10-76)
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