tailieunhanh - Reservoir Formation Damage Episode 2 Part 9

Tham khảo tài liệu 'reservoir formation damage episode 2 part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 432 Reservoir Formation Damage The rate of deposition in the nonplugging tubes can be expressed by Civan 1994 1995 1996 - v 14-76 subject to the initial condition 0 14-77 Here 0 Tw Tcr 14-78 0 Tw Tcr 14-79 For simplification purposes Civan 1995 assumed that organic deposits are sticky and therefore once deposited they cannot be removed. Consequently the second term in Eq. 14-76 can be dropped. Mansoori 1997 tends to support this argument. Although Leontaritis 1998 considered the possibility of erosion of deposits it is not apparent if he actually implemented this possibility in his calculational steps. kd and ke are the surface deposition and mobilization rate constants. T e is the fraction of the uncovered deposits estimated by I exp -te 14-80 Tcr is the minimum shear stress necessary to mobilize the surface deposits. Tw is the wall shear-stress given by the Rabinowitsch-Mooney equation Metzner and Reed 1995 k 8v D n 14-81 in which the interstitial velocity V is related to the superficial velocity u by v w ộ 14-82 and the mean pore diameter is given by D Kv ị np 12 14-83 Formation Damage by Organic Deposition 433 The permeabilities of the plugging and nonplugging pathways are given by the following empirical relationships Civan 1994 KP KP. exp - k- 4 exp - 14-84 and Knp K p v y2 14-85 Then the average permeability of the porous medium is given by K fpKp fnpKnp 14-86 The superficial flows in the plugging and nonplugging pathways are given respectively by up uKpIK Unp uKnp K 14-87 14-88 The total superficial flow is given by Gruesbeck and Collins 1982 u f u fll J p p J np np 14-89 Considering the simultaneous deposition of paraffins and asphaltenes ep and tnp in Eqs. 14-62 through 69 denote the sum of the paraffins and asphaltenes that is p F F p p par p asp F F F np np par x- np asp 14-90 14-91 Description of Fluid and Species Transport The preceding treatment of the porous media impairment phenomena implies that the suspended particle and dissolved species .