tailieunhanh - Reservoir Formation Damage Episode 2 Part 1

Tham khảo tài liệu 'reservoir formation damage episode 2 part 1', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 232 Reservoir Formation Damage _ c3 np C np- c in which 6 np G Unp u 10-189 10-190 because all flow goes through the plugging pathways. The fact that the cumulative amounts of deposits reach certain limiting values as shown in Figure 10-25 is indicative of attainment of such equilibrium conditions. Note however that the amounts shown in Figure 10- 25 are the cumulative amounts including the amount of deposits in the plugging pathways. Therefore at equilibrium e e e p 10-191 11 Constant-Pressure-Difference Tests Constant pressure tests are more representative of the producing well conditions. Gruesbeck and Collins 1982 flowed suspensions of glass particles through sand packs at constant pressure differences by applying relatively high pressure difference to a column of fine sand pack and relatively low pressure difference to a column of coarse sand pack. The results are reported in Figure 10-27. In the fine sand packs they observed more deposition near the injection side and the mean permeability of the sand Figure 10-27. Constant pressure deposition and entrainment of 5-10 mm diameter glass beads in a pack of a 177-210 mm diameter sand grains subjected to 900 kPa m pressure gradient and b 250-297 mm diameter sand grains subjected to 450 kPa m pressure gradient after Gruesbeck and Collins 1982 SPE reprinted by permission of the Society of Petroleum Engineers . Single-Phase Formation Damage by Fines Migration and Clay Swelling 233 pack decreased to zero. Because in the fine sand pack almost all the pathways are of the plugging type. Whereas in coarse sand packs the deposition tended to occur almost uniformly along the sand pack and the mean permeability of the sand pack decreased to an equilibrium value. Because in the coarse sand pack most of the pathways are of the nonplugging types. Gruesbeck and Collins 1982 state that their computer simulation produced results similar to measurement reported in Figure 10-27. Ci van et al. 1989 and Ohen and Ci van 1990 1993 also