tailieunhanh - Reservoir Formation Damage Episode 2 Part 3

Tham khảo tài liệu 'reservoir formation damage episode 2 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 282 Reservoir Formation Damage Equation 12-33 can be rearranged in a linear form as d i dq A _ B I z q dtyqJ q2 dt c c 12-76 Thus the intercept B C and slope -A C of the straight-line plot of Eq. 12-76 can be used with Eqs. 12-30 12-31 12-12 and 12-13 to obtain the following expressions _ -A C 1 - t e Kd - 12-77 12-78 Comparing Eqs. 12-75 and 12-77 yields an alternative expression for determination of the limit filtrate rate as B C A C 12-79 Eq. 12-79 can be used to check the value of q obtained by Eq. 12-72. Equation 12-74 can be used to determine the filter cake permeability Kc. Equations 12-70 and 12-75 or 12-77 and 12-78 can be used to calculate the particle deposition and erosion rates kd and ke if the cake porosity J c and the critical shear stress Tcr are known. ộc can be measured. Tcr can be estimated by Eq. 12-6 but the ideal theory may not yield a correct value as explained previously by Ravi et al. 1992 and in this chapter. Therefore Ravi et al. 1992 suggested that Tcr should be measured directly. Radial Filtration Given the filter cake thickness Ỗ the progressing surface cake radius rc can be calculated by Eq. 12-46. Then a straight line plot of In rc rw vs. 1 ợ data according to Eq. 12-62 yields the values of c and D as the slope and intercept of this line respectively. A straightline plot of dô dtị versus q rw -Ô data according to Eq. 12-49 yields the values of A and B as the slope and intercept of this line respectively. At static filtration conditions v 0 and T o according to Eq. 12-47. Therefore Cake Filtration Mechanism Parameters and Modeling 283 B o according to Eq. 12-13. Consequently substituting B o and Eq. 12-63 Eq. 12-65 can be expressed in the following linear form ln j tZi l 2 2 j ln - 7-3 dq dt __ . 12-80 ln â C -2CKz ạJ 2C 9 Thus a straightline plot of ln -ợ-3 dq dt versus 1 g yields the values of 2C and iln A c -2CKf qo as the slope and intercept of this line respectively. This allows for determination of the A and c coefficients .