Ejercicio 7 Pdd.xlsx

A 3 hour drawdown test was conducted in which the rate during the first hour averaged 478,5 STB/D; during the second hour, 319 STB/D; and during the third hour, 159.5 STB/D. Following table gives the flowing BHP’s measured during the test. Estimate permeability and skin factor. Other data are: Pi= 3000 psi; B=1,2 RB/STB; viscosity= 0,6 cp; porosity: 12%; h= 10 ft; Ct= 48*10-6 psi-1; rw= 0,25 ft.

t 0.000 0.333 0.667 1.000 2.000 2.333 2.667 3.000

pwf 3000.0 999.0 857.0 778.5 1378.5 2043.0 2067.5 2094.0

qn 478.5 478.5 478.5 319 159.5 159.5 159.5

(pi-pwf)/qn Σ

7

4.18181818 4.47857889 4.64263323 5.0830721 6 5.84639498 5.68025078

6

-0.4775558 -0.1758742 0 0.45154499 1.45646983 1.23200761 1.13033377

5 4 3 2 1 0 -1

Pi B Viscosidad Porosidad h C rw

3000 1.2 0.6 0.12 10 0.000048 0.25

-0.5

0

5 STB/D; during the wing BHP’s measured

0,25 ft.

7 6 5 4 3 2 1 0 -1

-0.5

0

x

0.5

P1 P2

y 0 4.64263323 0.45154499 5.0830721

m' b'

0.97540417 4.64263323

k(md) s

12.0024092 0.28186534

1

1.5

2