Page 498 - Petrophysics

466 PETROPHYSICS: RESERVOIR ROCK PROPERTIES

TABLE 7.2
CALCUlATlON OF [ J(qm)] VALUES FOR EXAMPLE

Repr qm fw Mqm)
0.1 0.0000706 4236.98 -2.03
0.2 0.000 14 13 1059.24 -1.17
0.5 0.0003 5 3 2 169.47 0.116
0.75 0.0005298 75032 0.73
1 0.0007065 42036 1.178
2 0.001413 10.59 2.301
5 0.003532 1.69 3.858
7.5 0.005298 0.75 4.569
10 0.007065 0.42 5.08

TURBULENT RADIAL FLOW

All of the radial steady-state flow equations presented so far are based
on the assumption that Darcy's law is applicable at all times and
throughout the reservoir. As shown in the previous sections, at high
gas flow rates inertial and/or turbulent flow effects are of significance
and should be accounted for. Non-Darcy flow effect is most significant
near the wellbore because, in radial flow systems, the velocity of the
flowing fluid increases as the fluid approaches the well. Under these
circumstances Equation 7.11 1 becomes:

(7.132)

Let:

and:

zRTp
Q2 = ( (2nh)zM)q'

Substituting Q1 and 42 into Equation 7.125 gives:

(7.133)