STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

982 Drilling and Well Completions
LATERAL
CURRENT
BIT
CURRENT
Figure 4-278. Computed current pattern in a homogeneous formation for the
MWD toroid system. (Courtesy SPWLA [115].)
(test continued from page 979)
Solution
1. 8,450 to 8,434 ft dolomite
8,434 to 8,430 ft shale
8,430 to 8,426 ft dolomite
8,426 to 8,423 ft shale
8,423 to 8,374 ft dolomite
8,374 to 8,350 ft shale
Rock nature is read on the Pe log.
2. Yes, a mud cake is seen on the caliper log.
3. Yes, the Rwa curve increases sharply in the main zone at 8425 ft. Oil from
8425 to 8400 ft. Gas above 8,400 ft. Gas is indicated by a density porosity
larger than the neutron porosity.
4. Rw = 0.05 Rem; read on Rwa curve in the lower porous zone.
5. At 8400 ft, porosity = 20%, R,, = 0.45, F = 25, R, = 11.25 Rem
S, = j2:i.:r = 0.33 = 33%
S,, = 67%