STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

Drilling Muds and Completion Fluids 665
500
450
0
400
9 350
i
E,
Q
g 300
z
250
2
w
I
200
a
U 150
a 3
100
50
0
SOLUBLE SALTS, Ibhbl of mud
1
Figure 4-110. Total water phase salinity of oil mud [26]. (Courtesy Baroid
Drilling Fluids, lnc.)
the filtration and filter cake properties of water-base muds. The comparison of
the yield of commercial clays and active clays is shown in Table 4-46. The yield
of clays is defined as the number of barrels of 15 cp mud that can be obtained
from 1 ton of dry material. The API requirements for commercial drilling
bentonite are as follows [27].
a. Bentonite concentration in distilled water-22.5 lb/bbl.
b. Sample preparation: 1. stir for 20 min. 2. Age overnight. 3. Stir for 5 min.
4. Test.
c. Apparent viscosity (viscometer dial reading at 600 rpm)-30 minimum.
d. Yield point, lb/lOO ft*-3 x plastic viscosity, maximum.
e. API filtrate, m1/30 min-15, maximum.
f. Yield, bbl mud/ton-91, minimum.
Classification of bentonite fluid systems is shown in Table 4-47 [28].