PROPERTIES OF OILFIELD BRINES - Petroleum Reservoir Fluid Property Correlations - page 147

Comparison of correlations of brine compressibility
Five methods for estimating brine compressibility were chosen for
evaluation against the compressibility database. Two of these methods,
one by Osif, the other by Rowe and Chou, were correlations developed
specifically for estimating compressibility. The third and fourth methods
use the Rogers-Pitzer and Archer equations of state, respectively, to
calculate the brine compressibility. The fifth method uses the modified
Spivey et al. density correlation to calculate the brine compressibility.
Osif presented a correlation for compressibility that covered a
relatively wide range of pressures, from 1,000 to 20,000 psia (6.9 to
138 MPa), but a limited range of temperatures, from 200ºF to 270ºF
(93.3ºC to 132ºC). 13 Osif warned that his correlation equation should
not be used outside of this range of temperatures. Osif 's data likewise
covered a limited range of salinities, from 0 to 200 g/L (0 to 17.7 wt%, 0
to 3.67 g-mol/kg H 2 O).
Rowe and Chou presented a correlation for brine compressibility. 14
The Rowe and Chou compressibility correlation was developed for
temperatures from 32ºF to 347ºF (0ºC to 175ºC), pressures from 14.5
to 4,930 psia (0.1 to 34 MPa), and sodium chloride concentrations from
0 to 25 wt% (0 to 5.7 g-mol/kg H 2 O).
Table 4-3 shows the results of the evaluation of correlations for brine
compressibility.

Table 4-3. Results of evaluation of brine compressibility correlations against brine compressibility
data subset of brine density database in table
Correlation

ARE AARE

Spivey et al. (modified) 0.16% 1.23%

Archer (1992) 0.23% 1.33%

Osif (1988)* -0.1% 1.57%

Rogers-Pitzer (1982) -0.55% 2.19%

Osif (1988) 2.42% 2.97%

Rowe-Chou (1970) 8.27% 9.81%

*Temperature range restricted to 200ºF to 270ºF

Figure 4-10 shows the AARE in brine compressibility as a function
of temperature for several correlations. As in the case of brine density,
because of the range of the magnitude of error, the ARE is not shown.
The modified Spivey et al. brine compressibility correlation is the best
correlation across the entire temperature range. The Rogers-Pitzer and
Archer equations of state, as well as the modified Spivey et al. correlation,