# Expansion and elasticity of brines

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1. Aug 10, 2016

Hello,

I am currently looking at a way to calculate brine density using temperature, pressure and salinity.
I found the following page which describes the change in fluid density with pressure and temperature :
http://www.engineeringtoolbox.com/fluid-density-temperature-pressure-d_309.html

However I am missing two parameters which I haven't been able to find for brines:
- β = volumetric temperature expansion coefficient (m3/m3 oC)
- E = bulk modulus fluid elasticity (N/m2)

Ideally I would need to find an equation which takes in pressure, temperature and salinity which are my known variables. Or tables, the salinity of my brine is 7 wt%, the pressure around 400 bars and the temperature of 141 °C . Note: Since the temperature used to work out β is the average between 0 °C and 141 °C, I would be looking for β at 70.5 °C.

2. Aug 10, 2016

### Staff: Mentor

You may be able to compare your calculation with that determined by the formula in this article:
http://www.ogj.com/articles/print/volume-99/issue-52/drilling-production/method-determines-brine-density-for-hpht-wells [Broken]
The image depicting the equation and parameters seems to be deliberately illegible low res in the online version of the publication.

Last edited by a moderator: May 8, 2017