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==Example of TDS vs. depth==
 
==Example of TDS vs. depth==
Water density is a function of its TDS concentration. The hydrostatic pressure at any depth is a function of TDS concentration from the surface to that point. The plot below of TDS vs. depth is from southern Arkansas. It shows a gradual increase in TDS from the surface to about [[depth::2000 ft]], probably due to meteoric effects, and then a linear, more rapid increase in TDS from 2000 to [[depth::10,000 ft]]. Generally, below the depth of meteoric water influence, the increase in TDS in connate brines is linear and ranges from 25,000 to 100,000 mg/1 per [[depth::1000 ft]] (80 to 300 mg/1 per m).<ref name=ch05r6>Dickey, P., A., 1969, Increasing concentration of subsurface brines with depth: Chemical Geology, vol. 4, p. 361–370., 10., 1016/0009-2541(69)90055-2</ref> There are exceptions to this general case.
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[[file:formation-fluid-pressure-and-its-application_fig5-4.png|thumb|{{figure number|1}}. Copyright: Dickey, 1969; courtesy Chemical Geology.]]
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Water density is a function of its TDS concentration. The hydrostatic pressure at any depth is a function of TDS concentration from the surface to that point. The plot in [[:file:formation-fluid-pressure-and-its-application_fig5-4.png|Figure 1]] of TDS vs. depth is from southern Arkansas. It shows a gradual increase in TDS from the surface to about [[depth::2000 ft]], probably due to meteoric effects, and then a linear, more rapid increase in TDS from 2000 to [[depth::10,000 ft]]. Generally, below the depth of meteoric water influence, the increase in TDS in connate brines is linear and ranges from 25,000 to 100,000 mg/1 per [[depth::1000 ft]] (80 to 300 mg/1 per m).<ref name=ch05r6>Dickey, P., A., 1969, Increasing concentration of subsurface brines with depth: Chemical Geology, vol. 4, p. 361–370., 10., 1016/0009-2541(69)90055-2</ref> There are exceptions to this general case.
    
Such consistent salinity increase with depth is not unique to the East Texas basin but is characteristic of most basins.
 
Such consistent salinity increase with depth is not unique to the East Texas basin but is characteristic of most basins.
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[[file:formation-fluid-pressure-and-its-application_fig5-4.png|thumb|{{figure number|5-4}}. Copyright: Dickey, 1969; courtesy Chemical Geology.]]
      
==See also==
 
==See also==

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