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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. | + | |
| + | [[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. |
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| 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.]]
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| ==See also== | | ==See also== |