Changes

[[file:formation-fluid-pressure-and-its-application_fig5-4.png|thumb|300px|{{figure number|1}}TDS vs. depth plot from southern Arkansas. Copyright: Dickey,<ref name=ch05r6 /> courtesy Chemical Geology.]]

[[file:formation-fluid-pressure-and-its-application_fig5-4.png|thumb|300px|{{figure number|1}}TDS vs. depth plot from southern Arkansas. Copyright: Dickey,<ref name=ch05r6 /> courtesy Chemical Geology.]]

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 brine]]s 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.

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 brine]]s 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.