Changes

The distribution of reservoirs and overpressuring is strongly controlled by the depositional environment ([[:file:pressure-detection_fig1.png|Figure 1]]). Overpressured reservoirs are commonly found where there are thick deposits of shaly sediments.

The distribution of reservoirs and overpressuring is strongly controlled by the depositional environment ([[:file:pressure-detection_fig1.png|Figure 1]]). Overpressured reservoirs are commonly found where there are thick deposits of shaly sediments.

[[file:pressure-detection_fig2.png|thumb|{{figure number|2}}Common patterns of increasing pressure with depth. In the case illustrated by line A, the pressure increases normally to a certain depth, then increases abruptly to almost the weight of the overburden, which it then parallels. In the case of line B, the increase of pressure above normal follows the aquathermal gradient (constant water density) and then follows the fracture gradient.<ref name=pt03r8>Barker, C., Horsfeld, B., 1982, [http://archives.datapages.com/data/bulletns/1982-83/data/pg/0066/0001/0050/0099.htm Mechanical versus thermal cause of abnormally high pore pressures in shales— discussion]: AAPG Bulletin, v. 66, n. 1, p. 99–100.</ref>]]

[[file:pressure-detection_fig2.png|thumb|300px|{{figure number|2}}Common patterns of increasing pressure with depth. In the case illustrated by line A, the pressure increases normally to a certain depth, then increases abruptly to almost the weight of the overburden, which it then parallels. In the case of line B, the increase of pressure above normal follows the aquathermal gradient (constant water density) and then follows the fracture gradient.<ref name=pt03r8>Barker, C., Horsfeld, B., 1982, [http://archives.datapages.com/data/bulletns/1982-83/data/pg/0066/0001/0050/0099.htm Mechanical versus thermal cause of abnormally high pore pressures in shales— discussion]: AAPG Bulletin, v. 66, n. 1, p. 99–100.</ref>]]

====Aquathermal effects====

====Aquathermal effects====