Changes

==Duration of hydrodynamic regimes==

==Duration of hydrodynamic regimes==

[[file:predicting-preservation-and-destruction-of-accumulations_fig11-3.png|thumb|{{figure number|1}}See text for explanation.]]

[[file:predicting-preservation-and-destruction-of-accumulations_fig11-3.png|thumb|{{figure number|1}}Effects of hydrodynamics on trapping.]]

Petroleum distribution adjusts to trapping hydrodynamics much faster than changes in natural hydrodynamic regimes.<ref name=ch11r15>Hubbert, M., K., 1953, [http://archives.datapages.com/data/bulletns/1953-56/data/pg/0037/0008/1950/1954.htm Entrapment of petroleum under hydrodynamic conditions]: AAPG Bulletin, vol. 37, p. 1954–2026.</ref> In general, hydrodynamic regimes, especially those established by elevation–head differences in recharge, are time-transient events that are much shorter than the theoretical lifetime of accumulations under hydrostatic conditions. If present hydrodynamic flow affects [[fluid contacts]] of reservoirs charged in the past, then spillage and tertiary migration probably have occurred.

Petroleum distribution adjusts to trapping hydrodynamics much faster than changes in natural hydrodynamic regimes.<ref name=ch11r15>Hubbert, M., K., 1953, [http://archives.datapages.com/data/bulletns/1953-56/data/pg/0037/0008/1950/1954.htm Entrapment of petroleum under hydrodynamic conditions]: AAPG Bulletin, vol. 37, p. 1954–2026.</ref> In general, hydrodynamic regimes, especially those established by elevation–head differences in recharge, are time-transient events that are much shorter than the theoretical lifetime of accumulations under hydrostatic conditions. If present hydrodynamic flow affects [[fluid contacts]] of reservoirs charged in the past, then spillage and tertiary migration probably have occurred.

==Evaluating ancient spillage==

==Evaluating ancient spillage==

Ancient hydrodynamic events that have occurred since charging can be identified by evaluating topographic evolution in the area around the basin of interest (evaluate patterns of subsurface salt dissolution, tectonic history, and map unconformities around the basin). Direction and magnitude of flow can be inferred but not quantified. Although petroleum resumes its hydrostatic configuration once hydrodynamic conditions cease, some traps may have essentially all movable petroleum flushed from their structural fetch area if potentiometric gradients were steep (as shown in Figure 11-3, A and B).

Ancient hydrodynamic events that have occurred since charging can be identified by evaluating topographic evolution in the area around the basin of interest (evaluate patterns of subsurface salt dissolution, tectonic history, and map unconformities around the basin). Direction and magnitude of flow can be inferred but not quantified. Although petroleum resumes its hydrostatic configuration once hydrodynamic conditions cease, some traps may have essentially all movable petroleum flushed from their structural fetch area if potentiometric gradients were steep (as shown in [[:file:predicting-preservation-and-destruction-of-accumulations_fig11-3.png|Figure 1 A and B]]).

==See also==

==See also==