Changes

===Hydrodynamic effect on traps===

===Hydrodynamic effect on traps===

[[file:formation-fluid-pressure-and-its-application_fig5-37.png|thumb|{{figure number|1}}Vectors and equipotential lines for a hydrocarbon accumulation in an anticline in a hydrodynamic environment. Modified. Copyright: North, 1985; courtesy Allen and Unwin.]]

[[file:formation-fluid-pressure-and-its-application_fig5-37.png|300px|thumb|{{figure number|1}}Vectors and equipotential lines for a hydrocarbon accumulation in an anticline in a hydrodynamic environment. Modified. Copyright: North, 1985; courtesy Allen and Unwin.]]

In a hydrostatic environment, the free-water level of a trap is horizontal. In a hydrodynamic environment, the free-water level of a trap is tilted because the buoyant force (P_b) is interfered with by the hydrodynamic force (P_w). The resultant interference is the vector known as the confining force (P_cf). U, an equipotential line, is perpendicular to P_cf and is tilted because of the effect of P_w. The diagram in [[:file:formation-fluid-pressure-and-its-application_fig5-37.png|Figure 1]] shows these vectors and the equipotential lines for a hydrocarbon accumulation in an anticline in a hydrodynamic environment.

In a hydrostatic environment, the free-water level of a trap is horizontal. In a hydrodynamic environment, the free-water level of a trap is tilted because the buoyant force (P_b) is interfered with by the hydrodynamic force (P_w). The resultant interference is the vector known as the confining force (P_cf). U, an equipotential line, is perpendicular to P_cf and is tilted because of the effect of P_w. The diagram in [[:file:formation-fluid-pressure-and-its-application_fig5-37.png|Figure 1]] shows these vectors and the equipotential lines for a hydrocarbon accumulation in an anticline in a hydrodynamic environment.