Changes

==Direction of dip leakage==

==Direction of dip leakage==

Although dip leakage is generally understood as the migration ''up'' the fault zone due to buoyant forces, leakage ''down'' the fault zone can also occur. Refraction of flow lines can occur when fluids cross a fault zone of differing [[permeability]] from the wall rock. Fluid flow across a fault of lower permeability than the adjacent wall rock could dip leak down the fault zone.<ref name=ch10r38>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, no. 8, p. 1954–2026.</ref> Similarly, a fault zone with higher permeability than the wall rock will refract flow lines up the fault zone. Pressure differences along and across faults can also cause down-dip flow in the area of lowest pressure.<ref name=ch10r43>Knutson, C., A., Erga, R., 1991, Effect of horizontal and vertical permeability restrictions in the Beryl reservoir: Journal of Petroleum Technology, vol. 43, p. 1502–1509., 10., 2118/19299-PA</ref><ref name=ch10r60>Niemann, J., Krowlow, M., 1992, Delineation of a pressure fault seal from shale resistivities, in Ebanks, J., Kaldi, J., Vavra, C., eds., Seals and Traps: A Multidisciplinary Approach: AAPG Hedberg Research conference, unpublished abstract.</ref>

Although dip leakage is generally understood as the migration ''up'' the fault zone due to buoyant forces, leakage ''down'' the fault zone can also occur. Refraction of flow lines can occur when fluids cross a fault zone of differing [[permeability]] from the wall rock. Fluid flow across a fault of lower permeability than the adjacent wall rock could dip leak down the fault zone.<ref name=ch10r38>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, no. 8, p. 1954–2026.</ref> Similarly, a fault zone with higher permeability than the wall rock will refract flow lines up the fault zone. Pressure differences along and across faults can also cause down-dip flow in the area of lowest pressure.<ref name=ch10r43>Knutson, C. A., and R. Erga, 1991, Effect of horizontal and vertical permeability restrictions in the Beryl reservoir: Journal of Petroleum Technology, vol. 43, p. 1502–1509., 10., 2118/19299-PA</ref><ref name=ch10r60>Niemann, J., and M. Krowlow, 1992, Delineation of a pressure fault seal from shale resistivities, in J. Ebanks, J. Kaldi, and C. Vavra, eds., Seals and Traps: A Multidisciplinary Approach: AAPG Hedberg Research conference, unpublished abstract.</ref>

==Caveat==

==Caveat==