Changes

==Seal continuity==

==Seal continuity==

The lateral extent and continuity of top seals can create and destroy plays within basins. In many basins, thick, continuous, areally extensive sequences of shale or salt act as regional top seals. The Gippsland basin and North Sea are only two of numerous examples. In some basins, this regional seal is lacking or limited. In the Gulf Coast, the North Frisco City field exists because the Buckner Anhydrite, a regional seal, is missing above a local basement high. Only where the regional seal is breached are hydrocarbons able to escape from the Smackover reservoir into the overlying Lower Haynesville sands.<ref name=ch10r81>Stephenson, M., Cox, J., Jones-Fuentes, P., 1992, How 3D seismic-CAEX combination affected development of N. Frisco City field in Alabama: Oil & Gas Journal, vol. 90, no. 43, p. 127–130.</ref> Where the Buckner Anhydrite is continuous, there is no Haynesville play.

The lateral extent and continuity of top seals can create and destroy plays within basins. In many basins, thick, continuous, areally extensive sequences of shale or salt act as regional top seals. The [[Gippsland Basin]] and [[North Sea]] are only two of numerous examples. In some basins, this regional seal is lacking or limited. In the Gulf Coast, the [[North Frisco City field]] exists because the [[Buckner Formation anhydrite]], a regional seal, is missing above a local [[basement]] high. Only where the regional seal is breached are hydrocarbons able to escape from the [[Smackover]] reservoir into the overlying lower [[Haynesville Formation]] sandstones.<ref name=ch10r81>Stephenson, M., Cox, J., Jones-Fuentes, P., 1992, How 3D seismic-CAEX combination affected development of N. Frisco City field in Alabama: Oil & Gas Journal, vol. 90, no. 43, p. 127–130.</ref> Where the Buckner anhydrite is continuous, there is no Haynesville play.

==See also==

==See also==