Changes

* The [[seal]] or [[Trap leakage|leak]] threshold [[shale gouge ratio]] (SGR) must be empirically calibrated for each basin, using known [[seal]]ing and [[leak]]ing faults. An SGR threshold for the [[Gulf Coast]] cannot be used for assessing prospects in the [[Gippsland basin]]. The confidence with which a seal can be risked is thus much greater in a production setting or mature basin than it is in a frontier setting.

* The [[seal]] or [[Trap leakage|leak]] threshold [[shale gouge ratio]] (SGR) must be empirically calibrated for each basin, using known [[seal]]ing and [[leak]]ing faults. An SGR threshold for the [[Gulf Coast]] cannot be used for assessing prospects in the [[Gippsland basin]]. The confidence with which a seal can be risked is thus much greater in a production setting or mature basin than it is in a frontier setting.

* It does not apply to all structural styles, and specifically it does not necessarily apply to faults in [[foreland fold and thrust belts]] or [[strike-slip]] basins. All basins in which quantitative fault seal analysis has been proven to date are dominated by detached or [[basement]]-involved [[normal fault]]s.

* It does not apply to all structural styles, and specifically it does not necessarily apply to faults in [[foreland fold and thrust belts]] or [[strike-slip]] basins. All basins in which quantitative fault seal analysis has been proven to date are dominated by detached or [[basement]]-involved [[normal fault]]s.

* [[Cataclasis]], [[Diagenesis|diagenetic effects]], localized fracturing, sharp changes in the [[permeability]] or [[displacement pressure]] of sands, reactivation of earlier normal faults in [[compression]], “[[shale-outs]],” and the lack of lateral sand continuity in [[fluvial]] sequences can affect seal behavior.

* [[Cataclasis]], [[Diagenesis|diagenetic effects]], localized fracturing, sharp changes in the [[permeability]] or [[displacement pressure]] of sands, reactivation of earlier normal faults in [[compression]], “[[shale-outs]],” and the lack of [[lateral]] sand continuity in [[fluvial]] sequences can affect seal behavior.

* The ability to predict fault seal behavior is only as good as the ability to predict the stratigraphy and structure. As with most variables in prospect assessment, uncertainties in structure and stratigraphy lead to a minimum, maximum, and most likely fault seal risk.

* The ability to predict [[fault seal behavior]] is only as good as the ability to predict the stratigraphy and structure. As with most variables in prospect assessment, uncertainties in structure and stratigraphy lead to a minimum, maximum, and most likely fault seal risk.

==See also==

==See also==

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Evaluating top and fault seal]]

[[Category:Evaluating top and fault seal]]