Fault Dependent Leak Points
Seal behavior can also be inferred from several different types of fault dependent leak points.
If a fault leaks at a sand/sand juxtaposition, hydrocarbon may be trapped only where sand/shale juxtaposition exists. At the leaking sand/sand juxtaposition hydrocarbons are free to migrate updip.
In this example (right) the OWC coincides with the top of the sand in the hanging-wall. The fault is cross leaking.
This type of fault dependent leak point is called a Juxtaposed Lithology Leak Point. It is an extremely common type that controls the spill points for many fields.
If this were a prospect and you were able to predict cross leakage from quantitative fault seal analysis, you could have predicted the percent fill and hydrocarbon column heights.
If the fault cross sealed, the hydrocarbon column height could be much greater. Identifying cross sealing faults can lead to new plays that do not require structurally independent closure. Large columns are trapped downdip of known fields and dry holes.