4,231
edits
Changes
Jump to navigation
Jump to search
Line 23:
Line 23: − + − +
→Leakage associated with faults
* Calculate smear-gouge ratio or shale smear factor to estimate fault-fill lithology. Petroleum leakage up faults is a type of membrane seal failure. The higher the shale content of the fault fill, the less the chance of fault-plane leakage.
* Calculate smear-gouge ratio or shale smear factor to estimate fault-fill lithology. Petroleum leakage up faults is a type of membrane seal failure. The higher the shale content of the fault fill, the less the chance of fault-plane leakage.
* Faults may localize fracturing through the top seal, so evaluate the potential for fractured membrane seal leakage in the top-seal lithology (p. 11–16).
* Faults may localize fracturing through the top seal, so evaluate the potential for fractured membrane seal leakage in the top-seal lithology.
* Faults must connect to permeable beds higher in the section or to the surface to leak significant amounts of petroleum. If [[growth fault]]s die upsection into a shale interval, leakage may be minimal except where natural hydrofracture ruptures seals (p. 11–17).
* Faults must connect to permeable beds higher in the section or to the surface to leak significant amounts of petroleum. If [[growth fault]]s die upsection into a shale interval, leakage may be minimal except where natural [[Natural hydraulic fracturing of top seals|hydrofracture]] ruptures seals.
* Fractures and fault fill may heal by cementation once fault movement stops. Leakage is less likely if trap charge significantly postdates fault movement.
* Fractures and fault fill may heal by cementation once fault movement stops. Leakage is less likely if trap charge significantly postdates fault movement.
* Conversely, fault movement during or after charge of the trap will always result in some leakage, probably by a form of natural hydraulic fracturing along the fault plane. If charge is sufficient, leakage may be slower than charge, so petroleum may [[Accumulation|accumulate]] and be preserved as long as charging continues.
* Conversely, fault movement during or after charge of the trap will always result in some leakage, probably by a form of natural hydraulic fracturing along the fault plane. If charge is sufficient, leakage may be slower than charge, so petroleum may [[Accumulation|accumulate]] and be preserved as long as charging continues.