4,231
edits
Changes
Jump to navigation
Jump to search
Line 22:
Line 22: − + − +
→Leakage associated with faults
Leakage is commonly associated with faults. [[Fault-dependent leak points, continuity, and charge|Fault leakage]] is a function of fault-fill lithology, lithology of surrounding rocks, and timing. Note these characteristics to evaluate fault-associated leakage:
Leakage is commonly associated with faults. [[Fault-dependent leak points, continuity, and charge|Fault leakage]] is a function of fault-fill lithology, lithology of surrounding rocks, and timing. Note these characteristics to evaluate fault-associated 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.
* Calculate [[shale-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.
* 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 [[Natural hydraulic fracturing of top seals|hydrofracture]] ruptures seals.
* 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.