− | Fault plane profiles and quantitative fault seal analysis are required for realistic reservoir simulations. Neither the seal behavior, transmissibility, [[permeability]], nor areas of sand/sand juxtaposition are constant over the entire fault surface. | + | [[Fault plane profile analysis|Fault plane profiles]] and quantitative [[Fault seal behavior|fault seal analysis]] are required for realistic reservoir simulations. Neither the seal behavior, [[transmissibility]], [[permeability]], nor areas of sand/sand juxtaposition are constant over the entire fault surface. |
− | Faults control changing pressure gradients within a field. Hydrocarbons move in response to these pressure gradients and not necessarily in response to structural dip. Gas in the Beryl field, for example, migrated downdip during production in response to changing pressure gradients, [[pressure compartments]], and [[migration pathway]]s controlled by sealing and leaking faults.<ref name=ch10r43>Knutson, C., A., Erga, R., 1991, Effect of horizontal and vertical permeability restrictions in the Beryl reservoir: Journal of Petroleum Technology, vol. 43, p. 1502–1509, DOI: 10.2118/19299-PA.</ref><ref name=ch10r74>Skerlec, G., M., 1997b, Atlas of fault seal behavior in the Gulf Coast: Franklin, Pennsylvania, SEALS International, 4356 p.</ref> | + | Faults control changing [[Hydrocarbon pressure gradient: plotting|pressure gradients]] within a field. [[Hydrocarbon]]s move in response to these pressure gradients and not necessarily in response to structural [[dip]]. Gas in the Beryl field, for example, migrated downdip during production in response to changing pressure gradients, [[pressure compartments]], and [[migration pathway]]s controlled by sealing and [[Hydrocarbon pressure gradient: plotting|leaking faults]].<ref name=ch10r43>Knutson, C., A., Erga, R., 1991, Effect of horizontal and vertical permeability restrictions in the Beryl reservoir: Journal of Petroleum Technology, vol. 43, p. 1502–1509, DOI: 10.2118/19299-PA.</ref><ref name=ch10r74>Skerlec, G., M., 1997b, Atlas of fault seal behavior in the Gulf Coast: Franklin, Pennsylvania, SEALS International, 4356 p.</ref> |
− | Faults can also leak over geologic time spans but seal during production time spans. Even a low fault-zone permeability may allow hydrocarbons to leak given a time span of 10<sup>6</sup> m.y. High production rates, however, creating pressure changes over a span of 1–10 years, will cause low-permeability fault zones to act as barriers to hydrocarbon movement. A cross-leaking fault may develop different hydrocarbon contacts and different pressures during production. Shale gouge ratio (SGR) thresholds for seal behavior may have to be calibrated separately for exploration and for reservoir simulations. | + | Faults can also leak over geologic time spans but seal during production time spans. Even a low fault-zone [[permeability]] may allow hydrocarbons to [[Fault seal breakdown during production|leak]] given a time span of 10<sup>6</sup> m.y. High production rates, however, creating pressure changes over a span of 1–10 years, will cause low-permeability fault zones to act as barriers to hydrocarbon movement. A [[Cross-leaking faults|cross-leaking fault]] may develop different hydrocarbon contacts and different pressures during production. Shale gouge ratio (SGR) thresholds for seal behavior may have to be calibrated separately for exploration and for reservoir simulations. |
− | Fault seal is important in field unitization. Ignoring fault seal and depending solely on reservoir parameters and estimated hydrocarbon contacts can lead to extremely unequal division of reserves. The sealing behavior of faults controls both the original distribution of hydrocarbons in a field as well as the volumes of hydrocarbons produced from individual fault compartments. | + | Fault seal is important in [[field unitization]]. Ignoring fault seal and depending solely on reservoir parameters and estimated hydrocarbon contacts can lead to extremely unequal division of reserves. The sealing behavior of faults controls both the original distribution of hydrocarbons in a field as well as the volumes of hydrocarbons produced from individual fault compartments. |