Changes

A comparison of top seal capacity determined from displacement pressures and actual hydrocarbon column heights in one African basin demonstrates that while top seals are capable of trapping more than [[depth::1000 ft]] of oil, most traps contain only a few hundred feet of oil.<ref name=ch10r68>Shea, W., T., Schwalbach, J., R., Allard, D., M., 1993, Integrated rock-log evaluation of fluvio-lacustrine seals, in Ebanks, J., Kaldi, J., Vavra, C., eds., Seals and Traps: A Multidisciplinary Approach: AAPG Hedberg Research conference, unpublished abstract.</ref> Oil column heights in this basin are controlled instead by fault-dependent leak points.<ref name=ch10r3>Allard, D., M., 1993, Fault leak controlled trap fill, rift basin examples (abs.), in Ebanks, J., Kaldi, J., Vavra, C., eds., Seals and Traps: A Multidisciplinary Approach: AAPG Hedberg conference, Crested Butte, Colorado, June 21–23.</ref><ref name=ch10r68 />

A comparison of top seal capacity determined from displacement pressures and actual hydrocarbon column heights in one African basin demonstrates that while top seals are capable of trapping more than [[depth::1000 ft]] of oil, most traps contain only a few hundred feet of oil.<ref name=ch10r68>Shea, W., T., Schwalbach, J., R., Allard, D., M., 1993, Integrated rock-log evaluation of fluvio-lacustrine seals, in Ebanks, J., Kaldi, J., Vavra, C., eds., Seals and Traps: A Multidisciplinary Approach: AAPG Hedberg Research conference, unpublished abstract.</ref> Oil column heights in this basin are controlled instead by fault-dependent leak points.<ref name=ch10r3>Allard, D., M., 1993, Fault leak controlled trap fill, rift basin examples (abs.), in Ebanks, J., Kaldi, J., Vavra, C., eds., Seals and Traps: A Multidisciplinary Approach: AAPG Hedberg conference, Crested Butte, Colorado, June 21–23.</ref><ref name=ch10r68 />

Similarly, only 5–10% of the fields in the Rocky Mountains and California are thought to have hydrocarbon column heights controlled by top seal capillary properties<ref name=ch10r98>Zieglar, D., M., 1992, [http://archives.datapages.com/data/bulletns/1992-93/data/pg/0076/0004/0000/0501.htm Hydrocarbon columns, buoyancy pressures, and seal efficiency: comparisons of oil and gas accumulations in California and the Rocky Mountain area]: AAPG Bulletin, vol. 76, no. 4, p. 501–508.</ref> The remaining 90–95% are controlled by some other factor, including charge, faults, and synclinal spill points.

Similarly, only 5–10% of the fields in the Rocky Mountains and California are thought to have hydrocarbon column heights controlled by top seal capillary properties<ref name=ch10r98>Zieglar, D., M., 1992, [http://archives.datapages.com/data/bulletns/1992-93/data/pg/0076/0004/0000/0501.htm Hydrocarbon columns, buoyancy pressures, and seal efficiency: comparisons of oil and gas accumulations in California and the Rocky Mountain area]: AAPG Bulletin, vol. 76, no. 4, p. 501–508.</ref> The remaining 90–95% are controlled by some other factor, including charge, faults, and [[Syncline|synclinal]] spill points.

==Seal continuity==

==Seal continuity==