Each of these facies has a distinct range of displacement pressures. [[:file:evaluating-top-and-fault-seal_fig10-49.png|Figure 1]] shows the range of seal capacities for the different facies. Shelfal carbonates and delta-front shales are excellent seals, with displacement pressures > 1000 psia (air-mercury) and capable of trapping approximately 1000–10,000 ft of oil. Delta-plain shales are relatively poor seals, with displacement pressures of 80–90 psia (air-mercury<sup>o</sup> and capable of trapping only 90–100 ft of oil. | Each of these facies has a distinct range of displacement pressures. [[:file:evaluating-top-and-fault-seal_fig10-49.png|Figure 1]] shows the range of seal capacities for the different facies. Shelfal carbonates and delta-front shales are excellent seals, with displacement pressures > 1000 psia (air-mercury) and capable of trapping approximately 1000–10,000 ft of oil. Delta-plain shales are relatively poor seals, with displacement pressures of 80–90 psia (air-mercury<sup>o</sup> and capable of trapping only 90–100 ft of oil. |