− | | Find the purest shale intervals on the GR or SP base line. They must be reasonably thick to allow valid responses of the other logs and free of sand or lime stringers. (See points a–e, Figure 5-20.) | + | | Find the purest shale intervals on the GR or SP base line. They must be reasonably thick to allow valid responses of the other logs and free of sand or lime stringers. (See points a–e, [[:file:formation-fluid-pressure-and-its-application_fig5-20.png|Figure 1]].) |