Figure 16. Well log primarily of subsalt section. The high-pressured gumbo shales below salt is referred to as basal shear zone. This zone, which is typically seen in subsalt wells, has pore pressures that may exceed #17ppg pressure gradients (0.88psi/ft). Pressure gradients regress with depth below the salt sheet back to more regional gradients (although still geopressured). Note the conductivity curve is increasing with decreasing pressure. The shallowest oil sand at Mahogany is the ‘J’ sand in the pressure transition zone. There are multiple pay zones, but the primary target is the P sand. Water-bearing sands are found just below the J sand and starting in R sand interval. Pressure increases once more near the bottom of the well. Salt has a large temperature halo below and the gradients gradually increase downward from the base of salt.