Hydrodynamic Effects on Oil Emplacement In the Permian San Andres Formation

Water plays an important role in the development of petroleum systems. Under hydrostatic conditions, oil/water systems stratify with a contact at an equipotential surface parallel to the gravitational field. Under hydrodynamic conditions, equipotentials are tilted in the direction of flow based on the density of the fluids and the potential gradient. Hydrodynamic conditions result in a tilted oil/water contact, a swept residual oil zone, and unusual hydrocarbon entrapment. The San Andres formation of the Permian Basin shows signs of hydrodynamic influence in the form of a tilted oil/water contact and larger than normal residual oil zone. This study attempts to model the water potentials required to create the observed tilt in the oil/water contact. Flow modeling is based on conductivity measurements derived from log observed porosity and core measured porosity/permeability correlations.