Theoretical Modeling of Gravity Segregation in WAG Improved Oil Recovery for Tilted Reservoirs

Water injection, gas injection or WAG flooding can have drawbacks such as increases in residual oil, introducing areas where oil sweeping does not occur and fluid segregation. Gravity segregation needs some time and distance to occur, so that the vertical conformance is good in places near the well and will be deterred as far from injected well. The size of these regions is principally related to injection rate, vertical permeability and density difference between water and gas. Furthermore, fluid injection has adequate length in which the vertical conformance is maintained. In IOR flooding processes it is essential to design a reservoir flooding that water-gas mixed the region is larger relative to the reservoir volume to be flooded by each well. This study benefits from prior associated researches to investigate the dominant factors controlling segregation around the injection wells and proposes a new analytic model for tilted reservoirs. The model has better prediction to the length of segregation rather than former models.