Scaled EOR Simulation Study for a Conventional Heavy Oil Reservoir with Wormholes

Ivan Ulovich


This work shows that for heavy oil simulation, sand transport option in STARS can be very useful; Average field performance in the field can be represented by a symmetry pattern model using appropriate well scaling factors;  Dual porosity can be used to represent wormhole networks in the field; When foamy oil effects are weak, the process can be simulated by the equilibrium solution-gas model with depressed end-point relative permeability to gas; Imbibition capillary pressure is insignificant in field-scale conditions and may be excluded from the model. For Heavy Oil Waterflood,  waterflood works in heavy oil with wormholes; Gravity-dominated crossflow is likely to play a key role in heavy oil waterflooding with upper-most channels and layers being the main source of oil production; Lower channels are the main source of early water breakthrough; In-depth gel treatment of lower-most channels is a must to improve viscous forces and recovery; Hot and Variable-rate waterfloods can improve the recovery factor. For heavy oil polymer flood, polymer flooding is proven to be a successful tertiary and secondary enhanced oil recovery method. No need to target M < 1; Field-scale heavy oil polymer flood is driven by the increased ratio of viscous-to-gravity forces caused by lower mobility ratio; Polymer retention due to adsorption is a single most critical parameter; The significance of dilution zone behind polymer front is not yet clear but correlates well with higher polymer adsorption; Decreasing polymer grading scheme should be considered as the first choice; Polymer rheology is likely to have little impact on production performance; Successful conformance control to increase the URF, while improving injectivity accelerates this recovery.