Abstract
Several studies have indicated polymer flooding to be an optimal enhanced oil recovery (EOR) strategy in fields with oil viscosities between 10 – 150 mPa.s. In the current oil price environment maximizing the output from exisiting fields, using the ideal EOR operation pertinent to each reservoir, is of increased importance. In addition, with almost half of the total global oil production for the coming decades projected to come from EOR operations, it is essential to select the right strategy for each field. For fields that have oil viscosities above 150 mPa.s, mobility ratio of the polymer containing injectant is an inhibiting factor to the polymers injectivity and pumping efficiency, and hence polymer flooding is not a viable EOR strategy in such fields.
Supramolecular systems are a viable alternative to conventional polymers used in polymer flooding, mainly due to their high resistance to temperature and salinity. A unique feature of these systems is its reversible viscosity, using which system viscosity can be adjusted from low values during injection to high values prior to oil contact within the reservoir. Supramolecular systems are highly resistant to degradation from shear and temperature due their inherent property of disassembling, when exposed to high shear and/or temperature, and re-assembling. This property is useful in restrictive environments such as flow through narrow channels, where supramolecular systems disassemble (molecular scission) and reassemble, thereby maintaining its molecular properties in a "self-healing" manner.
In this study, modeling and simulation of these "self-healing" supramolecular systems have been conducted to compare its displacement efficiency compared to conventional polymer systems. They have the potential to be applied to multiple types of reservoirs including those with thin layers and permafrost conditions. From the results of this study it is evident that supramolecular systems offers field operators considering polymer flooding a cost-effective, smarter and technologically feasible EOR strategy.
