Nano composites performance as direct thickeners for gas based enhanced oil recovery, a new approach

摘要

The thickeners for gas-based enhanced oil recovery must be both gas soluble and capable to significantly enhancing the gas viscosity. However, a large amount of co-solvent is problematic for dissolution of high molecular weight thickeners in hydrocarbon gas. Therefore, in this study the high molecular weight of P-1-D and graphene oxide/P-1-D nanocomposite were synthesized to improve the intermolecular interactions that can increase the gas viscosity at low cloud point pressure without any co-solvent requirement. Results show that the cloud point pressure for nanocomposite gas thickeners is lower than it compared to P-1-D thickener. The high molecular weight of P-1-D and nanocomposites increase the hydrocarbon gas viscosity about 4.5 and 22.9 fold, respectively. In addition, the use of nanocomposites as direct thickener leads to a significant IFT reduction in low concentrations and subsequently increasing the gas relative permeability curve sharply ("X" shape). Moreover, the mobility ratio decreases from 78 to 3.2 for P-1-D and nanocomposite thickeners respectively. However, the capillary numbers increase to 1*10(-3) and the residual oil saturation reduces from 38 to 24 percent.