Novel Cardanol-Based Viscosity Reducer for High Viscosity and High Permeability Reservoir Through Mechanism Study

In this study, a novel cardanol-based viscosity reducer was developed through learning from viscosity reducers derived from petroleum. Under the mechanism study through visual flooding experiment and computational fluid dynamics (CFD) simulation, the optimal petrochemical dodecyl dimethyl betaine (BS-12) stood out, and oil recovery efficiency (EOR) could be as high as 30.7%. Based on the developed empirical formula and structural analysis of BS-12, a completely new molecular structure was designed and applied in the visual flooding experiment, exhibiting comparable viscosity reduction performance and oil recovery efficiency. Graphical This study combined microfluidic visual flooding experiments with CFD simulations to reveal the oil displacement mechanism of viscosity-reducing combination flooding and establish an empirical formula for oil recovery efficiency. Guided by this formula, a novel cardanol carboxyl quaternary ammonium salt (CCQAS) was designed and synthesized based on the structural characteristics of the optimal surfactant BS-12. This bio-based viscosity reducer achieved an oil recovery efficiency of 27.7% in the compound system, demonstrating promising application prospects.