Abstract
This study investigates the salt-tolerant and emulsification properties of polymer flooding agents under X field conditions, focusing on their behavior in high-salinity and high-mineralization environments typical of mature reservoirs. Laboratory evaluation shows that the polymer maintains stable viscosity and structural integrity despite elevated ion concentrations, demonstrating strong resistance to salinityinduced degradation. Its emulsification performance further enhances oil–water interfacial interactions, contributing to improved mobilization of residual oil. In core-flow experiments, the polymer solution exhibited favorable rheology, stable injectivity, and consistent propagation through reservoir rock, indicating suitability for field application. The resulting displacement efficiency was approximately 13% higher than that achieved by conventional waterflooding, confirming the polymer’s potential to substantially enhance oil recovery under challenging reservoir conditions. Overall, the findings provide a technical basis for optimizing chemical flooding strategies in high-salinity fields and support the broader implementation of polymer flooding in complex reservoirs.