Study on the Synthesis and Performance Evaluation of a Composite High-Temperature Flushing Isolation Fluid Stabilizer

Under ultra-high temperature and high-density conditions, most existing wash isolation liquid suspending agents have limited suspension capabilities at low dosages. This study enhances the suspension ability, optimizes the surface charge distribution, and reduces the probability of precipitation by surface modification and graft polymerization of inorganic mineral materials, thus preparing an organic-inorganic hybrid high-temperature suspension component. By introducing crosslinkers and active monomers with large steric hindrance and high rigidity, the study optimizes the microstructure of the polymer molecular chain, enhances rotational freedom, and improves thermal resistance, leading to the preparation of organic micro-crosslinked ultra-high temperature suspension components. The composite anti- high temperature wash isolation liquid suspending agent prepared in this study combines the characteristics of both inorganic and organic materials. While ensuring rheological properties, it can control the free liquid of the isolation liquid with a density of 2.2 to 2.6 g/cm³ at 200°C to 0 mL, with a density difference of no more than 0.03 g/cm³ after 2 hours of standing, effectively improving the sedimentation stability under high temperature and ultra-high temperature conditions for high-density isolation liquid systems. The results of this study provide a theoretical basis for the safety of deep well cementing operations.