Synthesis and Evaluation of a Sulfonated Biophenol-Modified Resin as a High-Temperature and Environmentally Friendly Filtrate Reducer

With the ongoing expansion of oil and gas exploration into deep and ultra-deep wells, alongside escalating demands for green, low-carbon development and cost-effective efficiency, the development of drilling fluid additives that combine high-temperature resistance, low viscosity impact, environmental compatibility, and low cost has emerged as a critical direction for the industry. This study utilized lignin recovered from papermaking waste liquor as the primary raw material to successfully synthesize a high-temperature, environmentally friendly filtrate reducer—sulfonated biophenol-modified resin SMBMP-1—through alkali-oxygen degradation and graft modification processes. Experimental results demonstrate that the additive exhibits temperature resistance up to 180 ℃, salt tolerance to saturation, and calcium resistance of 3%. Its high-temperature, high-pressure fluid loss was only 14.6～15.4 mL, significantly outperforming the SMP-II industry standard (≤35 mL). Regarding environmental performance, it shows an EC₅₀ value of 259,000 mg/L and a BOD₅/COD_Cr ratio of 0.23, indicating it is non-toxic and readily biodegradable. Furthermore, the additive exhibits a low viscosity effect and demonstrates good compatibility within drilling fluid systems. The development of sulfonated biophenol-modified resin provides robust product support for rheological control and wellbore stability in deep and ultra-deep well drilling. It also holds significant importance for promoting the high-value utilization of biomass resources in the drilling fluid industry.