聚磺水基钻井液沉降稳定性影响因素及调控方法研究

Study on the Influencing Factors and Regulation Methods of the Settlement Stability of the Polysulfonated Water-Based Drilling Fluid

摘要: 钻井液的沉降稳定性对井下安全至关重要，针对聚磺水基钻井液施工要求，本文通过流变性、滤失性、润滑性和沉降稳定性测试，评价了聚磺水基钻井液的沉降稳定性，探究了温度、增粘剂、降滤失剂、加重材料对聚磺水基钻井液沉降稳定性的影响规律。结果表明，现场聚磺水基钻井液老化后的沉降因子均大于0.52，且随老化温度升高沉降因子变大；加入增粘剂、降滤失剂后实验浆的沉降因子均减小，沉降稳定性变好；选用铁矿粉作为加重材料时，聚磺水基钻井液的沉降稳定性较好；包被絮凝剂通过吸附在颗粒表面，形成桥接，可阻止颗粒聚结防止沉降。基于增粘剂、降滤失剂、加重材料和包被絮凝剂的种类与加量优选，优化了聚磺水基钻井液的沉降稳定性及调控方法。

Abstract: The settlement stability of drilling fluid is critical for downhole safety. To meet the operational requirements of polysulfonated water-based drilling fluids, this study evaluated their settlement stability through comprehensive testing of rheological properties, fluid loss, lubricity, and settlement stability. The investigation focused on the influence patterns of temperature, viscosifiers, fluid loss reducers, and weighting materials on the settlement stability of polysulfonated water-based drilling fluids. The results indicated that the settlement factor of field polysulfonated water-based drilling fluids exceeded 0.52 after aging and increased with rising aging temperature. The addition of viscosifiers and fluid loss reducers reduced the settlement factor of the experimental fluid, improving settlement stability. The use of iron ore powder as a weighting material resulted in better settlement stability of the polysulfonated water-based drilling fluid. Furthermore, encapsulating and flocculating agents enhanced stability by adsorbing onto particle surfaces and forming bridges, thereby preventing particle aggregation and settlement. Based on the optimization of the types and dosages of viscosifiers, fluid loss reducers, weighting materials, and encapsulating and flocculating agents, the settlement stability and control methods for polysulfonated water-based drilling fluids were effectively optimized.