水基钻井液用抗高温耐盐降滤失剂的制备与性能评价

Preparation and Performance Evaluation of High Temperature and Salt Resistant Fluid Loss Reducer for Water-Based Drilling Fluids

针对深井和超深井钻探中水基钻井液在高温高盐环境下性能衰减的问题,通过自由基聚合法合成了一种新型抗高温耐盐降滤失剂。通过引入2-丙烯酰胺-2-甲基丙磺酸、丙烯酰胺和对苯乙烯磺酸钠作为单体,并使用N,N'-亚甲基双丙烯酰胺作为交联剂,优化了聚合条件。结果表明,在最优单体浓度2.0 mol·L^(-1)、最优单体配比n(AMPS)∶n(AM)=4∶1和最佳反应温度80℃的条件下,合成的降滤失剂HTSR展现出优异的降滤失性能,其降滤失率达到75.2%,并在200℃的高温条件下保持了较低的滤失量(7.8 mL)。此外,HTSR在8%NaCl溶液中的滤失量仅为8.6 mL,表现出良好的抗盐性能。热重分析结果显示,HTSR在270℃之前的质量损失较小,具有出色的热稳定性。红外光谱分析进一步证实了其化学结构的正确性。研究成果为高温高盐环境下水基钻井液的降滤失剂设计提供了新的思路,对提高深井和超深井钻探的钻井液性能具有重要意义。

Aiming at the problem of performance degradation of water-based drilling fluids in deep and ultra-deep well drilling in high-temperature and high-salt environments,a new type of high-temperature and salt-resistant fluid loss agent was synthesized through free radical polymerization.The polymerization conditions were optimized by introducing 2-acrylamide-2-methylpropanesulfonic acid,acrylamide and sodium p-styrenesulfonate as monomers and using N,N'-methylenebisacrylamide as cross-linker.The research results showed that under the conditions of optimal monomer concentration 2.0 mol∙L^(-1),optimal monomer ratio n(AMPS)∶n(AM)=4∶1 and optimal reaction temperature 80℃,the synthesized fluid loss reducer HTSR exhibited excellent performance.The filter loss reduction performance reached 75.2%and maintained a low filter loss(7.8 mL)under high temperature conditions of 200℃.In addition,the filter loss of HTSR in 8%NaCl solution was only 8.6 mL,showing good salt resistance.Thermogravimetric analysis results showed that HTSR had less mass loss before 270℃and had excellent thermal stability.Infrared spectrum analysis further confirmed the correctness of its chemical structure.This study provides new ideas for the design of fluid loss additives for water-based drilling fluids in high-temperature and high-salt environments,and is of great significance to improving the performance of drilling fluids for deep and ultra-deep well drilling.