含双温敏单体的耐220 ℃高温降失水剂

Fluid Loss Additive Containing Double Temperature-sensitive Monomer with High Temperature 220 ℃ Resistance

李早元 陈建 黄盛 杜培伟 蒋卓颖 罗龙

LI Zaoyuan CHEN Jian HUANG Sheng DU Peiwei JIANG Zhuoying LUO Long

针对目前油井水泥降失水剂高温条件下耐温性差的问题，通过分子结构设计，以丙烯酰胺（AM）、对苯乙烯 磺酸钠（SSS）、双温敏单体N，N-二甲基丙烯酰胺（DMAA）与N，N-二乙基丙烯酰胺（DEAA）为原料，通过水溶液 自由基聚合法制备了一种耐高温降失水剂（LHF-1L）。以失水量为评价指标，对合成条件进行了优选，同时对 LHF-1L进行了结构表征和性能评价。结果表明，在AM、SSS、DMAA、DEAA物质的量比为4∶6∶2∶0.5，引发剂为 单体总质量0.75%的过硫酸钾（KPS）溶液，反应物溶液pH值为7，反应温度为65 ℃，反应时间为4 h 的条件下制 得的LHF-1L的降滤失性能最佳。在220 ℃、7%加量下的失水量为42 mL。FT-IR、TG和GPC测试结果表明，4 个单体均成功参与聚合并生成目标产物。当温度达到273 ℃后，LHF-1L才出现明显的热损失，其多分散系数为 1.396，数均分子量为171 351 g/mol。此外，LHF-1L 对水泥浆流动度和水泥石抗压强度发展的影响较小。在 220 ℃下，在水泥浆中加入7% LHF-1L后的失水量仍能控制在50 mL以内。在150 ℃、94.4 MPa下，LHF-1L不 会使水泥浆急剧增稠和超缓凝，稠化曲线正常，未发生异常胶凝现象。采用双温敏单体制备LHF-1L，增强了其 在高温下的温敏疏水缔合作用，从而提高了高温降滤失性能，可以满足高温条件下的固井技术需求。

To solve the problem of poor temperature resistance of oil well cement fluid loss additive under high temperature conditions，this study adopted acrylamide（AM），sodium p-styrene sulfonate（SSS），N，N-dimethylacrylamide（DMAA）and N， N-diethylacrylamide（DEAA）as organic synthesis materials through molecular structure design. A fluid loss additive LHF-1L with high temperature resistance was synthesized successfully by aqueous solution free radical polymerization method. The influence of synthetic conditions on the fluid loss reduction performance was discussed comprehensively，and then the chemical characterization and performance evaluation of LHF-1L were carried out. The results showed that the filtration reduction performance of LHF-1L was the best under the preparation condition of 4∶6∶2∶0.5 monomer ratio of AM∶SSS∶DMAA∶DEAA，0.75% initiator potassium persulfate（KPS）solution in total mass of monomer，7 pH value of reactant solution，65 ℃ reaction temperature，4 hrs reaction time. The water loss at 220 ℃ with LHF-1L dosage of 7% was 42 mL. The test results of FT-IR，TG and GPC showed that all four monomers were successfully involved in the polymerization，and then the target product was generated. Only when the temperature reached 273 ℃ ，apparent heat loss of LHF-1L appeared. The polydispersity coefficient was 1.396，meanwhile，the average molecular weight was 171 351 g/mol. In addition，LHF-1L had little influence on the development of cement slurry fluidity and cement compressive strength. At 220 ℃，the water loss after adding 7% LHF-1L to the cement slurry could still be controlled within 50 mL. At 150 ℃ and 94.4 MPa，LHF-1L would not cause the slurry to thicken sharply and super retarding. The thickening curve was normal，moreover，no abnormal gelling phenomenon occured. The preparation of LHF-1L by double temperature-sensitive monomer enhanced its thermosensitive hydrophobic association at high temperature，thus improving its fluid loss reduction performance at high temperature，and meeting the requirements of cementing technology at high temperature.

10.19346/j.cnki.1000-4092.2024.01.001