A series of amphoteric polycarboxylate (APC) dispersants for oil well cement were prepared by free radical polymerization of ω-hydroxy polyethylene glycol (HPEG), maleic anhydride (MA) and [2-(Methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA). The chemical structure of dispersants was characterized by Fourier Transform Infrared Spectrometer (FTIR), ¹H-Nuclear Magnetic Resonance (¹H NMR) and Gel Permeation Chromatography (GPC). The fluidity, rheology and compressive strength measurements were conducted to evaluate the performance of cement paste with various APC dispersants. The results show that APC dispersants with hydrolysable ester groups and cationic groups enhance dispersing ability, improve rheological property, and promote the compressive strength of cement. Meanwhile, the effect of various APC dispersants on cement hydration was also investigated, which indicate that APC dispersants have a higher adsorption capacity on cement particle than the conventional polycarboxylate (PC) dispersant, resulting in a visible impact on retardation of cement hydration. Besides, APC dispersant notably increases compactness of hardened cement and improves the microstructure of cement, which remarkably enhances mechanical properties of cement paste. Consequently, the APC dispersants show excellent performances in cement paste systems and have great potential for application in oil/gas well cementing.

通过ω-羟基聚乙二醇（HPEG），马来酸酐（MA）和[2-（甲基丙烯酰氧基）乙基]二甲基-（3-磺丙基）的自由基聚合反应制备了一系列油井水泥两性聚羧酸盐（APC）分散剂。氢氧化铵（SBMA）。分散剂的化学结构通过傅立叶变换红外光谱仪（FTIR），¹ H-核磁共振（¹1 H NMR和凝胶渗透色谱法（GPC）。进行了流动性，流变学和抗压强度测量，以评估具有各种APC分散剂的水泥浆的性能。结果表明，具有可水解酯基和阳离子基团的APC分散剂增强了分散能力，改善了流变性，并提高了水泥的抗压强度。同时，还研究了各种APC分散剂对水泥水化的影响，这表明APC分散剂对水泥颗粒的吸附能力比常规的聚羧酸盐（PC）分散剂高，从而对水泥水化的延迟产生了明显的影响。此外，APC分散剂可显着提高硬化水泥的密实度，并改善水泥的微观结构，显着提高水泥浆的机械性能。因此，APC分散剂在水泥浆体系中显示出优异的性能，在油/气井固井中具有巨大的应用潜力。