The conventional oil-well cement dispersant has the characteristics of poor dispersion at high temperature, poor compatibility with other additives, and environmental pollution during the production process. In this article, with ultra-early strong polyether monomer, acrylic acid, 2-acrylamine-2-methylpropyl sulfonic acid, sodium methacrylate as copolymer monomers, an environmentally friendly polycarboxylic acid dispersant, DRPC-1L, was prepared by the aqueous solution free-radical polymerization. The chemical composition and thermal stability of the synthetic copolymer were characterized by FTIR and TGA techniques. The evaluation results show that DRPC-1L has a wide temperature range (30~210 °C), good salt-resistance and dispersing effect. It can significantly improve the rheological performance of cement slurry, and it is well matched with oil-well cement additives such as fluid loss agent, retarder and so on. Moreover, it is beneficial to the mechanical strength development of set cement, especially the early compressive strength. It can also inhibit the abnormal gelation phenomenon of cement slurry, flash set, that occurs during high temperature thickening experiments, which plays an important role in enhancing the comprehensive performance of cement slurry. Consequently, the novel polycarboxylic acid dispersant has good application prospects in deep and ultra-deep wells cementing.
Synthesis and retarder mechanism study of a novel amphoteric composite high temperature-resistant retarder for oil well cement
