乙二醇对聚乙烯醇降失水效果的影响研究

Study on the effect of ethylene glycol on reducing water loss of polyvinyl alcohol

聚乙烯醇(PVA)作为油井水泥浆降失水剂使用时,适用温度低。采用硼砂作为交联剂时,PVA与硼砂易在混合水中发生过度交联,呈胶状物析出。以硼酸代替部分硼砂,混合水状态良好,但控失水效果不佳。本研究发现,以水/乙二醇(w/w=4∶1)作为溶剂,配制PVA与硼砂/硼酸交联剂溶液,可有效提高其控失水性能。同时,乙二醇的加入可提高产品的低温抗冻性,更符合我国海上平台材料的储存环境。

When polyvinyl alcohol(PVA)is used as a fluid loss additive for oil well cement slurry,the applicable temperature is low.When borax is used as a cross linking agent,PVA and borax are prone to excessive cross linking in the mixed water and precipitate in the form of a colloid.Part of the borax is replaced by boric acid,the mixed water is in good condition,but the fluid loss control effect is not good.In this study,it was found that water/ethylene glycol(w/w=4∶1)was used as a solvent to configure PVA and borax/boric acid crosslinking agent solution,which could effectively improve its water loss control performance.At the same time,the addition of ethylene glycol can improve the low-temperature frost resistance of the product,which is more in line with the storage environment of my country's offshore platform materials.