摘要
针对丁苯胶乳用于固井增韧剂存在耐温性、抗盐性差,且在使用过程中需要搭配胶乳调节剂的缺点,以对苯乙烯磺酸钠、衣康酸为功能单体,OP-10、SDS复合乳化体系,改性丁苯胶乳合成了SCMBR胶乳,研究了不同乳化剂复配比例对该胶乳性质的影响.通过粒径、Zeta电位、透射电子显微镜综合表征了该胶乳的微观结构,评价了其耐热性、抗盐性.结果表明,由于磺酸基团和羧基的引入,SCMBR胶乳的耐热性能良好,热分解温度达 400℃以上,且抗盐性能优异,TEM图像显示,SCMBR胶乳分散均匀,无团聚体.将SCMBR胶乳引入水泥,可明显改善水泥的稳定性,将游离液含量降低至 1%以下,水泥浆上下层密度差缩小至 0,对水泥流变性能抗折强度提升效果明显,效果最优的SCMBR-4:1改性水泥石28d的抗折强度相较于纯水泥提高了20.5%,在深层、超深层固井中应用前景广阔.
Abstract
Styrene butadiene latex as a toughening agent in well cement slurries has some deficiencies such as poor thermal stability and salt resistance,and the styrene butadiene latex has to be used together with latex conditioners.To solve these problems,the styrene butadiene latex is modified with other monomers,such as sodium styrenesulfonate and itaconic acid as the functional monomers,and a composite emulsion system containing OP-10 and SDS to produce an SCMBR latex.The effects of different emulsifier formulation on the properties of the latex were investigated.The microstructure of the SCMBR latex was characterized with particle size,Zeta potential and transmission electron microscope.The thermal stability and salt resistance of the SCMBR latex was evaluated.Laboratory experimental results show that the SCMBR latex has good thermal stability,the thermal decomposition temperature is as high as above 400℃.The SCMBT latex also shows good salt resistance.TEM image shows that the SCMBT latex is evenly dispersed with no aggregate existed.The SCMBT latex can significantly improve the stability of cement slurries,it reduces the amount of free liquid to less than 1%,and the difference between the density of the top and the density of the bottom can be reduced to 0.The SCMBT latex can also be used to improve the rheology of the cement slurries and the flexural strength of set cement.A set cement modified with the SCMBR latex has 28 d flexural strength 20.5%higher than the flexural strength of the pure set cement.In deep and ultra-deep well cementing the SCMBR latex will have broad application prospect.
基金项目
中国石油渤海钻探工程有限公司指导项目(2021D28F)
国家科技期刊平台
NSTL
万方数据