深水固井液体减轻低密度水泥浆体系

与传统的表层固井技术不同，深水表层固井由于受到深水环境和现场条件限制，对固井作业提出了新的要求。针对深水表层固井的难点，开发了一种新型液体减轻剂PC-P81L，并以其为主体构建出了深水固井液体减轻低密度水泥浆体系。室内实验结果表明，PC-P81L作为减轻剂对水泥浆具有密度调节作用，可在1.30~1.70 g/cm3之间调节水泥浆密度；具有高悬浮性，最高可悬浮水灰比为2的水泥浆；具有增强作用，还可以应用于常规密度水泥浆中作为增强剂；具有促凝作用，可在深水低温环境下缩短水泥浆稠化时间。构建的深水固井用液体减轻低密度水泥浆体系，通过增大水灰比降低水泥浆密度，提高了水泥浆的造浆率，减少现场水泥用量；且配方简单，易于调节，外加剂以全液体形式添加，减小了现场工作人员的劳动强度；同时满足深水低温环境下的水泥浆性能要求，为下部钻进提高保障；液体减轻水泥浆体系作业成本较漂珠体系也大幅度降低，满足深水低温条件的性能要求，可适用于深水表层固井。 

Liquid Cementing Fluid Reduced Lightened Deep Water Light-weight Cement Slurry

Contrary to the surface hole cementing operation, deep water surface hole cementing imposes new requirements on well cementing operation because of the deep water environment and the operation condition. A new liquid light weight agent PC-P81L has been developed for use in cementing the surface hole in deep water drilling, and a cementing fluid was formulated with PC-P81L. Laboratory experimental results showed that PC-P81L can be used to adjust the density of cement slurry between 1.30 g/cm3 and 1.70 g/cm3. PC-P81L has strong suspending capacity; it can suspend cement slurries with water/cement ratio of 2. PC-P81L is not only a light weight agent, it is also a strength enhancer in cement slurries with conventional densities. PC-P81L can accelerate the setting of cement slurry in deep water low temperature environment. By increasing the water/cement ratio, the density of the deep water low density cement slurry can be reduced, and the yield of the cement slurry increased, thereby reducing the consumption of cement in field application. The formulation of the cement slurry is simple and the properties of the cement slurry are easy to adjust. The additives used are added in liquid form, thereby lightening the field labor intensity. The use of the cement slurry has satisfied the needs for deep water low temperature operation, providing insurance for drilling the deeper formation. Compared with hollow microsphere, the operation cost of the light weight cement slurry is quite lower.