新型促凝剂DWA改善固井水泥低温性能的实验

Experiment on improving low-temperature properties of oil well cement by a novel accelerator DWA

模拟深水固井低温环境,考察新型锂盐复合类促凝剂DWA对固井水泥浆稠化时间、静胶凝强度和抗压强度的影响。结果表明:促凝剂DWA能促进固井水泥的低温水化能力,缩短水泥浆稠化时间,明显缩短稠度30～100 Bc、静胶凝强度48～240 Pa的时间,显著提高水泥石早期抗压强度,表现出优异的低温早强、防窜性能,有助于解决深水固井面临的低温、浅层水-气流动难题;DWA促凝作用优于CaCl2,对水泥浆初始稠度无影响,是一种无副作用的新型多功能促凝剂。

Simulating the low temperature environment of deepwater cementing,a series of laboratory experiments were carried out to investigate the effect of a novel lithium salt accelerator DWA on the thickening time,static gel strength and compressive strength of cement slurry.The results show that the lithium salt accelerator DWA can accelerate the hydrate ability of oil well cement at low temperature,can shorten the thickening time of cement slurry,distinctly shorten the time of the slurry consistency from 30 Bc to 100 Bc as well as the transit time of static gel strength from 48 Pa to 240 Pa,and significantly improve the early strength of set cement.The accelerator DWA s excellent performances of high early strength at low temperature and anti-channeling are very helpful to resolve the problems of low temperature and shallow water-gas flow during deepwater cementing.Compared with the accelerator CaCl2,DWA not only has remarkable good accelerating effect,but also has no effect on the initial consistency of cement slurry.The accelerator DWA is a novel multi-functional accelerator without secondary effect.