Experiment on improving lowtemperature properties of oil well cement by a novel accelerator DWA

Key words:  accelerator  oil well cement  deepwater cementing  high early strength at low temperature  antichanneling  static gel strength

Abstract:

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 antichanneling are very helpful to resolve the problems of low temperature and shallow watergas 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 multifunctional accelerator without secondary effect.