新型低温固井早强剂性能研究.

A new low temperature early-strength agent ES-22 has been developed through dispersion-coprecipitation method to solve the slow strength development of cement slurries in shallow and low temperature well cementing. In laboratory experiment, the particle size distribution and micro-structure of ES-22 were analyzed, the effects of ES-22 and other inorganic early-strength agents on the strength development of cement slurries at low temperatures were compared. The effects of ES-22 of different concentrations on the properties of cement slurries were also studied. It was found that ES-22 has particle sizes distributed between 15 μm and 25 μm. Compared with other early-strength agents, ES-22 is the best early-strength agent for the development of the early compressive strength of set cement. At low temperatures, ES-22 has even greater contribution to the development of the mechanical property of the set cement. ES-22 has little, if any, effects on the rheology of the cement slurry, the thickening time of the cement slurry becomes only a little short, and the volume of filter loss is reduced. In laboratory experiment, a set cement containing 4% ES-22 had its compressive strength and flexural strength increased by 204% and 136% respectively over the compressive strength and flexural trength of the blank set cement after aging at 20 ℃ for 24 hours. These results indicate that the early-strength agent ES-22 performs very well in oil well cement slurries. [ABSTRACT FROM AUTHOR]