Abstract:

As the cement slurry hydration speed is slow and curing time is relatively longer under the condition of low-temperature,it is easy to result in oil,gas and water invasion which leads to poor well cementation quality,and the early strength agent without chloride is lack in cementing of low temperatrue shallow formation.In order to cope with these situations,based on the principles of hydration and low temperature high early strength of cement slurry，the water-soluble chlorine-free chemical raw material，which has the function of low temperature high early strength on cement,is adopted in this research.According to experiment,two kinds of inorganics materials A and B,an organic salt C and an organic acid are selected out and ZC-2S which is a new kind of low temperature early strength accelerator without chloride is developed.ZC-2S can prominently accelerate early strength of general density/low density cement slurry and is of good compatibility with other cement additives.ZC-2S is good early strength accelerator used in low temperature shallow formation and can cement in absence of dry-mixing equipment.

Key words: low-temperature wells, early strength agent, cement slurry, well cementing