关键词: 低温 , 促凝剂 , 油井水泥

Abstract: As the cement slurry hydration speed is slow, the curing time is long and the increase of cement early compressive strength is slow in the low temperature cementing of conductor and surface casing, it is easy to result in oil, gas and water invasion which impairs cementing quality and operation safety. In view of the fact that the accelerator is lack in cementing of low temperature shallow formation currently at home, some accelerators have poor effectiveness and significant negative impact on slurry rheology etc, a new compound accelerator WSA1 was selected by laboratory study. The performance of slurry that mixed WSA1 was systematically evaluated. The result shows that the accelerator WSA1 can enhance the hydration of oil well cement, shorten the thickening time of cement slurry and significantly improve the early compressive strength of cementstones, which all accord with the requirement of the accelerator evaluation criterion. When WSA1 addition amount is 3%, the thickening time of cement slurry can be shortened more than 50%, the 6 h strength of cementstones enhanced from 3.2 MPa to 11.3 MPa and the 24 h strength of cementstones enhanced from 24.3 MPa to 46.1 MPa. Accelerator WSA1 is a kind of highperformance compound accelerator, which can be used in low temperature shallow formation and has no effect on the initial consistency and rheological parameter of cement slurry. 

Key words: Low temperature , Accelerator , Oil well cement