Study on new cement slurry system for heavy crude oil thermal recovery in well cementation

摘要

The multi-cycle recovery of heavy crude oil thermal by steam injection and stimulation has serious effects on the integrity of cementing sheath. At present, the class G oil well cement with silica sands, less resistant to high temperatures, does not meet the quality of the heavy crude oil well cementation and requirements of recovery and production. The laboratory results show that Aluminates cement has the characteristics of high early strength; meanwhile, it can maintain strength and stability in a long-term under the circulation of high and low temperature conditions. However, its hydration product C_3AH_6, which makes it a sharp recession in intensity at low temperature, limits its application. According to the clinker selection and compounding with the main item of Aluminates cement indoor experimentation, there comes out a new type of cement binder which generates C_3ASH_4 and other stable phase within rounds of high and low temperature cueing, and made the crystal structure of cement in dense arrangement. With this method, cement hydration structure can be maintained with a long-term stability; and it has the value of further development.