油井净水泥浆及水泥石优化措施研究

Study on optimazing measure of neat cement slurry and cement paste for oil well

邬钢

Wu Gang

华北分公司工程监督中心，河南 郑州 450006

(Supervising Center of Huabei Company, SINOPEC,Zhengzhou 450006, China).

油井水泥是以水硬性硅酸钙为主要成分的胶凝材料，其水化特性、使用环境和施工工艺决定了净水泥浆具有高失水、高密度和水泥浆凝固后水泥石的体积收缩、高脆性等缺陷，无法满足复杂井的固井要求。通过分析净水泥浆、水泥石缺陷给固井施工和储层带来的损害，提出了解决问题的国内常用的外加剂及其作用机理和水泥浆体系，对不同的井内条件下选择合适的水泥浆体系和外加剂具有借鉴和指导意义。

Oil well cement is a kind of binding material mainly made from calcium carbonate which is hydraulic binding material. Its
inherent hydration characteristics,application environment and cementing techniques determine on the neat cement slurry’s
defects as higher water-loss,higher density,higher volume shrinkage and higher brittleness of cement paste after concretion of
cement. Hence, the inherent defects of neat cement slurry and cement paste can’t meet the requirements of cementing. This paper
gives the additives commonly used at home to overcome defects of neat cement slurry and cement paste and its function mechanism.
It also gives a kind of slurry system through analyzing damage of performance index of neat cement slurry and cement paste’s
defects for cementing and formation. What we have done can be very useful for selecting proper cement system and additives under
different borehole condition.