Special cement here refers to cementing materials made by grinding the portland cement clinker and right amount of gypsum used for oil and gas well and the cementing engineering at a certain temperature.
Special cement features commendable flowability, strong stability, fast setting and hardening, strong impermeability and corrosion resistance. Special cement has suitable density and setting time, and low consistency. The ready-mixed oil well concrete made from this kind of special cement tends to have good settlement resistance and pumpability.
During well injection, the slurry prepared under the conditions of temperature and pressure at the bottom of the hole has proper fluidity and appropriate density; The cement slurry sets quickly after being injected into the well. It can also realize the required strength in a short time; Hardened set cement has impressive stability and impermeability against erosion in formation cement.
Used exclusively for oil Wells, gas Wells and other cementing works.
| 品质指标 | 单位 | 国家标准 | 企业标准 | ||||
| 烧失量（Loss） | % | ≤3.0 | ≤3.0 | ||||
三氧化硫（so） | % | ≤3.0 | ≤3.0 | ||||
氧化镁（MgO） | % | ≤6.0 | ≤6.0 | ||||
不溶物 | % | ≤0.75 | ≤0.75 | ||||
碱含量（R2O） | % | ≤0.75 | ≤0.75 | ||||
硅酸三钙（C3S） | % | ≥48且≤65 | ≥48且≤565 | ||||
| 铝酸三钙（C3A） | % | ≤3.0 | ≤3.0 | ||||
| C4AF+2C3A | % | ≤24 | ≤22 | ||||
| 游离液含量 | % | ≤5.9 | ≤5.5 | ||||
方案 | 52℃ | 15-30Min稠度 | BC | ≤30 | ≤30 | ||
| 35.6MPa | 稠化时间 | min | ≥90且≤120 | 90且≤120 | |||
| 抗压强度 | 38℃，常压，8h | MPa | ≥2.1 | ≥2.5 | |||
| 60℃，常压，8h | MPa | ≥10.3 | ≥11.5 | ||||
