通过测试腐蚀前后固井水泥石的渗透率、抗压强度和腐蚀深度,评价了不同微硅添加量的固井水泥石的耐蚀性,采用扫描电镜(SEM)和X射线衍射仪(XRD),分析了微硅固井水泥石的抗CO₂腐蚀性能。结果表明:与空白固井水泥浆相比,添加3%、6%和9%微硅的固井水泥浆的稠化时间缩短了11~38 min,失水量降低了8~27 mL,自由液降低为0,微硅固井水泥石的抗压强度和抗折强度分别提高了11.1%~46.7%和49.8%~104.9%,渗透率降低了0.026~0.046 mD,微硅促进了固井水泥浆的水化过程;当微硅添加量为9%时,腐蚀21 d后微硅固井水泥石的抗压强度衰退率和渗透率变化率分别为8%和16%,微硅的添加提高了水泥石的抗CO₂腐蚀性能,且微硅添加量越高,固井水泥石的抗CO₂腐蚀性能越好;微硅的添加提高了固井水泥石的致密度,在一定程度上降低了固井水泥石的腐蚀程度。

By testing the permeability, compressive strength and corrosion depth of cementing stone before and after corrosion, the corrosion resistance of cementing stone with different micro-silicon additions was evaluated. Using scanning electron microscope (SEM) and X-ray diffractometer (XRD), the CO₂ corrosion resistance of micro-silicon cementing stone was analyzed. The results showed that compared with the blank cementing stone, the thickening time of cementing stone with 3%, 6% and 9% micro-silicon added was shortened by 11-38 min, the water loss was reduced by 8-27 mL, and the free liquid was reduced to 0, compressive strength and flexural strength of micro-silica cementing cement were increased by 11.1%-46.7% and 49.8%-104.9%, respectively, and permeability was reduced by 0.026-0.046 mD. When micro-silicon addition amount was 9%, the compressive strength decline rate and permeability change rate of micro-silicon cementing stone after corrosion for 21 days were 8% and 16%, respectively. The addition of micro-silicon improved the CO₂ corrosion resistance of cementing stone, and the greater the amount of micro-silicon added, the better the CO₂ corrosion resistance of cementing stone. The addition of micro-silicon improved the density of cementing stone and reduced the corrosion degree of cementing stone to a certain extent.