振动对水泥颗粒堆积行为的影响直接决定着水泥石强度特征,也是保障振动固井施工质量的关键因素。利用EDEM离散元数值模拟软件计算了振动对水泥颗粒充填率的影响规律。结果显示:在振动参数方面,颗粒充填率随振动频率的增加而单调递增,随振幅的变化呈现二次函数关系,在振幅1 mm处颗粒充填率最高,在振动时间达到0.2 s以后,振动对颗粒充填率的提升幅度基本恒定,水平振动对颗粒充填率的提高幅度约为垂直振动时的3.08倍;在颗粒形貌方面,振动对不同尺寸、不同圆球度颗粒充填率均有提高,颗粒尺寸越大提高效果越显著。此外,不同尺寸颗粒混合后的充填率最高可提升40.22%,不同圆球度颗粒混合后充填率可提高8.33%。由于实际水泥颗粒无法保证均匀一致的粒径和圆球度,因此通过施加机械振动来改善颗粒堆积效果是提高水泥石强度的有效手段。

The influence of vibration on the accumulation behavior of cement particles directly determine the strength characteristics of the cement stone, and it’s also a key factor for ensuring the construction quality of vibration cementing. Therefore, the effect of vibration on the fill ratio of cement particles is calculated by using EDEM. The results show that the filling ratio monotonically increases with the increase of vibration frequency. There is a quadratic function relationship between the filling ratio and the amplitude, and the filling ratio is highest when the amplitude is about 1 mm. Raising the percentage of the filling ratio is basically constant when the vibration time exceeds 0.2 s. The increase value of the horizontal vibration to the filling ratio is about 3.08 times that of the vertical vibration. In terms of particle morphology, the filling ratio with different sizes and sphericity would be improved by vibrating. The larger particle size is, the more significant the effect is. In addition, the filling ratio of different size particles would be increased up to 40.22% after mixing, the value of different sphericity particles would be increased up to 8.33% . In summary, the actual cement particles couldn’t maintain the uniform size and sphericity, so it’s necessary to apply mechanical vibration to improve the particle accumulative effects.