硅酸盐水泥调剖剂粒度分形维及其与封堵性能的关系评价

Fractal dimension of particle size of silicate cement profile control agents and its relationship with plugging performance

基于粗集料粉体颗粒的Fuller堆积模型及分形理论,评价了4种硅酸盐水泥调剖剂实测和模型计算的粒度分布分形维及其与封堵性能的关系。结果表明,测试粒度分布与Fuller法计算结果均有偏差,粗颗粒比细颗粒的含量高。测试的4种样品粒度分布分形维2.079 4~2.233 3,小于Fuller法计算结果拟合得到的分形维数2.6。4种样品空隙率62.46%~65.01%,固化抗压强度22.1~25.5 MPa,硅酸盐水泥调剖剂颗粒粒度分布分形维数越大,其空隙率越小,颗粒堆积结构越紧密,固化后的抗压强度越高,调剖的封堵能力和抗后续注入水冲刷能力越强。调剖工程设计中,可将测算的粒度分布及分形维数作为硅酸盐水泥调剖剂种类选择、封堵性能评价的参考依据。

The fractal dimension of the particle size of 4 silicate cement profile control agents measured by Laser particle size analyzer and calculated by Fuller method and its relationship with plugging performance of the profile control agents are evaluated based on the Fuller packing model of coarse aggregate particles and fractal theory. The results show that there is difference between the measured particle size distribution and the calculated particle size distribution,the content of coarse particle in the measured particle size distribution is higher but the content of fine particle is lower than that in the calculated particle size distribution. The fractal dimension of the particle size distribution of 4 kinds of samples is in 2. 079 4 ~ 2. 233 3,which is less than 2. 6 of the fractal dimension of the particle size distribution calculated by Fuller method. The void radio of 4 kinds of samples is in 62. 46% ~ 65. 01%,and the compressive strength of solidified cement slurry samples is in 22. 1 ~ 25. 5 MPa. The larger the fractal dimension of the particle size distribution of cement profile control agents is,the smaller the void ratio of the particle is,the closer the particle packing is,the higher the compressive strength of solidified cement slurry is,and the stronger the sealing ability and the water scouring resistance ability of profile control a-gents are. In profile control design,the calculated particle size distribution and its fractal dimension are used as the reference indexes to choose the silicate cement profile control agent and to evaluate its sealing performance.