外加剂对水泥石力学性能的影响

Effect of Admixtures on Mechanical Properties of Cement

陈昌宏 张倩 朱彦飞 宫贺 黄莺 姚尧

CHEN Changhong ZHANG Qian ZHU Yanfei GONG He HUANG Ying YAO Yao

传统水泥石的硬脆性是致使油井整体性在复杂多变的井下工况及油气井后续施工中受到破坏、导致层间封隔失效的主要原因。为进一步提高水泥石性能，解决石油固井等实际问题，在普通固井水泥（G级纯水泥）中掺加定量的丁苯胶乳、硅粉、石棉等外加剂，形成胶乳水泥（G级水泥添加丁苯胶乳）、二元复配水泥（G级水泥添加丁苯胶乳和硅粉）和三元复配水泥（G级水泥添加丁苯胶乳、硅粉和石棉），研究了外加剂对水泥石抗压强度、杨氏模量、泊松比和体积弹性模量等9 项力学性能的影响。结果表明，普通固井水泥、胶乳水泥、二元复配水泥和三元复配水泥四种水泥石的泊松比均接近0.20。与普通水泥石相比，胶乳水泥石、二元复配水泥石和三元复配水泥石抗压强度分别提高24.6%、12.3%和降低11.2%。二元复配水泥石的杨氏模量和体积弹性模量均提高，分别为11.8%和12.9%；而胶乳水泥石分别降低2.9%和8.2%；三元复配水泥石分别降低14.7%和18.6%。二元复配水泥石有较强的刚度，胶乳水泥石和三元复配水泥石表现出较好的弯曲性能，具有柔性好的特点，此外胶乳水泥石表现出较好的抗冲击韧性。胶乳水泥为石油固井的最佳选择。表10 参16

The hard brittle of traditional cement was not only causing the damage of integrity of oil well in the course of work and subsequent construction，but also the main cause of failure of inter-zonal isolation. In order to study and improve the performance of cement further and solve practical problems of well cementation，the admixtures，such as styrene-butadiene latex，silica fume and asbestos，were added to the ordinary cement（G-pure cement），which formed latex cement（a combination of G-pure cement and styrene-butadiene latex），binary compound cement（a combination of G-pure cement，styrene-butadiene latex and silica fume），and ternary compound cement（a combination of G-pure cement，styrene-butadiene latex，silica fume and asbestos）. The effect of admixtures on nine kinds of mechanical properties of those cements were investigated，including compressive strength，Young’s modulus，Poisson’s ratio and bulk modulus，etc. The results showed that four types of cement，including traditional cement，latex cement，binary compound cement，and ternary compound cement had similar Poisson’s ratio values with about 0.2. Furthermore，compared with the traditional cement，the compressive strength of latex cement and binary compound cement enhanced 24.6% and 12.3% while that of ternary compound cement reduced 11.2%，respectively. Young’s modulus and bulk modulus of elasticity of binary compound cement increased 11.8% and 12.9%，respectively，while those of latex cement decreased 2.9% and 8.2%，and those of ternary compound cement decreased 14.7% and 18.6%. Binary compound cement showed more strength. On the contrary，latex cement and ternary compound cement showed better bending property and good flexibility. In addition，latex cement showed good impact toughness，which was the best choice for well cementation.

10.19346./j.cnki.1000-4092.2017.03.010