等离子改性岩沥青对油井水泥石的韧性化改造

Modification of Toughness of Oil Well Cement by Plasma Modified Rock Asphalt

针对油井水泥环易脆裂,抗冲击能力差的问题,系统研究了岩沥青对油井水泥石力学性能和微观结构的影响。采用低温等离子体技术对岩沥青颗粒进行表面亲水性处理,解决了岩沥青的憎水现象。通过红外光谱分析,等离子改性后的岩沥青中出现-COOH吸收峰。机械性能测试表明:岩沥青的加入提高了油井水泥石的抗拉强度和变形能力。观察水泥石的微观形貌发现,水泥水化产物与镶嵌于水泥水化产物中的改性岩沥青颗粒形成良好的胶结并构成了CRA水泥石的骨架。岩沥青的加入提高了CRA水泥石的粘弹性,其网络约束的作用使得裂缝间的摩擦力增大,消耗掉一部分外力功,对载荷起到缓冲作用,从而提高了水泥石的抗冲击性能和形变能力。

Forthe problem of oil wellcementsheath easy to rattle and poor impact resistance, studied the effects of rock asphalt on the mechanical properties and microstructure of oil well cement paste. The low temperature plasma technology is used to deal with the surface hydrophilicity of the rock asphalt particles, and the hydrophobic phenomenon of the rock asphalt is solved. By infrared spectrum analysis, the -COOH polar absorption peaksappeared in the plasma modified rock asphalt. Mechanical performance test showed that the tensile strength and deformation capacity of oil well cement paste were improved by the addition of rock asphalt. By seeing the microscopic morphology of cement paste, we found that cement hydration products and modified rock asphalt particles embedded in cement hydration products had good cementation and formed skeleton of CRA cement paste . The addition of rock asphalt improved the viscoelasticity of CRA cement paste, its network constraint made the frictional force between fractures increase, and consumed a part of external work, which can cushion the load and improve the impact resistance and deformation ability of cement paste.