硅烷偶联剂包覆油井水泥的性能与应用

Performance and Application of Oil Well Cement Coated with Silane Coupling Agent

为提高固井水泥环的耐久性,使用硅烷偶联剂KH-560对油井水泥颗粒表面进行包覆处理后以10%的加量加入固井水泥浆中配制成新型的自修复固井水泥浆体系。通过润湿性和水化放热试验研究了硅烷偶联剂包覆油井水泥的表面特性;通过SEM扫描电镜分析和固井水泥环微间隙与微裂缝自修复模拟试验研究了加入硅烷偶联剂包覆油井水泥的固井水泥浆体系固化体的微观结构和自修复性能。研究结果表明:硅烷偶联剂包覆处理后的油井水泥颗粒表面形成了憎水保护膜,降低了水化反应活性;将硅烷偶联剂包覆油井水泥以10%加量加入固井水泥浆后,明显增加了固井水泥环中的未水化产物数量,能够发生多次水化反应,为固井水泥环自修复性能的建立提供了有利条件;加入硅烷偶联剂包覆油井水泥的固井水泥浆固化体损伤试样(模拟微间隙与微裂缝)经过养护后抗窜强度恢复值高于50%,自修复能力优于普通的固井水泥浆,固井水泥环的耐久性和完整性增强,提高了复杂条件下的油气井和储气库的固井质量。

In order to improve the durability of the cement sheath, The silane coupling agent KH-560 was used to coating on the surface ofoil well cement particles, and a self-repairing well cementation cement slurry system was formulated by adding 10% oil well cement particles coated with the silane coupling agent to the cement slurry. Through the analysis of wettability and hydrate exothermal tests, the surface properties of oil well cement particles coated with the silane coupling agent KH-560 were studied; through the analysis of scanning electron microscope （SEM） and the model experiments of the cement sheath self-healing with micro-clearances and micro-cracks , the microstructure and self-repairing properties of the cement sheath formed by the new self- repairing well cementation cement slurry system were studied. The results showed that, the surface of oil well cement particles coated with the silane coupling agent KH-560 formed a hydrophobic protective membrane, which could decrease the activity of hydration reaction. The quantity of unhydrated particles and the ability of multiple hydration reaction of the cement sheath formed by the new self-repairing well cementation cementI slurry system were increased significantly compared to that of the common cement slurry, which improved the self-repairing performance of cement slurry. For the injured cement slurry samples （for modeling the micro-clearances and micro-cracks of the cement sheath）, it is found that the anti-channeling strength recovery value was higher than 50% in the cement sheath samples formed by the new self-repairing well cementation cement slurry system, and the self-healing performance for micro-clearance and micro-crack was superior to the ordinary cementing slurry, as a result, the durability and intergrity of the cement sheath was enhanced and the cementing quality ofoil and gas well and gas storage under complex conditions was improved.