摘要
许多油田在开发过程中 ,都遇到了地层中含有的诸如CO2 和H2 S等腐蚀性介质影响油井水泥环密封效果的问题 ,加强抗腐蚀水泥外加剂和水泥浆体系的研究变得至关重要。从水泥石腐蚀机理的研究出发 ,通过试验优选出了抗腐蚀性水泥填充料WG。WG的主要成分为非晶态SiO2 ,具有粒细 (平均粒径约为 0 .1μm)、比表面积大、活性高等特点。另外 ,选用不渗透剂G6 0S和硅粉 ,可以提高水泥石密实度 ,降低水泥石渗透率 ,从而提高水泥石的抗腐蚀性。通过对 9种配方水泥浆固化体进行不同龄期的CO2 、H2 S腐蚀 ,测定水泥石腐蚀后的抗压强度、渗透率和腐蚀深度 ,进行反光显微镜、X 射线衍射分析 ,比较了填充料WG水泥浆、现场水泥浆、纯水泥浆固化体的抗腐蚀性 ,优选出了抗腐蚀高密度和低密度水泥浆配方。该抗腐蚀水泥浆体系不但具有抗腐蚀性 ,还具有良好的防气窜、降低自由水、稳定浆体等综合性能 ,可以满足不同井深条件下的固井作业需要。
Many oilfields in the world encountered the problem of oil cement sealing property ruined by corrosive mediums in the formation such as CO 2 and H 2S. To improve the structure integrity and sealing property of cement stone down hole for a long time period in acidic environment, research on corrosion resisting cement additives and relevant cement slurry systems becomes vital. Based on the study of corrosive mechanism to cement stone, anti-corrosion cement packing material WG was optimized, and 9 cement slurry were prepared. After different-period corrosion by CO 2 and H 2S to the 9 cured cement stones, parameters such as pressure strength, permeability and corrosive depth were measured. At the same time, the stone properties were analyzed by SEM and XRD methods. As a result, two corrosion resisting cement slurry compositions of high and low density were proposed. The system exhibits not only corrosion resistivity, but also good comprehensive properties such as anti-gas channeling, free water volume reducing andstable properties, which can satisfy cementing requirements for different depth operation.
出处
《钻井液与完井液》
CAS
北大核心
2004年第6期37-40,共4页
Drilling Fluid & Completion Fluid
