深井固井风险及防控方法研究

Risks of Deep Well Cementing and Its Prevention-control Technology

针对深井固井过程中面临的高温、高压、气窜、井漏等挑战,探讨了深井固井质量影响因素,总结了针对性的固井风险防控方法。研究认为滤饼清除效率、顶替效率、井眼质量、井身结构、钻井液性能和水泥浆性能是影响固井质量的重要工程因素。采用遇烃膨胀水泥浆体系,可增加水泥石密度,封堵裂缝或二界面,延缓酸性气体的腐蚀并防止气窜。针对深井固井井漏难题,除可采用相应工艺措施外,还可配合纤维水泥浆堵漏。

In view of the challenges of high temperature,high pressure,gas channeling and lost circulation during deep well cementing,factors affecting cementing quality and methods for prevention and control of cementing risks are discussed.Researches show that filter cake removal efficiency,displacement efficiency,well bore quality,well bore structure and Drilling fluid properties,cement slurry performance are important engineering factors affecting cementing quality.Hydrocarbon-swellable cement slurry system can increase the density of cement stone,block cracks or the second interfaces,delay the corrosion of acid gas and prevent gas channeling.In order to solve the problem of lost circulation in deep well cementing,in addition to corresponding technological measures,fiber cement slurry can be used for plugging.