影响水泥环第二界面胶结质量的因素分析

ANALYSIS OF THE INFLUENCE FACTORS ON BONDING QUALITY OF THE SECOND CEMENTING INTERFACE

固井作业是油气井钻井工程的重要环节之一,油气井固井的第二界面是一个变化极大的界面,水泥环第二界面往往是发生油气水窜的薄弱环节,其影响因素众多。文章对影响固井第二界面胶结质量的因素进行综合分析,建议在钻井施工设计时要为固井施工考虑,形成好的井眼条件,为提高水泥浆顶替效率做好前期准备,提高冲洗液性能,水泥浆顶替时活动套管、使用辅助套管附件,充分清除静止在环空中的钻井液及井壁上的滤饼;采用钻井液转化水泥浆技术,将钻井液滤饼由水泥环胶结质量薄弱层转化为增强层;提高水泥浆的微膨胀性能,控制微间隙产生;水泥浆候凝期间要压稳,防止窜流发生。

The second cementing interface is a weak part leading to fluid channeling,and its influential factor is many.In this paper,the influence factors on bonding quality of the second cementing interface were analyzed comprehensively.Drilling operation design should take cementing into account,favorable well conditions were provided for enhancing displacement efficiency of slurry cement.The measures should be taken to remove the drilling fluid in the annulus and filter cake in borehole wall,such as rotating and moving casings up and down during displacement operation,using casing accessories,and so on.The bonding strength was enhanced by using transformation drilling fluid into cement slurry.Micro expansion cement slurry was used to avoid the micro-annulus produced by cement shrinkage,and the maintaining pressure balance to prevent fluid channels was carried out during cement slurry setting.