摘要
在一定的注汽压力下,随着热蒸汽的注入,热采井中套管与水泥环的温度逐渐升高,特别是封隔器失效及注汽段处,套管与水泥环的温度甚至可达350℃,产生的热应力足以使水泥环发生塑性变形而失效。当水泥环降至初始温度(注汽前)时,就会产生永久的塑性变形。文章运用弹塑性力学以及热力学基本理论,建立了套管-水泥环耦合模型,分析了套管与水泥环的应力分布,推导了冷热膨胀后水泥环内部的塑性变形方程,并以辽河油田常规注汽以及油井参数为例,借助Ansys及Matlab软件确定各项参数,得出了不同隔热方式下交界面处的微间隙值,为防套损及井下气窜提供了理论依据。
Under definite steam injection pressure, with continuous steaming, the temperature of casing and cement mantle increased gradually. The temperature could even rise up to 350℃ especially for the placement of packer failure. When the cement mantle was cooled to its original temperature(before steam injection), a permanent plastic deformation would be occurred in the mantle. The casing-cement mantle coupling model was established by using the elastic-plastic mechanics and the thermodynamics basic theories, the stress distribution between casing and cement mantle was analyzed and the equations of plastic deformation was derived in the cement mantle. Taking conventional steam injection and well parameters as example in Liaohe Oilfield, the corresponding variables in the equations were determined by ANSYS and MATLAB software, the micro-clearances value was calculated under different heat insulation conditions and some theory foundations were provided for preventing casing damage and gas channeling.
出处
《钻采工艺》
CAS
北大核心
2011年第6期68-70,78,共4页
Drilling & Production Technology
关键词
热应力
微间隙
水泥环
塑性变形
thermal stress, micro-clearance, plastic deformation
