基于应变的热采井套管设计方法

提出基于应变的热采井套管设计方法,确定基于应变的设计准则,通过建立三维弹塑性有限元模型,模拟分析热采井多轮次生产过程中应力和应变变化规律,并以胜利油田A井为例进行实例设计。结果表明,该设计方法密切结合热采井"注-焖-采"生产过程,可考虑多轮次循环温度载荷对套管的损伤程度,通过计算多轮次生产条件下套管上的累积塑性应变,依据热采井生产轮次要求及应变准则,科学灵活地设计套管,可以为热采井套管柱设计提供新思路。

A casing design method based on strain variations for wells in thermal recovery processes

A new casing design method based on strain variations was proposed for wells subjected in intensive thermal recovery processes, such as steam recycling for heavy oil recovery, and the corresponding design criteria were introduced. The thermal stress and strain generated on the casing tube in the wellbore were analyzed and simulated during multi-round production processes using a 3D elastic-plastic finite element method(FEM) model. A case study for casing design using the new method was conducted for a typical well used for steam injection and oil production in Shengli Oilfield. The varying load on the casing tube and its damage mode can be considered based on the thermal stress and strain due to temperature variations during the steam injection, soaking and oil production processes. The results show that the plastic strain accumulated in the casing tube during multi-round steam recycling processes is important for the damage of the casing tube, and the proposed design method is useful to provide a new casing design criteria for wells used in thermal recovery.