热采井中复合缝腔割缝筛管的抗压强度研究

根据热力学原理,结合特定现场地层特点,计算了在热采过程中筛管表面温度分布,并利用有限元软件分析了在此温度分布条件下筛管的抗压强度。结果表明,在外部围压作用下,筛管的应力分布不均衡,仅有局部极小的区域应力较大,该区域主要集中于筛管的缝腔处。在热采情况下计算的筛管整体Von Mises应力大于在常温下计算得到的应力。在较大的外压载荷下热采温度对筛管抗压强度的影响很小甚至可以忽略。筛管的抗压强度随缝长的减小和割缝数的减少而增大。这种分析方法对研究井下热采过程中割缝筛管复杂的温度应力情况有一定的指导意义。

Research on the pressure resistance strength of the slotted screen with compound cavity in the thermal recovery well

According to the thermodynamic principle and referring to the particular field formation feature, the temperature distribution on the screen surface in the process of thermal recovery was calculated. Meanwhile, the finite element software was utilized to analyze the pressure resistance strength of the screen under this temperature distribution. The result shows that, under the effect of peripheral pressure, the distribution of the screen’s stress is uneven, with a very small local area having a great stress. The area is concentrated at the slotted cavity of the screen. In thermal recovery, the calculated Von Mises stress of the whole screen is greater than the stress obtained in normal temperature through calculation. Under the load of relatively great external pressure, the effect of thermal recovery temperature on the screen’s pressure resistance strength is little or even negligible. The shorter the slot length and the smaller the number of slots, the greater the pressure resistance strength of the screen. This analysis can serve as a reference to the study of the complicated temperature and stress conditions of the slotted screen in thermal recovery.