射孔参数对热采井套管抗热应力能力影响分析

Analysis on the Effect of Perforating Parameters on Thermal Stress Resistance of Thermal Production Casing

热力采油使得套管承受较高水平的热应力,增加套管损坏风险,从而降低套管使用寿命。针对射孔参数对热采井射孔套管抗热应力能力的影响规律研究较少。利用有限元软件建立三维套管模型,结合基于应变的设计方法评价热采井射孔套管的抗热应力能力。结果表明,在安全内外压作用下,射孔排包含射孔数目较多且射孔直径较小的射孔参数可增强射孔套管的抗热应力能力;多轮次蒸汽吞吐过程对套管受热变形具有累加效应,保证强度安全前提下选择使得射孔排包含射孔数目较多的射孔参数组合可使得套管满足热应力安全性。研究结果从射孔参数对套管抗热应力能力的影响角度出发,为热采井实际射孔参数方案优选提供了参考。

Thermal oil recovery makes the casing bear high level of thermal stress,which increases the risk of casing damage,and reduces the service life of casing.At present,few studies focus on the impact of perforation parameters on thermal stress resistance of perforating casing in thermal production wells.Therefore,finite element software was used to establish 3D casing model,and a strain-based design method was used to evaluate the thermal stress resistance of perforating casing in thermal production wells.Under safe internal and external pressures,the thermal stress resistance could be enhanced by placing more perforating holes of smaller diameter in the perforating row.The process of steam huff and puff showed an accumulative effect on casing deformation,the thermal stress resistance could be satisfied in the process of multiple rounds of production by selecting proper perforating parameters,under the premise of ensuring the safety of strength,the combination of perforating parameters that make the perforating row contain more perforations can optimize the safety of thermal stress.Based on the influence of perforation parameters on casing thermal stress resistance,the results provide a reference for the optimization of practical perforating parameters for thermal production wells.