热采井割缝筛管的热应力分析

筛管内过热的蒸汽使地层及筛管温度升高,对筛管产生相当大的热应力,此应力可能使筛管产生弯曲变形或断裂,导致油井停产或油井报废。因此,通过ANSYS有限元分析软件的数值模拟,计算得到筛管-地层的温度场分布,然后将筛管温度场导入到三维模型的应力场中,得到温度变化对割缝筛管的热应力和热变形。实例计算结果认为,蒸汽温度为350℃时,在正常注汽和突然停注2种状况下的筛管热应力分别为682.147、703.229MPa,其中突然停注时的热应力超过了筛管材料的屈服极限690MPa,这是导致筛管损坏的最危险状态,最大热应力发生在筛管缝中央。

The thermal stress analysis of the slotting screen pipe in thermal recovery wells

The overheating steam in the screen pipe causes the temperature of the formation and the screen pipe to go up and produces rather large thermal stress on the screen pipe.The stress may cause the screen pipe to bend,deform or fracture,resulting in oil well shutdown or abandonment.By means of the numerical simulation of the finite element analysis software,the calculation was conducted to obtain the distribution of the formation's temperature field.Then,the screen temperature field was introduced into the stress field of the three-dimension model.The analysis obtained the thermal stress and deforming of the screen caused by the change of temperature.The results show that in normal injection and sudden stop of injection,the screen's thermal stresses are respectively 682.147 MPa and 703.229 MPa.The thermal stress caused by sudden stop of injection goes beyond the yield limit of the screen material,which will give rise to the most dangerous condition for screen damage.The maximum thermal stress takes place at the center of the screen opening.