油气井射孔段管柱动态响应及应力强度分析

Dynamic response and stress analysis on the perforating tubular string in oil-gas well

应用ANSYS有限元分析软件建立了射孔冲击载荷作用下油气井射孔段管柱有限元分析模型,并进行了动态响应及应力强度分析,得到了管柱振动位移、速度、加速度及等效应力对射孔冲击载荷的响应规律,考察了射孔段管柱长度、壁厚对管柱强度安全性的影响。算例分析结果表明:在射孔冲击载荷作用下,射孔段管柱受压缩载荷和拉伸载荷交替循环作用;全段管柱的振动位移、速度和加速度虽然幅值不同,但都随时间作周期性变化,且周期相同;离射孔爆轰源越近,管柱振动速度和振动加速度幅值越大;离封隔器越近,管柱振动位移幅值越小,但管柱的等效工作应力反而越大;射孔段管柱越长或壁厚越厚,管柱强度安全性越高,因此在射孔枪与封隔器间设置一定长度的减震油管,或采用厚壁油管可以提高射孔段管柱的强度安全性。

It analyzes the dynamic response and stresses of perforating tubular string to detonating impact load in oil-gas well in ANSYS,obtains the response of vibration displacement,velocity and acceleration of perforating tubular string caused by detonating impact load,finds the influence of the length and wall thickness of perforating tubular string to working stresses.The result shows that： when the detonating impact load exerts the perforating tubular string with compressive and tensile axial force alternatively; the vibration displacement,velocity and acceleration of perforating tubular string change periodically at same cycle; the closer to the perforating gun,the larger the amplitude of vibration velocity and acceleration; the closer to the packer the smaller the vibration displacement,the larger the working equivalent stress of perforating tubular string; the longer or the thicker the perforating tubular string,the smaller the working equivalent stress and the higher the strength safety.Therefore,it uses the damping tube between packer and perforating gun as well as thick walled tubing to increase the strength safety of perforating tubular string.