尤拉屯高产气井完井管柱振动损伤研究

Research on Vibration Damage of Completion String in Yolotan High-yield Gas Well

针对尤拉屯气田典型管柱在生产过程中高速气流诱发的振动问题,展开了管柱振动损伤研究,研究中采用了大型有限元分析软件ANSYS建立高产气井带封隔器油管柱振动的有限元模型。利用该模型对管柱进行了振动分析,分析结果表明:离封隔器越远振动位移、速度和加速度的幅值越大。详细地研究了全井段油管柱的轴向应力变化、屈曲损伤和中和点变化,同时分析了不同位置和不同产量下,屈曲管柱与套管柱的接触压力随时间的变化关系,为管柱摩擦磨损损伤机理的深入研究提供了定量的数据。最后对管柱进行了疲劳寿命预测,为管柱振动损伤预防措施的提出提供了理论基础。

Yolotan gas field is characterized by high temperature and high pressure gas field. The high-speed gas flow in tubing may cause erosion damage to the string, and the erosion seriously threats the security of gas production and operation. The tubing string with packers tends to be buckled, making the fatigue wear more damaging, which is prone to cause downhole string deformation or damage. Therefore, it is of great significance to study vibration damage and to predict fatigue life of tubing string. We established finite element vibration model of pipe string with packer in high-yield gas wells by ANSYS. The results of analysis of the tubing string vibration analysis show that the farther away the pipe string is from the packer the greater the amplitude of vibration displacement, velocity and acceleration. With detail studies on axial stress, buckling damage and neutral point changes of the whole sections of the tubing string, and analysis of the contact pressure changes over time between buckling string and casing string in different locations and different production, this study provides quantitative data for studies on friction and wear damage mechanism. Finally, we predict the fatigue life of string, which provides theoretical basis for putting forward string vibration damage prevention measures.