深水测试管柱振动模拟及动力学特性分析

Vibration Simulation and Dynamic Analysis of Deep Water Test String

深海油气资源的勘探与开发是中国能源战略的重要部分,也是世界能源发展的必然趋势。深水测试管柱作为勘探与开发的关键装备,其力学行为将直接影响测试管柱、井下工具等的工作性能以及安全可靠性。在广泛调研海洋管柱力学研究的基础上,根据深水测试管柱结构特点,建立基于隔水管变形作用的深水测试管柱耦合动力学模型,通过特征线法对模型进行求解,并开展深水测试管柱相似实验来验证该模型,结合南海某口井现场数据,分析深水测试管柱的振动特性,得到测试管柱振动变化规律。结果表明:气体通过测试管柱,管柱产生周期性振动,海水段测试管柱产生的横向振动明显比地层段大,其中在海水段中部振动幅值最大,地层段中上部振动幅值较大;越靠近测试管柱下端,管柱的纵向振动幅值越大;海水段管柱未变形时管柱的振幅明显比海水段管柱弯曲小,且管柱的振动衰减较快。

The exploration and exploitation of deep-sea oil and gas resources is an important part of China's energy strategy and an inevitable trend of world energy development.As a key equipment for exploration and development,the mechanical behavior of marine pipe strings will directly affect the working performance and safety reliability of testing columns,downhole tools,etc.Based on extensive research on the mechanics of marine pipe strings and the structural characteristics of deep-water test strings,a coupled dynamic model of deep-water test strings based on the deformation effect of risers was established,the model was solved using the characteristic line method and a deepwater test string similarity experiment was conducted to verify the model.Combined with on-site data from a well in the South China Sea,the vibration characteristics of the deepwater test string were analyzed and the vibration variation law of the test string was obtained.The results show that periodic vibrations occur when gas flows through the test string.Notably,transverse vibrations are significantly more pronounced in seawater sections compared to formation sections.Furthermore,within seawater sections,maximum vibration amplitudes are observed in the middle part while within formation sections they are concentrated in both middle and upper regions.Additionally,it is worth noting that lower ends of test strings exhibit larger longitudinal vibration amplitudes as they approach closer proximity to formations.Moreover,amplitude levels experienced by pipes within deformed seawater sections are evidently smaller than those encountered without deformation;furthermore,pipe column vibrations experience faster attenuation rates.