张紧器-高压隔水管耦合系统横向振动特性研究

为了准确分析张紧器-高压隔水管耦合动力学特性,考虑平台漂移以及张紧器、海水阻尼等影响,基于动力学基本原理建立深水钻井工况下张紧器-高压隔水管横向振动力学仿真模型,并在MATLAB中利用有限差分法进行离散求解,分析了管内高压流体、张紧器耦合作用、海流流速、平台漂移量、张紧器张力比等因素对高压隔水管和常规隔水管横向振动的影响。仿真结果表明:在管内高压流体、张紧器耦合作用的影响下,高压隔水管的横向振动位移减小、应力增大;随着海流流速的增大,隔水管的横向振动位移增大,位于海面附近的隔水管的横向振动应力增大,隔水管底部的横向振动应力基本不受海流流速的影响;随着平台漂移量的增大,隔水管的横向振动位移增大,且越靠近海面变化越明显,但横向振动应力基本保持不变;随着张紧器张力比的增大,隔水管横向振动位移减小、应力增大,且对于常规隔水管,易产生应力集中。研究结果可为深水钻井工况下张紧器-高压隔水管的耦合振动特性分析提供理论依据。

Study on transverse vibration characteristics of tensioner-high pressure riser coupling system

In order to accurately analyse the coupling dynamics characteristics of the tensioner-high pressure riser, considering the effects of platform drift, tensioner and seawater damping, the transverse vibration dynamics simulation model of the tensioner-high pressure riser in deepwater drilling condition was established based on the basic principle of dynamics. Subsequently, the finite difference method in MATLAB was used for discrete solution. The effects of internal high pressure fluid, tensioner coupling, sea current velocity, platform drift and tension ratio of tensioner on the transverse vibration of high pressure riser and conventional riser were analyzed. The simulation results showed that the transverse vibration displacement of high pressure riser decreased and the stress increased under the effect of internal high pressure fluid and tensioner coupling. With the increase of sea current velocity, the transverse vibration displacement of risers increased, the transverse vibration stress of risers near the sea surface increased, and the transverse vibration stress at the bottom of risers was basically not affected by current velocity. With the increase of platform drift, the transverse vibration displacement of riser increased, and the change was more obvious as the riser got closer to the sea surface, but the transverse vibration stress basically remained unchanged. With the increase of tension ratio, the transverse vibration displacement of riser decreased and the stress increased, and stress concentration was easy to occur for conventional riser. The research results can provide theoretical basis for the analysis of coupling vibration characteristics of tensioner-high pressure riser in deepwater drilling condition.