深水钻井隔水管紧急脱离后的反冲响应

Recoil response of deepwater drilling riser during emergency disconnection

深水钻井中,在恶劣海况或浮式平台定位失效等情况下,需紧急断开隔水管与水下防喷器的连接。隔水管突然脱离后会加速向上反冲,如果反冲作用控制不当,可能威胁钻井平台、隔水管体和水下井口的安全。介绍了国外隔水管紧急脱离与反冲响应的研究情况,分析了隔水管紧急脱离的原因与程序、脱离后的反冲过程、反冲控制方式和成功脱离标准、反冲响应的分析方法。建议:由于南海深水海况复杂,作业者需制定紧急脱离的预案和作业规程,并进行紧急脱离操作培训;由于隔水管紧急脱离后的反冲响应涉及多个非线性瞬态过程,研究者应该开展隔水管紧急脱离测试和反冲响应模拟计算,开发隔水管反冲响应分析软件。

In deepwater drilling,marine risers are required to perform emergency disconnection sequence in harsh environments or during loss of dynamic positioning control. Riser recoil response will occur after lower marine riser package is disconnected in emergency. Riser recoil behavior would bring serious dangers to drilling platform,riser body and subsea equipment if recoil velocity is not effectively controlled. Related theories of this issue in the past two decades are summarized,including reasons and procedures of drilling riser emergency disconnection,process and anti-recoil methods of riser recoil,and criterions of successful disconnection. The investigation shows that for drilling in deepwater of the South China Sea, riser emergency disconnection is an indispensable consideration,contingency plans and formal procedures should be seriously established,and special emergency disconnection training is necessary for well drillers. Moreover,recoil response of drilling riser during emergency disconnection is a complex transient process and several nonlinear relations of different systems are involved,yet related researches in China are still in an early stage. Therefore,it is necessary for domestic researchers to implement drilling riser disconnection tests and recoil response calculation researches,and to eventually develop a special recoil response analysis software.