深水套管切割装置数值模拟与试验研究

Numerical Simulation and Experimental Research of Casing Cutting Device

在海洋弃井作业中,浅水作业区域是依据扭矩骤降判断套管被切断;而在对现场深水套管切割资料研究中发现,即使套管被切断,扭矩也不会突然降低。针对以上问题,设计了一种深水套管切割装置,从理论和试验2个方面研究了该装置的水力特性。研究结果显示,在同一切割状态下,随着入口流量的增大,活塞前、后的压降增大;在相同流量下,工具在刚开始切割套管时的压降约为完全割断套管时的,理论分析与试验结果非常接近。研究结果验证了湍流模型的准确性以及工具设计的合理性,为现场判断套管是否被割断提供了理论依据和试验参数。

In marine abandonment operations, the casing cutoff in the shallow water area is usually deter?mined by the sudden torque fall?But analysis on the casing cutting data in deep water operations shows that sudden torque fall would not happen when the casing is cut off?To address the issue, a deepwater casing cutting device has been designed?Theoretical and experimental studies have been conducted on the hydraulic characteristics of the de?vice?The results show that, at the same cutting state, the differential pressure before and after the piston increases with the increase of the inlet flow rate?Given the same flow rate, the pressure drop of the tool at the beginning of casing cutting is half of the pressure drop of complete casing cutoff?The theoretical analysis is closely consistent with the experimental result?The results indicate the accuracy of turbulence model and the reasonableness of the de?signed tool, providing theoretical basis and test parameters for the onsite judgment of casing cutoff.