钻井液连续循环短节结构优化设计与分析

Optimal Design and Analysis of Drilling Fluid Continuous Circulation Sub Structure

阀式连续循环短节可实现钻井液连续循环,有效解决因常规钻井接单根过程中频繁开泵、停泵带来的各种问题。在钻井液含砂量较大时,短节侧阀阀板处容易出现冲蚀失效,不仅造成时间和经济损失,而且严重影响作业安全。根据侧阀结构特性,利用Fluent流体分析软件进行了侧循环时短节内部流场及冲蚀效果分析。根据侧循环不同流量、流体密度及含砂量条件下冲蚀模拟,完成了阀板结构优化设计。针对优化设计结果进行安全性研究。采用Ansys有限元软件模拟了侧阀关闭时的阀体力学行为,并通过理论计算进行了侧阀密封性分析与工作阈值流量分析。分析表明,装置优化设计结果安全可靠,可进行实际生产应用。

Continuous circulation sub could achieve continuous drilling fluid circulation,which effectively solves various problems caused by frequent pump openings and pump shutdowns in the process of conventional drilling.However,when the sand content of the drilling fluid is relatively large,the valve plate of the sub-side valve is prone to erosion failure,which not only causes time and economic losses,but also seriously affects the safety of operations.According to the structural characteristics of the side valve,Fluent fluid simulation software was used to analyze the internal flow field and erosion effect of the short section during side circulation.According to the erosion simulation under different flow rate,fluid density and sand content of side circulation,the optimal design of valve plate structure was completed.The Ansys finite element software was used to simulate the mechanical behavior and theoretical calculation to evaluate sealing performance and operation threshold valve.Analysis shows that the optimized design structure of the continuous circulation sub is safe and reliable,and can be used in actual production operation.