钻井用内防喷旋塞阀流场数值模拟研究

Study on Numerical Simulation of Flow Field of Internal Blowout Preventive Cock Valve for Drilling

针对钻杆内防喷旋塞阀出现的多种密封失效问题,以流道直径为76 mm的防喷旋塞阀为例,通过控制变量法,对旋塞阀内部流场进行液固两相流数值模拟实验,分析阀芯的不同关闭角度和不同井筒压力对旋塞阀内部压力场、速度场和固相体积分布的影响。根据模拟结果,认为最大的流速、压降出现在阀芯与阀座相接触的位置,固相颗粒主要分布在阀座和阀芯内部。针对旋塞阀密封失效的位置和原因,建议对旋塞阀内部及时进行清理,并尽量缩短旋塞阀关闭过程的时间;在制作防喷旋塞阀时,宜选用优质调质钢,适当增加上阀座材料的硬度。

In view of various sealing issues of in-service cock valves,taking the internal blowout proof cock valves for drilling with a flow diameter of 76 mm as an example,the numerical simulation of liquid-solid two-phase flow in the internal flow field of cock valves is carried out by controlling variable method from the angle of core closure and drilling hydraulic pressure of well-bore.The influence of different closing angles of valve core and different well-bore pressure on the pressure field,velocity field and solid volume distribution inside the cock valve are analyzed.The results show that it is the contact position between the valve core and the valve seat which has the maximum flow velocity and pressure drop,and the solid particles are mostly distributed in the valve seat and the valve core.According to the analysis,the location and cause of the failure are found out.And it is suggested that the inside of the cock valve should be cleaned up in time and the closing time of the cock valve should be shortened as far as possible.At the same time,the hardness of the upper seat material should be increased appropriately in the production of the blowout-proof cock valve,and the high-quality quenched and tempered steel should be selected to better serve the drilling site.