控压节流阀压降特性及结构改进

Flow resistance characteristics and structural improvements of managed pressure throttle

针对控压钻井过程中节流阀压降调节线性度差的问题,采用计算流体力学方法对塔里木油田现用节流阀进行数值模拟,分析现有结构下阀芯开度与压降的关系,并对阀芯进行了结构改进。结果表明,改进后的节流阀更加符合控压钻井工艺要求,其压降特性线性度明显提升,在开度20%~70%时,线性相关系数达到0.973,提高了节流阀压降可调性和控压钻井的安全性。阀芯结构的改进改善了内部流场的涡流现象,比较改进前后速度云图发现最大速度减小了29.78%,提高了节流管汇防冲蚀能力。

For the pressure control in the process of drilling, the non-linearity in the throttle valve pressure drop tuning is a serious problem. In this paper, using the computational fluid dynamics （CFD） method, numerical simulations of the throttle valve in the Tarim Oilfield are carried out, and the structural relationship between the valve opening and the pressure drop is analyzed, The structure of the valve core is improved on this basis, and the linearity of the relationship between the valve opening and the pressure drop is greatly improved. It is shown that the improved throttle valve can better satisfy the requirements of the drilling pressure control technology, the improved throttle valve pressure drop characteristics are significantly improved with better linearity, and in the opening of 20% to 70%, the linear correlation coefficient is 0.973. the adjustability of the throttle valve pressure drop and, therefore the safety of MPD, are greatly improved. With the improved.core structure of the valve, the vortex phenomenon of the internal flow field is ameliorated with the maximum speed being reduced by 29.78%, also the throttle manifold erosion prevention is improved.