小井眼射吸式液动冲击器工作性能数值模拟

液动冲击器钻井技术是解决深井硬地层钻速慢、钻井效率低的有效方法之一。为了研究射吸式冲击器的实际工作状况,对现有的射吸式冲击器进行了有限元模拟分析,研究了不同冲锤质量、泵排量、喷嘴直径对冲击功和冲击频率的影响,优选出最优的工作参数。结果表明,在边界条件、泵排量和喷嘴直径保持不变时,随着冲锤质量的提高,工具冲击功增大,冲击频率降低;当冲锤质量为9.675 kg时,冲击频率为1 397次/min,冲击功和冲击频率均较大,冲锤回程消耗能量较小,此时冲锤质量为最优;当喷嘴直径不变时,随着泵排量增大,工具内部压降和冲击频率均提高;当泵排量不变时,随着喷嘴直径增大,工具内部压降和冲击频率均降低。该有限元模拟分析了不同工作参数下冲击器的工作效果,为现场的实际应用奠定了良好的基础。

Numerical simulation on the working performance of slim-hole jet-suction hydraulic impactor

The hydraulic impactor based drilling technology is one effective method to improve the rate of penetration (ROP) and drilling efficiency of hard formations in deep wells. In order to study the actual working performance of jet-suction impactors, this paper carried out finite element simulation analysis on the existing jet-suction impactors, studied the influences of hammer mass, pump displacement and nozzle diameter on impact energy and impact frequency, and selected the optimal working parameters. It is indicated that at the constant boundary condition, pump displacement and nozzle diameter, the impact energy of the tool increases and the impact frequency decreases with the increase of the hammer mass. When the hammer mass is 9.675 kg, both impact energy and impact frequency (1 397 times/min) are higher and the hammer mass consumed in the backward stroke is less. And at this moment, the hammer mass is optimal. When the nozzle diameter is constant, both internal pressure drop and impact frequency of the tool increase with the increase of the pump displacement. When the pump displacement is constant, both internal pressure drop and impact frequency of the tool decrease with the increase of the nozzle diameter. By virtue of the finite element method, the working performance of impactors under different working parameters was simulated and analyzed, so as to lay the good base for its actual application in the field.