油基钻井液驱动下射流式液动冲击器的动态特性分析

在油气勘探领域,射流式液动冲击器常被用来加速硬岩钻井,降低钻柱摩擦,解决钻头粘滑等问题。实验表明,利用清水不能准确预测实际钻井中油基钻井液驱动的射流式液动冲击器性能。采用模拟和实验相结合的方法,研究了油基钻井液对射流式液动冲击器的动态特性的影响。结果表明,油基钻井液密度和固相颗粒对液动冲击器的压力降及运动特性具有显著影响。在液动冲击器的工作流量范围内,由于高速流体的剪切稀释特性,油基钻井液的非牛顿流变特性对其输出特性影响不大。总的来看,射流式液动冲击器可以在油基钻井液中稳定工作,具有正常的动力水平和良好的适应性。

Influence of oil-based drilling fluids on the dynamic behavior of the fluidic down-the-hole hammer

In the field of oil gas exploration, fluidic down-the-hole (DTH) hammer is used as a solution to the challenges associated with hard rock drilling, bit stick-slip and excessive friction along the drill string. Experiments show that the performance prediction scheme determined by using water cannot accurately predict the performance of the fluidic DTH hammer. In this paper, simulation and experiment methods are used to study the influence of oil-based on the dynamic behavior of the fluidic hammer. It is shown that the influence of the solid particles and density of the oil drilling fluid can be significant for the output performance and pressure drop of the fluidic hammer. In the rated supply flow range, the non-Newtonian rheological properties of oil-based drilling fluid have little influence on the output characteristics due to the shear thinning property. In conclusion, fluidic hammer can work stably with oil-based drilling fluid. It means that the fluidic DTH hammer has good adaptation and robustness, which is favorable to practical application.