粒子冲击钻井中液体携带粒子环空返流试验研究

为了研究粒子冲击钻井系统中钻井液携带硬质球形钢粒子成功上返时，钻杆与井筒配合的不同环空间隙对钻井液临界流速的影响，本文采用清水代替钻井液进行了相关的试验。通过试验测得所需数据，借助量纲分析理论推导出试验相关因素之间关系，并结合试验数据提出了2.5mm的粒子在水中的体积分数为3%的情况下，能够成功上返时环空间隙Δd和清水临界流速v*的经验公式v*=0.136(Δd)^-0.44732。结果表明随着钻杆与井筒配合的环空间隙的增大，粒子成功上返时所需的环空中清水临界流速反而减小，且相应的临界粒子雷诺数也减小。

Experimental study of the regurgitation of liquid-carrying particles in particle impact drilling

In order to study the relationship between the size of annular gaps and the drilling fluid critical flow rate,experiments were carried out using water instead of the drilling fluid.Experimental data were analyzed using dimensional theory.The expression relating the gap Δd and the water critical flow rate v* was obtained under special conditions.If the particle diameter is 2.5 mm and the particle volume fraction is 3% in water,the empirical formula is v*=0.136(Δd)-0.44732.Furthermore,the experimental results show that the critical flow rate and critical Reynolds number gradually decrease with increasing annular gap.