等离子钻井过程中岩石破碎的实验研究

Experimental Study on Rock Breaking in the Process of Plasma Drilling

为了明确工作电流、击穿电压、脉冲宽度、电极直径、电极极性和电解质溶液浓度等加工因素对等离子钻井过程中岩石破碎的影响,采用环状电极结合实验室自主研发的电源,在无围压的条件下进行了室内实验研究。结果表明:工作电流、击穿电压、脉冲宽度和脉冲间隔对岩石破碎的效果有明显影响;岩石破碎效率随着工作电流、击穿电压和脉冲宽度的增加而逐渐提高,随着脉冲间隔、电极直径的增加而降低;当内电极与电源阴极相连时,岩石破碎的效果更好。实验结果同时表明,随着电解质溶液浓度的增加,岩石破碎的效率先增加、后减小。

In order to determine the effect of processing factors such as current,breakdown voltage ,pulse width ,diameter of the electrode ,polarity of electrodes and concentration of electrolyte solution on rock breaking in the process of plasma drilling, indoor experimental research was conducted using annular electrode under the condition of no confining pressure. The experimental results showed that current,breakdown voltage,pulse width and pulse interval have obvious effect on rock breaking. The efficiency of rock breaking increases with the increase of current,breakdown voltage and pulse width ,while decreases with the increase of pulse interval and diameter of the electrodes. The rock breaking shows a better performance when the inner electrode is Connected to the cathode. Meanwhile, the experimental results showed that the efficiency of rock breaking increases firstly then decreases with the increase of concentration of electrolyte solution.