Abstract The electro-pulse boring (EPB) of deep and ultra-deep wells has great market prospects. It uses controllable energy and is pollution-free. In this paper, research into high-voltage short-pulse power supplies and EPB electrode bits is reviewed. The simulation model was established according to the common coaxial cylindrical structure of the electric pulse rock breaking bit. The effects of the electrode spacing and the shape of the high-voltage electrode on the electric pulse rock breaking were then studied. According to the simulation results, the maximum electrode spacing was determined and the shape of the high-voltage electrode was optimized. The electrode bits with 45- mm spacing and 25-mm spacing were designed. Numerical simulations of EPB using these two bit sizes were conducted in which the actual structure size of the electrode bits and rock physical parameters were used. Simulation revealed an electric field distortion in the rock due to naturally-occurring air gaps, which can enhance the internal electric field strength. An experimental EPB system based on a transformer-type pulse generator was then developed. Transformer oil was used as a drilling fluid and red sandstone was drilled. Electric breakdown of sandstone by 25-mm and 45-mm electrode bits was conducted at a voltage of 80 kV, which produced drilling diameters of 60 mm and 100 mm, respectively. According to the simulation analysis and experimental research of EPB, the effective technological parameters and the law of EPB were obtained, which provided theoretical and practical guidance for electrode bit design and the selection of drilling parameters in practical applications.

中文翻译：

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电脉冲破岩钻孔试验与数值分析

摘要 深井和超深井电脉冲钻孔（EPB）具有广阔的市场前景。它使用可控能源，无污染。本文综述了对高压短脉冲电源和EPB电极钻头的研究。根据电脉冲破岩钻头常见的同轴圆柱结构建立仿真模型。然后研究了电极间距和高压电极形状对电脉冲破岩的影响。根据仿真结果，确定了最大电极间距，优化了高压电极的形状。设计了间距为 45 毫米和 25 毫米的电极钻头。使用这两种钻头尺寸对 EPB 进行了数值模拟，其中使用了电极钻头的实际结构尺寸和岩石物理参数。模拟显示，由于天然存在的气隙，岩石中的电场畸变可以增强内部电场强度。然后开发了基于变压器型脉冲发生器的实验 EPB 系统。用变压器油作钻井液，钻红砂岩。25 毫米和 45 毫米电极钻头在 80 kV 电压下对砂岩进行电击穿，钻孔直径分别为 60 毫米和 100 毫米。根据EPB的模拟分析和实验研究，得到了EPB的有效工艺参数和规律，