液相冲击波破岩等离子体通道生长发展机理及敏感性探索  

Growth and development mechanism and sensitivity of plasma channels during rock breaking by electrohydraulic shock wave

作　　者：祝效华[1,2] 唐无忌 刘伟吉[1,2] 罗云旭 ZHU Xiaohua;TANG Wuji;LIU Weiji;LUO Yunxu(School of Mechatronic Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Geothermal Energy Research Center,Southwest Petroleum University,Chengdu,Sichuan 610500,China;School of Mechanical Engineering,Sichuan University of Science&Engineering,Yibin,Sichuan 644005,China)

机构地区：[1]西南石油大学机电工程学院 [2]西南石油大学地热能研究中心 [3]四川轻化工大学机械工程学院

出　　处：《天然气工业》2025年第1期14-24,共11页Natural Gas Industry

基　　金：国家自然科学基金项目“电脉冲—机械复合破岩提速机理研究”(编号:52034006)、“钻井提速理论与方法”(编号:52225401)。

摘　　要：地球深层、超深层油气资源丰富,但深部地层具有岩性致密、硬度高、研磨性强等特点,采用传统旋转钻井方式成本高、效率低,亟需探索针对深层、超深层硬地层的新型破岩技术。液相放电冲击波破岩技术因其高效、绿色、能量可控等特点受到广泛关注,为研究液相放电等离子体通道生长发展机理与液相放电等离子体通道的参数敏感性,基于电流场、传热场以及带电粒子碰撞扩散方程建立了二维液相的“针—针对排型”放电模型,分析了不同放电参数(加载电压、电极尖端形状、电极间距、电极夹角等)下等离子体通道内能量密度及局部电场强度等参数变化规律。研究结果表明:(1)加载电压、电极尖端形状以及电极间距是等离子体通道内能量密度大小的主要影响因素,其最佳放电电压为140~180 kV;(2)椭圆形放电电极形成的等离子体放电通道具有“区域宽、数值高”等特征,具备高电能密度的同时,减小了对电极头的损伤,可作为优选电极类型;(3)电极间距应在满足最小击穿场强的前提下,尽可能增大电极间距;(4)电极夹角对液相放电过程产生的直接影响微乎其微,但电极夹角的改变会影响等离子体通道在水中的形成位置。结论认为,该研究结果为液电破岩装置的研制和参数优化提供了重要参考,为未来液相冲击波技术在油气工程领域的探索与应用提供了理论支撑。There are abundant oil and gas resources in the deep and ultra-deep strata on the earth,but the deep strata have the characteristics of tight lithology,high hardness and strong abrasiveness.When the traditional rotary drilling is applied in such strata,the cost is high and the efficiency is low.Therefore,it is in urgent need to develop a novel rock breaking technology for deep and ultra-deep hard strata.The electrohydraulic shock wave rock breaking technology has attracted widespread attention due to its high efficiency,environmental friendliness,and controllable energy.To investigate the growth and development mechanisms and parameter sensitivity of electrohydraulic plasma channels,this paper establishes a two-dimensional"needle-to-needle"electrohydraulic model based on current field,heat transfer field,and charged particle collision diffusion equation,and then analyzes the variation patterns of energy density and local electric field intensity in plasma channels under the influences of different discharge parameters such as applied voltage,electrode tip shape,electrode spacing,and electrode angle.And the following research results are obtained.First,applied voltage,electrode tip shape,and electrode spacing are the main factors influencing energy density within the plasma channel.The optimal discharge voltage ranges from 140 kV to 180 kV.Second,the discharge plasma channel formed by elliptical discharge electrode is characterized by"broad region and high value",indicating it has high electric energy density while reducing the damage to electrode tip,so it can be taken as the preferred electrode type.Third,the electrode spacing shall be as large as possible while the minimum breakdown field intensity is satisfied.Fourth,the direct effect of electrode angle on the electrohydraulic process is negligible,but the changes in electrode angle influence the formation location of the plasma channel in water.In conclusion,the research results provide an important reference for the development and parameter optimization of

关 键 词：液相放电 等离子体通道 液相冲击波 能量密度 局部电场 电击穿 参数敏感性分析 

分 类 号：TE921[石油与天然气工程—石油机械设备] O539[理学—等离子体物理]