地热井钻井施工技术研究

Research on Drilling Construction Technology for Geothermal Wells

旋转冲击钻是为了提高地热井钻井施工中的破岩效率而设计的,其循环频率和应力波频率是影响钻速的关键因素,但相关技术研究报道较少。基于此,文章测量了旋转冲击钻具的循环频率和冲击过程中产生的应力波频率,建立了聚晶金刚石复合片(PDC)刀具切削硬质岩石的数值模型,并将测得的频率参数引入数值模型,研究了循环频率和应力波频率对岩石穿透深度的影响。研究结果表明,平均穿透深度随循环频率的增加而增加,随应力波频率的升高而减小;当这两个参数同时较高时,有利于产生较小的岩屑和井筒清洁;当循环频率较高、应力波频率较低时,最有利于钻齿穿透。

The rotary impact drill is designed to improve the rock breaking efficiency in geothermal well drilling construction.Its cycle frequency and stress wave frequency are key factors affecting the drilling speed,but there are few reports on related technical research.Based on this,this article measured the cyclic frequency of rotary impact drilling tools and the frequency of stress waves generated during the impact process.A numerical model for cutting hard rocks with polycrystalline diamond composite(PDC) tools was established,and the measured frequency parameters were introduced into the numerical model.The effects of cyclic frequency and stress wave frequency on penetration depth of rock are studied.The results show that the average penetration depth increases with the increase of cyclic frequency and decreases with the increase of stress wave frequency.When these two parameters are both high,it is beneficial to generate smaller rock cuttings and clean the wellbore.When the cycle frequency is high and the stress wave frequency is low,it is most beneficial to drilling tooth penetration.