摘 要 由于干热岩地层硬度高、研磨性强、可钻性差，PDC钻头钻进时面临

Abstract Because hot dry rock formations a high hardness, abrasive resistance, drillability difference, short working life when faced with a PDC bit drilling, cutting teeth projecting severe heat and wear. To study the hot dry rock drilling and rock cutting the heat generating mechanism of breaking teeth with a PDC bit, the rock sample at room temperature and 100 ℃, 200 ℃, 300 ℃ granite and sandstone were monodentate PDC cutting, cutting force using a test sensor, speed camera and a thermal infrared camera to study the cutting force, the cutting process and cutting temperature. The results show that temperature increases with granite, high-temperature rock samples cut flower cuttings compared to the number of cuttings more cold and brittle rock is more significant. The maximum size is not granite cuttings heating temperature affects the size, sandstone rock sample with the maximum size of the cuttings increase the heating temperature increases. Granite and sandstone are present a critical temperature, so that the cutting efficiency and cutting granite and sandstone heat mutations. As the temperature increases, the radial force during cutting granite increased and then decreased, is increased to decrease the tangential and axial forces to; and each of sand are first increases with increasing temperature after the cutting force decreases. The study revealed that the rock breaking heat and law PDC cutting teeth hot dry rock, as hot dry rock drilling efficiency and supporting the PDC bit design provides an important theoretical guidance and technical support. <br>Keywords hot dry rock cuttings PDC cutter cutting temperature cutting force

Picking Because of the high hardness, strong abrasiveness and poor drillability of the dry hot rock formation, the PDC drill bit is faced with short working life, cutting teeth and other serious. In order to study the cutting teeth and heat ingenuity mechanism of PDC drill teeth for dry hot rock drilling, PDC single-tooth cutting is carried out by the normal temperature rock sample and 100 oC, 200 oC, 300 oC granite and sandstone respectively, and the cutting force, cutting process and cutting temperature are studied by using cutting force test sensors, high-speed cameras and thermal infrared imagers. The results show that with the increase of granite temperature, the amount of high-temperature flower rock-like cutting rock chips is more than that of low-temperature rock chips, and the brittleness of the rock is more significant. The maximum rock debris size of granite is not affected by the heating temperature size, and the maximum rock debris size of sandstone increases with the increase of the heating temperature of the rock sample. There are critical temperatures in both granite and sandstone, which causes the cutting efficiency of granite and sandstone to mutate and produce heat. With the increase of temperature, the radial force of granite increases and then decreases in the cutting process, the tangent ial force and the axial force decrease first, while the sandstone cutting force increases first and then decreases with the temperature. The above-mentioned research reveals the law of PDC tooth cutting dry hot rock breaking rock and heat, which provides important theoretical guidance and technical support for the efficient drilling of dry hot rock and the design of supporting PDC drill bit.<br>Keywords Dry hot rock PDC cutting teeth rock chip analysis cutting temperature cutting force

Due to the high hardness, strong abrasiveness and poor drillability of the dry hot rock formation, PDC bit faces serious problems such as short working life and hot wear of cutting teeth during drilling. In order to study the mechanism of rock breaking and heat generation when PDC bit is used in dry hot rock drilling, the normal temperature rock samples and granite and sandstone samples at 100 ℃, 200 ℃ and 300 ℃ are respectively cut by PDC single tooth. The cutting force, cutting process and cutting temperature are studied by using cutting force test sensor, high-speed camera and thermal infrared imager. The results show that, with the increase of granite temperature, the amount of cutting cuttings of high temperature flower rock is more than that of low temperature, and the rock brittleness is more significant. The maximum cutting size of granite is not affected by the heating temperature. The maximum cutting size of sandstone increases with the increase of heating temperature. There is critical temperature in both granite and sandstone, which makes the cutting efficiency and heat generation of granite and sandstone change abruptly. With the increase of temperature, the radial force of granite increases first and then decreases, the tangential force and axial force decrease first and then increase, while the cutting force of sandstone increases first and then decreases with the increase of temperature. The above research reveals the law of rock breaking and heat generation of PDC tooth cutting dry hot rock, which provides important theoretical guidance and technical support for the efficient drilling of dry hot rock and the design of PDC bit.<br>Key words: dry hot rock PDC cutting tooth cuttings analysis cutting temperature cutting force