Research on the Key Parameters PDC Bit for Improving the Production of Hydrothermal Resources through Ultra-short Radius Lateral Well

Geothermal energy is an important clean and renewable energy source with low carbon emissions and stable supply. The hydrothermal resource has immense potential in global geothermal development. However, the efficient exploitation of hydrothermal resource is challenging due to the restricted porosity and permeability of the reservoir. The utilization of flexible drilling pipe presents a promising solution by enabling the drilling of multi-lateral wellbore in various aquifers with favorable fluid production and reinjection conditions. However, the high temperature of reservoir rock, high formation pressure, and pronounced abrasiveness result in substantial bit wear and a markedly reduced mechanical drilling speed, which impose significant constraints on the advancement of this technology. In this paper, we therefore conduct cutting experiments of non-planar PDC cutters under in situ temperature and pressure, comparing and analysing the cutting characteristics of the PDC cutters, and evaluating the performance of PDC cutters by analysing the mechanical specific energy (MSE), the characteristics of cutting force, and the distribution of cuttings. The experimental results demonstrate that the triple-ridged PDC cutter exhibit the highest rock-breaking efficiency under the specified experimental conditions. Subsequently, the optimized design of the PDC bit was employed in field tests of flexible drilling pipes ultra-short radius wells, resulting in a 110.26% extension of service life. The findings of this study offer a novel approach to the efficient development of hydrothermal geothermal resources.