Aiming at obvious elastic-plastic deformation of diamond drill bits in the process of drilling marine gas hydrate,a modeling approach that is suitable for the core drilling process of drill bits was proposed based on the Hertz theory.Firstly,the rock-breaking mechanism was analyzed for marine gas hydrates from elastic deformation to elastic-plastic deformation during the drilling process under sea,and the drilling pressure and cutting force of single diamond particle on the diamond bit during the drilling process were calculated.Secondly,according to the stress condition of a single diamond particle,the theoretical relationships between drilling pressure and torque on the whole bit and other drilling parameters were obtained,and a mechanical model was established for the diamond drilling bit.Finally,a relationship curve between the saturation of marine gas hydrate and the torque and drilling pressure was obtained based on analysis.An at-sea testing by adopting such method has successfully taken some samples of marine gas hydrate,which has verified the feasibility of this method.This research provides a theoretical reference for the design of drill bit parameters and optimization of efficient deep-sea core drilling operation.
关键词
深海海底钻机/海牛号/深海钻探/金刚石钻头/海底天然气水合物/钻进取芯
Key words
seafloor drill/Hainiuhao/deep-sea drilling/diamond drill bit/marine gas hydrate/core drilling
维普
万方数据