空气冲旋钻井冲击力和机械钻速仿真研究

在钻井机械钻速预测研究中，以前常根据现场数据或试验数据统计拟合得出经验或半经验方程，方程一般含有一些很难确定的系数甚至是不可靠的。为此，借鉴三牙轮钻头仿真理论，建立了冲击旋转钻井系统仿真模型，包括冲击器动力学模型、冲旋钻头真实仿真模型、动态变化的真实井底模型和牙齿与井底岩石相互作用模型，用计算机仿真方法预测出冲击器活塞的冲击力、冲击功和空气冲旋钻井机械钻速。仿真结果和试验数据吻合较好，模型可靠，研究成果可用于冲旋钻头、冲击器设计和钻井参数优选。

SIMULATION OF IMPACT FORCE AND PENETRATION RATE OF AIR HAMMER BIT DRILLING

For the research of the rate of penetration (ROP) prediction,the empirical or semiempirical equations of the ROP are derived from the laboratory or field data before. Some of them include some coefficients difficult to get,while some of them are not coincident with the field data. Based on the theory of the roller cone bit,the simulation model of the hammer bit drilling system is established,which includes dynamical model of the impactor,simulation model of the hammer bit,simulation model of the true bottom hole plane and the mathematical model between the tooth and the rock,by which the simulation software is developed. Hence the impacting force,the impacting work of the piston and ROP of the air hammer bit drilling can be predicted. Simulation results are coincident with that of the field so as to indicate that the model are reliable. The research can help to redesign the hammer bit or the impactor and select the drilling parameters.