研究了钻井过程中钻柱、钻头、岩石相互作用下的牙轮钻头动力学特性。根据汉弥尔顿原理和有限单元法，建立了全井钻柱纵向、横向扭转耦合振动动力学模型。在大量单元实验的基础上，建立了牙轮钻头与岩石相互作用力学模型。从系统动力学的角度出发，建立了基于钻柱、岩石相互作用下的牙轮钻头动力学模型。研究了牙轮钻头非线性系统模型的数值求解方法，编制了钻头动力学特性仿真分析软件，在不同钻井操作参数、钻具(钻柱、钻头)几何参数、地层性质条件下，对牙轮钻头动力学特性进行了仿真。明确了钻井过程中井下钻柱及钻头的运动规律、动力学特性、失效机理，为科学合理地预测和控制井眼轨迹提供了理论依据和技术手段。

钻井过程中，钻柱的振动使钻头与井壁产生的碰撞是钻头和钻柱早期失效的主要原因。通过建立钻头与井壁的碰撞模型，将碰撞简化为两个圆柱筒之间的碰撞，利用冲量定理和实验方法获得的钻头与井壁碰撞时的恢复系数及钻头碰撞前的速度，可计算出钻头与岩石碰撞后的速度和碰撞时产生的碰撞力。摸清钻头与井壁之间的碰撞规律，为有效预防钻头与钻柱的早期失效，预测井眼轨迹，有效提高钻井效率提供了理论依据。

With exploration moving into deeper waters, deserts and plateaus, operators and contractors will continue to face complex technical and financial challenges. After various advantages of slim-hole drilling, especially great reduce of cost, are well known, slim-hole drilling has become an important technology and been applied extensively. However, existing three-cone bits and PDC bits can not satisfy the requirements of slim-hole drilling owing to limited structure and short life. So, Southwest Petroleum University (SWPU) has developed a new slim-hole bit, named disc one-cone bit, which combines one-cone bit with disc bit. This new bit will have expansive application prospect in deep drilling, ultradeep drilling and slim-hole drilling because of its less torsion, higher bottom-hole coverage coefficient and longer bearing life. During the development of new disc one-cone bit, it is very important to ascertain the arrangement and the structural size of disc tooth reasonably according to its rock-breaking mechanism. Ilowever, the factors to affect hit rock-breaking efficiency are more and restrict each other. If laboratory evneriment is named mil in rrcrareh n kind of new hit it will berlong period, much cost and only under very simplified conditions. Therefore, computer simulation has important technical and economic value during studying the new bit. This paper discusses rock-breaking mechanism and kinematics simulation researches of disc one-cone bit emphatically.

在牙轮钻头与井底岩石互作用模型的基础之上，将钻头在井底作纵向往复运动的位移作为钻柱纵向振动的下端边界条件，在适当简化的条件下，利用弹性杆理论和单元法建立了钻柱在钻井过程中由于钻头与岩石互作用及钻柱的弹性变形而导致钻柱产生纵向振动的动力学模型在给定初始条件和边界条件的情况下，采用数值计算方法求解了钻柱纵振模型。为进一步弄清钻头、钻柱在钻井过程中的实际运动规律和动力学性能，改进钻头、钻柱的设计方法，预防钻头、钻柱早期失效奠定了基础。

在牙轮钻头几何学、运动学和钻头与岩石互作用静力学模型的基础上，对钻进过程进行适当简化后，建立了牙轮钻头动力学模型，主要包括钻头纵向动力学模型、钻头横向动力学模型和钻头扭转振动模型。在建立钻头动力学模型的基础上，完成了牙轮钻头动力学仿真分析软件的设计，利用该软件实现了对牙轮钻头动力学仿真分析计算，并与静力学模型的仿真计算结果进行分析对比，得出了影响钻头、钻柱动力学性能的因素除与钻头结构、牙齿结构、岩石性质和钻井参数有关外，还与钻具结构和钻具的组合形式有较大关系等结论。