利用计算机仿真技术,在三牙轮钻头几何学、运动学模型基础上,建立了钻头与岩石互作用模型.为解决软件运行效率及界面友好性问题,采用MATLAB软件编制程序进行模型求解,并将各求解模型分别编译成动态链接库.采用VB.NET开发软件的输入界面,实现了其与动态链接库的数据交换.利用该软件可在计算机上进行牙轮钻头仿真试验,这将大大提高牙轮钻头的开发效率,对解决工程实际应用问题有意义,对于其他仿真软件的开发具有很好的参考价值.

With the further development of drilling engineering,new requirements on the improvement of the bit structure are proposed.In this paper,using the method of computer simulation,on the basis of the cone bit geometry and kinematics models and the interaction model of bit and rock,the established models are solved through the MATALB programming.To resolve the problems of the running efficiency and the complex operation,VB.NET is used to compile the interface.The model file is transformed into.NET component(DLL file) through the MATLAB compiler,realizing the alternation with VB.NET and the development of the simulation software.By using this software to carry out the breaking rock process of cone bit simulation,the cutter bit figure,arbitrary bottom-hole pattern and drilling rate can be obtained.This is very important to the optimization design of bits.

In this paper, the interaction model between bit and rock is developed, based on computer simulation, geometry and kinematics models of three-cone bit. To solve the problems of operation efficiency and friendly interface of the software, the model solution is found by using MATLAB mathematic software for programming, and compiling every solving model into DLL. The input interface of software VB.NET is used to realize the data exchange between VB.NET and DLL. With structural parameters of bit, drilling parameters and rock mechanics property parameters on computer, cone bit simulation experiment can be conducted on the computer, greatly increasing the development efficiency, which is significant to optimize the design of cone bit.

In the petroleum drilling engineering,the combination mode of bit nozzle has been playing an important role in the drilling speed.At present,the bit nozzle selection is mainly based on experience.So,the optimization of nozzle combination seems especially important.This paper obtains it according to different formation characteristic.Then,the calculation results of bit nozzle diameter can be directly obtained by the computer programming software.The experiment shows the design method in this study satisfies drilling engineering needs and has a important meaning for field of drilling.

Piston of drilling pump is an important component in the production, and its length of the useful life will directly affect the production efficiency. Based on the principle of the work of traditional piston and the analysis of the forces situation and, in conjunction with its existing problems in using,the paper designs a new single-function piston.

The interaction of cone bit and rock is simulated through establishing the simplified teeth indentation model and the force model on the teeth.The half pyramidal angel θ of the indentation and coefficient κ express the comprehensive effect of drilling bit structure,drilling parameter and rock property.According to field drilling data,the parameter values of the two models are inversed by using error gradient descending method and computer simulation technology.Using the values,a computer simulation about the process of drilling is performed,and the simulation drilling curve and rate of penetration are very similar to the drilling data in the field.The research proves that a more accurate result can be got from relatively simplified models by a simulation method of inversing interaction between cone bit and formation based on drilling data.

通过建立牙齿的简化破碎坑模型和牙齿微面上的受力模型来模拟牙轮钻头与岩石的互作用,由破碎坑半锥角θ和力-压入系数k共同反映钻头结构、钻井参数以及岩石性质等因素的综合影响.根据现场钻井数据,采用误差梯度下降算法结合计算机仿真技术来反演这2个模型的参数值,并使用反演得到的参数值,进行钻进过程的计算机仿真致效,所得钻头的仿真钻进曲线和机械钻速与实际钻井十分吻合.研究结果表明,基于钻井数据反演的牙轮钻头与岩石互作用仿真方法,可以通过相对简单的模型求得更加准确的结果.