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 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.