Modeling And Control Of Point-the-Bit Rotary Steerable Drilling Tool System

As the geological conditions of drilling deteriorates and oil drilling technologies develop continuously,Rotary Steerable Drilling(RSD)technology becomes increasingly significant,which is a sophisticatedly automated and represents the highest level in current drilling technology.Firstly,the existing steering drilling techniques was introduced,which included slide steering drilling technology and rotary steering drilling technology,the principles and pros and cons of both steerable drilling techniques were analyzed,and the principle and the development of rotary steerable drilling tools at home and abroad was introduced.Secondly,based on the study of foreign advanced rotary steerable drilling technologies,the principle of stabilizer platform and the steerable offset mechanism of the developed independently dynamic point-the-bit rotary steerable drilling tool model were explained.The common geometrical parameters in directional drilling,and other parameters in rotary steerable drilling model were also introduced.The oriented trajectory control method and the steerable offset mechanism control approach used in the rotary steerable drilling system were introduced.Thirdly,modelling the steerable offset mechanism control system,mainly included modeling the permanent magnet synchronous motor(PMSM)and getting its mathematical model and transfer function in dq coordinates,building the mathematical model of the drive system,and the coupling of the direct-axis and quadrature-axis currents was eliminate by the use of bias decoupling control.Fourthly,various parameters necessary for the system were computed and the tool face angle control system was designed and analyzed using a frequency characteristic method.Then the design of the tool face angle control system was simulated and the test results were compared and analyzed with the actual model.Finally,the summary of the paper is made,laying a solid foundation for the further research into dynamic point-the-bit rotary steerable drilling tools.It is of great and far-reaching significance to carry out this research into the dynamic point-the-bit rotary steerable drilling technology and develop rotary steerable drilling system with independent intellectual property rights.