| With the increasing demand for unconventional oil and gas exploration and the drilling of complex Wells,conventional drilling techniques are unable to meet the demand,and advanced steering techniques are required to ensure accurate drilling of well trajectories.Rotary steerable drilling technology has become an indispensable key technology for complex structure well drilling due to its advantages of reducing friction and drag and precise guidance.China has been in a passive situation of "relying on imports and being controlled by others" for a long time for this technology.In order to break the monopoly of this technology,although China is also working on key issues,it is mainly to imitate foreign systems.The push-type rotary steerable system controls and stabilizes the platform by means of complex magnetic torque.This paper studies this technology,and designs a simple push-back three-disc valve rotary steering tool control system.This paper investigates the existing rotary steerable systems at home and abroad,and analyzes the working principle,advantages and disadvantages of three representative rotary steerable systems,and details the steering mechanism of Power Drive rotary steerable system.On this basis,the paper puts forward the overall structure design of the guided tool control system,using CAD,Solid Works professional drawing software to draw a schematic diagram,and analyze the working principle.The main content of this paper is to divide the steering tool into three parts: the overweight mechanism,the control mechanism of the hanging plate valve and the stepper motor control system.In the first part,a kind of partial stability mechanism based on gravity stability principle is proposed,and its structure design and principle analysis are carried out.The size,shape and weight of the key component in the mechanism are designed rationally through calculation,and the efficiency of driving the rotary middle disc valve is analyzed.In the second part,the tool face stability control mechanism of the hanging disc valve is designed based on the gear meshing drive,and the internal and external gear meshing drive models of the motor and the hanging disc valve are established.After the demonstration,the control mode of the internal meshing drive is selected,and the structural parameters are determined by analyzing the working mode,characteristics,stress calculation and error interference of the transmission mechanism.The third part is to design the motor and its control system,classify and compare the motor according to the working characteristics,select the stepper motor that meets the system control requirements,and analyze the working principle and characteristics of the stepper motor in the system.The closed-loop control system is formed based on PLC control theory,and the software and hardware of the control system are designed respectively.This paper simplifies the complex electromechanical hydraulic rotary steering system in foreign countries,which has important guiding significance for realizing the rotary steering system developed by our country independently. |
