Mandrel Displacement Vector Control System and Method for Pointing Rotary Steering Actuator

Abstract

The invention discloses a system of directing-type rotary steering actuator mandrel displacement vector control. The system is of a double closed-loop structure, and comprises a ground monitoring system, a communication system, an under-shaft microprocessor, a motion control card, a mandrel polarization device and a sensor set. The communication system is used for transmitting data on the ground and under the shaft, and the under-shaft microprocessor is positioned under the shaft. The motion control card drives two servo motors in the mandrel polarization device to polarize the mandrel; the sensor set performs a real-time feedback of mandrel displacement data to the under-shaft microprocessor to form an inner ring feedback; and the sensor set performs a real-time feedback of actual drilling number data to the ground monitoring system through the communication system to form an outer ring feedback. The invention further discloses a method of directing-type rotary steering actuator mandrel displacement vector control. The calculating process of the mandrel displacement vector is simplified to be combination of two displacement vectors respectively positioned in an overall coordination system and a local coordination system. The system structure and the control method are simple, accurate guided drilling of drilling tools in a well drilling system can be realized.

Description

technical field [0001] The invention relates to a system and a method for bias control of a rotary steering system, in particular to a system and a method for controlling the displacement vector of a mandrel of a pointing rotary steering actuator. Background technique [0002] At present, drilling technology has been developed towards complex wells such as three-dimensional multi-target wells. Traditional drilling tools can no longer meet the current drilling needs. High-tech rotary steerable drilling technology has emerged and has been gradually applied. Compared with traditional drilling tools, rotary steerable technology has significant advantages, including: high drilling speed, continuous drilling, closed-loop automatic control, smooth borehole, etc. In rotary steerable technology, the steering actuator is the core of the entire system. [0003] The rotary steerable control system mainly includes ground monitoring system, downhole tool system, downhole measurement syst...

AI Technical Summary

Problems solved by technology

Among them, the bias-guiding actuators can be divided into: static bias push type and static bias pointing type; among them, the static bias push type mainly depends on the eccentric control of the drilling tool to change the lateral force on the drill bit. Complex conditions make this system have many disadvantages, such as displacement work mode, static jacket, poor miniaturization ability, complex structure, etc.; the static offset pointing method uses the control of the bending characteristics of the drill string to achieve effective guidance and control of the drill bit axis. Its advantages are The build-up rate is determined by the tool itself and is not affected by the lithology of the drilled formation. The effect is obvious in soft formations and heterogeneous formations. However, since the static offset pointing actuators mostly use hydraulic mechanisms, the structure is complex, and the high-precision Machining is the key to ensure the guiding effect of this system, which requires high precision of the components of the mechanism, so the cost is high; oil leakage is prone to occur during use, and it is not easy to maintain; the response delay of hydraulic components is long, which leads to the error of guiding control accuracy Large; the drill string is subjected to high-intensity alternating stress, and the drill string is prone to fatigue damage

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