Research On The Key Technology Of RSS’s Signal Transmission And Closed Loop Control

With the development of oil and gas exploration in our country,rotary steering drilling system is an important guarantee for "increasing speed and efficiency","increasing storage and production".At present,the RSS used in China is still mainly imported.Therefore,it is of great significance to further master the key technology of RSS and realize the autonomy of RSS by carrying out the research on the key technology of signal’s uplink and instruction’s downlink of RSS.In this paper,the RSS is divided into an "up closed loop" system and a "down closed loop" system.Through theoretical analysis,simulation calculation,test verification and other means,the main research contents and results of this paper are as follows:High data rate mud pulse signal uplink technology.The source coding technology of Miller code and frame difference compression technology are used to realize the uplink of high data rate mud pulse signal.A BLDCM driver based on hall sensor’s position detection is designed to meet the control requirement of high data rate signal transmission.Combined with the mechanical assemble of mud pulser,the applicability and reliability of this set of high data rate signal uplink technology are verified by experiments.Command downlink technology.Through the design and implementation of the signal downlink coding scheme,according to the characteristics of the signals to be received downhole and the actual working conditions,different signal reception and implementation scheme design and method verification are adopted respectively.The feasibility and applicability of the command transmission control technology are verified by field tests under different operating conditions.Identification and decoding technology of uplinked signal.According to characteristics that the high data rate mud pulse signal is affected by noise,based on the dual processor architecture of ARM+ FPGA,a mud pulse signal noise simulator is designed to study the influence of different kinds of noise,well depth and other factors on channel transmission;through the design of data acquisition and processing system,combined with the advantages of wavelet transform in signal denoising,the system optimized the parameters of wavelet transform adopted for the denoising of mud pulse signal by the calculation of evaluation criteria.According to the characteristics of Miller coding signal and synchronous frame head,autocorrelation detection and bit synchronous closed-loop clock adjustment technology are used to realize the decoding of mud pulse signal.The feasibility and applicability of the decoding and recognition technology of the uploaded signal are verified by the field tests under different working conditions.Closed loop control technology of RSS.Based on the deep understand of its working mode and hydraulic driving principle,combined with the actual data obtained from Baker Hughes RSS,the principle of vector force synthesis and decomposition of three rib is analyzed,and an independent closed-loop control technology of vector force is formed.The feasibility of the method is verified by comparing the simulation results with the original ones.