The Problem Of Three-dimensional Error Correcting For Controlled Directional Drilling

The drilling technology is transiting from drilling out of control to directional drilling at present. Many techniques in coal mine safety, for example of the long borehole drilling for gas exhausting along the coal bed and the water plugging and slurry pouring for preparing the floor consolidating, are supported by direction drilling technology. To improve the efficiency of the gas exhausting and water resistant, the accuracy request of the borehole trajectory on space location under ground is more and more strict. If the measuring equipment can not give the accurate location parameter, the borehole trajectory will not get to the target location according to the design trajectory, even happen the accidents such as blocking up the drill , cutting off the drill since the borehole bending seriously , and cause the great economic expense or threatening the miner's life. Therefore, improve the accuracy of measuring while drilling and study the data emendation problem is the key of high-accuracy orientation measures.The thesis based on the 10th Five Years Key Programs for Science and Technology Development of China "Drainage of gas underground mine with long hole construction equipment and craft technological development in coal mine" and the Key Program for industry technology development of National Development and Reform Commission "The Research of 1000m branched long hole construction equipment and craft technology for Drainage of gas underground". In the analysis of direction drilling technology research and present situation development at home and abroad, suggest that a measuring while drilling system based on the accelerometer sensor and semiconductor magnetism sensor according to the reality and requirement on drilling direct underground, through the research of calculate method and error analysis, a series of error compensation are presented.Through the research of direction drilling technology and space orientation method, the thesis introduced the measuring principle and calculation of space orientation, and the structure of the system is given according to the main design, the sensor part is particular introduced, and then analysis the reason which may cause the error in system, and bring forward the corresponding error compensation scheme finally. According to the scheme, the error is compensated from hardware and the software. Considering the particularity of the environment for the azimuth measuring, the Be-copper is chosen as the material of instrument holder by analysis the several kinds of materials; To make every effort to minis the machinery error by the optimization design on installation structure from the sensor; Specifically for the semiconductor magnetism sensor, set / reset circuit is designed to solve the system error which brings along the magnetism accumulate or magnetism polarization from the sensor; For the uprightness and superposition problems of the sensor sensitive axis which can not compensate by hardware, bring forward the optimization algorithm to compensation the angle error; Adopt eight position method and ellipse-specific fitting method which are common compensation methods used in navigation to avoid the environment magnetic disturbance, the results show that this method is effective.The results of experiments show that, the precision is improved evidently through the emendation, the error of obliquity angle is±0.2°, and the error of azimuth is±1.5°. The vibration resistant and stabilization of this measurement-while-drilling system are reach to the request.and conformable for measuring while drilling. The result is comparatively satisfied, attains the desired objective.