The Research Of Calibration System About Attitude Sensor Of MWD

In the MWD and the rotary steering drilling,the measurement of well trajectory profile is the key to the whole process of drilling. Attitude sensors’calibration and correction in MWD, to improve the accuracy of the inclinometer, so the well trajectory is better and better, the rotary steerable drilling is more conductive.This article takes accelerometers and magnetometers which compose short section of inclinometer as the study object, the whole system is built by the data acquistion and PC warefrom. First of all,to brief the short section of inclinometer; the second,it gives the inclinometer mathmatical model and the necessary conversion formula; the third, the current used for correction of inclinometer-K factor correction, to give the mathematical model, and by the least square method and the multiple linear regression model to calculate the correction factor,in the article is based on the Halliburton’s K factor, and juxtapose, to demonstrate the feasibility of generating K factor procedures; Finally, introducing another correction that direct the shaft ot orthogonal an don’t coaxial-Q correction, and the derivation, meanwhile,it is based on the Kcorrection and Q correction, and extend another four correction, among them,the K+Q corrction fuse temperature of K correction and Q correction,through the contrast of experiment discover the accuracy of angle,which is calibrated by the K+Q corrction,has been greatly improved.In this system, in order to facilitate data processing and playback, the collected data is direct saved to EXCEL; at the same time, in the PC softwave, it introduces the low-pass filter, in order to improve the accuracy, the PC software was introduced in low-pass filter, the main program is written by VB, correction procedures (including K correction, Q correction, and K+Q correction) use matlab programming, and then call them in the VB. The method is used to achieve the EXCEL data stored, and speeds up the processing of data, improves the accuracy of data processing.