旋转工况下随钻定向测量方法研究及仿真分析

Calculation Method Research and Simulation Analysis of Directional Measurement While Drilling in Rotating Conditions

基于三轴磁通门和三轴加速度计的随钻定向测量仪是当今主流的定向测量仪器,其根据三轴磁通门和三轴加速度计的测量值可以实时解算出当前的方位、井斜和工具面角。但利用现有的解算方法,定向测量只能在非旋转工况下进行,否则,由于离心加速度和振动的影响,测量误差将非常大。针对旋转工况,在现有的方位解算方法的基础上,推导2种新的方位角解算方法:迭代法和三角法。对其进行精度分析,得出2种方法本质相同的结论,且在不考虑某些特殊区域时,方位角仿真精度能到达0.8°。最后,通过Matlab编程,进行了仿真验证。

The directional measurement instrument while drilling, based on tri-axial fluxgate and three axis accelerometers, is the current mainstream. According to measured values of the tri-axial fluxgate and three axis accelerometers, current azimuth angle, inclination angle and tool face angle can be real-time calculated. But using the existing solution methods, the directional measurement can be done only in non-rotating conditions ; otherwise, due to the effect of centrifugal acceleration and vibration, measurement errors wiU be very large. Based on the existing solution methods, two new azimuth calculation methods were derived,iterative method and triangular method,which can be used in rotating conditions. After accuracy analysis, the conclusion, two methods are essentially same, is obtained;and without considering the specific areas, azimuth accuracy of simulation can reach 0.8°. Finally, through the MATLAB programming, verified simulation is made.