基于数据融合的近钻头井眼轨迹参数动态测量方法

采用三轴加速度计、磁通门和速率陀螺测量系统随钻测量井眼轨迹参数时,由于旋转、振动和磁干扰等因素的影响,造成测量结果存在较大偏差,无法满足随钻地质导向的要求.为此,针对三轴加速度计、磁通门和速率陀螺随钻测量系统,建立了基于四元数井眼轨迹参数测量模型,并依据状态方程和量测方程,应用3个捷联式卡尔曼滤波器和磁干扰校正系统对加...

Dynamic Measurement Method of Near-Bit Borehole Trajectory Parameters Based on Data Fusion

When borehole trajectory parameters are measured while drilling by a measurement system of triaxial accelerometers, fluxgates, and rate gyros, the results show huge deviations due to the influence of factors such as rotation, vibration, and magnetic interference, etc. As a result, the requirements of geosteering while drilling cannot be met. Considering this, a quaternion-based measurement model of borehole trajectory parameters was built for the above measurement system. In addition, according to state equations and measurement equations, three strap-down Kalman filters and a correction system for magnetic interference were applied to filter and correct accelerometer and fluxgate signals. In this way, a dynamic measurement method of near-bit borehole trajectory parameters based on data fusion was developed. The simulations in the laboratory and on-site drilling showed that the measurement precision of borehole trajectory parameters was significantly improved by using the proposed method. The research indicates that the proposed method can eliminate the influence of rotation, vibration, and magnetic interference on the results of the measurement system of triaxial accelerometers, fluxgates, and rate gyros while drilling to upgrade the measurement precision for geosteering, thus meeting the requirements of geosteering while drilling.