高精度油井测斜系统及校正方法的研究

Study on High-accuracy Oil-well Inclinometer System and Relevant Correction Techniques

为提高旋转导向钻井姿态(井斜角、方位角和工具面角)的测量精度,研究了高精度油井测斜系统及校正方法。对该系统的下位机硬件数据采集系统和上位机软件进行设计,根据试验数据确定传感器的性能,设计传感器的标定流程。测试结果表明,传感器工作正常,其输出范围符合标示指标。为避免误差超过设计指标,建立传感器误差补偿模型,提出12参数自动校正算法,据此可以计算出传感器的零位偏差、标度因子和不同心度偏差,从而对传感器输出数据进行误差补偿。应用结果表明,井斜角绝对误差在±0.29°以内,工具面角绝对误差最大为0.484 01°,均满足工业标准要求。说明该校正算法能提高井眼测量精度,从而可以指导钻头钻出更优的井眼轨迹,更有利于旋转导向钻进。

To enhance measurement accuracy for rotary steering drilling positions （deviation angle, azimuth and tool face angle） , high-accuracy oil-well inclinometer system and relevant correction techniques have been developed. Hardware data acquisition system of slave unit and software of master unit have been designed. Relevant data have been used to clarify performances of sensors and highlight procedures for calibration of such sensors. Test results show that these sensors may function properly with outputs conforming to relevant specifications. Error compensation model has been developed for sensors to eliminate possibility of error exceeding designed specification. In addition, automatic correction algorithm with 12 parameters has been developed to determine zero deviation, cali- bration factor and different eccentricity of sensors. In this way, error compensation can be performed on data expor- ted from these sensors. Field performances show that the absolute error of deviation angles can be maintained within ±0. 29°, whereas maximum absolute error of tool face angles can be maintained at 0. 484 01°. All these errors can fulfill requirements specified in relevant industrial standards. It can be seen that the calibration algorithm can effectively enhance accuracy of borehole measurement, and may determine optimal borehole trajectories. In other words, the algorithm may facilitate rotary steering drilling operations.