随钻方位电磁波电阻率仪器性能指标检测方法

Main Specifications Test Method of Azimuthal Electromagnetic Logging While Drilling Tool

为提高油藏采收率,大斜度井、水平井被广泛采用,对井眼轨迹提出了更高要求。地质导向技术能根据实时测量数据调整井眼轨迹,被越来越多地应用于水平井钻井过程。随钻方位电磁波电阻率仪器作为目前地质导向的核心仪器,电阻率测量范围、精度及边界探测距离是其最重要的性能指标,目前没有标准刻度井验证或测试仪器性能。从电阻率测量和边界探测原理出发,利用数值模拟分析测量电路信号与电阻率以及界面距离指标的关系。通过实验室测量电路指标确定出方位电阻率仪器的相位差精度为±002°,界面探测信号有效动态为70 dB,以此代替标准环境下实体测试试验,方便和简化了仪器指标测试流程,为随钻方位电磁波电阻率仪器准确进行地层评价和地质导向提供了保障。

Highly deviated and horizontal wells are wildly used to improve reservoir recovery rate, which propose higher requirements to well trajectory. Geosteering technology can adjust well trajectory by real time measurement, so it is more and more common used in horizontal well drilling. Azimuthal electromagnetic logging while drilling tool is kernel tool of geosteering. Resistivity range, accuracy and depth of detection are main specifications of azimuthal electromagnetic logging while drilling tool. But there are lack of clear test methods and test instruments to these specifications. The relationship between measured signals and resistivity and depth of detection are analyzed by numerical simulation based on principles of resistivity and boundary detection measurements. The phase shift accuracy of ±0.02° and geosteering voltage dynamic range of 70 dB can be tested or confirmed by laboratory circuit specifications. The real environment test can be avoided by this method, which facilitates the test process and ensures the application of formation evaluation and geosteering.