Recalibration of downhole sensors

摘要

In downhole drilling tools, a first set of inexpensive and/or relatively small sensors that typically have lower accuracy and higher drift than conventional downhole sensors are located in the drill string adjacent to the bit. A second set of highly accurate sensors is located in a more protected location higher in the drill string away from the drill bit. As drilling progresses these sensors pass through the same portion of the formation measured by the first set of sensors. Key properties are measured by the second set of sensors which allow a calibration offset to be applied the data measured by the first set of sensors.