Error Analysis in Accelerometers Calibration of Measurement while Drilling Instrument used in Directional Drilling Operations

The aim of this paper is to analyze the sensor errors in measurement while drilling (MWD) instrument used in directional drilling operations. The MWD consist of three orthogonal accelerometers, three orthogonal magnetometers and one temperature sensor. The system formulation is achieved through the system analysis and functional consideration. The obtained formulation is validated and verified by comparing the results obtained from measurements and simulations. The accelerometers calibration, to estimate bias factors, scale factors and non-orthogonal factors of sensors, is done using optimal non-linear Newton Raphson algorithm by considering the high temperature calibration coefficients. The accuracy of the experimental results, obtained from several measurement while drilling systems in Iranian national oil drilling company shows the effectiveness of the approach.