Downhole Pressure Gauge Temperature Correction Model Design

During the pressure measurement, the measured value may drift with the changing temperature; therefore a special mathematical model should be established to correct the measurement. Several temperature points were selected when calibrating, and the line fitting with least square method was used for test data of pressure at every temperature point. Between the two adjacent temperature points, the piecewise linear interpolation function was used, thus the original curve was replaced with a polyline. A slicing plane fitting was constructed in a three-dimensional space constructed from the values of pressure, temperature and measurement; a three-dimensional graphics of the slicing plane fitting was built by Matlab. Generated from the actual test data and corrected according to the mathematical model, the results coincided with the facts. This model can also be applied to amend pressure in general application situation.