CALCULATION OF SENSITIVITY FIELD FOR ELECTROMAGNETIC TOMOGRAPHY IN MULTIPHASE FLOW WELL LOGGING
多相流动电磁波成像测井测量敏感场计算

The sensitivity field is of great importance for the optimal design of the Electromagnetic Tomography (EMT) in multiphase flow well logging tools and images reconstruction. We calculate using a numerical method. For the facility of analysis, the calculation is performed in 2 planes based on the symmetry of the sensor, though the sensitivity field is 3 dimensional. The analysis contains 2 connected steps. First, the potential distribution within the measure array is calculated using FEM (Finite Element Method). Then, the gradient of the potential is acquired according to the numerical computation. The result shows that the sensitivity field has an arc-shape within the region from transmitting electrode to measuring electrode, and it can be expressed approximately using an exponential function.