Dynamic impedance matching of transmission cables for downhole tools

The operational requirements of communication cables used in the offshore environment are very different from those used for terrestrial telecommunications. Using the matching condition where the load termination, Z_L equals the conjugate of Z_T, maximum power is transferred to the load. In order to evaluate the effect of varying temperature gradients on the cable, a model has been successfully used. A software-based system would update the matrix coefficients and termination impedance when required. From this study, it is found that the cable terminating impedance Z_T is not required to be dynamically matched as the cable advances into the pipeline, although the transducer parameters need to be compensated for optimal matching