Electro Submersible Pump (ESP) telemetry system allows getting information of different types of heavy electromagnetic noise: random, pulsing, harmonic etc. in the neighborhood They are pump unit's intake pressure, temperature and most importantly its insulation resistance for submersible motor stator coil reliability - for the successful exploitation of the oil complexes. The change from analog to digital communication techniques is going at a fast rate in almost all technical fields. But increasing disturbance levels with corrupted analog communication result in an increased noise level, but are often still "audible" or the control system is still reliable. With increasing disturbance levels, the analog signal will be audible, but will remain low. However beyond a certain disturbance level, the so called "digital cliff", the digital communication and the control stop abruptly. In this study, the extended Kalman filter (EKF) is designed and examined under severe noise conditions for the high-noise cancelation in control telemetry channels of oil ESP. The results approve a high performance of the developed EKF. (C) 2013 Elsevier B.V. All rights reserved.