An abrupt growth of periodic wells, which are operated by electric submersible pumps (ESP), that is indicated in recent years in all oil companies, leads to development of the mathematical models and tools for its modelling. The simple engineering approaches, which were used earlier, have large errors and do not able to make operative fitting of well and equipment working mode to fast-changing operating conditions. The main difficulty is that one has to deal with non-stationary regime of well operating, when each working cycle, at which the pump is switched on, changes with accumulation cycle, at which the pump is switched off. In this paper the description of mathematical models and the algorithm of solving the problem of fitting the present and optimization the forecast periodic mode is presented. The model simplifications for calculation of reservoir and multiphase flow in the well elements are discussed, which enable to essentially increase the speed of calculations avoiding the noticeable accuracy loss. The comparison with field data is presented on the example of the wells with operable and non-hermetic check valve. It is shown how the leaks in the check valve can be taken into account in the model. The short description of the modules “Analysis of the periodic regime of ESP” and “Serial optimization of conditionally stable mode/Automatic re-enabling mode” is done, which are realized in Rosneft Oil Company for aims of monitoring and optimization of periodic mode of oil wells. Their functions and solvable problems are presented, which help technological service to increase oil rate and to diminish the power inputs at periodic wells.
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