ISSN 2542–0380 
Труды Института механики им. Р.Р. Мавлютова
Электронный научный журнал  Electronic Scientific Journal
Proceedings of the Mavlyutov Institute of Mechanics

In the paper the argumentation of application of quasistationary model of gasliquid flow is presented to describe periodic regime of oil well operating. It is shown that this simplification actually does not affect the solution accuracy, but allows to essentially diminish the calculating time. In view of the considered problem specification the transition from nonstationary model of media to the quasistationary model greatly increases the computational speed, which is the necessary condition for execution the optimization calculations.
multiphase flow,
mass transfer,
oil recovery
Purpose:
Monitoring and optimization of periodical regime of oil wells, which are operated by sets of electrical submersible pump, by the help of mathematical modeling methods
Methodology:
To describe multiphase flow in the reservoir and well elements (casing, tubing, annulus) the quasistationary model is suggested to use as an alternative to nonstationary model. This enables to accelerate the duration of optimization calculations without losses in computational accuracy
Findings:
1) The problem of spreading of disturbance in multiphase flow in round tube is studied. Three characteristic time stages of nonstationary solution are highlighted
2) The comparison of results of calculations of nonstationary and quasistationary models for describing of multiphase flow in well elements is done. It is obtained that the quasistationary model shows error of calculation of the main parameters of the problem (averaged and extreme during one periodic cycle of pumping/accumulation values of liquid rate, well flow pressure, dynamic level) of about 1% compared with nonstationary model
Conclusions:
1) By the model examples (part of a tube and oil well) it is shown that the influence of nonstationary effects in multiphase flow in tubes with reference to the problem of periodic operating of oil well by electric submersible pump is minimum and nonstationary model of the well in such problems can be replaced by quasistationary without losses in solution accuracy
2) For practical use it is advisable to switch from the solution of partial differential equations to the simplified correlations like BeggsBrill or Ansari to calculate the pressure drop in tubes, which is solved by explicit numerical methods