The analysis of correction factors of recalculation characteristic of electrical submersible pump at influence viscosity of a prouced fluid

At present time the amount of light oil in our country decreases, and the share of more viscous and heavy oil from total amount of production becomes more and more. In this article influence of viscous liquid on performance of the electrical submersible pump (ESP) is considered. As at operation of the electrical ubmersible pumps operating staff know only the pump performance during the work on water, they should make recalculation of pump performance taking into account conditions at which the pump will work. Comparison of the recalculating factors received experimentally and theoretically by a methodology of P.D.Lyapkov which is taken as a basis at many companies of oil industry.
Materials and methods
Methodology of definition of correction factors of recalculation for delivery, head and efficiency of the electrical submersible pump at its work on viscous liquid is using. Tests of pump stages of ESP 5–30 and 5–35 had carried out.
Results
Analyzing the received schedules, we can notice that the factors of recalculation received at experiment are distinct from the factors of recalculation received on formulas. Therefore, for definition of factors of recalculation it is necessary to deduce the new formulas having dependences on dimensionless number of Reynolds. It is possible to explain discrepancy of factors of recalculation by change of manufacturing techniques of flowing parts of impellers and diffusers (both change of a roughness of a surface, and geometry of impellers and diffusers). And also, a divergence between schedules of KQ, KH received experimentally and calculated on formulas, could arise because transition of one regime liquid current to the other (presumptively transition from ‘conditionally turbulent regime’ to ‘conditionally laminar regime’) wasn't considered. In this regard, there is an assumption of need to use of different formulas for definition of KQ, KH as it was made earlier for K? definition. It is quite possible that for achievement of the smallest error in receiving recalculating factors, for each design of the impeller (defined by factor of rapidity) it is necessary to deduce other formulas. In operating range from 0,75 Q opt to 1,25 Q opt, factors of recalculation are calculated with some error in this connection not always there is a possibility to define factors of recalculation in all operating range on known formulas with acceptable degree of accuracy.
Сonclusions
On the basis of experimental data formulas of correction factors of recalculation for delivery, head and efficiency are received. And further recalculating factors on new formulas are considered at ESP selection to a well.