Calculation of production at low flowing pressure for polymer flooding oil wells

In order to avoid the calculation error under the conditions of low-flowing pressure with the earlier inflow performance model of polymer flooding oil wells, combining the law that power-law fluids flow through porous media with continuity equation and state-equation, the inflow performance equation is established for the case that power-law fluid stably flows through porous medium. A modified coefficient is introduced, and corresponding production calculation method is put forward by the relative value of the forecasted flowing pressure and the tested flowing pressure. The verification and analysis of effect factors are studied. The results indicate that, by this method, the productivity prediction of the polymer flooding oil wells under the low-flow pressure has been solved. Its calculation value and test value are close. The inflow performance relation curve of polymer flooding oil well is bent down at high-flow pressure part and is bent up at low-flow pressure part, so the IPR curve is S shape that inclines to the left. With the increasing polymer concentration, IPR curve will become a steeper one, then oil well productivity will decline. With increasing water cut, IPR curve span will increase, then oil well production will increase in the same flow pressure.