Prediction method of produced polymer concentration based on interwell connectivity

Abstract To forecast some key parameters of produced liquid containing polymer, including the time of polymer output, polymer concentration, a polymer concentration prediction method based on interwell connectivity methodology was established, its prediction results were compared with those from numerical simulation software, and it has been used in a case study. On the basis of water flooding interwell connectivity model, a polymer flooding production performance prediction model considering the viscosity, concentration, adsorption and water-phase permeability reduction factor of polymer was built. Compared with the traditional numerical simulation, the pressure equations in this model have lower dimension, and it inverses the interwell conductivity and connected volume through automatic history matching, enhancing calculation speed and precision significantly. The calculation model was used to the history matching of a homogeous reservoir model with 1 injector and 4 producers, and the comparison of its results and the results from numerical simulation software shows the model is reliable and accurate. Moreover, sensitivity analysis of major model parameters reveals that the increase of water-phase permeability reduction factor, injected polymer concentration and pore volume injected and early polymer injection time can improve oil recovery. The real reservoir application shows the model can predict the change of produced polymer concentration of different development schemes accurately.