Abstract
Laboratory investigations and field applications have proved injection of polymer solutions to be an effective means to improve oil recovery for reservoirs of medium oil viscosity. This numerical study was undertaken to investigate and compare the performances of polymer flood processes through horizontal and/or vertical wells. To achieve the object of this study, an extensive numerical simulation was performed for three different well configurations under polymer flood followed by waterflood.
A three-dimensional numerical model for fluid flow and mass transport is used to analyze the performance of the reservoir. The potential for a horizontal well application was assessed through different scenarios in combinations of injection and production wells and reservoir geometry. Other parameters include the length and spacing of horizontal injectors and horizontal or vertical producers. For different parameters of the system, performances were compared in terms of cumulative recovery and water-oil ratio at the production well and pressure drop or injectivity at the injection well.
Results from the study have demonstrated that additional oil can be recovered and injectivity was significantly improved by utilizing a combination of horizontal wells when the same volume of fluid is injected into the reservoir. The improvement of injectivity through a horizontal injection well was higher when it was combined with horizontal producer. Parameters such as reservoir thickness, well spacing, and well length are also shown to impact the predicted injectivity. Improvement in injectivity is obtained for thicker and larger reservoirs and longer horizontal wells.
