本文已被:浏览次 下载次 |
码上扫一扫! |
|
|
Start-up pressure gradient of polymer flooding in low permeability reservoirs |
WANG Youqi, YU Hongmin, LIU Ping, XU Guanli, ZHANG Li, NIE Jun
|
(Petroleum Exploration & Production Research Institute, SINOPEC, Beijing 100083, China)
|
Abstract: |
Polymer flooding experiments are conducted using cores with different permeability and polymer solutions with different viscosity, in order to study the flow behavior in porous media and the characteristics of the start-up pressure gradient for polymer injection in oil reservoirs with low permeability. A combined method of differential pressure via flow rate and capillary equilibrium was used in the core flooding experiments. Based on the theory of nonlinear flow in porous media, the start-up pressure gradient for polymer flooding was characterized quantitatively, and was correlated with the non-linear flow coefficient, the viscosity of polymer solution, the permeability of the core and fluid 's mobility. A flow chart of polymer flow in low permeability reservoirs has been figured out. The results show that the flow resistance and the start-up pressure gradient increase with the decrease of core permeability and the increase of polymer viscosity. The flow behavior of polymer solutions in porous media can be well described using the nonlinear characterization method, and the nonlinear flow coefficient increases with the decrease of core 's permeability and the fluid mobility, and it increases with the increase of polymer viscosity. The flow chart can give a quantitative description of different flow regions, such as no-flow zones, non-linear and quasi-linear flow zones. |
Key words: low permeability polymer flooding start-up pressure gradient non-linear flow experiment flow characterization chart |
|
|