Pore-scale analysis of oil recovery by injection of polymer solution

Nicolle Miranda de Lima¹; Márcio da Silveira Carvalho¹

¹ Pontifícia Universidade Católica do Rio de Janeiro

doi:10.20906/CPS/COB-2015-0457

Resumo

Waterflooding is the most commonly used oil recovery method in the industry. However, the high mobility ratio limits the amount of oil displaced by the water phase. An effective alternative to minimize this limitation is the application of technologies that act as mobility control agents. Polymer solution is used in many cases as a way to increase the water phase viscosity and consequently reduce the mobility ratio. Experimental evidences have shown that the elastic behavior of some polymer solution may contribute to a better pore level oil displacement, reducing the residual oil saturation. This pore level behavior is not clearly understood. Here, a glass microfluidic chip is used as a two-dimensional model porous space. This device has the principal features of a porous media and provides means for pore level flow visualization. The evolution of the water phase as it displaces oil is recorded. Three different water phases were used: pure water, a high molecular weight PEO solution and a glycerol-water mixture with the same viscosity of the polymer solution. Flow visualization provides specific information about the presence of the trapped oil phase and the movement of the oil/water interface in the network. Results show that the polymer solution can modify the liquid distribution in the porous media, improving the displacement efficiency at pore scale and consequently the final oil recovery factor.

Palavras-chave: polymer; enhanced oil recovery; viscoelasticity; porous media; micromodel