Oil Displacement Effect Evaluation of SP Foam System in Two-tube Parallel Cores

The high flow resistance of foam system in porous medium makes foam system can effectively block high permeability layers and increase the sweep efficiency. In this paper, two-tube parallel cores model was used to conduct laboratory core displacement experiments under condition of permeability contrast 1:3, 1:5, 1:10 respectively. The experimental systems are high concentration polymer + oil resistant and low tension foam system, high concentration polymer + low tension SP system and foam + low tension SP system. Through analyzing the recovery and flow distribution we can know the applicable system for permeability contrast 1:3 and 1:5 is foam + low tension SP system. And the applicable system for permeability contrast 1:10 is high concentration polymer + oil resistant and low tension foam system. Compare core displacement experiment results of different slug size combinations, the best slug size combination of permeability contrast 1:5 is 0.1PV foam + 0.4PV low tension SP system, while the best slug size combination of permeability contrast 1:10 is 0.3PV high concentration polymer + 0.2PV oil resistant and low tension foam system.