Table 7: Relationship between injected PV of Cr3+/APP5 plugging agent and recovery efficiency.

    Experimental scheme     Recovery efficiency (%)     The added value of recovery efficiency (%)
    Early water flooding     Subsequent water flooding     Compared with Early water flooding
    Water flooding 90%+0.1PV Cr3+/APP5 plugging agent+ Water flooding 98%     43.5     56.1     12.6
    Water flooding 90%+0.2PV Cr3+/APP5 plugging agent+ Water flooding 98%     44.6     58.4     13.8
    Water flooding 90%+0.3PV Cr3+/APP5 plugging agent+ Water flooding 98%     44     60.9     16.9
    Water flooding 90%+0.4PV Cr3+/APP5 plugging agent+ Water flooding 98%     43.6     61.2     17.6