5.2. Continuous CO2 injection followed with water

This process is the same as the continuous CO2 injection process except for chase water that follows the total injected CO2 slug volume.

#### 5.3. Conventional water-alternating-gas (WAG) followed with water

In this process, a predetermined volume of CO2 is injected in cycles alternating with equal volumes of water. The water alternating with CO2 injection helps overcome the gas override and reduces the CO2 channeling consequently, improving overall CO2 sweep efficiency.

#### 5.4. Tapered WAG

This design is similar in concept to the conventional WAG but with a gradual reduction in the injected CO2 volume relative to the water volume.

#### 5.5. WAG followed with gas

This process is a conventional WAG process followed by a chase of less expensive gas (e.g., air or nitrogen) after the full CO2 slug volume has been injected.
