*4.1.2 CO2 distribution and injection*

In most cases, CO2 is distributed throughout the system and facilities as a dry gas through a trunkline system [33, 35, 37] using bare carbon steel systems as there is no concern for corrosion when the pumping pressure is set at around 1800–2400 psi [37]. However, precautions should be taken by moving the flange valve and tying the valve above ground to avoid leaks and the dry ice formation if loose. Blowdowns consisting of a buried flanged blowdown valve, a blowdown stack, and a line blind are installed (refer **Figures 3** and **4**) to remove excess CO2 impurities in the pipe.

Special consideration should be taken into account for Christmas tree if water alternating gas (WAG) method is applied. If water and CO2 are alternately injected, the part of the system will be vulnerable to corrosion as high-pressured CO2 will come into contact with water and form an acidic solution [36].

**Figure 3.** *A typical system utilized in CO2-EOR [4].*

At the CO2 well head, an additional tee is necessary to be installed, which allows the high-pressure CO2 stream to be closed off away from the well head, which in turn will increase the safety of workovers and similar operations (refer **Figures 5** and **6**). No modifications are required in terms of artificial lift equipment or the well head equipment during the implementation of the CO2 project mainly due to economic reasons and uncertainties of design parameters [37].

Injected CO2 eventually recycles back. The recycled stream may contain H2S [43]. While this may raise a cause for a higher possibility for stress cracking, unlike most systems, the recycle stream will be sufficiently dehydrated, so the need for protection can be minimized through mill analysis and inspection.

### *4.1.3 Field production facilities*

Modifications to the well head were implemented in the ADCO's Wasson ODC Unit, which include 80 nipples, 2000 psi-rated ball valves on the tubing head, and new elastomers in both the secondary seal and tubing slip seal. For beam pumped wells, the blowout preventer elastomers are also changed. For electrical submersible pumps, the tubing valve is being replaced with a 2000 psi-rated gate valve. Many equipment changes and tests are being conducted with respect to all artificial lift equipment. Pre-CO2 injection flowlines are to be replaced with higher pressure rated fiberglass pipes to increase line capacity, and not for corrosion resistance [38].

### *4.1.4 Remote production headers*

The remote headers and satellite battery headers are responsible to collect, or centralize, production from numerous wells and to provide individual well test

*CO2-EOR/Sequestration: Current Trends and Future Horizons DOI: http://dx.doi.org/10.5772/intechopen.89540*

### **Figure 4.**

*Enhanced Oil Recovery Processes - New Technologies*

At the CO2 well head, an additional tee is necessary to be installed, which allows the high-pressure CO2 stream to be closed off away from the well head, which in turn will increase the safety of workovers and similar operations (refer **Figures 5** and **6**). No modifications are required in terms of artificial lift equipment or the well head equipment during the implementation of the CO2 project mainly due to economic reasons and uncertainties of design parameters [37]. Injected CO2 eventually recycles back. The recycled stream may contain H2S [43]. While this may raise a cause for a higher possibility for stress cracking, unlike most systems, the recycle stream will be sufficiently dehydrated, so the need for

Modifications to the well head were implemented in the ADCO's Wasson ODC Unit, which include 80 nipples, 2000 psi-rated ball valves on the tubing head, and new elastomers in both the secondary seal and tubing slip seal. For beam pumped wells, the blowout preventer elastomers are also changed. For electrical submersible pumps, the tubing valve is being replaced with a 2000 psi-rated gate valve. Many equipment changes and tests are being conducted with respect to all artificial lift equipment. Pre-CO2 injection flowlines are to be replaced with higher pressure rated fiberglass pipes to increase line capacity, and not for corrosion resistance [38].

The remote headers and satellite battery headers are responsible to collect, or centralize, production from numerous wells and to provide individual well test

protection can be minimized through mill analysis and inspection.

*4.1.3 Field production facilities*

*A typical system utilized in CO2-EOR [4].*

**Figure 3.**

*4.1.4 Remote production headers*

**132**

*CO2 trunkline blowdown station [5].*

facilities for oil, water, hydrocarbon gas, and CO2 gas production. Remote headers are operated at pressure range of 30–35 psi, while the satellite batteries' headers operate from 25 to 30 psi, whereas satellite batteries are to remove the majority of the hydrocarbon and CO2 gas from the produced fluids and to pump liquids to the fluid gathering, and obtain well tests [39]. Each satellite battery includes a header, test separator, production separator, and transfer pumps.

The specific design criteria for satellite batteries include the following:

1.Minimum of two phase production separators per satellite
