1.The CO₂ metering and reinjection system typically includes:
(1) CO₂ Supply & Storage Unit
- CO₂ Source: Captured from industrial emissions, natural gas processing, or purchased commercially.
- Storage Tanks: High-pressure vessels or cryogenic tanks for liquid CO₂ storage.
- Vaporizers (if needed): Convert liquid CO₂ into gas for injection.
(2) CO₂ Metering & Flow Control System
- Coriolis or Ultrasonic Flow Meters: Precisely measure CO₂ mass flow rate.
- Control Valves & Regulators: Maintain stable injection pressure and flow.
- Gas Chromatographs (Optional): Monitor CO₂ purity and detect impurities.
(3) Compression & Injection Unit
- CO₂ Compressors: Increase gas pressure to reservoir injection requirements (typically 1,500–5,000 psi).
- Injection Wellhead Equipment: Includes pressure control valves, safety systems, and downhole tubing.
(4) Monitoring & Automation System
- SCADA/PLC Control: Real-time monitoring of pressure, flow rate, and injection performance.
- Leak Detection Sensors: Ensure safe handling of CO₂.
- Remote Telemetry (Optional): For unmanned or offshore operations.
2. Working Principle
- CO₂ Supply: CO₂ is delivered from storage (liquid or gas phase).
- Metering & Conditioning: Flow meters measure CO₂, and pressure/temperature adjustments are made.
- Compression: CO₂ is compressed to required injection pressure.
- Injection: CO₂ is injected into the reservoir via dedicated wells.
- Monitoring: Real-time data ensures optimal injection rates and reservoir response.
3. Applications in Oilfield Waterflooding
- Enhanced Oil Recovery (EOR): CO₂ mixes with oil, reducing viscosity and improving sweep efficiency.
- Carbon Sequestration (CCUS): Stores CO₂ underground, reducing atmospheric emissions.
- Pressure Maintenance: Helps sustain reservoir pressure for improved waterflood performance.
4. Advantages
✔ Increased Oil Recovery – CO₂ injection can boost recovery rates by 10–20%.
✔ Environmental Benefits – Supports carbon neutrality by storing CO₂ underground.
✔ Precise Control – Automated metering ensures accurate injection rates.
✔ Scalability – Suitable for both small-scale pilots and large commercial projects.
5. Challenges
⚠ High Initial Cost – Requires significant investment in compression and metering equipment.
⚠ Corrosion Risks – CO₂ can react with water, requiring corrosion-resistant materials.
⚠ Reservoir Suitability – Not all formations are ideal for CO₂ injection (requires proper geology).
6. Summary
The CO₂ metering and reinjection system is a cutting-edge solution for oilfield waterflooding, combining EOR benefits with carbon management. By integrating precise metering, compression, and real-time monitoring, this system enhances oil production while supporting sustainable energy practices.
