Which gas is commonly used in gas injection?

Which gas is commonly used in gas injection?

• A. Carbon Dioxide
• B. Water Vapor
• C. Oxygen
• D. Helium

Answer: (A)

Gas injection in oil recovery aims to push more oil toward the producing wells by filling empty pore spaces with gas and keeping the reservoir pressurized. Carbon dioxide is the gas most commonly used because it can mix with many crude oils to form a miscible flood at practical pressures. When CO2 becomes miscible with the oil, the interfacial tension drops and the oil’s viscosity decreases, allowing it to flow more easily toward the wells. As the reservoir pressure declines, CO2 expands, helping to push additional oil out of the rock. CO2 is often available as a byproduct of natural gas processing and can be captured and recycled, making it a cost-effective option. Water vapor is associated with steam/thermal recovery rather than gas injection, while oxygen and helium aren’t suitable for this purpose due to safety concerns and cost, respectively.

Gas injection in oil recovery aims to push more oil toward the producing wells by filling empty pore spaces with gas and keeping the reservoir pressurized. Carbon dioxide is the gas most commonly used because it can mix with many crude oils to form a miscible flood at practical pressures. When CO2 becomes miscible with the oil, the interfacial tension drops and the oil’s viscosity decreases, allowing it to flow more easily toward the wells. As the reservoir pressure declines, CO2 expands, helping to push additional oil out of the rock. CO2 is often available as a byproduct of natural gas processing and can be captured and recycled, making it a cost-effective option. Water vapor is associated with steam/thermal recovery rather than gas injection, while oxygen and helium aren’t suitable for this purpose due to safety concerns and cost, respectively.