Method for injecting carbon dioxide into a well

摘要

A method for injecting carbon dioxide into an oil or gas well. The carbon dioxide is transported to the well site in a tank while maintaining it at a temperature and pressure sufficient to retain the carbon dioxide primarily in a liquid state. The liquid carbon dioxide is drawn off and pumped to an intermediate pressure by a booster pump. To avoid flashing in the line due to the pressure drop as the liquid is withdrawn, a feedback loop between the output of the booster pump and the tank is utilized. A vaporizer is located in the feedback loop for vaporizing the carbon dioxide injected back into the tank. The amount injected is controlled to maintain the tank at a sufficient pressure to avoid flashing in the discharge line. After the booster pump, the remainder of the liquid carbon dioxide is pumped to a higher pressure by a high pressure pump. The high pressure liquid is commingled with other high pressure liquids and pumped down the well. The high pressure carbon dioxide can also be vaporized by high pressure vaporizer at the surface and injected into the well as a gas.