CO₂ injection, water injection and gas lift in the oil & gas industry

The natural pressure in an oil field decreases over time, as oil is extracted. To maintain an efficient oil production rate for such a reservoir, pressure can be increased by well water injection (also called water-flooding) – which can re-circulate produced water recovered from the oil-water separators. Artificial lift techniques can also be applied, using gas lift to assist the flow of oil up the well bore tube, or CO₂ injection into the reservoir, which helps reduce the oil viscosity and help oil flow.

In cases where a well has insufficient reservoir pressure to push the oil up to the top of the bore hole, the artificial gas lift can be used to aerate the oil, and so reduce its density. The formation pressure is then able to lift the oil column and forces the two phase fluid out of the well. Gas may be injected continuously or intermittently: by measuring the gas flow with a gas lift flowmeter, and the multiphase oil/gas production flow using a mass flowmeter, the gas injection can be optimized.

KROHNE offers a range of high pressure flow meters for accurate and reliable measurement of liquids and gasses for well water injection or CO₂ injection, and for artificial lift flowmeters. These include OPTIFLUX electromagnetic flowmeters rated at up to 2500 bar. The KROHNE OPTIMASS Coriolis mass flowmeters, available in Super Duplex materials, offer entrained gas management, enabling oil production measurement to custody transfer standards despite any remaining entrained gas.