Keeping CO2 out of the atmosphere by sequestering it underground
Carbon sequestration is the practice of pumping emissions into depleted oil reservoirs or other geologic formations deep beneath the Earth’s surface where they cannot affect the climate. Since CO2 is non-toxic and non-flammable, when sequestered underground it poses no threat to people or the environment. Moreover, it is estimated that there is enough space in these rock formations to sequester all of the world’s potential carbon emissions for thousands of years to come.
From the power plant, CO2 is compressed and carried by pipeline to a wellhead where it is pumped deep underground. Typically, wells previously used for oil or gas production can now be used to deliver the CO2 into these same underground rock formations that previously held oil or gas.
Today’s CO2 pipelines must adopt the latest pipeline safety technologies, including electronic monitoring devices placed throughout the entire length of the pipeline that can instantly pinpoint leaks and automatically isolate the area and shut off the pipeline. This ensures containment of any CO2, and minimizes the release potential to the atmosphere to contribute to global warming. And since carbon dioxide is non-flammable and non-toxic, the potential environmental and safety threats of any pipeline accident are minimal.
Oil and gas exist in networks of billions of pores within layers of sandstone rock sediments. Oil excavation involves drilling though layers of solid, non-porous ‘cap rock’ to reach the porous, oil-rich sandstone layers underneath. Once the oil and gas have been extracted, there are huge volumes of empty space within these porous layers of sandstone. In carbon sequestration, this porous rock space beneath the Earth is used to permanently sequester CO2.
Since CO2 would be sent primarily into oil fields, existing land and facilities can be used as part of any project employing CCS. This is why carbon sequestration is an efficient and cost-effective means of managing CO2 -- portions of the infrastructure are already in place.