The Department of Energy’s National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implementing United States Patent Number 7,704,746 titled "Method of Detecting Leakage from Geologic Formations Used to Sequester CO2."
Disclosed in this patent is a method to measure carbon dioxide leakage from sequestration reservoirs and, specifically, an enhanced method for the detection and quantification of carbon dioxide leaks from geologic formations. The method injects tracers along with the carbon dioxide, monitors leakage with gas chromatography, and provides early detection of leakage by measuring the leakage rates of other gases within the geologic formation.
Sequestration of carbon dioxide produced from fossil fuel-fired electric power generating plants, as well as other stationary sources, is an important goal of the nation’s effort to reduce greenhouse gas emissions. U.S. policy may ultimately require carbon dioxide sequestration in geologic repositories, such as oil and gas wells, saline aquifers, salt domes, and unmineable coal deposits. However, validating long-term storage is complicated by a number of factors including depth of reservoirs, seepage around cap rock, and existence of atmospheric carbon dioxide near the formation site. In a reservoir, carbon dioxide displaces methane and a host of other gases. Previously, radioactive tracers were used to detect leakage, but regulations and public opinion blocked their use.
In this patented method, researchers demonstrated that perfluorocarbon (PFTs) tracers were an effective way to evaluate leakage of carbon dioxide. PFTs had been successfully used to locate and quantify leaks within nuclear power plant generators. The method pumps the PFT tracers into the reservoirs along with the carbon dioxide. The levels of the tracers are not affected by atmospheric gases, thereby allowing researchers to collect leaked tracer molecules at and near the external surfaces of the reservoirs.
Since no previous method existed to detect carbon dioxide leakage from a sequestration reservoir, particularly as they applied to background, soil, and bacterial sources of carbon dioxide, this method provides that option while being environmentally benign and cost-effective. It also provides a way to brand, or identify, the source or ownership of the sequestered carbon dioxide.
This method of detecting carbon dioxide leakage from geologic formations provides the following advantages:
U.S. Patent No: 7,704,746
Title: Method of Detecting Leakage from Geologic Formations Used to Sequester CO2
Inventors: Curt White, Arthur Wells, Rodney Diehl, Brian Strazisar
NETL Reference No: S-117,708