Abstract: An apparatus and methods for characterizing and communicating carbon dioxide presence in a subterranean formation traversed by a wellbore including collecting fluid from the wellbore at a wellhead, analyzing the fluid for the presence, concentration, or both of the carbon dioxide using an instrument connected to a line collecting the fluid from the wellhead, and communicating the instrument analysis information within 24 hours of analyzing the fluid. Some embodiments may control the introduction of carbon dioxide into the formation. An apparatus and methods for monitoring the presence of carbon dioxide in a fluid produced from a wellbore including continuously collecting and conditioning a sample line from a wellbore, analyzing the sample line with an instrument at the wellsite, recording information from the analyzing continuously over time, and controlling the collecting, conditioning, analyzing, and recording with a process control device.

Abstract: An apparatus and methods for characterizing and communicating chemical tracer presence in a subterranean formation traversed by a wellbore including collecting fluid from the wellbore at a wellhead, analyzing the fluid for the presence or concentration or both of the tracer using a gas chromatograph connected to a line collecting the fluid from the wellhead, and communicating the gas chromatograph analysis information within 24 hours of analyzing the fluid. In some embodiments, the tracing chemical is a perfluorocarbon. In some embodiments, the collecting fluid is continuous. Some embodiments condition a flow of fluid. Some embodiments control the collecting, analyzing, and communicating using a controller that may include an autonomous system that includes a multiplex valve that controls for multiple inputs. The multiple inputs may include time, wellhead identity, calibration, signals from the gas chromatograph or the controller, or a combination thereof.