Continuous characterization and communication of chemical tracer

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. Some embodiments may also analyze for the concentration of the tracing chemicals. In some embodiments, the gas chromatograph measures the fluid from the wellbore after a conditioning activity. The conditioning activity may include adjusting the fluid composition, fluid gas to liquid ratio, time between analyzing, phase separation, temperature control, pressure control, or a combination thereof. In some embodiments, the gas chromatograph has a line in direct communication with the wellbore. In some embodiments, communicating includes a transmitter to transmit a signal to a remote device. An apparatus and method for monitoring the presence of a chemical tracer in a fluid produced from a wellbore including continuously collecting and conditioning a sample line from a wellbore, analyzing the sample line with a gas chromatograph at the wellsite, recording information from the analyzing continuously over time; and controlling the collecting, conditioning, analyzing, and recording with a process control device. In some embodiments, the process control device is a microprocessor. Some embodiments communicate information to a remote location. In some embodiments, the collecting, conditioning, analyzing, recording, and communicating occur within 10 minutes or are repeated continuously over 24 hours. Some embodiments may adjust a heater or air conditioner.

Dependencies are inferred from the claim text.