Tunable laser spectroscopy measurement of C13 ethane
AssigneeSchlumberger Technology Corporation
InventorsMahdi Ammar, Dariusz Strapoc, Jerome Breviere
Life of this patent
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Abstract
An apparatus for making isotopic ethane measurements of a gas sample includes a tunable infrared laser configured to emit an infrared laser beam; an infrared sensor configured to receive the infrared laser beam; a gas cell deployed in a path between the tunable infrared laser and the infrared sensor such that the infrared laser beam passes through the gas cell, the gas cell configured to receive the gas sample; and a controller configured to evaluate the received infrared laser beam to estimate a ratio of C13 ethane to C12 ethane in the gas sample.
Claims14
An apparatus for making isotopic ethane measurements of a gas sample, the apparatus comprising:
- a tunable infrared laser configured to emit an infrared laser beam;
- an infrared sensor configured to receive the infrared laser beam;
- a gas cell deployed in a path between the tunable infrared laser and the infrared sensor such that the infrared laser beam passes through the gas cell, the gas cell configured to receive the gas sample via a gas inlet and expel the gas sample via a gas outlet;
- and
- a controller configured to evaluate the received infrared laser beam to estimate at least a ratio of C13 ethane to C12 ethane in the gas sample, wherein the controller is further configured to:
- cause the tunable infrared laser to scan the emitted infrared laser beam between first and second wavenumbers;
- cause the infrared sensor to measure a spectrum corresponding to the scanned infrared laser beam;
- identify a first C13 ethane absorption peak and a second C12 ethane absorption peak in the measured spectrum;
- compute first and second amplitudes of the corresponding first and second absorption peaks by removing a spectral background;
- and
- compute a ratio of the first and second amplitudes to estimate the ratio of C13 ethane to C12 ethane in the gas sample.
A method for making isotopic ethane measurements of a gas sample, the method comprising:
- introducing the gas sample into a gas cell, the gas cell deployed in a path between a tunable infrared laser and an infrared sensor, the tunable infrared laser configured to emit an infrared laser beam that passes through the gas cell and is received at an infrared sensor;
- scanning the emitted infrared laser beam between first and second wavenumbers;
- measuring a spectrum corresponding to the scanned infrared laser beam;
- identifying a first C13 ethane absorption peak and a second C12 ethane absorption peak in the measured spectrum;
- computing first and second amplitudes of the first and second absorption peaks by removing a spectral background;
- and
- computing a ratio of the first and second amplitudes to estimate a ratio of C13 ethane to C12 ethane in the gas sample.
Dependencies are inferred from the claim text.