Patent ID: 11867682
Assignee: BAKER HUGHES OILFIELD OPERATIONS LLC
Field: Measurement (Instruments)
Classification: CPC G  E | IPC E  G

Claim 0:
1. A method to measure a concentration of natural methane in a sample of drilling fluid, the method comprising:
pumping the drilling fluid through a drill string into a wellbore;
taking the sample of the drilling fluid to a terranean surface, the sample comprising a first hydrocarbon component, a second hydrocarbon component, and methane, the methane comprising the natural methane originating from an earth formation and artificially-produced methane caused by drill bit metamorphism;
determining a δ13C isotopic signature of the first hydrocarbon component in the sample;
determining a δ13C isotopic signature of the second hydrocarbon component in the sample;
determining a δ13C isotopic signature of the methane in the sample; and
determining, using a processor, the concentration of the natural methane in the sample based in part on the δ13C isotopic signature of the first hydrocarbon component, the δ13C isotopic signature of the second hydrocarbon component, and the δ13C isotopic signature of the methane.