Method for quantitative monitoring of a gas injected in a reservoir in particular in a natural environment
AssigneeInstitut Francais du Petrole
InventorsAlain Prinzhofer, Alexandre Rojey
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AssigneeInstitut Francais du Petrole
InventorsAlain Prinzhofer, Alexandre Rojey
Estimating the term…
Method intended for quantitative monitoring of a gas injected into a reservoir and likely to react chemically with the injection medium. The method essentially consists in injecting into a reservoir a mixture of the potentially reactive gas to be quantified with a low proportion of a tracer gas whose chemical inertia is total, and in determining the variation with time of the initial proportion of reactive gas that may have disappeared through conversion, by measuring the concentration variation of the tracer gas in the mixture. The tracer gas is preferably selected from the rare gas family and from isotopes thereof, unlikely to be contaminated by contact of the mixture with the injection medium, and which have physical properties such as solubility in water or diffusion coefficients as close as possible to the gas injected. Applications: monitoring of the evolution and conversion of a reactive gas such as carbon dioxide or methane, injected into an underground reservoir for example.
1) A method intended for quantitative monitoring of a gas injected into a reservoir, likely to react chemically with the injection medium, characterised in that it comprises injecting into the reservoir a mixture of the gas with a low proportion of a tracer gas whose chemical inertia is total, and determining the variation with time of the initial proportion of gas that may have disappeared through conversion, by measuring the concentration variation of the tracer gas in the mixture.
4) A method as claimed in any one of the previous claims, characterised in that it comprises injecting into the reservoir a mixture of methane and of a rare gas such as argon.
5) A method as claimed in any one of the previous claims, characterised in that it comprises injecting into the reservoir a mixture of carbon dioxide and of a rare gas such as xenon or krypton.
6) A method as claimed in any one of the previous claims, characterised in that measurement of the variation with time of the initial proportion of reactive gas is carried out by gas chromatography.
7) A method as claimed in any one of the previous claims, characterised in that measurement of the variation with time of the initial proportion of reactive gas is carried out by quadrupole spectrometry.
8) A method as claimed in any one of the previous claims, characterised in that measurement of the variation with time of the initial proportion of reactive gas is carried out by coupling a preparation line to a magnetic spectrometer.
Dependencies are inferred from the claim text.