METHOD FOR DETERMINING GENESIS OF NITROGEN IN GAS DEPOSITS BY ISOTOPIC COMPOSITION Russian patent published in 2024 - IPC B01D59/44 C01B21/00 

FIELD: search, exploration and operation of hydrocarbon deposits.

SUBSTANCE: disclosed is a method for determining the genesis of nitrogen in gas deposits by isotopic composition, during which first studying isotopic composition of atmospheric air in the area of operations, isotopic composition of nitrogen emitted into atmosphere of uncompressed air of compressor stations and isotopic composition of pumped into wells technical nitrogen δ¹⁵Nt, after that, on exploratory wells or on one production well of each development object allocated on the field, a series of measurements of the isotopic composition of the nitrogen of the produced gas mixture δ¹⁵Np₁ is carried out, with an arbitrary sampling interval, until stable values are obtained, indicating the depletion of technical nitrogen, which makes it possible to take the last value of δ¹⁵Np₁ as the isotopic composition of natural nitrogen of the deposit without man-made impurities δ¹⁵Nd, on the basis of which the genesis of the natural nitrogen of the deposit is determined; in the future, during development of all other production wells and wells put into operation after repair, at each investigated well in an arbitrary period of its operation, performing a single measurement of the isotopic composition of nitrogen δ¹⁵Np₂ of the produced gas, according to which the fraction Mt of technogenic nitrogen in the total nitrogen of the produced gas of the well is determined.

EFFECT: high accuracy of determining the genesis of nitrogen in natural gas and optimization of analytical studies of nitrogen in the mixture of the produced gas.

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