On-line degassing system for isotopc analysis of gaseous hydrocarbon acidolysis gas in rock

Abstract

The invention discloses an on-line degassing system for isotopc analysis of gaseous hydrocarbon acidolysis gas in rock. The system comprises an acidolysis gas degasser, an adsorption enrichment apparatus, a six-way valve and a separator; the acidolysis gas degasser comprises a sample disk, a sample bottle, an acid needle, a sample introduction needle; a cover is arranged on the sample disc, the sample bottle passes through the cover and is placed in the sample disc, the acid needle and the sample introduction needle respectively pass through a sample bottle plug and are inserted into the sample bottle; the adsorption enrichment apparatus comprises an alkali lye bottle, a de-watering trap and a cold trap made by a special material; one end of the sample introduction needle is inserted into the alkali lye bottle, the de-watering trap inlet tube is inserted into the alkali lye bottle, the de-watering trap outlet pipe is connected to the six-way valve, the separator comprises a chromatographic column, an oxidation furnace and an opening shunt tube; two ends of the cold trap are respectively connected to the six-way valve; a port 5 of the six-way valve is connected to a helium introduction pipe, and a port 6 of the six-way valve is connected to the chromatographic column. The on-line degassing system realizes the on-line analysis of acidolysis hydrocarbon isotope and avoids the isotope fractionation effect, and the test result is accurate.

Description

technical field [0001] The invention relates to the field of oil and gas geochemistry, and more particularly, relates to an online degassing system for gas isotope analysis of gaseous hydrocarbon acidolysis gas in rocks. Background technique [0002] In the geochemical study of oil and gas accumulation, after long geological accumulation of oil and gas, hydrocarbon gas molecules are adsorbed and wrapped in the mineral lattice of rock or soil. This adsorbed hydrocarbon is stable in nature and can truly reflect the original hydrocarbon content of source rocks . For many years experimenters have used acids (such as H 3 PO 4 ) decomposes carbonate minerals in geological samples such as rocks and soils, so that the gaseous hydrocarbons adsorbed by the minerals and wrapped in their lattices are accompanied by the generated CO 2 Released together, the released mixed gas absorbs CO through concentrated lye (such as KOH) 2 After the gas is purified to enrich the hydrocarbon gas, ...

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Problems solved by technology

[0006] In order to solve the problems existing in the prior art that "the degassing device is an offline device, the gaseous hydrocarbons produced by acid hydrolysis are prone to isotope fractionation, and the original sample volume is large", which greatly affects the isotope analysis results, and the demand for samples cannot be satisfied. To solve the problems of parallel experiment testing, etc., the present invention provides an online degassing system for acidolysis gas isotope analysis of gaseous hydrocarbons in rocks. Gas equipment is out of touch with the analysis items of modern scientific analysis instruments, and accurate and reliable isotope analysis results are obtained, providing technical support for oil and gas exploration and development

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