阅读说明：本技术 用于录井现场测量碳同位素的气相色谱—同位素分析联用装置 (Gas chromatography-isotope analysis combined device for logging field measurement of carbon isotope ) 是由 刘兴杰 孙合辉 张欣欣 王智 陶青龙 李怀玉 万康 陈玉新 于 2020-11-05 设计创作，主要内容包括：本发明公开了一种用于录井现场测量碳同位素的气相色谱—同位素分析联用装置,包括气相色谱仪、同位素分析仪,在气相色谱仪的鉴定器的排出口与同位素分析仪的进样口之间设置有控制流速的蠕动泵和控制温湿度的电子冷凝器,蠕动泵收集鉴定器中烃类气体燃烧生成的二氧化碳气体并控制流速,通过电子冷凝器控制温湿度后送达同位素分析仪进行碳同位素测量；气相色谱仪的预色谱柱、主色谱柱采用填充柱,色谱柱口径φ3mm,预色谱柱柱长2.5m,主色谱柱柱长5m,色谱柱内填充60-80目13X分子筛。本发明能够实现录井现场实时连续测量钻井液中轻烃含量及其所含甲烷、乙烷、丙烷碳同位素含量。满足同位素分析对单一气体间分离度以及温湿度的技术条件。(The invention discloses a gas chromatography-isotope analysis combined device for measuring carbon isotopes in logging sites, which comprises a gas chromatograph and an isotope analyzer, wherein a peristaltic pump for controlling flow rate and an electronic condenser for controlling temperature and humidity are arranged between a discharge port of an identifier of the gas chromatograph and an injection port of the isotope analyzer, the peristaltic pump collects carbon dioxide gas generated by combustion of hydrocarbon gas in the identifier and controls flow rate, and the carbon dioxide gas is sent to the isotope analyzer for carbon isotope measurement after the temperature and humidity are controlled by the electronic condenser; the pre-chromatographic column and the main chromatographic column of the gas chromatograph adopt packed columns, the caliber of the chromatographic column is phi 3mm, the length of the pre-chromatographic column is 2.5m, the length of the main chromatographic column is 5m, and the chromatographic column is filled with a 60-80 mesh 13X molecular sieve. The invention can realize real-time continuous measurement of the light hydrocarbon content and the content of the isotopes of methane, ethane and propane in the drilling fluid on the logging site. The technical conditions of isotope analysis on the separation degree between single gases and the temperature and humidity are met.)

1. A gas chromatography-isotope analysis combined device for measuring carbon isotopes on logging sites comprises a gas chromatograph and an isotope analyzer, and is characterized in that a peristaltic pump (3) for controlling flow rate and an electronic condenser (4) for controlling temperature and humidity are arranged between a discharge port of an identifier (1-3) of the gas chromatograph (1) and a sample inlet of the isotope analyzer (2), the peristaltic pump (3) collects carbon dioxide gas generated by combustion of hydrocarbon gas in the identifier (1-3) and controls flow rate, and the carbon isotopes are sent to the isotope analyzer for carbon isotope measurement after the temperature and humidity are controlled by the electronic condenser (4); the pre-chromatographic column (1-1) and the main chromatographic column (1-2) of the gas chromatograph adopt packed columns, the caliber of the chromatographic column is phi 3mm, the length of the pre-chromatographic column is 2.5m, the length of the main chromatographic column is 5m, and the chromatographic column is filled with a 60-80-mesh 13X molecular sieve.

2. The apparatus for integrated gas chromatography-isotope analysis for in-situ carbon isotope measurement in well logging as defined in claim 1 wherein the gas chromatograph (1) has a sample gas flow rate of 0.04MPa and 104ml/min, and a carrier gas flow rate of 0.25MPa and 20ml/min is controlled by using hydrogen as a carrier gas.

3. The apparatus for gas chromatography-isotope analysis for carbon isotope measurement at a logging site as claimed in claim 1, wherein the flow rate is controlled by adjusting the rotation speed of the peristaltic pump (3) so that the flow rates of the gas from the peristaltic pump (3) and the gas from the analyzers (1-3) are equal.

4. The apparatus for combined GC-isotopic analysis for in-situ carbon isotope measurement in well logging applications as claimed in claim 1, wherein said electronic condenser (4) outlet gas temperature is below 25 ℃ and relative humidity is below 20% RH.

Technical Field

The invention relates to the field of petroleum geological exploration and development, in particular to a gas chromatography-isotope analysis combined device for measuring carbon isotopes on a logging site, which is used for developing shale oil, shale gas and coal gas.

Background

The gas chromatograph is a logging instrument for measuring hydrocarbon gas in the field of petroleum exploration and development operation, and mainly comprises a gas circuit control module, a quantifying pipe, a pre-chromatographic column, a main chromatographic column, a 10-pass rotary valve, a constant temperature box, an identifier and a quantitative acquisition module.

Isotope analyzer for real-time measurement of C in logging process₁、C₂、C₃The instrument for stabilizing carbon isotope information is developed by adopting the principle of cavity ring-down spectroscopy (CRDS), the logging technology has unique advantages in the exploration and development of offshore oil and shale oil gas,

at present, an FID gas chromatograph is generally adopted in a logging field to monitor the content of hydrocarbon gas, if carbon dioxide generated by combustion of the hydrocarbon gas can be collected to carry out carbon isotope measurement, the logging technical content is also improved, a large amount of information which cannot be found by a conventional gas chromatograph hidden in the hydrocarbon gas can be found, and the method has important significance in improving the application technology of the oil gas exploration and development field.

The isotope analyzer has long measuring time for single gas, so the interval between different gases cannot be less than 30 seconds, the existing gas chromatographs applied to the field are all fast chromatographs, and the separation time interval of methane and ethane is only 1-2 seconds, which cannot meet the requirement. The identifier is an open gas outlet and is in an emptying state, carbon dioxide gas generated after combustion needs to be collected, and analysis and measurement of the carbon isotope analyzer can be influenced by high temperature and high humidity and gas flow rate change caused by pipeline diameter change.

Disclosure of Invention

The invention aims to solve the technical problem of providing a gas chromatography-isotope analysis combined device for measuring carbon isotopes on a logging site, which meets the technical conditions of isotope analysis on separation time interval and temperature and humidity between single gases.

In order to solve the technical problems, the invention adopts the technical scheme that: a gas chromatography-isotope analysis combined device for measuring carbon isotopes on logging sites comprises a gas chromatograph and an isotope analyzer, wherein a peristaltic pump for controlling flow rate and an electronic condenser for controlling temperature and humidity are arranged between a discharge port of an identifier of the gas chromatograph and an injection port of the isotope analyzer, the peristaltic pump collects carbon dioxide gas generated by combustion of hydrocarbon gas in the identifier and controls flow rate, and the carbon dioxide gas is sent to the isotope analyzer for carbon isotope measurement after the temperature and humidity are controlled by the electronic condenser; the pre-chromatographic column and the main chromatographic column of the gas chromatograph adopt packed columns, the caliber of the chromatographic column is phi 3mm, the length of the pre-chromatographic column is 2.5m, the length of the main chromatographic column is 5m, and the chromatographic column is filled with a 60-80 mesh 13X molecular sieve.

The gas chromatograph has sample gas flow rate of 0.04MPa and 104ml/min, and carrier gas flow rate controlled by hydrogen as carrier gas of 0.25MPa and 20 ml/min.

The flow is controlled by adjusting the rotating speed of the peristaltic pump, so that the flow of the gas flowing out of the peristaltic pump is equal to that of the gas flowing out of the identifier.

The temperature of the gas at the outlet of the electronic condenser is below 25 ℃, and the relative humidity is required to be below 20% RH.

The invention has the beneficial effects that: the method can realize real-time continuous measurement of the light hydrocarbon content and the content of the isotopes of methane, ethane and propane in the drilling fluid on the logging site. The stable flow, stable pressure and dry carbon dioxide gas is provided to an isotope analyzer, and the technical conditions of isotope analysis on the separation degree and the temperature and humidity of single gas are met.

Drawings

Fig. 1 is a schematic structural diagram of a gas chromatography-isotope analysis combined device for measuring carbon isotopes in a logging site according to the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The working principle of the gas chromatograph and the isotope analyzer of the present invention is the same as the prior art, and reference can be made to the prior art, so the present invention is not described again, and the present invention is different from the prior art in that the parameters and the packing of the pre-chromatographic column and the main chromatographic column of the gas chromatograph are different, and in addition, components for adjusting the flow rate and the temperature and humidity are added to the gas chromatograph and the isotope analyzer, and the following detailed description is provided:

as shown in fig. 1, the gas chromatography-isotope analysis combined device for measuring carbon isotopes in logging sites comprises a gas chromatograph and an isotope analyzer, wherein a peristaltic pump 3 for controlling flow rate and an electronic condenser 4 for controlling temperature and humidity are arranged between a discharge port of an identifier 1-3 of the gas chromatograph 1 and a sample inlet of the isotope analyzer 2, the peristaltic pump 3 collects carbon dioxide gas generated by combustion of hydrocarbon gas in the identifier 1-3 and controls flow rate, and the carbon dioxide gas is sent to the isotope analyzer for carbon isotope measurement after the temperature and humidity are controlled by the electronic condenser 4; a pre-chromatographic column 1-1 and a main chromatographic column 1-2 of the gas chromatograph adopt packed columns, the caliber of the chromatographic column is phi 3mm, the length of the pre-chromatographic column is 2.5m, the length of the main chromatographic column is 5m, and the chromatographic column is filled with a 60-80-mesh 13X molecular sieve.

The gas chromatograph 1 has a sample gas flow of 0.04MPa and 104ml/min, and a carrier gas flow of 0.25MPa and 20ml/min controlled by hydrogen as a carrier gas.

The flow rate is controlled by adjusting the rotating speed of the peristaltic pump 3, so that the flow rates of the gas flowing out of the peristaltic pump 3 and the gas flowing out of the identifiers 1-3 are equal.

The temperature of the gas at the outlet of the electronic condenser 4 is below 25 ℃, and the relative humidity is required to be below 20% RH.

The invention controls the flow rate by the peristaltic pump and sends the flow rate to the isotope analyzer to measure the carbon isotope. Electric powerThe sub-condenser is a CEMS electronic condenser, and the output temperature and humidity are controlled within a certain range, so that the technical conditions of the isotope analyzer are met. The invention is designed and modified on the basis of the conventional gas chromatograph, so that the isotope analyzer can meet the requirements of measuring the gas separation degree, the period, the temperature and the humidity and the like. Not only can real-time measure the quantitative data of methane, ethane and propane gas returned by well drilling fluid in the well drilling construction process, provide hydrocarbon gas abnormal monitoring for the site, simultaneously transmit carbon dioxide gas generated after methane, ethane and propane gas are combusted to an isotope analyzer, and measure the methane carbon isotope (delta)¹³C₁) Ethane carbon isotope (delta)¹³C₂) Carbon isotope of propane (. delta.)¹³C₃) Relative amounts of (c). By measuring carbon isotopes, the method has unique advantages in the aspects of distinguishing natural gas properties and causes, biodegradation research in oil reservoirs, oil-producing rock maturity analysis, gas-oil source comparison, fault sealing properties and the like. The isotope analyzer has longer measuring time for single gas, the interval between different gases cannot be less than 30 seconds, and the separation degree between gases is ensured by adjusting the length from the filling material to the chromatographic column and the pressure of the carrier gas. The structure of the identifier and the connection of the gas pipeline at the rear end can cause gas accumulation, and is also not beneficial to the analysis of the isotope gauge on the detected gas. And water vapor is generated during the combustion process, so that the high-temperature and high-humidity gas is not suitable for the technical conditions of the isotope analyzer. A precise peristaltic pump is added at the rear end of the identifier to control the flow rate, and a temperature and humidity control system is added to ensure that the gas delivered to the isotope analyzer achieves the technical conditions of steady flow, stable pressure and drying.

The following is illustrated with reference to specific examples:

first, sample gas sample introduction and separation

Firstly, a sample gas is pumped by a sample pump and is subjected to pressure stabilization control and regulation, and the gas flow of the sample is controlled at 0.04MPa and 104 ml/min. Hydrogen is used as carrier gas, the flow rate of the carrier gas is controlled at 0.25MPa and 20ml/min, and the carried sample gas enters the quantitative tube → the pre-chromatographic column → the main chromatographic column for separating hydrocarbon gas. The quantitative pipe ensures that the gas sampling amount detected in each period is the same. The chromatographic column adopts a packed column, the diameter of the chromatographic column phi is 3mm, and the length of the pre-chromatographic column is 2.5 m. The main chromatographic column is 5m long and is filled with a 60-80 mesh 13X molecular sieve with good light hydrocarbon separation effect. The tests were carried out with thirty seconds between methane and ethane and 90 seconds between ethane and propane. The whole period is 300 seconds, and the expected design purpose is achieved. The pre-chromatographic column is arranged to avoid column efficiency reduction caused by long-term use of heavy hydrocarbon component pollution on site, and when propane is separated out, back flushing is carried out to empty isobutane and subsequent heavy hydrocarbon components. The working processes of the quantitative tube, the pre-chromatographic column, the emptying and the main chromatographic column are periodically controlled through a 10-way rotary valve, and the components and the identifier are uniformly placed in a constant temperature box, so that the stability of the whole work is ensured.

Combustion and quantitative collection of hydrocarbon components

The single component separated from the main chromatographic column enters an identifier (combustion chamber), the gas flow is controlled at 0.2MPa and 10ml/min, and the combustion air flow is controlled at 0.15MPa and 310 ml/min. Ion flow generated after combustion ionization of hydrocarbon components such as methane, ethane and propane is subjected to signal amplification, and quantitative acquisition data of methane, ethane and propane is obtained by an ARM platform and corresponding software and hardware systems and is used as a basis for corresponding carbon isotope content.

Third, gas collection and temperature and humidity control

Carbon dioxide generated after the combustion of hydrocarbon components such as methane, ethane, propane and the like and combustion air are mixed and pumped by a peristaltic pump to be conveyed to an isotope analyzer. The peristaltic pump is of a BT300-02 YZ2515 type produced by Hebei Baoding constant-flow pump limited company, and the flow is accurately controlled by adjusting the rotating speed so that the flow is equal to the gas flowing out of the identifier. Thus avoiding gas accumulation caused by the structure of the identifier and the diameter change of the connecting pipeline, and ensuring that the interval time of carbon dioxide generated by burning each component is consistent with the separation time of each component passing through the chromatographic column. The analysis interval time of the isotope analyzer for the carbon isotopes generated by different components can be correspondingly controlled. The carbon dioxide content in the air is relatively stable, and background subtraction can be performed in an isotope analyzer. The identifier is a closed space, gas combustion can generate high temperature and water vapor, and the isotope analyzer requires the temperature of the detected gas to be below 25 ℃ and the relative humidity to be below 20% RH. Therefore, a semiconductor electronic condenser is arranged on the conveying pipeline, and an YNLN-200 CEMS electronic dehumidification condenser produced by Jiangsu Wuxi Steady safety electronics Limited company is selected, and all parameter indexes of the condenser completely meet the requirements. The exit temperature was 5 ℃ and the relative humidity was 10% RH. The transported sample gas is made to meet the technical requirements of an isotope analyzer.

The invention is designed and modified on the basis of the conventional gas chromatograph, so that the isotope analyzer can meet the requirements of measuring the gas separation degree, the period, the temperature and the humidity and the like. The device not only can measure the quantitative data of methane, ethane and propane gas returned by well drilling fluid in the drilling construction process in real time, provide hydrocarbon gas abnormity monitoring for a site, simultaneously transmit carbon dioxide gas generated after methane, ethane and propane gas are combusted to an isotope analyzer, and measure the relative contents of a methane carbon isotope (delta 13C1), an ethane carbon isotope (delta 13C2) and a propane carbon isotope (delta 13C 3). By measuring carbon isotopes, the method has unique advantages in the aspects of distinguishing natural gas properties and causes, biodegradation research in oil reservoirs, oil-producing rock maturity analysis, gas-oil source comparison, fault sealing properties and the like.

In summary, the disclosure of the present invention is not limited to the above-mentioned embodiments, and persons skilled in the art can easily set forth other embodiments within the technical teaching of the present invention, but such embodiments are included in the scope of the present invention.