The conversion of shale gas preservation and isotope response simulation device and method
阅读说明：本技术 页岩气赋存转化与同位素响应模拟装置和方法 (The conversion of shale gas preservation and isotope response simulation device and method ) 是由 陶成 俞凌杰 张彩明 腾格尔 范明 申宝剑 翟常博 杨华敏 于 2018-05-21 设计创作，主要内容包括：本发明公开了一种页岩气赋存转化与同位素响应模拟装置,包括饱和-解吸罐、色谱-同位素质谱分析系统和采送样机构。饱和-解吸罐用于对岩心进行气体高压饱和,并对高压饱和后的岩心进行解吸；色谱-同位素质谱分析系统用于实时监控碳同位素或氢同位素的变化；采送样机构用于收集岩心解吸后的气体,并将岩心解吸后的气体送入色谱-同位素质谱分析系统。该页岩气赋存转化与同位素响应模拟装置,用于页岩岩心气体高压饱和—解吸实验,实验室内模拟页岩气的产出过程,并实时监控碳同位素或氢同位素的变化,为示踪页岩气井的开发状态,进行产能预测提供基础数据和理论支撑。(The invention discloses a kind of conversions of shale gas preservation and isotope response simulation device, including saturation-solution cucurbitula, chromatography-mass spectrometric analysis for isotope system and adopt sample feeding mechanism.Saturation-solution cucurbitula is used to carry out rock core gas high pressure saturation, and desorbs to the rock core after high pressure saturation；Chromatography-mass spectrometric analysis for isotope system is used to monitor in real time the variation of carbon isotope or hydrogen isotope；Sample feeding mechanism is adopted for the gas after collecting rock core desorption, and the gas after rock core is desorbed is sent into chromatography-mass spectrometric analysis for isotope system.Shale gas preservation conversion and isotope response simulation device, for shale core gas high pressure saturation-desorption experiment, test the output process of indoor simulation shale gas, and monitor the variation of carbon isotope or hydrogen isotope in real time, for the development status of tracer shale gas well, carries out capability forecasting and basic data and theory support are provided.)
1. a kind of shale gas preservation conversion and isotope response simulation device characterized by comprising
Saturation-solution cucurbitula for carrying out gas high pressure saturation to rock core, and desorbs the rock core after high pressure saturation；
Chromatography-mass spectrometric analysis for isotope system, for monitoring the variation of isotope in real time；
Sample feeding mechanism is adopted, for collecting the gas after rock core desorption, and described in the gas after rock core desorption is sent into Chromatography-mass spectrometric analysis for isotope system.
2. shale gas preservation conversion according to claim 1 and isotope response simulation device, which is characterized in that described full And-solution cucurbitula and described adopt are successively arranged pressure reducing valve and flow controller along gas circulating direction between sample feeding mechanism.
3. shale gas preservation conversion according to claim 1 and isotope response simulation device, which is characterized in that described to adopt Sample feeding mechanism is six-way valve, and probe tube is equipped in the six-way valve.
4. shale gas preservation conversion according to claim 1 and isotope response simulation device, which is characterized in that the color Spectrum-mass spectrometric analysis for isotope system includes the chromatograph and isotope mass spectrometer set gradually along gas circulating direction, the color Combustion furnace is equipped between spectrometer and the isotope mass spectrometer, the combustion furnace is used to aoxidize gas or by the high anneal crack of gas Solution.
5. shale gas preservation conversion according to claim 1 and isotope response simulation device, which is characterized in that described full It is equipped with heating mantle with the outside of-solution cucurbitula, the heating mantle is used to for the saturation-solution cucurbitula provide suitable temperature.
6. shale gas preservation conversion according to claim 1 and isotope response simulation device, which is characterized in that described full Connect high pressure tank with the import of-solution cucurbitula, the outlet of the high pressure tank is equipped with first pressure meter, the saturation-solution The outlet of cucurbitula is equipped with second pressure meter.
7. shale gas preservation conversion according to claim 2 and isotope response simulation device, which is characterized in that described full With-solution cucurbitula lower part connect vacuum pump.
8. a kind of shale gas preservation conversion according to claim 1-7 is rung with isotope response simulation device The method that should be simulated, which comprises the following steps:
S1, the saturation-solution cucurbitula for being placed with rock core is vacuumized, gas is carried out to the saturation-solution cucurbitula using high pressure tank Body high pressure saturation；
S2, the rock core after gas saturation is desorbed, and the gas after rock core desorption is sampled；
S3, acquired sample is sent into the chromatography-mass spectrometric analysis for isotope system, to monitor the variation of isotope in real time.
9. the method for isotope response simulation according to claim 8, which is characterized in that before the step S1, also wrap Include step S0:
Rock core after drying is placed in the saturation-solution cucurbitula, and the saturation-solution cucurbitula is vacuumized；
It is passed through inert gas into the saturation-solution cucurbitula using the high pressure tank, until the pressure of the high pressure tank Power and the saturation-solution cucurbitula pressure reach balance；
Pressure change before and after being passed through inert gas to the saturation-solution cucurbitula according to the high pressure tank obtains described full With-desorption tank void space volume；
The body of the gas of required filling in the high pressure tank is calculated according to the saturation of acquisition-desorption tank void space volume Product.
10. the method for isotope response simulation according to claim 8 or claim 9, which is characterized in that the rock core saturated air being passed through Body is methane or shale gas.
Technical field
The present invention relates to petroleum and gas geology and exploration technical fields, ring more particularly, to a kind of conversion of shale gas preservation with isotope Answer simulator and method.
Background technique
China reaches 5.1 × 10 in the blocks shale gas yield such as Sichuan Basin coke masonry dam, Weiyuan9m3, it is in exploration now The critical stage of exploitation, it is pre- about adsorbed gas during shale gas output/free gas ratio, shale gas well development state and production capacity The problems such as survey is oil field unit emphasis concern.Recent isotope method is gradually paid close attention to, tentatively present for The application potential of the above problem.In principle in adsorption/desorption, diffusion process, it may appear that apparent methane isotope fractionation effect It answers, to will cause isotope fractionation phenomenon.It has been found that the carbon isotope value of shale gas drilling mud gas methane will be lighter than rock Bits degassing, and methane isotope δ during shale gas exploitation13C has the tendency that becoming weight with mining time.Obviously with shale aspiration Isotope fractionation effect in attached/desorption, diffusion process is related.
Zhong Ningning (2016) etc. is observed in the parsing for sticking together group shale core to Upper Yangtze Longma small stream group shale and well In shale gas adsorption/desorption, diffusion process, Methane Carbon Isotope forms (δ13C1 up to 7 ‰~14.4 ‰) be can produce Fractionation.Australia is utilized using multi component adsorption and basis of dual porosity gas flow model to this apparent isotopic fractionation The SIMEDWin software simulation of big Leah University of New South Wales and CSIR O research and development calculates shale gas desorption-diffusion process Isotopic fractionation.According to simulation calculated result, free gas/adsorbed gas ratio in different moments resolution gas has further been sought Example and its with parsing the time variation.
Currently, the research of isotope method is also only at the early-stage, for studying conversion and the shale of shale gas occurrence status There are also very big potentiality for the tracer of gas development status.Emphasis be to master shale gas parsing (adsorption/desorption, diffusion) during Isotope fractionation rule, and establish the fractionation effect quantitatively characterizing model with theoretical basis.
Summary of the invention
For the above-mentioned technical problem in the presence of the prior art, the invention proposes a kind of conversion of shale gas preservation and together The plain response simulation device and method in position.According to an aspect of the present invention, shale gas preservation conversion is filled with isotope response simulation It sets and includes:
Saturation-solution cucurbitula for carrying out gas high pressure saturation to rock core, and solves the rock core after high pressure saturation It inhales；
Chromatography-mass spectrometric analysis for isotope system, for monitoring the variation of carbon isotope or hydrogen isotope in real time；
Sample feeding mechanism is adopted, is sent into for collecting the gas after the rock core desorbs, and by the gas after rock core desorption The chromatography-mass spectrometric analysis for isotope system.
In one embodiment, it the saturation-solution cucurbitula and described adopts between sample feeding mechanism along gas circulating direction successively Equipped with pressure reducing valve and flow controller.
In one embodiment, the sample feeding mechanism of adopting is six-way valve, is equipped with probe tube in the six-way valve.
In one embodiment, the chromatography-mass spectrometric analysis for isotope system includes setting gradually along gas circulating direction Chromatograph and isotope mass spectrometer, between the chromatograph and the isotope mass spectrometer be equipped with combustion furnace, the combustion furnace For gas to be aoxidized or by gas Pintsch process.
In one embodiment, the saturation-solution cucurbitula outside is equipped with heating mantle, and the heating mantle is used to be described full With-suitable the temperature of solution cucurbitula offer.
In one embodiment, the import of the saturation-solution cucurbitula connects high pressure tank, and the high pressure tank goes out Mouth is equipped with first pressure meter, and the outlet of the saturation-solution cucurbitula is equipped with second pressure meter.
In one embodiment, the saturation-solution cucurbitula lower part connects vacuum pump.
According to another aspect of the present invention, the method for shale gas preservation conversion and isotope response simulation, including it is following Step:
S1, the saturation-solution cucurbitula for being placed with rock core is vacuumized, using high pressure tank to the saturation-solution cucurbitula into Row gas high pressure saturation；
S2, the rock core after gas saturation is desorbed, and the gas after rock core desorption is sampled；
S3, acquired sample is sent into the chromatography-mass spectrometric analysis for isotope system, with monitor in real time carbon isotope or The variation of hydrogen isotope.
In one embodiment, further include step S0 before the step S1:
Rock core after drying is placed in the saturation-solution cucurbitula, and the saturation-solution cucurbitula is vacuumized；
It is passed through inert gas into the saturation-solution cucurbitula using the high pressure tank, until the high pressure tank Pressure and the saturation-solution cucurbitula pressure reach balance；
Pressure change before and after leading to inert gas to the saturation-solution cucurbitula according to the high pressure tank, described in acquisition Saturation-desorption tank void space volume；
The gas of required filling in the high pressure tank is calculated according to the saturation of acquisition-desorption tank void space volume Volume.
In one embodiment, the rock core saturated gas being passed through is methane or shale gas.
Compared with the prior art, the advantages of the present invention are as follows provide a kind of conversion of shale gas preservation and respond with isotope Simulator is used for shale core gas high pressure saturation-desorption experiment, tests the output process of indoor simulation shale gas, and real When monitor the variation of isotope, clear with during shale gas output, changing rule of the isotope in mass transfer transition process And fractionation mechanism, clear the relationship of the conversion of shale gas preservation with isotope response, the development status of tracer shale gas well.
Detailed description of the invention
The preferred embodiment of the present invention is described in detail below in conjunction with attached drawing.In figure:
Fig. 1 shows the knot of a kind of shale gas preservation conversion and isotope response simulation device according to an embodiment of the present invention Structure schematic diagram.
Fig. 2 shows the stream of a kind of shale gas preservation conversion and isotope response simulation method according to an embodiment of the present invention Cheng Tu.
In the accompanying drawings, identical component uses identical appended drawing reference.The attached drawing is not drawn according to the actual ratio.
Specific embodiment
Below in conjunction with attached drawing, the present invention will be further described.
Fig. 1 shows that shale gas preservation conversion according to the present invention and isotope response simulation device, the device include full Cucurbitula 1, chromatography-mass spectrometric analysis for isotope system 2 and sample feeding mechanism 3 is adopted with-solution.Saturation-solution cucurbitula 1 is for carrying out gas to rock core Body high pressure saturation, and the rock core after high pressure saturation is desorbed.Chromatography-mass spectrometric analysis for isotope system 2 is for monitoring in real time The variation of isotope.Sample feeding mechanism 3 is adopted for the gas after collecting rock core desorption, and the gas after rock core is desorbed is sent into color Spectrum-mass spectrometric analysis for isotope system 2.When carrying out gas high pressure saturation to rock core, gas used can be pure methane or page Rock gas.
According in shale gas development process, there are certain corresponding for the isotope variation of methane and the recovery ratio of shale gas well Relationship, thus the development status of the isotope variation tracer shale gas well using methane.The present invention utilizes above-mentioned principle, by shale The conversion of gas preservation is used for shale core gas high pressure saturation-desorption experiment with isotope response simulation device, can be used for complete Diameter shale core (without cutting and split point, the whole section of column rock core for carrying out analysis measurement for laboratory) gas high pressure is full With-desorption experiment, the output process of indoor simulation shale gas is tested, and monitors the variation of isotope in real time, tracer shale gas well Development status.
In one embodiment, it saturation-solution cucurbitula 1 and adopts between sample feeding mechanism 3 along gas circulating direction (arrow b as shown in figure 1 It is shown) it is successively arranged pressure reducing valve 11 and flow controller 12.The pressure that pressure reducing valve 11 exports for reducing saturation-solution cucurbitula 1, stream Amount controller 12 is used to control the flow of gas, it is preferable that the flow for controlling gas is 5.0ml/min.
In one embodiment, adopting sample feeding mechanism 3 is six-way valve, is equipped with probe tube 31 in six-way valve, the import of six-way valve 3 is also Equipped with air supply plant (not shown), with the inert gas (as shown in figure 1 shown in arrow a) of air supply plant feeding for carrier, The gas being collected into probe tube 31 is sent into chromatography-mass spectrometric analysis for isotope system 2.In six-way valve as shown in Figure 1, do not receive Collect the gas of probe tube 31 by label 1., 4., 5. and 6. shown in pipeline emptying.Preferably, the length of probe tube is 10ul.Inert gas as carrier can be helium, be also possible to other inert gases.
In one embodiment, chromatography-mass spectrometric analysis for isotope system 2 includes along gas circulating direction (such as arrow c institute in figure Show) chromatograph 21 and isotope mass spectrometer 22 that set gradually, combustion furnace is equipped between chromatograph 21 and isotope mass spectrometer 22 23.Combustion furnace 23 can be oxidation furnace, be also possible to pyrolysis furnace.
When carrying out gas high pressure saturation to rock core, when gas used is pure methane, chromatograph 21 may be deposited for removing Foreign gas, interference to avoid the foreign gas to methane.Gas after the separation of chromatograph 21, through oxidation furnace by first Alkane gas is oxidized to carbon dioxide, or through pyrolysis furnace by methane gas Pintsch process is hydrogen.Later, pass through isotope mass spectrometry Instrument 22 detects carbon isotope or hydrogen isotope.
When gas used is shale gas, chromatograph 21 is in addition to for also using other than removing foreign gas that may be present In by methane and ethane separation.Gas after the separation of chromatograph 21, is oxidized to carbon dioxide for shale gas through oxidation furnace, or Through pyrolysis furnace by shale gas Pintsch process be hydrogen.Later, methane, ethane can be detected by isotope mass spectrometer 22 respectively Carbon isotope chromatographic peak, or detect the hydrogen isotope chromatographic peak of methane, ethane respectively.
In one embodiment, saturation-solution cucurbitula 1 outside is equipped with heating mantle 13, and heating mantle 13 is used to be saturation-solution cucurbitula 1 provides suitable temperature.It under normal circumstances, is the temperature on stratum where rock core by the temperature setting, utmostly to simulate rock Environment of the heart on its stratum.
In one embodiment, the import of saturation-solution cucurbitula 1 connects high pressure tank 14, and saturation-solution cucurbitula 1 and high pressure are stored up Valve is equipped between gas tank 14.The outlet of high pressure tank 14 is equipped with first pressure meter 15, and the outlet of saturation-solution cucurbitula 1 is equipped with Second pressure meter 17.In the embodiment, saturation-solution cucurbitula 1 lower part connects vacuum pump 16.To rock core carry out methane gas or Before person's shale gas saturation-desorption experiment, the inert gas that pressure is P will be first filled in the high pressure tank 14, and (preferably, this is lazy Property gas select helium), the pressure value of high pressure tank 14 is observed by first pressure meter 15.Then rock core is placed in full With-solve in cucurbitula 1, it is vacuumized later using 16 pairs of saturations of vacuum pump-solution cucurbitula, after vacuumizing, opens 14 He of high pressure tank Valve between saturation-solution cucurbitula 1, until high pressure tank 14 and saturation-solution cucurbitula 1 pressure reach balance (by first Pressure gauge 15 and second pressure meter 17 observe high pressure tank 14 and whether saturation-solution cucurbitula 1 pressure reaches balance), and lead to The variation of 15 pressure of first pressure meter is crossed, the volume of saturation-solution cucurbitula 1 void space is calculated.The void space refers to placement There are the space in saturation-solution cucurbitula 1 of rock core and the summation of rock core hole.
According to another aspect of the present invention, the method for shale gas preservation conversion and isotope response simulation, including it is following Step:
S1, the saturation-solution cucurbitula for being placed with rock core is vacuumized, gas is carried out to saturation-solution cucurbitula using high pressure tank Body high pressure saturation；
S2, the rock core after gas saturation is desorbed, and the gas after rock core desorption is sampled；
S3, acquired sample is sent into the chromatography-mass spectrometric analysis for isotope system, to monitor the change of isotope in real time Change.
In one embodiment, further include step S0 before the step S1:
Rock core after drying is placed in saturation-solution cucurbitula, and saturation-solution cucurbitula is vacuumized；
It is passed through inert gas into saturation-solution cucurbitula using high pressure tank, until the pressure of high pressure tank and described Saturation-solution cucurbitula pressure reaches balance；
Pressure change before and after being passed through inert gas to the saturation-solution cucurbitula according to the high pressure tank obtains institute State saturation-desorption tank void space volume；
The gas of required filling in the high pressure tank is calculated according to the saturation of acquisition-desorption tank void space volume Volume.
In one embodiment, the conversion of shale gas preservation is as follows with the method for isotope response simulation:
1) high-purity helium that certain pressure will be filled in high pressure tank 14, records the pressure value of first pressure meter 15；
2) rock core to be measured is placed in vacuum drying oven sufficiently degassing and removes water, temperature setting is 85 DEG C under vacuum condition, dry Time is set as 1 hour；
3) rock core after drying is placed in saturation-solution cucurbitula 1, it is carried out after saturation-solution cucurbitula 1 is sealed to take out true Sky, time are about 1 hour；
4) after vacuumizing, high pressure tank 14 is connected to saturation-solution cucurbitula 1, until high pressure tank 14 and saturation-solution After the pressure of cucurbitula 1 reaches balance, according to the variation of 15 pressure value of first pressure meter, the saturation-desorption for being placed with rock core is calculated The volume of the void space of tank 1；
5) saturation-solution cucurbitula 1 for being placed with rock core is vacuumized again；
6) high pressure tank 14 is calculated according to the volume of the saturation for being placed with rock core-solution cucurbitula 1 void space of acquisition In required filling methane pressure, and the methane for the pressure being filled in high pressure tank 14；
7) valve between high pressure tank 14 and saturation-solution cucurbitula 1 is opened, so that the methane in high pressure tank flows to Methane high pressure saturation is carried out to rock core in saturation-solution cucurbitula 1, and the pressure in saturation-solution cucurbitula 1 is detected according to second pressure meter 17 Power variation, until rock core is sufficiently saturated；
8) valve between high pressure tank 14 and saturation-solution cucurbitula 1 is closed, starts to desorb, in desorption process, passes through stream Amount controller controls the flow velocity of methane gas as 5ml/min, and real-time accumulated gas outflow；
9) it when the methane gas of rock core desorption outflow flows through six-way valve 3, is sampled using probe tube 31.It can set and take The time interval that sample pipe 31 samples, when not needing sampling, methane gas by the pipeline of six-way valve 3 1., 4., 5. and 6. shown in Pipeline is vented；
10) using helium as carrier, as shown in figure 1 shown in arrow a, the methane gas being collected into probe tube 31 is sent into color Spectrum-mass spectrometric analysis for isotope system, methane gas carry out component separation in chromatograph 21, and methane gas is converted by oxidation furnace For CO2, or through pyrolysis furnace Pintsch process be H2, carbon isotope or hydrogen isotope are monitored by isotope mass spectrometer 22 later.
According to this experimental method, can design different time, different pressures, the carbon isotope under gas with various flow conditions or The situation of change of person's hydrogen isotope simulates the fractionation mechanism of isotope during shale core output, and inverting shale gas developed The changing rule of isotope in journey.
In another embodiment, methane gas can be substituted with shale gas, shale is carried out to the rock core in saturation-solution cucurbitula The gas being collected into is sent into chromatograph 21 after desorption and carries out component separation, and is converted into CO through oxidation furnace by gas high pressure saturation2, Or through pyrolysis furnace Pintsch process be H2, the variation of carbon isotope or hydrogen isotope is monitored by isotope mass spectrometer 22 later Situation.Other steps are as above-mentioned the step of being passed through methane gas.
The foregoing is merely the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, Ren Heben The technical staff in field can be easy to carry out and be altered or varied in technical scope disclosed by the invention, and this change or change Change should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be with the protection model of claims Subject to enclosing.