A method of measuring adsorbed and free oil content in shale

Abstract

The application discloses a kind of, belong to oil and gas field development technical field, it is characterized in that, including the following steps: selecting shale sample, carries out specific surface experiment;Vacuum pump is opened, to the reaction tube vacuum, shale particle sample is heated at 60 DEG C at least 120 min;Shale particle sample heating temperature is set to 200 DEG C, by gas chromatograph to the light oil component and content that become steam are analyzed and detected;Heating temperature is set to 350 DEG C constant temperature heating, the component and content of light and medium oil that have become steam are detected;At 450 DEG C constant temperature heating, the component and content of heavy oil that have become steam are detected;The total oil content of shale particle sample is calculated, and the content of adsorbed oil in shale particle sample and the content of free oil in shale particle sample are calculated.The application can provide more accurate adsorbed oil and free oil content data for shale oil reserves calculation, which is beneficial to accurately evaluate shale oil reservoir.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas field development, and particularly relates to a method for measuring contents of absorbed oil and free oil in shale. BACKGROUND

[0002] Shale oil, namely a collection of liquid hydrocarbons mainly in adsorbed state and free state in shale and carbonate rock interbeds or clastic rock interbeds in shale, has a low average single-well production at present, and the main reason for this situation is that under the current technical conditions, the movable crude oil in the shale reservoir is mainly free oil in free state in the reservoir, and the absorbed oil is often difficult to be moved due to the strong adsorption with the pore surface. Therefore, in the current shale oil exploration, the free oil content is often taken as the maximum movable amount of shale oil, so in the shale oil exploration work, it is very necessary to provide the experimental data of the free oil content in the shale oil reservoir as the experimental basis for reservoir evaluation, sweet spot optimization and the like.

[0003] Since the shale oil in adsorbed state and free state does not have a particularly significant boundary, and the shale oil is a complex compound of hydrocarbons and colloid, bitumen, it is difficult to determine the contents of free shale oil and absorbed shale oil in the reservoir. At present, the commonly used traditional experimental method is a swelling experiment method: first, the crude oil, bitumen and the like are dissolved in an organic solvent such as toluene, after the shale sample is placed in the solution for a period of time, the change of the absorbance of the solution is detected by a spectroscopy method to determine the adsorption amount of the shale to the crude oil or bitumen, and the adsorption characteristics of the shale are evaluated by establishing the relationship between the adsorption amount and the equilibrium time to determine the content of the absorbed oil.

[0004] Although the swelling experiment method can analyze the content of the absorbed oil adsorbed by the shale and analyze the component characteristics of the absorbed oil by the spectroscopy method, the mixed solution of the crude oil, bitumen and toluene interacts with each other, and generally speaking, the stronger the interaction between the selected crude oil, bitumen and toluene, the more uniform the solution mixing, and the more conducive to ensuring the uniformity of the adsorption process of the core sample, but the stronger the interaction, the more it will inhibit the core sample from adsorbing the crude oil and bitumen from the solution, and further affect the total adsorption amount. At the same time, the experiment cannot be carried out at the formation temperature, otherwise the material composition of the solution will be changed, and the adsorption process of the crude oil in the shale is greatly affected by the temperature, and the adsorption amount data obtained without considering the temperature factor cannot reflect the distribution of the free oil and the absorbed oil in the shale reservoir under the real formation conditions.

[0005] The Chinese patent document with the publication number CN110687612A and the publication date of January 14, 2020 discloses a shale oil analysis method and device for continuously characterizing adsorbed oil and free oil content, comprising: performing nuclear magnetic resonance measurement, saturation measurement, and self-adsorption method wettability measurement on a core sample obtained from a shale oil sweet spot section to obtain nuclear magnetic resonance T2 spectrum, nuclear magnetic porosity, oil saturation, and wettability index, and determine the calculation lower limit value of adsorbed oil according to the same; determine the calculation lower limit value of free oil according to the T2 volume relaxation spectrum of crude oil of the well section or adjacent well section and the nuclear magnetic resonance T2 spectrum of the core sample; and continuously and quantitatively calculate the content of adsorbed oil and the content of free oil of the well section to be analyzed according to the nuclear magnetic resonance logging data of the well to be analyzed, the calculation lower limit value of adsorbed oil, and the calculation lower limit value of free oil, and analyze the shale oil of the well section to be analyzed according to the same.

[0006] The shale oil analysis method and device for continuously characterizing adsorbed oil and free oil content disclosed in the patent document realizes the continuous characterization of the adsorbed oil and free oil logging quantification of shale oil. However, the density parameters of adsorbed oil and free oil in different pore sizes cannot be obtained, so that more accurate adsorbed oil and free oil content data cannot be provided for shale oil reserve calculation, thereby affecting the evaluation of shale oil reservoirs. SUMMARY

[0007] The present application provides a method for measuring the content of adsorbed oil and free oil in shale, which obtains the density parameters of adsorbed oil and free oil in different pore sizes by the change of the pore structure of shale particle samples before and after heating and the specific surface experiment, so that more accurate adsorbed oil and free oil content data can be provided for shale oil reserve calculation, and the shale oil reservoir can be accurately evaluated.

[0008] The present application is realized by the following technical solutions:

[0009] A method for measuring the content of adsorbed oil and free oil in shale, characterized in that it comprises the following steps:

[0010] S1, select a shale sample, crush it into a shale particle sample with a particle size of 100-150 μm, weigh 50 g of the shale particle sample, and evenly divide it into two parts, the original mass of the two parts of shale particle sample is the same, and is recorded as m t , one part is put into a reaction tube, the reaction tube is connected to a specific surface instrument, nitrogen is selected as the adsorbed gas, a specific surface experiment is performed, the specific surface area, pore size distribution, pore volume θ1, and pore size-pore volume distribution data of the shale particle sample containing adsorbed oil and free oil are obtained, and the other part is put into a desiccator for storage;

[0011] S2, detach the reaction tube from the specific surface instrument, pour out the shale particle sample from the reaction tube, clean and dry the reaction tube;

[0012] S3, pour another shale particle sample stored in the desiccator into the reaction tube, first connect the vacuum gauge and the temperature sensor to the reaction tube, keep it sealed, then connect the reaction tube to the vacuum pump, and connect the gas chromatograph to the reaction tube through the high-temperature resistant pipeline;

[0013] S4, connect the magnetron to the waveguide, install the waveguide outside the reaction tube, then install the metal reflecting plate outside the waveguide, and install the microwave leakage shielding device outside the metal reflecting plate;

[0014] S5, turn on the vacuum pump to vacuumize the reaction tube, so that the vacuum degree in the reaction tube is below-100 KPa, and at the same time, adjust the microwave power controller to set the heating temperature of the shale particle sample to 60℃, and heat the shale particle sample at 60℃ for at least 120 min;

[0015] S6, remove the reaction tube, weigh the mass m1 of the shale particle sample after removing the moisture, then put the shale particle sample back into the reaction tube, reconnect the specific surface area instrument and the gas chromatograph, and reinstall the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device outside the reaction tube;

[0016] S7, open the valve between the gas chromatograph and the reaction tube to make the gas chromatograph communicate with the reaction tube, adjust the microwave power controller to set the heating temperature of the shale particle sample to 200℃;

[0017] S8, under the constant heating at 200℃, the components volatilized into gas in the shale particle sample are light oil in the shale oil, and the light oil components and content volatilized into steam are analyzed and detected by the gas chromatograph;

[0018] S9, when the gas chromatograph cannot detect the hydrocarbon components at 200℃, close the valve, adjust the microwave power controller to stop heating, wait until the temperature in the reaction tube drops to room temperature, disassemble the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device, connect the reaction tube to the specific surface area instrument, select nitrogen as the adsorption gas, and perform the specific surface area experiment to detect the specific surface area, the pore size distribution, the pore volume θ2 and the pore size-pore volume distribution data of the shale particle sample from which the light oil is separated;

[0019] S10, pour the shale particle sample from which the light oil is separated out of the reaction tube, and detect the mass m2 of the shale particle sample from which the light oil is separated;

[0020] S11, recharging the reaction tube, opening the vacuum pump, vacuumizing the reaction tube, making the vacuum degree in the reaction tube below-100KPa, then closing the vacuum pump, adjusting the microwave power controller, setting the heating temperature of the shale particle sample as 350℃, keeping the shale oil in which the components volatilized into gas as the light and medium oil in the shale oil, keeping the gas chromatograph connected with the reaction tube, detecting the components and content of the light and medium oil volatilized into steam by the gas chromatograph;

[0021] S12, when the gas chromatograph cannot detect the hydrocarbon components at 350℃, closing the valve, adjusting the microwave power controller, stopping the heating, waiting for the temperature in the reaction tube to drop to room temperature, carrying out the specific surface experiment, detecting the specific surface area, pore size distribution, pore volume θ3 and pore size-pore volume distribution data of the shale particle sample in which the light oil and the light and medium oil are separated;

[0022] S13, pouring the shale particle sample from the reaction tube, detecting the mass m3 of the shale particle sample in which the light oil and the light and medium oil are separated;

[0023] S14, recharging the reaction tube, opening the vacuum pump, vacuumizing the reaction tube, making the vacuum degree in the reaction tube below-100KPa, closing the vacuum pump, adjusting the microwave power controller, heating at 450℃, keeping the shale oil in which the components volatilized into gas as the heavy oil in the shale oil, keeping the gas chromatograph connected with the reaction tube, detecting the components and content of the heavy oil volatilized into steam by the gas chromatograph;

[0024] S15, when the gas chromatograph cannot detect the hydrocarbon components produced in the reaction tube at 450℃, closing the valve, adjusting the microwave power controller, stopping the heating, waiting for the temperature in the reaction tube to drop to room temperature, carrying out the specific surface experiment, detecting the specific surface area, pore size distribution, pore volume θ4, pore size-pore volume distribution data, porosity α and density β of the shale particle sample in which the light oil, the light and medium oil and the heavy oil are separated;

[0025] S16, pouring the shale particle sample from the reaction tube in which the light oil, the light and medium oil and the heavy oil are separated, detecting the mass m4 of the shale particle sample in which the light oil, the light and medium oil and the heavy oil are separated;

[0026] S17, calculating the total oil content of the shale particle sample

[0027] S18, calculating the volume θ of the light oil in the shale particle sample q , the volume θ of the light and medium oil in the shale particle sample q-z and the volume θ of the heavy oil in the shale particle sample z ;

[0028] S19, calculate the content of adsorbed oil in the shale particle sample μ 吸附油 and the content of free oil in the shale particle sample μ 游离油 .

[0029] The total oil content of the shale particle sample in step S17 calculated by formula 1;

[0030]

[0031] wherein, The total oil content of the shale particle sample, m t The original mass of the shale particle sample, m1 is the mass of the shale particle sample after removing moisture, m4 is the mass of the shale particle sample after separating light oil, light and medium oil and heavy oil.

[0032] The volume of light oil in the shale particle sample in step S18 q calculated by formula 2;

[0033] θ q = θ4- θ1- θ3 Formula 2

[0034] wherein, θ q The volume of light oil in the shale particle sample, θ1 is the pore volume of the shale particle sample containing adsorbed oil and free oil, θ3 is the pore volume of the shale particle sample after separating light oil and light and medium oil, θ4 is the pore volume of the shale particle sample after separating light oil, light and medium oil and heavy oil.

[0035] The volume of light and medium oil in the shale particle sample in step S18 q-z calculated by formula 3;

[0036] θ q-z = θ4- θ1- θ2 Formula 3

[0037] wherein, θ q-z The volume of light and medium oil in the shale particle sample, θ1 is the pore volume of the shale particle sample containing adsorbed oil and free oil, θ2 is the pore volume of the shale particle sample after separating light oil, θ4 is the pore volume of the shale particle sample after separating light oil, light and medium oil and heavy oil.

[0038] The volume of heavy oil in the shale particle sample in step S18 z calculated by formula 4;

[0039] θ z = θ4- θ3- θ2- θ1 Formula 4

[0040] wherein, θ zis the volume of heavy oil in the shale particle sample, θ1 is the pore volume of the shale particle sample containing adsorbed oil and free oil, θ2 is the pore volume of the shale particle sample from which light oil is separated, θ3 is the pore volume of the shale particle sample from which light oil and light-medium oil are separated, and θ4 is the pore volume of the shale particle sample from which light oil, light-medium oil, and heavy oil are separated.

[0041] In step S19, the content of adsorbed oil in the shale particle sample μ 吸附油 The free oil content in the shale particle sample μ is calculated by formula 5. 游离油 Calculated by formula 6;

[0042]

[0043]

[0044] Among them, μ 吸附油 is the content of adsorbed oil in shale particle samples, μ 流离油 is the content of free oil in shale particle sample, θ z is the volume of heavy oil in the shale particle sample, α is the porosity, β is the density, m t is the original mass of the shale particle sample, θ q is the volume of light oil in the shale particle sample, θ q-z is the volume of light-medium oil in the shale particle sample.

[0045] The specific surface area meter is used to detect the pore size distribution, specific surface area, porosity and density of the shale particle sample; the vacuum meter is used to measure the vacuum degree in the reaction tube; the temperature sensor is used to measure the temperature in the reaction tube; the waveguide tube is in the shape of a hollow cylinder and is used to transmit the microwaves generated by the magnetron to the shale particle sample in the reaction tube to increase the temperature of the shale particle sample; the metal reflector is used to cover the outside of the waveguide tube and reflect the microwaves emitted by the waveguide tube so that the microwaves are repeatedly reflected in the reaction tube. During the reflection process, the microwaves come into contact with the shale particle sample to increase the temperature of the shale particle sample; the microwave leakage shield is covered on the outside of the magnetron, waveguide tube, metal reflector and reaction tube to prevent microwave leakage; the microwave power controller is used to control the vibration frequency and power of the microwaves generated by the magnetron; the dryer is located between the reaction tube and the gas chromatograph and is used to remove water vapor.

[0046] The magnetron is used to generate microwaves, and the frequency of the generated microwaves is 2450 MHz.

[0047] The gas chromatograph is used to detect shale oil components that volatilize at different temperatures. The detector of the gas chromatograph is a flame ionization detector or a flame thermal ionization detector.

[0048] The reaction tube is a glass tube for connecting the specific surface instrument and the gas chromatograph, the top diameter of the reaction tube is 4cm, and the bottom diameter of the reaction tube is 20cm.

[0049] The beneficial effects of the present application mainly manifest in the following aspects:

[0050] 1、The present application obtains the density parameters of the adsorbed oil and the free oil in different pore diameters by obtaining the changes of the pore structure of the shale particle sample through the changes of the weight of the shale particle sample before and after heating and the specific surface experiment, so that more accurate adsorbed oil and free oil content data can be provided for shale oil reserve calculation, and accurate evaluation of the shale oil reservoir can be facilitated.

[0051] 2、The present application heats the shale particle sample by microwave and is isolated from the external environment, that is, the moisture in the air or nitrogen is prevented from interfering with the specific surface experiment and affecting the experimental results, and high temperature generated by direct heating is avoided, so that the pore structure of the shale particle sample is not damaged.

[0052] 3、The present application detects the components and mass fraction of the adsorbed oil and the free oil released at different temperatures by using the gas chromatograph while the adsorbed oil and the free oil in the shale particle sample are volatilized by heating, compared with the prior art, not only the content data of the adsorbed oil and the free oil can be provided, but also the component and mass fraction parameters of the adsorbed oil and the free oil can be provided, since the gas chromatograph is connected, so that the component characteristics and mass fraction of the crude oil occurring in the pore space of different pore diameters of the shale can be truly reflected.

[0053] 4、The content data of the adsorbed oil and the free oil is obtained by direct measurement and calculation, and the porosity and pore structure parameters of the shale particle sample are obtained by the specific surface experiment at the same time, so that the occurrence mode of the adsorbed oil and the free oil in the shale pore structure can be better characterized.

[0054] 5、S12, when the gas chromatograph has detected no hydrocarbon components at 350℃, close the valve, adjust the microwave power controller, stop heating, and wait for the temperature in the reaction tube to drop to room temperature, then perform the specific surface experiment, and detect the specific surface area, pore size distribution, pore volume θ3, and pore size-pore volume distribution data of the shale particle sample from which the light oil and light-medium oil have been separated; S13, pour the shale particle sample from the reaction tube, and detect the mass m3 of the shale particle sample from which the light oil and light-medium oil have been separated; S14, re-charge the reaction tube, open the vacuum pump, vacuumize the reaction tube to a vacuum degree below -100 KPa, close the vacuum pump, adjust the microwave power controller, and heat at 450℃, the components of the shale oil that have been volatilized into gas are heavy oil in the shale oil, keep the gas chromatograph connected to the reaction tube, and detect the components and content of the heavy oil that has been volatilized into gas through the gas chromatograph; S15, when the gas chromatograph has detected no hydrocarbon components produced at 450℃ in the reaction tube, close the valve, adjust the microwave power controller, stop heating, and wait for the temperature in the reaction tube to drop to room temperature, then perform the specific surface experiment, and detect the specific surface area, pore size distribution, pore volume θ4, pore size-pore volume distribution data, porosity α, and density β of the shale particle sample from which the light oil, light-medium oil, and heavy oil have been separated, in steps S12-S15, the crude oil of different components in the shale particle sample is removed through step-by-step heating, and the proportion of the shale pore space occupied by the crude oil of different components is detected through the specific surface experiment, which is beneficial to improving the accuracy of subsequent shale oil reservoir evaluation.

[0055] 6、S17, the total oil content of the shale particle sample can be obtained, and can be compared with the adsorbed oil content and free oil content data, so as to facilitate analysis of the proportion of free oil and adsorbed oil in the total shale oil reserves. BRIEF DESCRIPTION OF DRAWINGS

[0056] The present application will be further described below in combination with the drawings and specific embodiments:

[0057] Figure 1 The flowchart of the present application. DETAILED DESCRIPTION

[0058] Embodiment 1

[0059] Reference Figure 1 A method for measuring the contents of adsorbed oil and free oil in shale, comprising the following steps:

[0060] S1, select a shale sample, crush it into a shale particle sample with a particle size of 100 μm, weigh 50 g of the shale particle sample, and evenly divide it into two parts, the original masses of the two parts of shale particle sample are the same, and are denoted as m t, One is loaded into the reaction tube, and the reaction tube is connected to the specific surface instrument according to the requirements of SY / T6154-2019 "Determination of Specific Surface Area and Pore Size Distribution of Rocks by Static Adsorption Capacity Method", nitrogen is selected as the adsorption gas, and specific surface experiments are carried out to obtain the specific surface area, pore size distribution, pore volume θ1 and pore size-pore volume distribution data of the shale particle sample containing adsorbed oil and free oil, and the other is placed in a desiccator; S2, the reaction tube is detached from the specific surface instrument, the shale particle sample is poured out of the reaction tube, the reaction tube is cleaned and dried; S3, the other shale particle sample stored in the desiccator is poured into the reaction tube, the vacuum gauge and the temperature sensor are connected to the reaction tube, and the sealing is maintained, then the reaction tube is connected to the vacuum pump, and the gas chromatograph is connected to the reaction tube through the high-temperature resistant pipeline; S4, the magnetron is connected to the waveguide, the waveguide is installed outside the reaction tube, the metal reflecting plate is installed outside the waveguide, and the microwave leakage shielding device is installed outside the metal reflecting plate; S5, the vacuum pump is turned on, the reaction tube is vacuumized, the vacuum degree in the reaction tube is below-100KPa, the microwave power controller is adjusted, the heating temperature of the shale particle sample is set to 60℃, and the shale particle sample is heated at 60℃ for 120min; S6, the reaction tube is detached, the mass m1 of the shale particle sample after removing water is weighed, then the shale particle sample is reloaded into the reaction tube, the specific surface instrument and the gas chromatograph are reconnected, and the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device are reinstalled outside the reaction tube; S7, the valve between the gas chromatograph and the reaction tube is opened, the gas chromatograph is communicated with the reaction tube, the microwave power controller is adjusted, and the heating temperature of the shale particle sample is set to 200℃; S8, under the constant temperature heating of the shale particle sample at 200℃, the components volatilized into gas are light oil in shale oil, and the light oil components and content volatilized into steam are analyzed and detected by the gas chromatograph; S9, when the gas chromatograph cannot detect hydrocarbon components at 200℃, the valve is closed, the microwave power controller is adjusted, the heating is stopped, the temperature in the reaction tube is reduced to room temperature, the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device are detached, the reaction tube is connected to the specific surface instrument according to the requirements of SY / T6154-2019 "Determination of Specific Surface Area and Pore Size Distribution of Rocks by Static Adsorption Capacity Method", nitrogen is selected as the adsorption gas, and specific surface experiments are carried out to detect the specific surface area, pore size distribution, pore volume θ2 and pore size-pore volume distribution data of the shale particle sample after separation of light oil; S10, the shale particle sample after separation of light oil is poured out of the reaction tube, and the mass m2 of the shale particle sample after separation of light oil is detected;S11. Reinstall the reaction tube, turn on the vacuum pump, and evacuate the reaction tube to make the vacuum degree in the reaction tube below -100 kPa. Then turn off the vacuum pump and adjust the microwave power controller to set the heating temperature of the shale particle sample to 350° C. for constant temperature heating. The components of the shale oil that evaporate into gas are the light and medium oil in the shale oil. Keep the gas chromatograph connected to the reaction tube, and detect the components and content of the light and medium oil that has turned into vapor through the gas chromatograph. S12. When the gas chromatograph is at 350° C. After no hydrocarbon components are detected, the valve is closed, the microwave power controller is adjusted, and the heating is stopped. After the temperature in the reaction tube drops to room temperature, a specific surface area test is performed to obtain the specific surface area, pore size distribution, pore volume θ3, and pore size-pore volume distribution data of the shale particle sample from which light oil and light medium oil have been separated; S13, the shale particle sample is poured out from the reaction tube, and the mass m3 of the shale particle sample from which light oil and light medium oil have been separated is measured; S14, the reaction tube is reloaded, the vacuum pump is turned on, and the reaction tube is The reaction tube is evacuated to a vacuum degree below -100 kPa, the vacuum pump is turned off, and the microwave power controller is adjusted to heat at a constant temperature of 450°C. The components of the shale oil that are volatilized into gas are the heavy oil in the shale oil. The gas chromatograph is kept in communication with the reaction tube, and the components and content of the heavy oil that has been converted into vapor are detected by the gas chromatograph. S15. When the gas chromatograph can no longer detect the hydrocarbon components generated in the reaction tube at 450°C, the valve is closed, the microwave power controller is adjusted, and the heating is stopped. , after the temperature in the reaction tube drops to room temperature, a specific surface area experiment is conducted to detect the specific surface area, pore size distribution, pore volume θ4, pore size-pore volume distribution data, porosity α and density β of the shale particle sample from which light oil, light medium oil and heavy oil have been separated; S16, the shale particle sample from which light oil, light medium oil and heavy oil have been separated is poured out from the reaction tube, and the mass m4 of the shale particle sample from which light oil, light medium oil and heavy oil have been separated is detected; S17, the total oil content of the shale particle sample is calculated; S18. Calculate the volume of light oil θ in the shale particle sample q , the volume of light and medium oil in shale particle samples θ q-z and the volume of heavy oil in the shale particle sample θ z ; S19, calculate the content of adsorbed oil in the shale particle sample μ 吸附油 and the free oil content in shale particle samples μ 游离油 .

[0061] This embodiment is the most basic implementation method. By analyzing the change in the weight of shale particle samples before and after heating and the specific surface area experiment, the change in the pore structure of the shale particle samples is obtained, and the density parameters of adsorbed oil and free oil in different pore sizes are obtained. This can provide more accurate adsorbed oil and free oil content data for shale oil reserve calculations, which is conducive to the accurate evaluation of shale oil reservoirs.

[0062] Example 2

[0063] Referring to Figure 1 A method for measuring the content of absorbed oil and free oil in shale, comprising the following steps:

[0064] S1, select a shale sample, crush it into a shale particle sample with a particle size of 120 μm, weigh 50 g of the shale particle sample, and evenly divide it into two parts, the original mass of the two parts of the shale particle sample being the same, denoted as m t, One is loaded into the reaction tube, and the reaction tube is connected to the specific surface instrument according to the requirements of SY / T6154-2019 "Determination of Specific Surface Area and Pore Size Distribution of Rocks by Static Adsorption Capacity Method", nitrogen is selected as the adsorption gas, and specific surface experiments are carried out to obtain the specific surface area, pore size distribution, pore volume θ1 and pore size-pore volume distribution data of the shale particle sample containing adsorbed oil and free oil, and the other is placed in a desiccator; S2, the reaction tube is detached from the specific surface instrument, the shale particle sample is poured out of the reaction tube, the reaction tube is cleaned and dried; S3, the other shale particle sample stored in the desiccator is poured into the reaction tube, the vacuum gauge and the temperature sensor are connected to the reaction tube, and the sealing is maintained, then the reaction tube is connected to the vacuum pump, and the gas chromatograph is connected to the reaction tube through the high-temperature resistant pipeline; S4, the magnetron is connected to the waveguide, the waveguide is installed outside the reaction tube, the metal reflecting plate is installed outside the waveguide, and the microwave leakage shielding device is installed outside the metal reflecting plate; S5, the vacuum pump is turned on, the reaction tube is vacuumized, the vacuum degree in the reaction tube is below-100KPa, the microwave power controller is adjusted, the heating temperature of the shale particle sample is set to 60℃, and the shale particle sample is heated at 60℃ for 150min; S6, the reaction tube is detached, the mass m1 of the shale particle sample after removing the moisture is weighed, then the shale particle sample is reloaded into the reaction tube, the specific surface instrument and the gas chromatograph are reconnected, and the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device are reinstalled outside the reaction tube; S7, the valve between the gas chromatograph and the reaction tube is opened, the gas chromatograph is communicated with the reaction tube, the microwave power controller is adjusted, and the heating temperature of the shale particle sample is set to 200℃; S8, under the constant heating at 200℃, the components volatilized into gas are light oil in the shale oil, and the light oil components and content volatilized into steam are analyzed and detected by the gas chromatograph; S9, when the gas chromatograph cannot detect hydrocarbon components at 200℃, the valve is closed, the microwave power controller is adjusted, the heating is stopped, the temperature in the reaction tube is reduced to room temperature, the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device are detached, the reaction tube is connected to the specific surface instrument according to the requirements of SY / T6154-2019 "Determination of Specific Surface Area and Pore Size Distribution of Rocks by Static Adsorption Capacity Method", nitrogen is selected as the adsorption gas, and specific surface experiments are carried out to detect the specific surface area, pore size distribution, pore volume θ2 and pore size-pore volume distribution data of the shale particle sample from which the light oil is separated; S10, the shale particle sample from which the light oil is separated is poured out of the reaction tube, and the mass m2 of the shale particle sample from which the light oil is separated is detected;S11. Reinstall the reaction tube, turn on the vacuum pump, and evacuate the reaction tube to make the vacuum degree in the reaction tube below -100 kPa. Then turn off the vacuum pump and adjust the microwave power controller to set the heating temperature of the shale particle sample to 350° C. for constant temperature heating. The components of the shale oil that evaporate into gas are the light and medium oil in the shale oil. Keep the gas chromatograph connected to the reaction tube, and detect the components and content of the light and medium oil that has turned into vapor through the gas chromatograph. S12. When the gas chromatograph is at 350° C. After no hydrocarbon components are detected, the valve is closed, the microwave power controller is adjusted, and the heating is stopped. After the temperature in the reaction tube drops to room temperature, a specific surface area test is performed to obtain the specific surface area, pore size distribution, pore volume θ3, and pore size-pore volume distribution data of the shale particle sample from which light oil and light medium oil have been separated; S13, the shale particle sample is poured out from the reaction tube, and the mass m3 of the shale particle sample from which light oil and light medium oil have been separated is measured; S14, the reaction tube is reloaded, the vacuum pump is turned on, and the reaction tube is The reaction tube is evacuated to a vacuum degree below -100 kPa, the vacuum pump is turned off, and the microwave power controller is adjusted to heat at a constant temperature of 450°C. The components of the shale oil that are volatilized into gas are the heavy oil in the shale oil. The gas chromatograph is kept in communication with the reaction tube, and the components and content of the heavy oil that has been converted into vapor are detected by the gas chromatograph. S15. When the gas chromatograph can no longer detect the hydrocarbon components generated in the reaction tube at 450°C, the valve is closed, the microwave power controller is adjusted, and the heating is stopped. , after the temperature in the reaction tube drops to room temperature, a specific surface area experiment is conducted to detect the specific surface area, pore size distribution, pore volume θ4, pore size-pore volume distribution data, porosity α and density β of the shale particle sample from which light oil, light medium oil and heavy oil have been separated; S16, the shale particle sample from which light oil, light medium oil and heavy oil have been separated is poured out from the reaction tube, and the mass m4 of the shale particle sample from which light oil, light medium oil and heavy oil have been separated is detected; S17, the total oil content of the shale particle sample is calculated; S18. Calculate the volume of light oil θ in the shale particle sample q , the volume of light and medium oil in shale particle samples θ q-z and the volume of heavy oil in the shale particle sample θ z ; S19, calculate the content of adsorbed oil in the shale particle sample μ 吸附油 and the free oil content in shale particle samples μ 游离油 .

[0065] Furthermore, in step S17, the total oil content of the shale particle sample Calculated by formula 1;

[0066]

[0067] in, m is the total oil content of the shale particle sample t m1 is the original mass of the shale particle sample, m4 is the mass of the shale particle sample after removing the water, and m5 is the mass of the shale particle sample after separating the light oil, the light-middle oil, and the heavy oil.

[0068] Further, in the step S18, the light oil volume θ q is calculated by formula 2.

[0069] θ q = θ4- θ1- θ3 Formula 2

[0070] wherein θ q is the light oil volume in the shale particle sample, θ1 is the pore volume of the shale particle sample containing the adsorbed oil and the free oil, θ3 is the pore volume of the shale particle sample after separating the light oil and the light-middle oil, and θ4 is the pore volume of the shale particle sample after separating the light oil, the light-middle oil, and the heavy oil.

[0071] Further, in the step S18, the light-middle oil volume θ q-z is calculated by formula 3.

[0072] θ q-z = θ4- θ1- θ2 Formula 3

[0073] wherein θ q-z is the light-middle oil volume in the shale particle sample, θ1 is the pore volume of the shale particle sample containing the adsorbed oil and the free oil, θ2 is the pore volume of the shale particle sample after separating the light oil, and θ4 is the pore volume of the shale particle sample after separating the light oil, the light-middle oil, and the heavy oil.

[0074] Further, in the step S18, the heavy oil volume θ z is calculated by formula 4.

[0075] θ z = θ4- θ3- θ2- θ1 Formula 4

[0076] wherein θ z is the heavy oil volume in the shale particle sample, θ1 is the pore volume of the shale particle sample containing the adsorbed oil and the free oil, θ2 is the pore volume of the shale particle sample after separating the light oil, θ3 is the pore volume of the shale particle sample after separating the light oil and the light-middle oil, and θ4 is the pore volume of the shale particle sample after separating the light oil, the light-middle oil, and the heavy oil.

[0077] Further, in the step S19, the adsorbed oil content μ 吸附油 of the shale particle sample is calculated by formula 5, and the free oil content μ 流离油calculated by formula 6;

[0078]

[0079]

[0080] wherein, μ 吸附油 is the content of adsorbed oil in the shale particle sample, μ 流离油 is the content of free oil in the shale particle sample, θ z is the volume of heavy oil in the shale particle sample, α is the porosity, β is the density, m t is the original mass of the shale particle sample, θ q is the volume of light oil in the shale particle sample, θ q-z is the volume of light and medium oil in the shale particle sample.

[0081] The embodiment is a preferred implementation, which heats the shale particle sample by microwave and isolates from the external environment, that is, prevents the moisture or nitrogen in the air from interfering with the specific surface experiment and affecting the experimental results, and avoids high temperature generated by direct heating, thereby protecting the pore structure of the shale particle sample from being damaged.

[0082] Embodiment 3

[0083] Referring to Figure 1 A method for measuring the contents of adsorbed oil and free oil in shale, comprising the following steps:

[0084] S1, selecting a shale sample, crushing it into a shale particle sample with a particle size of 150 μm, weighing 50 g of the shale particle sample, and evenly dividing it into two parts, the original masses of the two parts of shale particle sample being the same, denoted as m t One part is loaded into a reaction tube, the reaction tube is connected to a specific surface instrument according to the requirements of SY / T6154-2019 “Determination of Rock Specific Surface Area and Pore Size Distribution by Static Adsorption Capacity Method”, nitrogen is selected as the adsorption gas, a specific surface experiment is performed, and the specific surface area, pore size distribution, pore volume θ1 and pore size-pore volume distribution data of the shale particle sample containing adsorbed oil and free oil are obtained, and the other part is placed in a desiccator for storage;

[0085] S2, dismounting the reaction tube from the specific surface instrument, pouring out the shale particle sample from the reaction tube, cleaning and drying the reaction tube;

[0086] S3, pouring the other part of the shale particle sample stored in the desiccator into the reaction tube, connecting the vacuum gauge and the temperature sensor to the reaction tube in advance and keeping it sealed, connecting the reaction tube to the vacuum pump, and connecting the gas chromatograph to the reaction tube through a high-temperature resistant pipeline;

[0087] S4, connect the magnetron with the waveguide, install the waveguide outside the reaction tube, install the metal reflecting plate outside the waveguide, and install the microwave leakage shielding device outside the metal reflecting plate;

[0088] S5, open the vacuum pump, vacuumize the reaction tube, so that the vacuum degree in the reaction tube is below -100 KPa, and at the same time, adjust the microwave power controller, set the heating temperature of the shale particle sample to 60℃, and heat the shale particle sample at 60℃ for 180 min;

[0089] S6, remove the reaction tube, pour out the shale particle sample, weigh the mass m1 of the shale particle sample after removing the moisture, then re-enclose the shale particle sample into the reaction tube, re-connect the specific surface area tester and the gas chromatograph, and re-install the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device outside the reaction tube;

[0090] S7, open the valve between the gas chromatograph and the reaction tube, so that the gas chromatograph is connected with the reaction tube, adjust the microwave power controller, and set the heating temperature of the shale particle sample to 200℃;

[0091] S8, under the constant heating at 200℃, the components volatilized into gas in the shale particle sample are light oil in the shale oil, and the light oil components and content volatilized into steam are detected and analyzed by the gas chromatograph;

[0092] S9, when the gas chromatograph cannot detect the hydrocarbon components at 200℃, close the valve, stop heating by adjusting the microwave power controller, wait until the temperature in the reaction tube drops to room temperature, disassemble the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device, connect the reaction tube to the specific surface area tester according to the requirements of SY / T 6154-2019 “Determination of Specific Surface Area and Pore Size Distribution of Rocks-Static Adsorption Capacity Method”, select nitrogen as the adsorption gas, and perform the specific surface experiment to detect the specific surface area, the pore size distribution, the pore volume θ2 and the pore size-pore volume distribution data of the shale particle sample from which the light oil is separated;

[0093] S10, pour out the shale particle sample from which the light oil is separated from the reaction tube, and detect the mass m2 of the shale particle sample from which the light oil is separated;

[0094] S11, re-enclose the shale particle sample from which the light oil is separated into the reaction tube, open the vacuum pump, vacuumize the reaction tube so that the vacuum degree in the reaction tube is below -100 KPa, then close the vacuum pump, and adjust the microwave power controller to set the heating temperature of the shale particle sample to 350℃ for constant heating, the components volatilized into gas in the shale oil are light and medium oil in the shale oil, the gas chromatograph is kept connected with the reaction tube, and the components and content of the light and medium oil volatilized into steam are detected by the gas chromatograph;

[0095] S12, after the gas chromatograph has detected no hydrocarbon components at 350℃, the valve is closed, the microwave power controller is adjusted, the heating is stopped, and the temperature in the reaction tube is reduced to room temperature, a specific surface experiment is performed, and the specific surface area, pore size distribution, pore volume θ3, and pore size-pore volume distribution data of the shale particle sample from which the light oil and light-medium oil have been separated are detected;

[0096] S13, the shale particle sample from which the light oil and light-medium oil have been separated is poured out of the reaction tube, and the mass m3 of the shale particle sample from which the light oil and light-medium oil have been separated is detected;

[0097] S14, the reaction tube is reloaded, the vacuum pump is turned on, the reaction tube is vacuumed to a vacuum degree of below -100 KPa, the vacuum pump is turned off, the microwave power controller is adjusted, and the heating at a constant temperature of 450℃ is performed, the components of the heavy oil in the shale oil that have been volatilized into gas are the heavy oil in the shale oil, the gas chromatograph is kept in communication with the reaction tube, and the components and content of the heavy oil that have been volatilized into gas are detected by the gas chromatograph;

[0098] S15, after the gas chromatograph has detected no hydrocarbon components produced in the reaction tube at 450℃, the valve is closed, the microwave power controller is adjusted, the heating is stopped, and the temperature in the reaction tube is reduced to room temperature, a specific surface experiment is performed, and the specific surface area, pore size distribution, pore volume θ4, pore size-pore volume distribution data, porosity α, and density β of the shale particle sample from which the light oil, light-medium oil, and heavy oil have been separated are detected;

[0099] S16, the shale particle sample from which the light oil, light-medium oil, and heavy oil have been separated is poured out of the reaction tube, and the mass m4 of the shale particle sample from which the light oil, light-medium oil, and heavy oil have been separated is detected;

[0100] S17, the total oil content of the shale particle sample is calculated

[0101] S18, the volume θ of the light oil in the shale particle sample is calculated q , the volume θ of the light-medium oil in the shale particle sample is calculated q-z , and the volume θ of the heavy oil in the shale particle sample is calculated z ;

[0102] S19, the content μ of the adsorbed oil in the shale particle sample is calculated 吸附油 , and the content μ of the free oil in the shale particle sample is calculated 游离油 .

[0103] In the step S17, the total oil content of the shale particle sample is calculated by formula 1;

[0104]

[0105] wherein, is the total oil content of the shale particle sample, m t is the original mass of the shale particle sample, m1 is the mass of the shale particle sample after removing moisture, m4 is the mass of the shale particle sample after separating light oil, light-medium oil and heavy oil.

[0106] In the step S18, the light oil volume θ q is calculated by formula 2.

[0107] θ q = θ4- θ1- θ3 Formula 2

[0108] wherein, θ q is the light oil volume in the shale particle sample, θ1 is the pore volume of the shale particle sample containing adsorbed oil and free oil, θ3 is the pore volume of the shale particle sample after separating light oil and light-medium oil, and θ4 is the pore volume of the shale particle sample after separating light oil, light-medium oil and heavy oil.

[0109] In the step S18, the light-medium oil volume θ q-z is calculated by formula 3.

[0110] θ q-z = θ4- θ1- θ2 Formula 3

[0111] wherein, θ q-z is the light-medium oil volume in the shale particle sample, θ1 is the pore volume of the shale particle sample containing adsorbed oil and free oil, θ2 is the pore volume of the shale particle sample after separating light oil, and θ4 is the pore volume of the shale particle sample after separating light oil, light-medium oil and heavy oil.

[0112] In the step S18, the heavy oil volume θ z is calculated by formula 4.

[0113] θ z = θ4- θ3- θ2- θ1 Formula 4

[0114] wherein, θ z is the heavy oil volume in the shale particle sample, θ1 is the pore volume of the shale particle sample containing adsorbed oil and free oil, θ2 is the pore volume of the shale particle sample after separating light oil, θ3 is the pore volume of the shale particle sample after separating light oil and light-medium oil, and θ4 is the pore volume of the shale particle sample after separating light oil, light-medium oil and heavy oil.

[0115] In the step S19, the content μ 吸附油 of adsorbed oil in the shale particle sample is calculated by formula 5, and the content μ 游离油calculated by formula 6;

[0116]

[0117]

[0118] wherein, μ 吸附油 is the content of adsorbed oil in the shale particle sample, μ 流离油 is the content of free oil in the shale particle sample, θ z is the volume of heavy oil in the shale particle sample, α is the porosity, β is the density, m t is the original mass of the shale particle sample, θ q is the volume of light oil in the shale particle sample, θ q-z is the volume of light and medium oil in the shale particle sample.

[0119] Further, the specific surface instrument is used to detect the pore size distribution, specific surface area, porosity and density of the shale particle sample; the vacuum gauge is used to measure the vacuum degree in the reaction tube; the temperature sensor is used to measure the temperature in the reaction tube; the waveguide tube is in the form of a hollow cylinder and is used to conduct the microwaves generated by the magnetron to the shale particle sample in the reaction tube to heat the shale particle sample; the metal reflecting plate is used to cover the outside of the waveguide tube and reflect the microwaves emitted by the waveguide tube so that the microwaves repeatedly reflect in the reaction tube, and in the process of reflection, the microwaves contact the shale particle sample to heat the shale particle sample; the microwave leakage shielding device covers the outside of the magnetron, the waveguide tube, the metal reflecting plate and the reaction tube and is used to prevent microwave leakage; the microwave power controller is used to control the vibration frequency and power of the microwaves generated by the magnetron; and the dryer is located between the reaction tube and the gas chromatograph and is used to remove water vapor. The magnetron is used to generate microwaves, and the frequency of the generated microwaves is 2450 MHz. The gas chromatograph is used to detect the shale oil components volatilized at different temperatures, and the detector of the gas chromatograph is a flame ionization detector or a flame thermal ionization detector. The reaction tube is a glass tube and is used to connect the specific surface instrument and the gas chromatograph, the top diameter of the reaction tube is 4 cm, and the bottom diameter of the reaction tube is 20 cm.

[0120] The present embodiment is the best mode of the present application. By heating the shale particle sample to volatilize the adsorbed oil and free oil therein and simultaneously using the gas chromatograph to detect the components and mass fraction of the adsorbed oil and free oil released at different temperatures, compared with the prior art, not only the content data of the adsorbed oil and free oil can be provided, but also the components and mass fraction parameters of the adsorbed oil and free oil can be provided. Since the gas chromatograph is connected, the component characteristics and mass fraction of the crude oil occurring in the pore space of different pore diameters in the shale can be truly reflected.

[0121] The content data of the adsorbed oil and the free oil are calculated by direct measurement, and the porosity and the pore structure parameters of the shale particle sample are obtained by specific surface area experiment at the same time, so that the occurrence mode of the adsorbed oil and the free oil in the shale pore structure can be better characterized.

[0122] In steps S12-S15, the crude oil of different components in the shale particle sample is removed by step-by-step heating, and the proportion of the shale pore space occupied by the crude oil of different components is detected by the specific surface area experiment, so as to improve the accuracy of subsequent shale oil reservoir evaluation.

[0123] Through step S17, the total oil content of the shale particle sample can be obtained, and can be compared with the adsorbed oil content and the free oil content data, so as to facilitate the analysis of the proportion of the free oil and the adsorbed oil in the total shale oil reserves.

Claims

1. A method of measuring the content of adsorbed oil and free oil in shale, characterized by, The method comprises the following steps: S1, select shale sample, crush into shale particle sample with particle size of 100-150 μm, weigh 50 g of shale particle sample, evenly divide into two parts, the original mass of the two parts of shale particle sample is same, recorded as m t One part is loaded into a reaction tube, the reaction tube is connected to a specific surface area meter, nitrogen is selected as adsorption gas, specific surface area experiment is carried out, and the specific surface area, pore size distribution, pore volume θ1 and pore size-pore volume distribution data of the shale particle sample containing adsorbed oil and free oil are obtained, and the other part is placed in a desiccator for storage. S2, the reaction tube is detached from the specific surface apparatus, the shale particle sample is poured out of the reaction tube, the reaction tube is cleaned and dried; S3, another shale particle sample stored in a desiccator is poured into the reaction tube, the vacuum gauge and the temperature sensor are connected to the reaction tube, the connection is kept sealed, the reaction tube is connected to the vacuum pump, and the gas chromatograph is connected to the reaction tube through a high-temperature resistant pipeline; S4, the magnetron is connected to the waveguide, the waveguide is installed outside the reaction tube, a metal reflecting plate is installed outside the waveguide, and a microwave leakage shielding device is installed outside the metal reflecting plate; S5, the vacuum pump is turned on, the reaction tube is vacuumized, the vacuum degree in the reaction tube is below -100 KPa, the microwave power controller is adjusted, the heating temperature of the shale particle sample is set to 60 DEG C, and the shale particle sample is heated at 60 DEG C for at least 120 min; S6, the reaction tube is detached, the mass m1 of the shale particle sample from which water is removed is weighed, the shale particle sample is reloaded into the reaction tube, the specific surface apparatus and the gas chromatograph are reconnected, and the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device are reinstalled outside the reaction tube; S7, the valve between the gas chromatograph and the reaction tube is opened, the gas chromatograph is connected to the reaction tube, the microwave power controller is adjusted, and the heating temperature of the shale particle sample is set to 200 DEG C; S8, under the constant heating at 200 DEG C, the components volatilized into gas in the shale particle sample are light oil in shale oil, the light oil components and content volatilized into steam are detected by the gas chromatograph; S9, when the gas chromatograph cannot detect hydrocarbon components at 200 DEG C, the valve is closed, the microwave power controller is adjusted, the heating is stopped, the temperature in the reaction tube is reduced to room temperature, the magnetron, the waveguide, the metal reflecting plate and the microwave leakage shielding device are detached, the reaction tube is connected to the specific surface apparatus, nitrogen is selected as the adsorption gas, and the specific surface experiment is performed to detect the specific surface area, the pore size distribution, the pore volume θ2 and the pore size-pore volume distribution data of the shale particle sample from which the light oil is separated; S10, the shale particle sample from which the light oil is separated is poured out of the reaction tube, and the mass m2 of the shale particle sample from which the light oil is separated is detected; S11, the shale particle sample is reloaded into the reaction tube, the vacuum pump is turned on, the reaction tube is vacuumized, the vacuum degree in the reaction tube is below -100 KPa, the vacuum pump is turned off, the microwave power controller is adjusted, the heating temperature of the shale particle sample is set to 350 DEG C, the components volatilized into gas in the shale oil are light medium oil in the shale oil, the gas chromatograph is kept connected to the reaction tube, and the components and content of the light medium oil volatilized into steam are detected by the gas chromatograph; S12, when the gas chromatograph cannot detect hydrocarbon components at 350 DEG C, the valve is closed, the microwave power controller is adjusted, the heating is stopped, the temperature in the reaction tube is reduced to room temperature, the specific surface experiment is performed, and the specific surface area, the pore size distribution, the pore volume θ3 and the pore size-pore volume distribution data of the shale particle sample from which the light oil and the light medium oil are separated are detected. S13, the shale particle sample is poured out from the reaction tube, and the mass m3 of the shale particle sample from which the light oil and the light medium oil are separated is detected; S14, the reaction tube is reloaded, the vacuum pump is opened, the reaction tube is vacuumized, the vacuum degree in the reaction tube is below-100 KPa, the vacuum pump is closed, the microwave power controller is adjusted, heating is performed at 450 DEG C, the components volatilized from the shale oil and changed into gas are heavy oil in the shale oil, the gas chromatograph is kept in communication with the reaction tube, and the components and content of the heavy oil changed into steam are detected by the gas chromatograph; S15, when the gas chromatograph cannot detect the hydrocarbon components generated in the reaction tube at 450 DEG C, the valve is closed, the microwave power controller is adjusted, the heating is stopped, the temperature in the reaction tube is lowered to room temperature, the specific surface experiment is performed, and the specific surface area, the pore size distribution, the pore volume θ4, the pore size-pore volume distribution data, the porosity α and the density β of the shale particle sample from which the light oil, the light medium oil and the heavy oil are separated are detected; S16, the shale particle sample from which the light oil, the light medium oil and the heavy oil are separated is poured out from the reaction tube, and the mass m4 of the shale particle sample from which the light oil, the light medium oil and the heavy oil are separated is detected; S17, calculating the total oil content of the shale particle sample S18, calculating the volume of light oil in the shale particle sample q , the volume of light oil in the shale particle sample q-z and the volume of heavy oil in the shale particle sample z ; S19, the content of the adsorbed oil in the shale particle sample μ is calculated 吸附油 and the content of the free oil in the shale particle sample μ 游离油 .

2. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The total oil content of the shale particle sample is calculated in step S17 Calculated by Equation 1; wherein, is the total oil content of the shale particle sample, m t is the original mass of the shale particle sample, m1is the mass of the shale particle sample with moisture removed, m4is the mass of the shale particle sample with light oil, light-medium oil, and heavy oil separated.

3. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The step S18, the volume of light oil in the shale particle sample θ q Calculated by formula 2; θ q = θ4- θ1- θ3 Equation 2 where θ q is the volume of light oil in the shale particle sample, θ1is the pore volume of the shale particle sample containing adsorbed and free oil, θ3is the pore volume of the shale particle sample with light oil and light-medium oil separated, and θ4is the pore volume of the shale particle sample with light oil, light-medium oil, and heavy oil separated.

4. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: In the step S18, the volume θ of light and medium weight oil in the shale particle sample is calculated by the following equation 3. q-z Calculated by equation 3; θ q-z = θ4- θ1- θ2 Equation 3 where θ q-z is the volume of light and medium oil in the shale particle sample, θ1 is the pore volume of the shale particle sample containing adsorbed and free oil, θ2 is the pore volume of the shale particle sample with the light oil separated, and θ4 is the pore volume of the shale particle sample with the light and medium oil and heavy oil separated.

5. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The step S18, the heavy oil volume θ in the shale particle sample z Calculated by formula 4; θ z = θ4- θ3- θ2- θ1 Equation 4 wherein θ z is the volume of heavy oil in the shale particle sample, θ1is the pore volume of the shale particle sample containing adsorbed and free oil, θ2is the pore volume of the shale particle sample with light oil separated, θ3is the pore volume of the shale particle sample with light oil and light-medium oil separated, and θ4is the pore volume of the shale particle sample with light oil, light-medium oil, and heavy oil separated.

6. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The content μ of the adsorbed oil in the shale particle sample is calculated by formula 5 吸附油 The content μ of the free oil in the shale particle sample is calculated by formula 6 游离油 The content μ of the free oil in the shale particle sample is calculated by formula 6 wherein μ 吸附油 is the content of adsorbed oil in the shale particle sample, μ 游离油 is the content of free oil in the shale particle sample, θ z is the volume of heavy oil in the shale particle sample, α is the porosity, β is the density, m t is the original mass of the shale particle sample, θ q is the volume of light oil in the shale particle sample, θ q-z is the volume of light and medium oil in the shale particle sample.

7. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The specific surface instrument is used for detecting the pore size distribution, the specific surface area, the porosity and the density of the shale particle sample; the vacuum gauge is used for measuring the vacuum degree in the reaction tube; the temperature sensor is used for measuring the temperature in the reaction tube; the waveguide is in a hollow cylindrical shape and is used for conducting the microwave generated by the magnetron to the shale particle sample in the reaction tube, so that the shale particle sample is heated; the metal reflecting plate is used for covering the outside of the waveguide and reflecting the microwave emitted by the waveguide, so that the microwave repeatedly reflects in the reaction tube, and the microwave contacts the shale particle sample in the process of reflection, so that the shale particle sample is heated; the microwave leakage shielding device is used for covering the outside of the magnetron, the waveguide, the metal reflecting plate and the reaction tube, and is used for preventing the microwave from leaking; the microwave power controller is used for controlling the vibration frequency and the power of the microwave generated by the magnetron; and the dryer is located between the reaction tube and the gas chromatograph and is used for removing water vapor.

8. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The magnetron is used for generating the microwave, and the frequency of the generated microwave is 2450 MHz.

9. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The gas chromatograph is used for detecting the components of the shale oil volatilized at different temperatures, and the detector of the gas chromatograph is a flame ionization detector or a flame thermal ionization detector.

10. The method of measuring the content of adsorbed oil and free oil in shale according to claim 1, characterized in that: The reaction tube is a glass tube, is used for connecting the specific surface instrument and the gas chromatograph, the diameter of the top of the reaction tube is 4 cm, and the diameter of the bottom of the reaction tube is 20 cm.

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