Method for measuring content of adsorbed oil and free oil in shale

Abstract

The invention belongs to the technical field of oil-gas field development, and discloses a shale specific surface experiment method which is characterized by comprising the following steps: selecting a shale sample, and carrying out a specific surface experiment; opening a vacuum pump, vacuumizing the reaction tube, and heating the shale particle sample at 60 DEG C for at least 120 minutes; setting the heating temperature of the shale particle sample to be 200 DEG C, and analyzing and detecting the components and content of the light oil changed into steam through a gas chromatograph; the heating temperature is set to be 350 DEG C, constant-temperature heating is conducted, and the components and the content of the light and medium oil which is changed into steam are detected; heating at the constant temperature of 450 DEG C, and detecting the components and content of the heavy oil which is changed into steam; the total oil content of the shale particle sample is calculated, and the content of adsorbed oil in the shale particle sample and the content of free oil in the shale particle sample are obtained through calculation. According to the method, more accurate adsorbed oil and free oil content data can be provided for shale oil reserve calculation, and accurate evaluation on the shale oil reservoir is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and in particular to a method for measuring the contents of adsorbed oil and free oil in shale. Background Art

[0002] Shale oil is a collection of liquid hydrocarbons that are mainly stored in mudstone and carbonate or clastic interlayers in mudstone in adsorbed and free states. Currently, the average single-well production of shale oil is relatively low. The main reason for this is that under current technical conditions, the crude oil that can be mobilized in shale reservoirs is mainly free oil that exists in the reservoir in a free state, while adsorbed oil is often difficult to mobilize due to its strong adsorption effect on the pore surface. Therefore, in the current shale oil exploration, the free oil content is often used as the maximum movable amount of shale oil. Therefore, in the exploration of shale oil, it is very necessary to provide experimental data on the free oil content in shale oil reservoirs as an experimental basis for reservoir evaluation, sweet spot optimization, etc.

[0003] Since there is no particularly significant boundary between adsorbed shale oil and free shale oil, and shale oil has a complex composition, which is a complex compound of hydrocarbons, colloids and asphaltene, it is difficult to determine the content of free shale oil and adsorbed shale oil in the reservoir. At present, the commonly used traditional experimental method is the swelling test method: this method first dissolves crude oil, asphalt, etc. in organic solvents such as toluene, and after the shale sample is placed in the solution for a period of time, the change in the absorbance of the solution is detected by spectroscopy to determine the amount of crude oil or asphalt adsorbed by shale, and the adsorption characteristics of shale are evaluated by establishing the relationship between the adsorption amount and the equilibrium time to determine the adsorbed oil content.

[0004] The swelling experiment method can analyze the adsorbed oil content adsorbed by shale and analyze the component characteristics of the adsorbed oil by spectroscopy. However, there is interaction between the mixed solution of crude oil, asphalt and toluene. Generally speaking, the stronger the interaction between the selected crude oil, asphalt and toluene, the more uniform the solution mixing, and the more conducive to ensuring the uniformity of the adsorption process of the core sample. However, the stronger the interaction, the more it will inhibit the core sample from adsorbing crude oil and asphalt from the solution, thereby affecting the total adsorption amount. At the same time, the experiment cannot be carried out at formation temperature, otherwise it will change the material composition of the solution, and the adsorption process of crude oil in shale is greatly affected by temperature. Without considering the temperature factor, the adsorption amount data actually obtained cannot reflect the distribution of free oil and adsorbed oil in shale reservoirs under real formation conditions.

[0005] A Chinese patent document with publication number CN110687612A and publication date January 14, 2020 discloses a shale oil analysis method and device for continuous characterization of adsorbed oil and free oil content, including: performing nuclear magnetic resonance measurement, saturation measurement, and self-imbibition wettability measurement on a core sample obtained from a shale oil sweet spot section to obtain a nuclear magnetic resonance T2 spectrum, nuclear magnetic porosity, oil saturation, and wettability index, and determining the calculated lower limit of adsorbed oil based on the obtained spectrum; determining the calculated lower limit of free oil based on the T2 volume relaxation spectrum of crude oil in the well section or an adjacent well section and the nuclear magnetic resonance T2 spectrum of the core sample; continuously and quantitatively calculating the adsorbed oil content and the free oil content of the well section to be analyzed based on the nuclear magnetic resonance logging data of the well to be analyzed, the calculated lower limit of adsorbed oil, and the calculated lower limit of free oil, and analyzing the shale oil in the well section to be analyzed based on the obtained spectrum.

[0006] The shale oil analysis method and device for continuous characterization of adsorbed oil and free oil content disclosed in the patent document realizes the quantitative continuous characterization of shale oil adsorbed oil and free oil logging. However, it is impossible to obtain the density parameters of adsorbed oil and free oil in different pore sizes, and thus it is impossible to provide more accurate adsorbed oil and free oil content data for shale oil reserve calculation, which in turn affects the evaluation of shale oil reservoirs. Summary of the invention

[0007] In order to overcome the defects of the above-mentioned prior art, the present invention provides a method for measuring the content of adsorbed oil and free oil in shale. The present invention obtains the change of the pore structure of the shale particle sample by the change of the weight of the shale particle sample before and after heating and the specific surface area experiment, and obtains the density parameters of the adsorbed oil and free oil in different pore sizes, thereby providing more accurate adsorbed oil and free oil content data for shale oil reserve calculation, which is conducive to accurate evaluation of shale oil reservoirs.

[0008] The present invention is achieved through the following technical solutions:

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

[0010] S1. Select shale samples and crush them into shale particle samples with a particle size of 100μm-150μm. Weigh 50g of shale particle samples and divide them into two parts evenly. The original mass of the two shale particle samples is the same, recorded as m t , one portion is loaded into a reaction tube, the reaction tube is connected to a specific surface area meter, nitrogen is selected as the adsorption gas, a specific surface area 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 portion is stored in a desiccator;

[0011] S2. Remove the reaction tube from the surface area analyzer, pour the shale particle sample out of the reaction tube, and clean and dry the reaction tube;

[0012] S3. Pour another portion of the shale particle sample stored in the dryer into the reaction tube, first connect the vacuum meter 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 a high temperature resistant pipeline;

[0013] S4, connecting the magnetron and the waveguide, installing the waveguide outside the reaction tube, installing a metal reflector outside the waveguide, and installing a microwave leakage shield outside the metal reflector;

[0014] S5. Turn on the vacuum pump to evacuate the reaction tube to make the vacuum degree in the reaction tube 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° C., and heat the shale particle sample at 60° C. for at least 120 min;

[0015] S6, remove the reaction tube, pour out the shale particle sample and weigh the mass m1 of the shale particle sample from which the water has been removed, then reinstall the shale particle sample back into the reaction tube, reconnect the surface area analyzer and the gas chromatograph, and reinstall the magnetron, waveguide, metal reflector and microwave leakage shield outside the reaction tube;

[0016] S7, opening the valve between the gas chromatograph and the reaction tube to connect the gas chromatograph and the reaction tube, adjusting the microwave power controller to set the heating temperature of the shale particle sample to 200° C.;

[0017] S8. When the shale particle sample is heated at a constant temperature of 200°C, the component that volatilizes into gas is the light oil in the shale oil. The components and content of the light oil that is converted into steam are analyzed and detected by gas chromatography;

[0018] S9. When the gas chromatograph can no longer detect hydrocarbon components at 200°C, close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, disassemble the magnetron, waveguide, metal reflector and microwave anti-leakage shield, connect the reaction tube to the surface area analyzer, select nitrogen as the adsorption gas, conduct a surface area test, and detect and obtain 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;

[0019] S10, pouring out the shale particle sample from which the light oil has been separated from the reaction tube, and detecting the mass m2 of the shale particle sample from which the light oil has been separated;

[0020] S11, re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, then turn off the vacuum pump, adjust the microwave power controller, set the heating temperature of the shale particle sample to 350° C. constant temperature heating, the component volatilized into gas in the shale oil is the light and medium oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the light and medium oil that has become steam by the gas chromatograph;

[0021] S12. When the gas chromatograph can no longer detect hydrocarbon components at 350° C., close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, and conduct a specific surface area experiment to obtain 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 are separated;

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

[0023] S14, re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, turn off the vacuum pump, adjust the microwave power controller, heat at a constant temperature of 450° C. The component volatilized into gas in the shale oil is the heavy oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the heavy oil that has become steam by the gas chromatograph;

[0024] S15. When the gas chromatograph fails to detect the hydrocarbon components produced at 450° C. in the reaction tube, 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 performed 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 are separated;

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

[0026] S17. Calculate the total oil content of shale particle samples

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

[0028] 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 .

[0029] In step S17, the total oil content of the shale particle sample Calculated by formula 1;

[0030]

[0031] in, is the total oil content of 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, and m4 is the mass of the shale particle sample after separating light oil, light medium oil and heavy oil.

[0032] In step S18, the volume of light oil in the shale particle sample θ q Calculated by formula 2;

[0033] θ q =θ4-θ1-θ3 Formula 2

[0034] Among them, θ q is 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 with light oil and light medium oil separated, and θ4 is the pore volume of the shale particle sample with light oil, light medium oil and heavy oil separated.

[0035] In step S18, the volume of light medium oil in the shale particle sample θ q-z Calculated by formula 3;

[0036] θ q-z =θ4-θ1-θ2 Formula 3

[0037] Among them, 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 oil and free oil, θ2 is the pore volume of the shale particle sample from which light oil is separated, and θ4 is the pore volume of the shale particle sample from which light oil, light and medium oil, and heavy oil are separated.

[0038] In step S18, the volume of heavy oil in the shale particle sample θ z Calculated by formula 4;

[0039] θ z =θ4-θ3-θ2-θ1 Formula 4

[0040] Among them, 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 with light oil separated, θ3 is the pore volume of the shale particle sample with light oil and light medium oil separated, and θ4 is the pore volume of the shale particle sample with light oil, light medium oil and heavy oil 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 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 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 medium oil in the shale particle sample.

[0045] 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 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 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 reflection plate is used to cover the outside of the waveguide and reflect the microwaves emitted by the waveguide so that the microwaves are repeatedly reflected in the reaction tube. During the reflection process, the microwaves contact 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, the waveguide, the metal reflection plate and the 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 volatilizing at different temperatures, and 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 used to connect the specific surface area meter 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.

[0049] The beneficial effects of the present invention are mainly manifested in the following aspects:

[0050] 1. The present invention obtains the change of the pore structure of the shale particle sample by the change of the weight of the shale particle sample before and after heating and the specific surface area experiment, and obtains the density parameters of the adsorbed oil and free oil in different pore sizes, thereby providing more accurate adsorbed oil and free oil content data for shale oil reserve calculation, which is conducive to accurate evaluation of shale oil reservoirs.

[0051] 2. The present invention heats the shale particle sample by microwaves and isolates it from the external environment, thereby preventing moisture or nitrogen in the air from interfering with the specific surface area experiment and affecting the experimental results, and avoiding high temperatures generated by direct heating, thereby ensuring that the pore structure of the shale particle sample is not destroyed.

[0052] 3. The present invention, by heating shale particle samples to volatilize adsorbed oil and free oil therein, uses a gas chromatograph to detect the components and mass fractions of adsorbed oil and free oil released at different temperatures. Compared with the prior art, the present invention can not only provide content data of adsorbed oil and free oil, but also provide components and mass fraction parameters of adsorbed oil and free oil. Since it is connected to the gas chromatograph, it can truly reflect the component characteristics and mass fraction of crude oil stored in the pore spaces of different pore sizes in shale.

[0053] 4. In the present invention, the content data of adsorbed oil and free oil are obtained by direct measurement and calculation, and the porosity and pore structure parameters of the shale particle sample are obtained by specific surface area experiments at the same time, thereby being able to better characterize the occurrence mode of adsorbed oil and free oil in the shale pore structure.

[0054] 5. The present invention, S12, when the gas chromatograph can no longer detect hydrocarbon components at 350°C, close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, conduct a specific surface area 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 light oil and light medium oil have been separated; S13, pour the shale particle sample out of the reaction tube, and detect the mass m3 of the shale particle sample from which light oil and light medium oil have been separated; S14, reload the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100KPa, turn off the vacuum pump, adjust the microwave power controller, and heat at a constant temperature of 450°C. The component in the shale oil that evaporates into gas is the 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 turned into steam through the gas chromatograph; S15, when the gas chromatograph cannot detect the hydrocarbon components produced at 450°C in the reaction tube, close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, and conduct a specific surface area experiment 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 that separates light oil, light medium oil and heavy oil. In steps S12-S15, different components of crude oil in the shale particle sample are removed by gradually heating, and the proportion of shale pore space occupied by different components of crude oil is detected by specific surface area experiment, which is conducive to improving the accuracy of subsequent shale oil reservoir evaluation.

[0055] 6. The present invention, through step S17, can obtain the total oil content of the shale particle sample, and can compare it with the adsorbed oil content and free oil content data, so as to analyze the ratio of free oil and adsorbed oil in the total shale oil reserves. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0057] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION

[0058] Example 1

[0059] See also Figure 1 , a method for measuring adsorbed oil and free oil content in shale, comprising the following steps:

[0060] S1. Select a shale sample and crush it into shale particle samples with a particle size of 100 μm. Weigh 50 g of the shale particle sample and divide it into two parts. The original mass of the two shale particle samples is the same, recorded as m t, one portion is loaded into the reaction tube, and in accordance with the requirements of SY / T6154-2019 "Static adsorption capacity method for determination of specific surface area and pore size distribution of rocks", the reaction tube is connected to the specific surface area meter, and nitrogen is selected as the adsorption gas to conduct a specific surface area experiment 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 portion is stored in a dryer; S2, remove the reaction tube from the specific surface area meter, pour the shale particle sample out of the reaction tube, clean and dry the reaction tube; S3, pour the other shale particle sample stored in the dryer into the reaction tube, first connect the vacuum meter and the temperature sensor to the reaction tube S4, connect the magnetron to the waveguide tube, install the waveguide tube outside the reaction tube, install a metal reflector plate outside the waveguide tube, and install a microwave leakage shield outside the metal reflector plate; S5, turn on the vacuum pump, evacuate the reaction tube to make the vacuum degree in the reaction tube below -100KPa, 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 120min; S6, remove the reaction tube, pour out the shale particle sample, and weigh the mass m of the shale particle sample from which the water has been removed 1. Then, the shale particle sample is reinstalled into the reaction tube, the specific surface area meter and the gas chromatograph are reconnected, and the magnetron, waveguide, metal reflector and microwave leakage shield are reinstalled outside the reaction tube; S7. The valve between the gas chromatograph and the reaction tube is opened to connect the gas chromatograph and the reaction tube, and the microwave power controller is adjusted to set the heating temperature of the shale particle sample to 200°C; S8. When the shale particle sample is heated at a constant temperature of 200°C, the component that evaporates into gas is the light oil in the shale oil, and the component and content of the light oil that has become steam are analyzed and detected by the gas chromatograph; S9. When the gas chromatograph can no longer detect hydrocarbon components at 200°C, Close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, disassemble the magnetron, waveguide, metal reflector and microwave leakage shield, connect the reaction tube to the surface area meter in accordance with the requirements of SY / T6154-2019 "Static adsorption capacity method for determining specific surface area and pore size distribution of rocks", select nitrogen as the adsorption gas, conduct a specific surface experiment, and 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 light oil has been separated; S10, pour out the shale particle sample from which light oil has been separated from the reaction tube, and detect the mass m2 of the shale particle sample from which light oil has been separated;S11. Re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, then turn off the vacuum pump, adjust the microwave power controller, set the heating temperature of the shale particle sample to 350°C for constant temperature heating, the component in the shale oil that evaporates into gas is the light and medium oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the light and medium oil that has become steam by the gas chromatograph; S12. When the gas chromatograph is at 350°C, the gas chromatograph is used to detect the content of the light and medium oil that has become steam; S13. After no hydrocarbon components are detected, the valve is closed, the microwave power controller is adjusted, and the heating is stopped. When the temperature in the reaction tube drops to room temperature, a specific surface area experiment is performed to 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 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 detected; S14, the reaction tube is reloaded, the vacuum pump is turned on, and the reaction tube is heated to 100 ℃ and the temperature is kept at 400 ℃. The tube should be evacuated to make the vacuum degree in the reaction tube below -100KPa, the vacuum pump is turned off, and the microwave power controller is adjusted to heat at a constant temperature of 450°C. The component in the shale oil that evaporates into gas is the heavy oil in the shale oil. The gas chromatograph is kept connected with the reaction tube, and the component and content of the heavy oil that has turned into steam 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 in the shale particle sample θ q , the volume of light and medium oil in the shale particle sample 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 obtaining the change in the weight of the shale particle sample before and after heating and the specific surface area experiment, the change in the pore structure of the shale particle sample is obtained, and the density parameters of the adsorbed oil and free oil in different pore sizes are obtained, thereby providing more accurate adsorbed oil and free oil content data for shale oil reserve calculation, which is conducive to accurate evaluation of shale oil reservoirs.

[0062] Example 2

[0063] See also Figure 1 , a method for measuring adsorbed oil and free oil content in shale, comprising the following steps:

[0064] S1. Select a shale sample and crush it into shale particle samples with a particle size of 120 μm. Weigh 50 g of the shale particle sample and divide it into two parts evenly. The original mass of the two shale particle samples is the same, recorded as m t, one portion is loaded into the reaction tube, and in accordance with the requirements of SY / T6154-2019 "Static adsorption capacity method for determination of specific surface area and pore size distribution of rocks", the reaction tube is connected to the specific surface area meter, and nitrogen is selected as the adsorption gas to conduct a specific surface area experiment 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 portion is stored in a dryer; S2, remove the reaction tube from the specific surface area meter, pour the shale particle sample out of the reaction tube, clean and dry the reaction tube; S3, pour the other shale particle sample stored in the dryer into the reaction tube, first connect the vacuum meter and the temperature sensor to the reaction tube S4, connect the magnetron to the waveguide tube, install the waveguide tube outside the reaction tube, install a metal reflector plate outside the waveguide tube, and install a microwave anti-leakage shield outside the metal reflector plate; S5, turn on the vacuum pump, evacuate the reaction tube to make the vacuum degree in the reaction tube below -100KPa, and 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 150min; S6, remove the reaction tube, pour out the shale particle sample, and weigh the mass m of the shale particle sample from which the water has been removed 1. Then, the shale particle sample is reinstalled into the reaction tube, the specific surface area meter and the gas chromatograph are reconnected, and the magnetron, waveguide, metal reflector and microwave leakage shield are reinstalled outside the reaction tube; S7. The valve between the gas chromatograph and the reaction tube is opened to connect the gas chromatograph and the reaction tube, and the microwave power controller is adjusted to set the heating temperature of the shale particle sample to 200°C; S8. When the shale particle sample is heated at a constant temperature of 200°C, the component that evaporates into gas is the light oil in the shale oil, and the component and content of the light oil that has become steam are analyzed and detected by the gas chromatograph; S9. When the gas chromatograph can no longer detect hydrocarbon components at 200°C, Close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, disassemble the magnetron, waveguide, metal reflector and microwave leakage shield, connect the reaction tube to the surface area meter in accordance with the requirements of SY / T6154-2019 "Static adsorption capacity method for determining specific surface area and pore size distribution of rocks", select nitrogen as the adsorption gas, conduct a specific surface experiment, and 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 light oil has been separated; S10, pour out the shale particle sample from which light oil has been separated from the reaction tube, and detect the mass m2 of the shale particle sample from which light oil has been separated;S11. Re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, then turn off the vacuum pump, adjust the microwave power controller, set the heating temperature of the shale particle sample to 350°C for constant temperature heating, the component in the shale oil that evaporates into gas is the light and medium oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the light and medium oil that has become steam by the gas chromatograph; S12. When the gas chromatograph is at 350°C, the gas chromatograph is used to detect the content of the light and medium oil that has become steam; S13. After no hydrocarbon components are detected, the valve is closed, the microwave power controller is adjusted, and the heating is stopped. When the temperature in the reaction tube drops to room temperature, a specific surface area experiment is performed to 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 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 detected; S14, the reaction tube is reloaded, the vacuum pump is turned on, and the reaction tube is heated to 100 ℃ and the temperature is kept at 400 ℃. The tube should be evacuated to make the vacuum degree in the reaction tube below -100KPa, the vacuum pump is turned off, and the microwave power controller is adjusted to heat at a constant temperature of 450°C. The component in the shale oil that evaporates into gas is the heavy oil in the shale oil. The gas chromatograph is kept connected with the reaction tube, and the component and content of the heavy oil that has turned into steam 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 in the shale particle sample θ q , the volume of light and medium oil in the shale particle sample 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, is the total oil content of 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, and m4 is the mass of the shale particle sample after separating light oil, light medium oil and heavy oil.

[0068] Furthermore, in step S18, the volume of light oil in the shale particle sample θ q Calculated by formula 2;

[0069] θ q =θ4-θ1-θ3 Formula 2

[0070] Among them, θ q is 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 with light oil and light medium oil separated, and θ4 is the pore volume of the shale particle sample with light oil, light medium oil and heavy oil separated.

[0071] Furthermore, in step S18, the volume of light medium oil in the shale particle sample θ q-z Calculated by formula 3;

[0072] θ q-z =θ4-θ1-θ2 Formula 3

[0073] Among them, 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 oil and free oil, θ2 is the pore volume of the shale particle sample from which light oil is separated, and θ4 is the pore volume of the shale particle sample from which light oil, light and medium oil, and heavy oil are separated.

[0074] Furthermore, in step S18, the volume of heavy oil in the shale particle sample θ z Calculated by formula 4;

[0075] θ z =θ4-θ3-θ2-θ1 Formula 4

[0076] Among them, θ z is 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 with light oil separated, θ3 is the pore volume of the shale particle sample with light oil and light medium oil separated, and θ4 is the pore volume of the shale particle sample with light oil, light medium oil and heavy oil separated.

[0077] Furthermore, 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 is calculated by formula (5): 流离油Calculated by formula 6;

[0078]

[0079]

[0080] 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 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 medium oil in the shale particle sample.

[0081] This embodiment is a preferred implementation method, in which the shale particle sample is heated by microwaves and isolated from the external environment, thereby preventing moisture or nitrogen in the air from interfering with the specific surface area experiment and affecting the experimental results, and avoiding high temperatures generated by direct heating, thereby ensuring that the pore structure of the shale particle sample is not destroyed.

[0082] Example 3

[0083] See also Figure 1 , a method for measuring adsorbed oil and free oil content in shale, comprising the following steps:

[0084] S1. Select shale samples and crush them into shale particle samples with a particle size of 150 μm. Weigh 50 g of shale particle samples and divide them into two parts evenly. The original mass of the two shale particle samples is the same, recorded as m t , one portion was loaded into a reaction tube, and in accordance with the requirements of SY / T6154-2019 "Static adsorption capacity method for determination of specific surface area and pore size distribution of rocks", the reaction tube was connected to a specific surface meter, and nitrogen was selected as the adsorption gas to conduct a specific surface experiment to obtain the specific surface area, pore size distribution, pore volume θ1 and pore size-pore volume distribution data of shale particle samples containing adsorbed oil and free oil, and the other portion was stored in a desiccator;

[0085] S2. Remove the reaction tube from the surface area analyzer, pour the shale particle sample out of the reaction tube, and clean and dry the reaction tube;

[0086] S3. Pour another portion of the shale particle sample stored in the dryer into the reaction tube, first connect the vacuum meter 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 a high temperature resistant pipeline;

[0087] S4, connecting the magnetron and the waveguide, installing the waveguide outside the reaction tube, installing a metal reflector outside the waveguide, and installing a microwave leakage shield outside the metal reflector;

[0088] S5, turning on the vacuum pump to evacuate the reaction tube to make the vacuum degree in the reaction tube below -100 KPa, and at the same time adjusting the microwave power controller to set the heating temperature of the shale particle sample to 60° C., and heating the shale particle sample at 60° C. for 180 min;

[0089] S6, remove the reaction tube, pour out the shale particle sample and weigh the mass m1 of the shale particle sample from which the water has been removed, then reinstall the shale particle sample back into the reaction tube, reconnect the surface area analyzer and the gas chromatograph, and reinstall the magnetron, waveguide, metal reflector and microwave leakage shield outside the reaction tube;

[0090] S7, opening the valve between the gas chromatograph and the reaction tube to connect the gas chromatograph and the reaction tube, adjusting the microwave power controller to set the heating temperature of the shale particle sample to 200° C.;

[0091] S8. When the shale particle sample is heated at a constant temperature of 200°C, the component that volatilizes into gas is the light oil in the shale oil. The components and content of the light oil that is converted into steam are analyzed and detected by gas chromatography;

[0092] S9. When the gas chromatograph can no longer detect hydrocarbon components at 200°C, close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, disassemble the magnetron, waveguide, metal reflector and microwave leakage shield, and connect the reaction tube to the surface area analyzer in accordance with the requirements of SY / T 6154-2019 "Static adsorption capacity method for determination of specific surface area and pore size distribution of rocks", select nitrogen as the adsorption gas, conduct a specific surface area experiment, and 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 light oil is separated;

[0093] S10, pouring out the shale particle sample from which the light oil has been separated from the reaction tube, and detecting the mass m2 of the shale particle sample from which the light oil has been separated;

[0094] S11, re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, then turn off the vacuum pump, adjust the microwave power controller, set the heating temperature of the shale particle sample to 350° C. constant temperature heating, the component volatilized into gas in the shale oil is the light and medium oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the light and medium oil that has become steam by the gas chromatograph;

[0095] S12. When the gas chromatograph can no longer detect hydrocarbon components at 350° C., close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, and conduct a specific surface area experiment to obtain 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 are separated;

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

[0097] S14, re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, turn off the vacuum pump, adjust the microwave power controller, heat at a constant temperature of 450° C. The component volatilized into gas in the shale oil is the heavy oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the heavy oil that has become steam by the gas chromatograph;

[0098] S15. When the gas chromatograph fails to detect the hydrocarbon components produced at 450° C. in the reaction tube, 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 performed 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 are separated;

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

[0100] S17. Calculate the total oil content of shale particle samples

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

[0102] 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 .

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

[0104]

[0105] in, is the total oil content of 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, and m4 is the mass of the shale particle sample after separating light oil, light medium oil and heavy oil.

[0106] In step S18, the volume of light oil in the shale particle sample θ q Calculated by formula 2;

[0107] θ q =θ4-θ1-θ3 Formula 2

[0108] Among them, θ q is 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 with light oil and light medium oil separated, and θ4 is the pore volume of the shale particle sample with light oil, light medium oil and heavy oil separated.

[0109] In step S18, the volume of light medium oil in the shale particle sample θ q-z Calculated by formula 3;

[0110] θ q-z =θ4-θ1-θ2 Formula 3

[0111] Among them, 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 oil and free oil, θ2 is the pore volume of the shale particle sample from which light oil is separated, and θ4 is the pore volume of the shale particle sample from which light oil, light and medium oil, and heavy oil are separated.

[0112] In step S18, the volume of heavy oil in the shale particle sample θ z Calculated by formula 4;

[0113] θ z =θ4-θ3-θ2-θ1 Formula 4

[0114] Among them, θ z is 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 with light oil separated, θ3 is the pore volume of the shale particle sample with light oil and light medium oil separated, and θ4 is the pore volume of the shale particle sample with light oil, light medium oil and heavy oil separated.

[0115] 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 is calculated by formula (5): 游离油Calculated by formula 6;

[0116]

[0117]

[0118] 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 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 medium oil in the shale particle sample.

[0119] Furthermore, the specific surface 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 is in the shape 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 increase the temperature of the shale particle sample; the metal reflector is used to cover the outside of the waveguide and reflect the microwaves emitted by the waveguide so that the microwaves are repeatedly reflected in the reaction tube. During the reflection process, the microwaves contact the shale particle sample to increase the temperature of the shale particle sample; the microwave leakage shield is covered outside the magnetron, the waveguide, the metal reflector and the 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. The magnetron is used to generate microwaves, and the frequency of the generated microwaves is 2450MHz. The gas chromatograph is used to detect 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, which is used to connect the surface area meter and the gas chromatograph, and the top diameter of the reaction tube is 4 cm, and the bottom diameter of the reaction tube is 20 cm.

[0120] This embodiment is the best implementation method. By heating the shale particle sample to volatilize the adsorbed oil and free oil therein, a gas chromatograph is used to detect the components and mass fractions of the adsorbed oil and free oil released at different temperatures. Compared with the prior art, it can not only provide the content data of the adsorbed oil and free oil, but also provide the components and mass fraction parameters of the adsorbed oil and free oil. Since it is connected to the gas chromatograph, it can truly reflect the component characteristics and mass fraction of the crude oil stored in the pore spaces of different pore sizes in the shale.

[0121] The content data of adsorbed oil and free oil are obtained by direct measurement and calculation, and the porosity and pore structure parameters of shale particle samples are obtained through specific surface area experiments at the same time, so as to better characterize the occurrence mode of adsorbed oil and free oil in the shale pore structure.

[0122] In steps S12-S15, different components of crude oil in the shale particle sample are removed by gradually heating, and the proportion of the shale pore space occupied by different components of crude oil is detected by specific surface area experiment, which is conducive to improving 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 compared with the adsorbed oil content and free oil content data, so as to analyze the ratio of free oil to adsorbed oil in the total shale oil reserves.

Claims

1. A method for measuring the content of adsorbed oil and free oil in shale, characterized in that: The following steps are involved: S1. Select shale samples and crush them into shale particle samples with a particle size of 100μm-150μm. Weigh 50g of shale particle samples and divide them into two parts evenly. The original mass of the two shale particle samples is the same, recorded as m t , one portion is loaded into a reaction tube, the reaction tube is connected to a specific surface area meter, nitrogen is selected as the adsorption gas, a specific surface area 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 portion is stored in a desiccator; S2. Remove the reaction tube from the surface area analyzer, pour the shale particle sample out of the reaction tube, and clean and dry the reaction tube; S3. Pour another portion of the shale particle sample stored in the dryer into the reaction tube, first connect the vacuum meter 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 a high temperature resistant pipeline; S4, connecting the magnetron and the waveguide, installing the waveguide outside the reaction tube, installing a metal reflector outside the waveguide, and installing a microwave leakage shield outside the metal reflector; S5. Turn on the vacuum pump to evacuate the reaction tube to make the vacuum degree in the reaction tube 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° C., and heat the shale particle sample at 60° C. for at least 120 min; S6, remove the reaction tube, pour out the shale particle sample and weigh the mass m1 of the shale particle sample from which the water has been removed, then reinstall the shale particle sample back into the reaction tube, reconnect the surface area analyzer and the gas chromatograph, and reinstall the magnetron, waveguide, metal reflector and microwave leakage shield outside the reaction tube; S7, opening the valve between the gas chromatograph and the reaction tube to connect the gas chromatograph and the reaction tube, adjusting the microwave power controller to set the heating temperature of the shale particle sample to 200° C.; S8. When the shale particle sample is heated at a constant temperature of 200°C, the component that volatilizes into gas is the light oil in the shale oil. The components and content of the light oil that is converted into steam are analyzed and detected by gas chromatography; S9. When the gas chromatograph can no longer detect hydrocarbon components at 200°C, close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, disassemble the magnetron, waveguide, metal reflector and microwave anti-leakage shield, connect the reaction tube to the surface area analyzer, select nitrogen as the adsorption gas, conduct a surface area test, and detect and obtain 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, pouring out the shale particle sample from which the light oil has been separated from the reaction tube, and detecting the mass m2 of the shale particle sample from which the light oil has been separated; S11, re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, then turn off the vacuum pump, adjust the microwave power controller, set the heating temperature of the shale particle sample to 350° C. constant temperature heating, the component volatilized into gas in the shale oil is the light and medium oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the light and medium oil that has become steam by the gas chromatograph; S12. When the gas chromatograph can no longer detect hydrocarbon components at 350° C., close the valve, adjust the microwave power controller, stop heating, wait for the temperature in the reaction tube to drop to room temperature, and conduct a specific surface area experiment to obtain 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 are separated; S13, pouring out the shale particle sample from the reaction tube, and detecting the mass m3 of the shale particle sample from which the light oil and the light-medium oil have been separated; S14, re-install the reaction tube, turn on the vacuum pump, evacuate the reaction tube, make the vacuum degree in the reaction tube below -100 KPa, turn off the vacuum pump, adjust the microwave power controller, heat at a constant temperature of 450° C. The component volatilized into gas in the shale oil is the heavy oil in the shale oil, keep the gas chromatograph connected with the reaction tube, and detect the component and content of the heavy oil that has become steam by the gas chromatograph; S15. When the gas chromatograph fails to detect the hydrocarbon components produced at 450° C. in the reaction tube, 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 performed 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 are separated; S16, pouring out the shale particle sample from which the light oil, light medium oil and heavy oil have been separated from the reaction tube, and detecting the mass m4 of the shale particle sample from which the light oil, light medium oil and heavy oil have been separated; S17. Calculate the total oil content of shale particle samples S18. Calculate the volume of light oil in the shale particle sample θ q , the volume of light and medium oil in the shale particle sample 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 .

2. A method for measuring adsorbed oil and free oil content in shale according to claim 1, characterized in that: In step S17, the total oil content of the shale particle sample Calculated by formula 1; in, is the total oil content of 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, and m4 is the mass of the shale particle sample after separating light oil, light medium oil and heavy oil.

3. A method for measuring adsorbed oil and free oil content in shale according to claim 1, characterized in that: In step S18, the volume of light oil in the shale particle sample θ q Calculated by formula 2; i q =θ4-θ1-θ3 Equation 2 Among them, θ q is 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 with light oil and light medium oil separated, and θ4 is the pore volume of the shale particle sample with light oil, light medium oil and heavy oil separated.

4. A method for measuring adsorbed oil and free oil content in shale according to claim 1, characterized in that: In step S18, the volume of light medium oil in the shale particle sample θ q-z Calculated by formula 3; i q-z =θ4-θ1-θ2 Equation 3 Among them, 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 oil and free oil, θ2 is the pore volume of the shale particle sample from which light oil is separated, and θ4 is the pore volume of the shale particle sample from which light oil, light and medium oil, and heavy oil are separated.

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

6. A method for measuring adsorbed oil and free oil content in shale according to claim 1, characterized in that: 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 is calculated by formula (5): 游离油 Calculated by formula 6; Among them, μ 吸附油 is the content of adsorbed oil in shale particle samples, 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 medium oil in the shale particle sample.

7. A method for measuring adsorbed oil and free oil content in shale according to claim 1, characterized in that: 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 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 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 reflection plate is used to cover the outside of the waveguide and reflect the microwaves emitted by the waveguide so that the microwaves are repeatedly reflected in the reaction tube. During the reflection process, the microwaves contact 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, the waveguide, the metal reflection plate and the 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.

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

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

10. The method for 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 used to connect the specific surface area meter 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.

Images