Method and device for in-situ upgrading of shale oil based on underground nuclear radiation pattern

Abstract

The application discloses a shale oil in-situ modification method and device based on an underground nuclear radiation mode, and the method comprises the following steps: carrying out a nuclear radiation field simulation experiment; according to the nuclear radiation field simulation experiment result, establishing a corresponding model of radiation and in-situ modification shale oil production, and determining specific nuclear radiation parameters; according to the nuclear radiation field simulation experiment result, selecting and determining an experimental area with the best shale geological characteristics; inserting the shale oil in-situ modification device of the underground nuclear radiation mode into the experimental area with the best shale geological characteristics, and setting the specific nuclear radiation parameters; adjusting the nuclear radiation parameters, and starting a production well to produce. The shale oil in-situ modification device of the underground nuclear radiation mode comprises a radiation layer pipeline and a heating device, the heating device is located in the radiation layer pipeline, the radiation layer pipeline is used for storing radiation agents, and the heating device is used for heating oil-containing reservoirs in the medium-low maturity shale.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil exploration technology, and particularly relates to a shale oil in-situ upgrading method and device based on underground nuclear radiation mode. BACKGROUND

[0002] Unconventional shale oil resources are abundant, and preliminary estimates show that China's unconventional shale oil resources with medium-high maturity are 21 billion tons, and shale oil resources with medium-low maturity can reach 90 billion tons, which will become an important type of unconventional oil. Organic-rich shale formations are widely developed in China's Mesozoic and Cenozoic sedimentary basins, but the exploration and development of shale oil is relatively low. One of the important reasons is that the maturity of part of the shale oil is relatively low, and a large amount of retained hydrocarbons are difficult to flow and develop. If the in-situ cracking reaction of crude oil or kerogen is promoted through technical processes, light components can be formed to improve the quality of crude oil and increase the recovery rate in the underground.

[0003] The commonly used in-situ upgrading method at present is to use heating method to improve the formation temperature and accelerate the in-situ cracking reaction rate. Patent No. CN106499376A provides a heating cable in the wellbore of a heating well, and connects an electric heating rod to heat the oil-bearing reservoir, so as to improve the thermal effect of the oxidation reaction of crude oil and air to realize in-situ upgrading. In this method, the wellbore electric heating mode mainly uses heat conduction to transfer heat, and the heating range is relatively small, the heating time is too long, and it has certain limitations. Patent No. CN104619947A introduces a hot fluid containing heavy hydrocarbon fractions, hydrogen and catalyst into the oil-bearing layer to promote the upgrading of heavy oil and bitumen. In this method, the fluid retention time is relatively long, and a hydrogen and catalyst injection system needs to be provided.

[0004] Since the late 1970s, radioactive irradiation experiments have attracted more and more attention in the study of the characteristics of sedimentary organic matter. Irradiation refers to the energy transfer of electron beams (beta rays) generated by an electron accelerator (0.2MeV-10MeV) or gamma rays generated by radioactive isotopes (Cs-137 or Co-60) to the irradiated substance. Ionizing radiation acts on the irradiated substance, ionizes and excites, releases orbital electrons, forms free radicals, and changes the physical properties and chemical composition of the irradiated substance by controlling the radiation conditions. It can also make biological organisms (microorganisms, etc.) suffer irreversible damage and destruction, and achieve the desired goal.

[0005] The scholars at home and abroad discuss the relationship between oil and gas and uranium enrichment and the effect of low concentration uranium on hydrocarbon generation of source rock, and only discuss that uranium plays an important role in the process of hydrocarbon generation of organic hydrocarbon source rock. Dahl (1988) studied the extractable organic matter in the Alum shale in Sweden, and believed that the organic matter was changed due to the radiation produced by the natural decay of uranium. The content of extractable bitumen is inversely proportional to the uranium concentration, indicating that the transformation of bitumen can be caused by irradiation. In the presence of radiation, aromatic hydrocarbons are more stable than saturated hydrocarbons, and the bitumen from uranium-rich samples is often relatively rich in aromatic hydrocarbons, and the ratio of aromatic hydrocarbons to saturated hydrocarbons increases with the increase of uranium concentration. Lu Hongxuan (2007) studied the influence of uranium-containing substances on the pyrolysis of lignite samples through water heating simulation experiment. He believed that the uranium-containing substances promoted the degradation of high-carbon n-alkanes produced in the pyrolysis process, increased the light-heavy ratio of saturated hydrocarbon components in the extract, and reduced the odd-even advantage value, to some extent, accelerated the maturation process of lignite organic matter. Mao Guangzhou (2012) carried out hydrocarbon generation simulation experiment under the condition of adding sandstone type uranium ore in type I low mature hydrocarbon source rock, and compared the related parameters of hydrocarbon generation simulation experiment products of uranium-free and uranium-added samples, and believed that the presence of uranium promoted the cracking of long-chain hydrocarbons into low relative molecular mass short-chain hydrocarbons after 400 DEG C, reduced the relative molecular mass of hydrocarbons, evolved to dry gas, and generated a large amount of CO2 and H2, and the presence of uranium made the temperature point of the change advance by 50 DEG C, in addition, uranium can promote the advance of the total oil generation peak.

[0006] Few scholars discuss the relationship between oil and gas and uranium enrichment and the effect of low concentration uranium on hydrocarbon generation of source rock. However, there is a lack of research on the irradiation of organic matter by rays. At present, there is little research on the effect of different nuclear radiation intensities on the gas-oil ratio, free hydrocarbon in rock and aromaticity of pyrolysis products of different types of low mature shale oil in freshwater and saltwater lake basins, and the effect of ray irradiation produced by radioactive elements on the hydrocarbon generation of organic matter is not clear, and there is a lack of experimental data support. In particular, there is no research on the in-situ upgrading of different types of low mature shale oil by using uranium radioactivity. SUMMARY

[0007] With the increasing difficulty of exploration and development of conventional resources, shale oil has become an important field of oil and gas resource replacement in China. In order to speed up the further exploration and development of shale oil favorable areas, it is very important to improve the crude oil quality. At present, the in-situ upgrading of low mature shale is mainly realized by heating, but the organic matter types of low mature shale are various, and the hydrocarbon generation precursors are obviously different. The experimental research on the in-situ upgrading of different types of low mature shale by different doses of nuclear radiation has not been involved. In view of the above factors, the present application provides an economic and effective method for the in-situ upgrading of different types of low mature shale, which can promote the in-situ cracking and upgrading of shale oil, so as to further realize the in-situ upgrading of low mature shale. In order to achieve the above purpose, the present application provides the following technical scheme:

[0008] A method for in-situ upgrading of shale oil based on underground nuclear radiation mode, the method comprising the following steps: carrying out a nuclear radiation field simulation experiment; establishing a corresponding model of radiation and in-situ upgrading shale oil production according to the results of the nuclear radiation field simulation experiment, and determining specific parameters of nuclear radiation; selecting and determining an experimental area with optimal shale geological characteristics according to the results of the nuclear radiation field simulation experiment; inserting an in-situ upgrading device for shale oil based on underground nuclear radiation mode into the experimental area with optimal shale geological characteristics, and setting the specific parameters of nuclear radiation; adjusting the parameters of nuclear radiation, and opening a production well for production.

[0009] Preferably, the in-situ upgrading device for shale oil based on underground nuclear radiation mode is used for storing radiation agents and heating oil-bearing reservoirs inside low-mature shale.

[0010] Preferably, the experimental object for carrying out the nuclear radiation simulation field experiment is different shale samples with low-mature.

[0011] Preferably, the specific parameters of nuclear radiation are determined according to the differences of shale with different organic matter abundance.

[0012] Preferably, the specific parameters of nuclear radiation include time, dose, intensity, mode and source parameters of nuclear radiation.

[0013] Preferably, the optimal shale geological characteristics are determined according to the parameters of shale organic matter abundance, thickness and lithology.

[0014] Preferably, the corresponding model of radiation and in-situ upgrading shale oil production is established by using Matlab professional software.

[0015] Preferably, the production well can be opened for production only after the parameters of nuclear radiation reach the designed radiation concentration and time.

[0016] A device for in-situ upgrading of shale oil based on underground nuclear radiation mode, the device comprising a radiation layer pipeline and a heating device, characterized in that the heating device is located inside the radiation layer pipeline.

[0017] Preferably, the radiation layer pipeline is used for storing radiation agents; and the heating device is used for heating oil-bearing reservoirs inside low-mature shale.

[0018] Preferably, the underground nuclear radiation device is installed inside oil-bearing reservoirs of low-mature shale.

[0019] The present application provides a new method suitable for different types of low mature shale, which realizes in-situ cracking modification of shale oil by optimizing specific parameters such as underground nuclear radiation dose, radiation time, etc., and clearly defines the nuclear radiation geological parameters and standards of favorable low mature shale, determines the key field test standards such as nuclear radiation intensity and time of fresh water and salinization two types of continental low mature shale, greatly improves the economy of in-situ modification, and realizes efficient production of in-situ modification of shale oil.

[0020] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a schematic diagram of underground nuclear radiation device;

[0022] Figure 2 It is a graph of organic carbon content change of irradiated samples with different doses;

[0023] Figure 3 It is a chromatogram of shale oil before and after nuclear radiation modification. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] To solve the problems of the prior art, the present application discloses a method and device for in-situ modification of shale oil based on an underground nuclear radiation mode, as shown in Figure 1As shown, the underground nuclear radiation device includes a radiation layer pipeline and a heating device, wherein the heating device is located inside the radiation layer pipeline. The underground nuclear radiation device is inserted into an oil-bearing reservoir inside the low-mature shale. The low-mature shale includes a cap rock and a reservoir containing the reservoir, the radiation layer pipeline is used to store a radiation agent; and the heating device is used to heat the oil-bearing reservoir inside the low-mature shale. The device is suitable for different types of low-mature shale. The present application uses the underground nuclear radiation device to achieve a new method for in-situ cracking and upgrading of shale oil by using specific parameters such as preferred underground nuclear radiation dose, radiation time, etc., including the following steps:

[0026] For target low-mature shale samples, nuclear radiation field simulation experiments are carried out; according to the results of the nuclear radiation field simulation experiments, the parameters of different types of low-mature shale, such as nuclear radiation time, radiation dose, radiation intensity, radiation mode and radioactive source, are determined; a corresponding model of radiation and in-situ upgrading of shale oil production is established by using Matlab professional software to determine the specific parameters of nuclear radiation; according to the results of the nuclear radiation field simulation experiments of different low-mature shales, the best shale geological characteristics are determined, and the favorable target experimental area is optimized; for target low-mature shale, conventional drilling tools are used to drill production well groups, and the type and well spacing density of the well group depend on the geological conditions of the shale. For the reservoirs that have been put into development, adjustment can be made on the basis of the existing well groups, and infilled wells are reasonably drilled. The underground nuclear radiation device is inserted into the experimental area with the best shale geological characteristics, and the specific parameters of the nuclear radiation are set; a radiation material layer is installed on the heating rod, and is lowered into the wellbore by combining with the coiled tubing technology, and by adjusting the parameters such as radiation time, radiation dose, radiation intensity and radioactive source, the in-situ cracking and upgrading of crude oil underground is promoted; after reaching the designed radiation concentration and time, the production well is opened for production.

[0027] The technical scheme provided by the embodiment of the present application achieves the following beneficial technical effects:

[0028] Shale oil, as an unconventional oil, is one of the key areas for future development and has become a highlight of global unconventional oil development. my country's shale oil is widely distributed and has good resource prospects. During the Chang 7 oil-bearing formation period in the Ordos Basin, the basin was strongly subsided, reaching its maximum area, and developed a large amount of dark mudstone and organic-rich shale, which are the main source rocks of the Ordos Basin. This set of high-quality source rocks is widely distributed, mainly in the central and southern parts of the basin, including Dingbian, Zhidan, Wuqi, Fuxian, and Huangling, with a thickness generally ranging from 30 to 90 meters. The total organic carbon content of the Chang 7 source rocks in the Ordos Basin is generally 2% to 20.5%, and the vitrinite reflectance is 0.7% to 1.1%, placing it within a major oil-generating window. The Lucao Gou Formation in the Santanghu Basin is rich in low-maturity shale resources in a saline lacustrine basin, with a TOC of approximately 2% to 5% and a vitrinite reflectance of 0.7% to 1.0%, also placing it within a major oil-generating window. This study selected the Chang 7 Formation shale from the Ordos Basin and the Lucao Gou Formation from the Santanghu Basin to conduct nuclear radiation simulation experiments. This patent uses the Nong'an oil shale as the research object and employs radioactive isotopes (…) 60 Samples were irradiated with gamma rays and high-energy electrons generated from Co at doses of 0.5, 1, 10, 50, 100, and 1000 kGy. Using rock thin sections, X-ray diffraction analysis, TOC content analysis, scanning electron microscopy, infrared spectroscopy, and pyrolysis testing, the changes in organic matter before and after irradiation at different doses were analyzed. Based on this, the mechanism of organic matter change was explored, and research on organic matter in irradiated shale was conducted. This research clarifies the specific parameters for in-situ remediation of different types of low-maturity shale and the selection criteria for favorable shale formation, which has significant scientific and theoretical implications for improving the formation mechanism of shale oil and gas and enriching petroleum geological theory.

[0029] ICP-MS measurements showed a sample background of 0.1 × 10⁻⁶. -6 The samples tested were from the Permian and Triassic periods, and received a dose of approximately 150-200 kGy in the strata. Therefore, the radiation doses used in this study were 500 Gy, 1000 Gy, 10 kGy, 100 kGy, and 1000 kGy, respectively. The sample irradiation was 97,892 Curies. 60 The experiment was conducted at the Co source device and the high-energy electron linear accelerator, with dose monitoring performed using a potassium dichromate dosimeter. The experiment was completed at the China Institute of Atomic Energy. 60 The Co source device dose is 10 Gy / h, and 500 Gy and 1000 Gy are used. 60 The samples were irradiated with a Co source device at an ambient temperature below 30 degrees Celsius for 2-5 days. Considering time costs, high-energy electron irradiation was used for 10kGy, 50kGy, 100kGy and 1000kGy samples at an ambient temperature below 70 degrees Celsius. The mineral composition and organic matter composition of the original samples and irradiated samples were then tested and compared.

[0030] Optical microscopy, X-ray diffraction mineral analysis, and field emission scanning electron microscopy were performed at the State Key Laboratory of Nuclear Resources and Environment, East China University of Technology. The optical microscope used a Zeiss polarizing microscope (Germany); X-ray diffraction was performed on 200-mesh powder samples using a Bruker D8advance X-ray diffractometer (Germany), with a Cu target, voltage of 35 kV, and current of 15 mA; the scanning electron microscope used an Apreo high-resolution field emission scanning electron microscope, observed at a working voltage of 5 kV and a working distance of 7.0 mm. Ro analysis was performed at the Key Laboratory of Oil and Gas Resources and Exploration Technology, Ministry of Education, Yangtze University, using an MSP200 micro-coal and petrography analysis system, with an ambient temperature of 20 degrees Celsius and humidity of 59%. TOC content analysis and Rock-Eval pyrolysis were performed at the Key Laboratory of Oil and Gas Geochemistry, China National Petroleum Corporation (CNPC). TOC content analysis was performed using a CS-i carbon-sulfur analyzer, and Rock-Eval pyrolysis was performed using equipment from Vinci Technologies (France).

[0031] Furthermore, the changes in Toc and Ro values ​​before and after irradiation of medium- and low-maturity shale were analyzed.

[0032] Furthermore, organic matter abundance reflects the relative content of organic matter in source rocks and is the main factor determining the hydrocarbon generation capacity of source rocks. Currently, commonly used organic matter abundance indicators mainly include total organic carbon content (TOC), chloroform bitumen “A”, total hydrocarbon content (HC), and hydrocarbon generation potential (S1+S2).

[0033] This embodiment analyzes the organic carbon content of the original sample and samples irradiated with different doses, such as... Figure 2 As shown, the results indicate that the total organic carbon (TOC) content of shale decreased to varying degrees after irradiation. The sample irradiated with a dose of 1000 kGy showed the largest decrease compared to the original sample. For example, the TOC content of sample M-1 decreased by 0.02% after 1000 kGy irradiation, 0.43% after 10 kGy, 0.6% after 100 kGy, and 1.11% after 1000 kGy. This demonstrates that the higher the dose, the greater the decrease in TOC, exhibiting a good linear relationship. Other samples also showed similar trends after irradiation, but the changes were relatively smaller. This may be due to the different effects of irradiation on different types of organic matter. The decrease in TOC after irradiation may be due to the generation of new gaseous substances from organic matter during the irradiation process.

[0034] The vitrinite reflectance (Ro) of shale samples generally increased after irradiation. After irradiation with a dose of 1000 kGy, the Ro value of sample M-1 increased from the original 0.74 to 0.76. Other doses of irradiation also showed varying degrees of increase, indicating that irradiation has a certain impact on the maturity of organic matter.

[0035] Furthermore, the samples were analyzed using gas chromatography and infrared spectroscopy.

[0036] Furthermore, the gas chromatographic analysis samples were the original samples and 60 The experimental test and analysis results of samples irradiated with 500 Gy and 1000 Gy of Co show significant differences in hydrocarbon composition between terrestrial freshwater and saline lake basin samples. The carbon number range of the unirradiated sample from the saline Santang Lake is [C range missing]. 12 -C 28 The primary source of carbon numbers in the unirradiated freshwater samples from Ordos ranged from C6 to C7. 20 Mainly. For example... Figure 3 As shown, after the M-1 sample was irradiated with 500 Gy, C 23 -C 28 The content of alkane decreased significantly, C 14 -C 20 The alkane content increased significantly, and the trend of the 1000 Gy irradiated sample was consistent with that of the 500 Gy sample; after 500 Gy irradiation, the C content of the M-2 sample increased. 23 -C 28 The content of alkane decreased significantly, C 16 -C 21 The alkane content increased significantly, with a large difference between the 1000 Gy irradiated sample and the 500 Gy irradiated sample. Overall, the content shifted towards lower carbon numbers, specifically C6-C. 15 The alkane content increased significantly. After irradiation with 500 Gy, the C content of sample M-3 increased. 29 -C 31 Alkanes disappear, C6-C 10 Alkanes appear, C 20 -C 28 The content of alkane decreased significantly, C 13 -C 18 The alkane content increased significantly, and the overall carbon number shifted towards lower carbons. The results of the 1000 Gy irradiated sample showed the same trend as the 500 Gy sample. Irradiation had a relatively small impact on the freshwater samples from Ordos. After 500 Gy irradiation, the ZK-1 sample showed C6 alkanes, with little change in other carbon number hydrocarbons. However, the 1000 Gy irradiated sample showed a large amount of C6 alkanes and C7-C6 alkanes. 113 Alkyl content decreased significantly; the experimental data trends of ZK-2 sample after irradiation with 500 Gy and 1000 Gy were basically consistent with those of ZK-1 sample.

[0037] Molecular structure parameters derived from the ratio of the Fourier-transform infrared (FTIR) functional group peak areas have been widely used in the field of petroleum geochemistry, typically for the characterization of organic matter structure, properties and maturity. The FTIR spectra of five groups of 20 samples were analyzed. The identification of FTIR functional groups was mainly based on the methods of Abbas, Weng Shifu and Weigel. The FTIR spectra of organic matter typically include three types of functional groups, namely saturated hydrocarbons, aromatic hydrocarbons and oxygen-containing functional groups. Among them, the saturated hydrocarbon functional groups mainly include the symmetric and asymmetric stretching and bending vibrations of the methyl (CH3) and methylene (CH2) functional groups, with wavelengths near 2962 cm -1 , 2874 cm -1 , 1457 cm -1 and 1372 cm -1 . The aromatic hydrocarbon functional groups mainly include C-H stretching vibration at 3160 cm -1 , C=C double bond stretching vibration at 1600 cm -1 , and two C-H bending vibrations at 880 cm -1 and 817 cm -1 . The oxygen-containing functional groups mainly include aldehyde group (C-O) at 2727 cm -1 , ketone group (C=O) at 1700 cm -1 , sulfoxide (S=O) at 1160 cm -1 and 1070 cm -1 .

[0038] The M-1 original sample has ketone group (C=O) at 1700 cm -1 , and the 500 Gy, 1000 Gy and 1000 kGy irradiated samples have no ketone group at 1700 cm -1 ; the M-2 original sample has methylene (CH2) functional group at 2946 cm -1 , and the 500 Gy and 1000 kGy irradiated samples have no methylene, and the 1000 Gy irradiated sample has no ketone group at 1700 cm -1 , while new methylene is produced; the M-3 500 Gy irradiated sample has new ketone group at 1712 cm -1 compared with other samples; the ZK-1 original sample and 500 Gy irradiated sample have no ketone group (C=O) at 1700 cm -1 , and the 1000 Gy and 1000 kGy irradiated samples have ketone group (C=O) near 1700 cm -1 , and the 1000 kGy sample with the largest irradiation dose has ketone group (C=O) at 1625 cm -1presence of C=C aromatic hydrocarbon functionality; ZK-2 original sample at 1700 cm -1 absence of ketone (C=0), 500 Gy, 1000 Gy and 1000 kGy irradiated samples at 1700 cm -1 presence of ketone (C=0), 1000 kGy irradiated sample at 2946 cm -1 disappearance of methyl (CH2).

[0039] Further, the samples were analyzed for the relationship between irradiation intensity and cracking process.

[0040] Further, source rocks are one of the key factors controlling the formation and distribution of oil and gas reservoirs. Determining effective source rocks is the basis of oil and gas systems, and source rock evaluation involves many aspects. Although the evaluation focus varies at different exploration stages and in different sedimentary basins, it generally includes two main aspects: (1) geochemical characteristics evaluation of source rocks, such as the abundance of organic matter, the type of organic matter, and the maturity of organic matter; (2) evaluation of the hydrocarbon-generating capacity of source rocks, such as hydrocarbon-generating intensity, hydrocarbon-generating amount, and hydrocarbon-exhausting intensity. This study analyzes the effect of irradiation on shale hydrocarbon generation through the relationship between different irradiation intensities and cracking processes.

[0041] The experiment determines the soluble hydrocarbon S1, pyrolysis hydrocarbon S2, effective carbon and hydrocarbon potential (Pg=S1+S2) in the sample by Rock-Eval pyrolysis test before and after irradiation, analyzes the change of hydrogen index (HI) and oxygen index (OI), and the test results show that the free hydrocarbon S1 of the M-1 original sample is 1.25 mg / g, the values of the 500 Gy and 1000 Gy irradiated samples increase to 1.60 mg / g and 1.58 mg / g respectively compared with the original sample, and the S1 of the 1000 kGy irradiated sample is reduced to 0.29 mg / g, the pyrolysis hydrocarbon S2 of the M-1 original sample is 48.81 mg / g, the values of the 500 Gy, 1000 Gy and 1000 kGy irradiated samples are 42.63 mg / g, 40.33 mg / g and 37.07 mg / g respectively, and the value of the pyrolysis hydrocarbon S2 gradually becomes smaller with the increase of the irradiation dose; the free hydrocarbon S1 of the M-2 original sample is 0.8 mg / g, the values of the 500 Gy and 1000 Gy irradiated samples increase to 0.81 mg / g and 0.82 mg / g respectively compared with the original sample, and the S1 of the 1000 kGy irradiated sample is reduced to 0.30 mg / g, which shows similar characteristics as the M-1 sample. The pyrolysis hydrocarbon S2 of the M-2 original sample is 10.50 mg / g, and the values of the 500 Gy, 1000 Gy and 1000 kGy irradiated samples are relatively small; the free hydrocarbon S1 of the M-3 original sample is 0.56 mg / g, the values of the 500 Gy and 1000 Gy irradiated samples increase to 1.42 mg / g and 1.35 mg / g respectively compared with the original sample, and the S1 of the 1000 kGy irradiated sample is reduced to 0.38 mg / g; the free hydrocarbon S1 of the ZK-1 original sample is 2.30 mg / g, the values of the 500 Gy and 1000 Gy irradiated samples increase to 2.83 mg / g and 3.08 mg / g respectively compared with the original sample, and the S1 of the 1000 kGy irradiated sample is reduced to 1.36 mg / g, the pyrolysis hydrocarbon S2 of the ZK-1 original sample is 65.75 mg / g, and the content of the 500 Gy, 1000 Gy and 1000 kGy irradiated samples is reduced compared with the original sample; the free hydrocarbon S1 of the ZK-2 original sample is 0.98 mg / g, the values of the 500 Gy and 1000 Gy irradiated samples increase to 1.08 mg / g and 1.13 mg / g respectively compared with the original sample, and the S1 of the 1000 kGy irradiated sample is reduced to 0.49 mg / g, and the pyrolysis hydrocarbon S2 of the ZK-2 irradiated sample is reduced compared with the original sample. The hydrocarbon potential (S1+S2) of all irradiated samples is reduced compared with the original sample, and the greater the irradiation dose, the lower the value of the hydrocarbon potential (S1+S2).

[0042] Further, the influence of irradiation on the hydrocarbon generation of organic matter is analyzed.

[0043] Further, the results of Rock-Eval pyrolysis tests of the samples before and after irradiation show that, compared with the original sample, the free hydrocarbon S1 value of the sample irradiated at 500 Gy and 1000 Gy increases, the free hydrocarbon S1 value of the sample irradiated at 1000 kGy decreases, and the pyrolysis hydrocarbon S2 content of the irradiated sample decreases compared with the original sample. The hydrocarbon potential (S1+S2) of all the irradiated samples decreases compared with the original sample, and the greater the irradiation dose, the lower the hydrocarbon potential (S1+S2) value, which shows that part of the shale organic matter is converted into carbon-containing or non-carbon-containing gaseous substances during irradiation, resulting in a decrease in the hydrocarbon potential of the irradiated sample.

[0044] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for in-situ upgrading of shale oil based on underground nuclear radiation model, characterized in that, The method includes the following steps: Conduct on-site simulation experiments of nuclear radiation; Based on the results of the nuclear radiation field simulation experiment, a model corresponding to radiation and the generation of in-situ modified shale oil was established. And determine the specific parameters of nuclear radiation, including the time of nuclear radiation, radiation dose, radiation intensity, radiation mode, and radiation source parameters; Based on the results of the nuclear radiation field simulation experiment, the experimental area with the best shale geological characteristics was selected and determined; The underground nuclear radiation model shale oil in-situ reforming device is inserted into the experimental area with the best shale geological characteristics, and the specific parameters of the nuclear radiation are set; the underground nuclear radiation model shale oil in-situ reforming device includes a radiation layer pipeline and a heating device, and the heating device is located inside the radiation layer pipeline; Adjust the specific parameters of the nuclear radiation and start production at the production well; The specific parameters of nuclear radiation were determined based on the differences in shale with varying organic matter abundance. The optimal shale geological characteristics are determined based on parameters such as shale organic matter abundance, thickness, and lithology. The model establishing the correspondence between radiation and in-situ modified shale oil generation was created using the professional software Matlab.

2. The method for in-situ shale oil upgrading based on underground nuclear radiation mode according to claim 1, characterized in that, The underground nuclear radiation mode shale oil in-situ reforming device is used to store radioactive agents and heat oil-bearing reservoirs inside medium- and low-maturity shale.

3. The method for in-situ shale oil upgrading based on underground nuclear radiation model according to claim 1, characterized in that, The experimental subjects for the field experiment simulating nuclear radiation were shale samples of different medium and low maturity levels.

4. The method for in-situ shale oil upgrading based on underground nuclear radiation model according to claim 1, characterized in that, The specific parameters of nuclear radiation must first reach the designed radiation concentration and time before the production well can be opened for production.

5. A device for in-situ shale oil reforming based on underground nuclear radiation mode, wherein the underground nuclear radiation mode shale oil reforming device is applied to the method described in any one of claims 1-4, characterized in that, The underground nuclear radiation mode shale oil in-situ reforming device includes a radiation layer pipeline and a heating device, with the heating device located inside the radiation layer pipeline.

6. The device for in-situ shale oil upgrading based on underground nuclear radiation mode according to claim 5, characterized in that, The radiation layer pipes are used to store radioactive materials; the heating device is used to heat the oil-bearing reservoir inside the medium- to low-maturity shale.

7. The device for in-situ shale oil upgrading based on underground nuclear radiation mode according to claim 5, characterized in that, The underground nuclear radiation mode shale oil in-situ upgrading device is installed inside the oil-bearing reservoir of medium- and low-maturity shale.

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