A quantitative characterization method for shale oil production efficiency based on elastic energy depletion-NMR measurement

Abstract

A method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-nuclear magnetic resonance measurement, relating to the field of oil and gas exploration and development. A method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-nuclear magnetic resonance measurement, comprising the following steps: obtaining a characterization model of shale oil production efficiency under the elastic energy development mode under the influence of comprehensive shale oil viscosity, fluid pore pressure, oil saturation, and reservoir physical properties, thereby quantitatively characterizing the shale oil production efficiency. This technical solution can achieve quantitative characterization of shale oil production efficiency under the influence of multiple factors in tight reservoirs, and achieve classification evaluation and optimization of tight reservoirs.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration and development, and in particular to a method for quantitatively characterizing shale oil production efficiency based on elastic energy exhaustion-nuclear magnetic resonance imaging (NMR) measurement. Background Art

[0002] With the continuous advancement of oil and gas exploration and development technology and the increasing demand for energy, the goal of global oil and gas exploration and development has gradually shifted from conventional structural trap oil and gas reservoirs to tight oil and gas and shale oil and gas in unconventional fields, making tight reservoirs a new focus in oil and gas geological research. In recent years, domestic and foreign scholars have done a lot of research on the influencing factors of the tight depletion development model, and they all realize that the discharge of crude oil is affected by many factors during the elastic energy development process, but they have never comprehensively considered the various factors in the elastic energy oil discharge process, which makes the evaluation of shale oil utilization efficiency in actual production always inaccurate. Summary of the invention

[0003] The purpose of the present invention is to provide a method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-nuclear magnetic resonance measurement. By establishing the relationship between oil saturation, reservoir physical properties, pore pressure, crude oil viscosity and elastic energy oil drainage efficiency, the lower limit of the physical properties of elastic energy oil drainage is determined, and a quantitative characterization model for shale oil production efficiency under the depletion development mode is established.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A quantitative characterization method for shale oil production efficiency based on elastic energy exhaustion-nuclear magnetic resonance measurement includes the following processes:

[0006] Step 1: Obtain the physical property data of the target sample, analyze the pore throat distribution and mercury injection characteristics of the sample, and establish the porosity and permeability parameters based on the porosity and permeability data ;

[0007] Step 2: Determine the shale oil production efficiency under different physical properties based on the elastic performance exhaustion-NMR joint measurement experiment, and obtain the shale oil production efficiency under different physical properties Porosity and permeability parameters positive correlation;

[0008] Step 3: Determine the shale oil production efficiency under different pore pressures based on the elastic energy exhaustion-NMR experiment under different pore pressures and physical properties, and obtain the shale oil production efficiency combining the two influencing factors of pore pressure and physical properties The representation model of

[0009] Step 4: Based on the elastic energy exhaustion-NMR experiment under different oil saturation and different physical properties, the shale oil recovery efficiency combining the two influencing factors of oil saturation and physical properties is obtained. The representation model of

[0010] Step 5: Combine the shale oil recovery efficiency obtained in step 3 and step 4 The characterization model is used to obtain the shale oil production efficiency under the influence of oil saturation, physical properties and pore pressure. The representation model of

[0011] Step 6: Obtain the influence relationship between viscosity and shale oil production efficiency through the influence of shale oil viscosity on shale oil production efficiency;

[0012] Step 7: Combine steps 2 to 6 to obtain the shale oil production efficiency under the elastic energy development mode under the influence of comprehensive shale oil viscosity, pore pressure, oil saturation, and physical properties. The characterization model is used to quantitatively characterize the shale oil recovery efficiency.

[0013] As a preferred technical solution, in step 7, the shale oil production efficiency under the elastic energy development mode is calculated by comprehensively considering the factors affecting shale oil viscosity, pore pressure, oil saturation and physical properties. The representation model is: In the formula, C is the comprehensive constant, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %; is the fluid pore pressure, MPa; μ is the shale oil viscosity, mPa·s.

[0014] As an optimal technical solution, the shale oil production efficiency at different temperatures was determined based on the elastic energy exhaustion-NMR joint measurement experiment at different temperatures, and the comprehensive constant C was determined to be 25.94. The shale oil production efficiency characterization model based on shale oil viscosity, pore pressure, oil saturation and reservoir physical properties is: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %; is the fluid pore pressure, MPa; μ is the shale oil viscosity, mPa·s.

[0015] As a preferred technical solution, in step 2, the shale oil recovery efficiency is established by elastic energy-NMR joint measurement experiment under 35MPa pore pressure Porosity and permeability parameters positive correlation;

[0016] Shale oil production efficiency under 35Mpa Porosity and permeability parameters The relationship is: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %.

[0017] As a preferred technical solution, in step 3, parallel experiments of samples with different physical properties under different pore pressures are set up to analyze the shale oil recovery efficiency based on different pore pressures. Affected by the pore pressure, a shale oil production efficiency characterization model combining the two influencing factors of pore pressure and physical properties is obtained: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the fluid pore pressure, MPa.

[0018] As a preferred technical solution, in step 4, parallel experiments of samples with different physical properties under different oil saturation conditions are set up to obtain the shale oil recovery efficiency combining the two influencing factors of oil saturation and physical properties. Representation model: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %.

[0019] As an optimal technical solution, the shale oil production efficiency characterization model combined with the influence of oil saturation, physical properties and pore pressure is as follows: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %; is the fluid pore pressure, MPa.

[0020] As an optimal technical solution, parallel experiments of samples under different temperature conditions were set up to obtain the relationship between viscosity and shale oil recovery efficiency: In the formula, is the shale oil recovery efficiency, %; μ is the shale oil viscosity, mPa·s.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] Under geological conditions, the seepage capacity of shale oil reservoirs is generally low, and the fluid in the matrix pores is easily compressed by elastic compression to form abnormally high pressure, which provides power for the discharge of shale oil in the depletion development mode. The resistance to shale oil discharge is controlled by many factors such as pore throat structure, crude oil viscosity, oil-water interfacial tension, etc. It can be seen that shale oil production should be comprehensively controlled by multiple factors such as reservoir microstructure, temperature and pressure, and fluid properties. The present invention establishes a method for quantitative characterization model of shale oil production efficiency in the depletion development mode by conducting simulation experiments on shale oil elastic energy drainage under different physical properties, different viscosities, and different oil saturations, and realizes the determination of the relationship between elastic energy drainage efficiency and pore pressure, reservoir physical properties, oil saturation, and crude oil viscosity. It can be used to determine the lower limit of physical properties and oil saturation of shale oil production in the study area. The method and results are highly reliable, have sufficient basis, and are easy to operate, which has important guiding significance for the exploration and development of tight oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] When considered in conjunction with the accompanying drawings, the present invention can be more completely and better understood, and the scientificity and practicality of the present invention can be better explained by referring to the detailed description below. However, the drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The example description of the present invention is used to explain the present invention and does not constitute an improper limitation on the present invention.

[0024] Figure 1 The characteristics of the elastic energy oil displacement efficiency changing with the permeability;

[0025] Figure 2 The characteristics of the elastic energy oil displacement efficiency changing with porosity;

[0026] Figure 3 The characteristics of elastic energy oil displacement efficiency with comprehensive physical property parameters;

[0027] Figure 4 The characteristics of the elastic energy oil displacement efficiency changing with the pore pressure;

[0028] Figure 5 The characteristics of the elastic oil displacement efficiency changing with physical properties and pore pressure;

[0029] Figure 6 is the characteristic of parameter A changing with pore pressure;

[0030] Figure 7 The variation characteristics of parameter B with parameter A under different pore pressures;

[0031] Figure 8 The characteristics of elastic energy oil displacement efficiency and oil saturation;

[0032] Fig. 9 It is the characteristics of the efficiency of oil displacement by elastic energy under the dual control of oil saturation and physical properties;

[0033] Fig.10 is the variation characteristics of parameter A with oil saturation;

[0034] Fig.11 The variation characteristics of parameter B with parameter A at different oil saturations;

[0035] Fig.12 The elastic energy oil displacement NMR T2 spectrum characteristics at different temperatures;

[0036] Fig.13 The characteristics of the change of the elastic energy oil displacement efficiency at different temperatures;

[0037] Fig.14 The viscosity variation characteristics of crude oil at different temperatures;

[0038] Fig.15 The characteristics of the elastic energy oil displacement efficiency changing with the crude oil viscosity;

[0039] Fig.16 Quantitative evaluation of the mobility and productivity characteristics of single shale oil wells;

[0040] Fig.17 Figure 1 is a diagram for grading shale oil sweet spots based on movable oil porosity. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example 1

[0043] A quantitative characterization method for shale oil production efficiency based on elastic energy exhaustion-nuclear magnetic resonance measurement includes the following processes:

[0044] Step 1: Obtain the physical property data of the target sample, analyze the pore throat distribution and mercury injection characteristics of the sample, and establish the porosity and permeability parameters based on the porosity and permeability data ;

[0045] Step 2: Determine the shale oil production efficiency under different physical properties based on the elastic performance exhaustion-NMR joint measurement experiment, and obtain the shale oil production efficiency under different physical properties Porosity and permeability parameters positive correlation;

[0046] Step 3: Determine the shale oil production efficiency under different pore pressures based on the elastic energy exhaustion-NMR experiment under different pore pressures and physical properties, and obtain the shale oil production efficiency combining the two influencing factors of pore pressure and physical properties The representation model of

[0047] Step 4: Based on the elastic energy exhaustion-NMR experiment under different oil saturation and different physical properties, the shale oil recovery efficiency combining the two influencing factors of oil saturation and physical properties is obtained. The representation model of

[0048] Step 5: Combine the shale oil recovery efficiency obtained in step 3 and step 4 The characterization model is used to obtain the shale oil production efficiency under the influence of oil saturation, physical properties and pore pressure. The representation model of

[0049] Step 6: Obtain the influence relationship between viscosity and shale oil production efficiency through the influence of shale oil viscosity on shale oil production efficiency;

[0050] Step 7: Combine steps 2 to 6 to obtain the shale oil production efficiency under the elastic energy development mode under the influence of comprehensive shale oil viscosity, pore pressure, oil saturation, and physical properties. The characterization model is used to quantitatively characterize the shale oil recovery efficiency.

[0051] In this embodiment, the shale oil production efficiency under different physical properties, the shale oil production efficiency under different pore pressures, the shale oil production efficiency under different oil saturations, and the shale oil production efficiency at different temperatures are determined based on the elastic energy exhaustion-NMR joint measurement experiment under different conditions; based on the shale oil production efficiency under different physical properties, the shale oil production efficiency under different pore pressures, the shale oil production efficiency under different oil saturations, and the shale oil production efficiency under different temperatures; a quantitative characterization model for comprehensive evaluation of shale oil mobility is established; based on the elastic energy exhaustion-NMR joint measurement experiment under different conditions refers to: based on the elastic energy exhaustion-NMR joint measurement experiment under different physical properties, the shale oil production efficiency under different physical properties is determined; based on the elastic energy exhaustion-NMR joint measurement experiment under different pore pressures, the shale oil production efficiency under different pore pressures is determined; based on the elastic energy exhaustion-NMR joint measurement experiment under different oil saturations, the shale oil production efficiency under different oil saturations is determined; based on the elastic energy exhaustion-NMR joint measurement experiment at different temperatures, the shale oil production efficiency at different temperatures is determined.

[0052] Based on the elastic energy depletion-NMR experiment under different physical properties, the physical property data required for determining the shale oil production efficiency under different physical properties are obtained by selecting typical tight reservoir samples in the study area and conducting high-pressure mercury injection and pore permeability experiments; the relationship between physical properties and elastic energy oil drainage efficiency is established through elastic energy-NMR experiment under 35MPa pore pressure.

[0053] Specifically, based on high-pressure mercury injection and pore permeability experimental data, the pore throat distribution and mercury injection characteristics of dense sandstone samples were analyzed, and parameters were established based on the pore permeability data. , and believes that shale oil production efficiency is related to There is a good positive correlation.

[0054] Shale oil production efficiency and utilization rate under 35Mpa The relationship is: (1) In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %.

[0055] Specifically, under the experimental conditions of 35Mpa pore pressure and 90℃, the results of elastic energy oil drainage experiments of samples with different physical properties showed that the porosity and permeability of the samples were positively correlated as a whole, but some samples were abnormal. For example, the porosity of dolomitic sandstone sample #7 of the same lithology was higher than that of sample #6, but due to the lower permeability of sample #7, its oil drainage efficiency was much lower than that of sample #6. Figure 1 For example, the permeability of #2 feldspar lithic sandstone is higher than that of #1 sample, but due to the lower porosity of #2, its oil drainage efficiency is much lower than that of #1 sample. Figure 2 It can be seen that the use of crude oil in the elastic energy drainage mode is subject to the dual constraints of porosity and permeability. By constructing a parameter that reflects the permeability of unit pore fluid , revealing that its correlation with oil drainage efficiency is significantly better than the relationship between single porosity or permeability and oil drainage efficiency, such as Figure 3 .

[0056] In some feasible embodiments, the shale oil production efficiency under different pore pressures is determined based on the elastic energy depletion-NMR joint measurement experiment under different pore pressures:

[0057] Based on different pore pressures, the main purpose is to analyze the influence of pore pressure on shale oil production efficiency. The key is to set up parallel experiments of samples with different physical properties under different pore pressures (5Mpa, 15Mpa, 25Mpa, 35Mpa), so as to further deduce a shale oil production efficiency characterization model combining the two influencing factors.

[0058] Therefore, it can be further deduced from (Formula 1): (2) Where: is the fluid pore pressure, MPa; other parameters are the same as above.

[0059] Specifically, elastic oil drainage experiments were conducted on seven samples at different pore pressures at 90°C. The results show that Figure 4 ; Combining the relationship between physical properties and shale oil production efficiency, the shale oil production efficiency under the combined influence of physical properties and pore pressure can be obtained, such as Figure 5 ; Comprehensive quantitative characterization model of shale oil production efficiency under different pore pressures, such as Figure 6 and Figure 7 , the relationship between parameter A and pore pressure and between parameter A and parameter B is established. Combining the above models, a characterization model of elastic energy oil displacement efficiency of samples with different physical properties at different oil saturations is established (Formula 2).

[0060] Based on the elastic energy oil displacement experiments under different physical properties and the elastic energy oil displacement experiments under different pore pressures, a characterization model for the elastic energy oil displacement efficiency of samples with different physical properties under different pore pressures was established and the parameter characteristics were determined.

[0061] In some feasible embodiments, based on the elastic energy failure-NMR experiment under different oil saturation conditions, the shale oil production efficiency under different oil saturations is determined:

[0062] The elastic energy oil drainage experiment with different oil saturation is mainly to analyze the influence of oil content on shale oil recovery efficiency. The key is to set up parallel experiments with different physical property samples under different oil saturation (So=80%, 65%, 45%, 35%). There is a good positive correlation, so we can further deduce the shale oil production efficiency characterization model combining the two influencing factors. From (Formula 1), we can further deduce: (3) In the formula, is the oil saturation, %; other parameters are the same as above.

[0063] When the temperature is 90°C, the oil saturation is 100%, and the pressure is 35 MPa, the results obtained by equation (2) and equation (3) are equal, and we can get: (4) Specifically, elastic energy oil displacement experiments were conducted on core samples at different oil saturations (So = 80%, 65%, 45%, 35%) at 90°C and 35 MPa pore pressure, and nuclear magnetic resonance testing was performed. According to the experimental results, as the oil saturation increased from 35% to 80%, the oil recovery efficiency increased from 0.1%~3.3% to 8.7%~19.1%. This experiment revealed that the shale oil recovery efficiency was positively correlated with the oil saturation, such as Figure 8 ; Combining the relationship between physical properties and shale oil production efficiency, the shale oil production efficiency under the combined influence of physical properties and oil saturation can be obtained, such as Fig. 9; Comprehensive quantitative characterization model of shale oil production efficiency under different oil saturations, such as Fig.10 and Fig.11 , the relationship between parameter A and oil saturation and between parameter A and parameter B is established. Combining the above models, a characterization model of elastic energy oil displacement efficiency of samples with different physical properties at different oil saturations is established (Formula 3).

[0064] In some feasible embodiments, the shale oil production efficiency at different temperatures is determined based on elastic energy failure-NMR experiments at different temperatures:

[0065] Based on different temperatures, the main purpose is to analyze the influence of viscosity on shale oil recovery efficiency. The key is to set up elastic energy oil displacement experiments of samples at different temperatures (20℃, 35℃, 55℃, 75℃, 90℃);

[0066] The effect of the original viscosity on the utilization efficiency after the temperature rises is: (5) Where: μ is the viscosity of shale oil, mPa·s; other parameters are the same as above.

[0067] Specifically, in order to reveal the effect of temperature on shale oil production, the elastic energy oil displacement characteristics of sample #4 at different temperatures under 35MPa pore pressure were studied. The results showed that when the experimental temperature was 20°C, the elastic energy oil displacement was significantly higher than that of the shale oil after the NMR T 2 The spectrum signal decreases less, from 130512.u. to 12466.6 au. Fig.12 ; The oil drainage efficiency is only 4.5%. When the temperature rises to 55°C, the nuclear magnetic signal drops to 11565.8 au, and the oil drainage efficiency can reach 11.4%. As the temperature continues to rise, the signal volume further decreases. When the experimental temperature reaches the highest 90°C, the signal volume drops to a minimum of 9868.8 au, and the oil drainage efficiency can reach 24.4%. This experiment reveals that the efficiency of shale oil production increases exponentially with increasing temperature, such as Fig.13 ; Combined with the relationship between temperature and crude oil viscosity, such as Fig.14 The effect of crude oil viscosity on shale oil recovery efficiency can be obtained, and the two are significantly negatively correlated, such as Fig.15 In general, the efficiency of elastic energy oil displacement increases exponentially with temperature, and the oil displacement phenomenon mostly occurs at T 2 >8ms in large pores, such as Fig.12 According to the elastic energy oil displacement experiments at different temperatures, a characterization model of elastic energy oil displacement efficiency at different viscosities was established (Equation 5).

[0068] In some feasible embodiments, a quantitative characterization model for comprehensive evaluation of shale oil mobility is established:

[0069] Taking into account factors such as shale oil viscosity, fluid pore pressure, oil saturation, and reservoir properties, the drainage efficiency under the elastic energy development mode can be expressed as: (6) In the formula, C is a comprehensive constant, dimensionless; other parameters are the same as above.

[0070] Select the experimental sample with porosity of 19.69% and permeability of 0.63mD. According to formula (5), its shale oil recovery efficiency is 23.7% at 90℃. When the production pressure difference of sample #4 is 35Mpa and saturated with oil, the results of Eq.12 and Eq.11 are equal, so C is determined to be 25.94. The comprehensive expression of shale oil recovery efficiency with respect to shale oil viscosity, pore pressure, oil saturation and reservoir physical parameters is as follows: (7)

[0071] Specifically, considering factors such as crude oil viscosity, fluid pore pressure, oil saturation, and reservoir physical properties, a quantitative characterization model for shale oil based on elastic energy exhaustion-NMR measurement is established (Equation 6). ) Comprehensive evaluation, such as Fig.16 ; Establish the evaluation criteria for the target layer classification in the study area, such as Fig.17 , and determine =1.0% is the lower limit of the geological sweet spot in the region. Below this value, the shale oil production capacity per 100 meters is generally less than 1t / d. The shale oil content is greater than 1.5%, which is classified as the Class I geological sweet spot. The daily production capacity of a single well of 100 meters can reach more than 4t / d. The geological sweet spot of shale oil Class II is between 1.0% and 1.5%, and the daily production capacity of a single well per 100 meters is between 1 and 4 t / d.

[0072] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed herein. Those skilled in the art should understand that the above embodiments can be modified or some technical features can be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the attached claims.

Claims

1. A quantitative characterization method for shale oil production efficiency based on elastic energy exhaustion-NMR measurement, characterized in that: The process includes: Step 1: Obtain the physical property data of the target sample, analyze the pore throat distribution and mercury injection characteristics of the sample, and establish the porosity parameters based on the porosity data ; Step 2: Determine the shale oil production efficiency under different physical properties based on the elastic performance exhaustion-NMR joint measurement experiment, and obtain the shale oil production efficiency under different physical properties Porosity and permeability parameters positive correlation; Step 3: Determine the shale oil production efficiency under different pore pressures based on the elastic energy exhaustion-NMR experiment under different pore pressures and physical properties, and obtain the shale oil production efficiency combining the two influencing factors of pore pressure and physical properties The representation model of Step 4: Based on the elastic energy exhaustion-NMR experiment under different oil saturation and different physical properties, the shale oil recovery efficiency combining the two influencing factors of oil saturation and physical properties is obtained. The representation model of Step 5: Combine the shale oil recovery efficiency obtained in step 3 and step 4 The characterization model is used to obtain the shale oil production efficiency under the influence of oil saturation, physical properties and pore pressure. The representation model of Step 6: Obtain the influence relationship between viscosity and shale oil production efficiency through the influence of shale oil viscosity on shale oil production efficiency; Step 7: Combine steps 2 to 6 to obtain the shale oil production efficiency under the elastic energy development mode under the influence of comprehensive shale oil viscosity, pore pressure, oil saturation, and physical properties. The characterization model is used to quantitatively characterize the shale oil recovery efficiency.

2. The method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-NMR measurement according to claim 1 is characterized in that: In step 7, the shale oil production efficiency under the elastic energy development mode is calculated by comprehensively considering the influence factors of shale oil viscosity, pore pressure, oil saturation and physical properties. The representation model is: In the formula, C is the comprehensive constant, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %; is the fluid pore pressure, MPa; μ is the shale oil viscosity, mPa·s.

3. The method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-NMR measurement according to claim 2 is characterized in that: Based on the elastic energy exhaustion-NMR joint measurement experiment at different temperatures, the shale oil production efficiency at different temperatures was determined, and the comprehensive constant C was determined to be 25.

94. The shale oil production efficiency considering the shale oil viscosity, pore pressure, oil saturation and physical properties is: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %; is the fluid pore pressure, MPa; μ is the shale oil viscosity, mPa·s.

4. The method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-NMR measurement according to claim 1 is characterized in that: In step 2, the shale oil recovery efficiency was established by elastic energy-NMR measurement experiment under 35MPa pore pressure. Porosity and permeability parameters positive correlation; shale oil production efficiency under 35Mpa Porosity The relationship is: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %.

5. The method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-NMR measurement according to claim 1 is characterized in that: In step 3, parallel experiments of samples with different physical properties under different pore pressures are set up to analyze the shale oil recovery efficiency based on different pore pressures. Affected by the pore pressure, a shale oil production efficiency characterization model combining the two influencing factors of pore pressure and physical properties is obtained: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the fluid pore pressure, MPa.

6. The method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-NMR measurement according to claim 1 is characterized in that: In step 4, parallel experiments with samples of different physical properties under different oil saturation conditions are set up to obtain the shale oil recovery efficiency combining the two influencing factors of oil saturation and physical properties. Representation model: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %.

7. The method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-NMR measurement according to claim 1 is characterized in that: The shale oil production efficiency characterization model combined with the influence of oil saturation, physical properties and pore pressure is: In the formula, is the shale oil recovery efficiency, %; is the permeability, mD; is the porosity, %; is the oil saturation, %; is the fluid pore pressure, MPa.

8. The method for quantitatively characterizing shale oil production efficiency based on elastic energy depletion-NMR measurement according to claim 1 is characterized in that: Parallel experiments were set up for samples under different temperature conditions to obtain the relationship between viscosity and shale oil recovery efficiency: Where: is the shale oil recovery efficiency, %; μ is the shale oil viscosity, mPa·s.

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