Method, system, equipment and medium for dividing shale fluid occurrence types

Abstract

The invention discloses a method, a system, equipment and a medium for dividing shale fluid occurrence types. The method comprises the following steps: manufacturing a standard plunger sample; carrying out water removal treatment on the standard plunger sample, and recording the weight; pressurizing the dehydrated sample by using a preset fluid, and recording the weight of a saturated fluid sample; carrying out gradient centrifugal treatment on the saturated fluid sample according to different rotating speeds, correspondingly carrying out nuclear magnetic resonance testing, and recording the weight corresponding to each rotating speed; crushing the centrifuged saturated fluid sample into a crushed sample with a preset particle size, carrying out gradient centrifugal treatment and nuclear magnetic resonance testing according to different rotating speeds, and recording the weight corresponding to each rotating speed; based on the change of the spectrum peak form and the nuclear magnetic semaphore corresponding to the nuclear magnetic resonance test in the centrifugal process, judging the recoverable fluid and the adsorption fluid, and calculating the corresponding content. The shale fluid occurrence characteristics are effectively evaluated, and the problems that fluid occurrence types are difficult to recognize, and the lower limit of industrial mining aperture is not clear are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of unconventional oil and gas development, and in particular to a method, system, equipment and medium for classifying shale fluid occurrence types. Background Art

[0002] my country has developed three types of organic-rich shales: marine shale, marine-continental transitional shale, and continental shale. Recently, industrial oil flows have been obtained in the Bohai Bay Basin, Songliao Basin in eastern China, and Sichuan Basin in western China, fully demonstrating the huge resource potential of shale oil in China. Unlike traditional reservoirs, shale is mainly nanopores, and the microscopic pore structure controls the occurrence and distribution of fluids. Therefore, it is clear that the microscopic pore structure characteristics of shale and its fluid occurrence characteristics play an important role in shale oil and gas production.

[0003] In the prior art, many scholars have realized that the pore structure of shale controls the enrichment and migration of shale oil and gas, and have done a lot of work on this. Based on high-pressure mercury injection technology and fractal theory, shale pores are divided into large pore throats (>1000nm), medium pore throats (100-1000nm), small pore throats (25-100nm) and micropore throats (<25nm) with 1000nm, 100nm and 25nm as boundaries. Some scholars use nuclear magnetic resonance T1-T2 technology to divide shale fluids into free fluids and adsorbed fluids. Current studies have recognized that the occurrence state of fluids is affected by the pore structure of shale, but at this stage, the classification of shale fluids still uses standard plunger samples for experiments. Shale reservoirs use hydraulic fracturing during the exploitation process, and the fluid classification method based on plunger samples cannot accurately characterize the occurrence characteristics of shale fluids. Therefore, a method, system, equipment and medium for classifying the occurrence types of shale fluids are needed. Summary of the invention

[0004] The embodiments of the present invention provide a method, system, equipment and medium for classifying the occurrence types of shale fluids, thereby at least partially solving the technical problem that the fluid classification method based on plunger samples in the prior art cannot accurately characterize the occurrence characteristics of shale fluids, and achieving the technical effect of effectively evaluating the occurrence characteristics of shale fluids.

[0005] In the first aspect, to solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0006] A method for classifying shale fluid occurrence types, comprising:

[0007] Typical samples from shales of different lithofacies are made into standard plunger samples of preset sizes;

[0008] Dehydrating the standard plunger sample to obtain a dehydrated sample, and recording the first weight of the dehydrated sample;

[0009] Using a preset fluid to pressurize the dehydrated sample to obtain a saturated fluid sample, and recording a second weight of the saturated fluid sample;

[0010] The saturated fluid sample is subjected to gradual centrifugation at different speeds, and a nuclear magnetic resonance test is performed accordingly, and the weight corresponding to each speed is recorded;

[0011] The saturated fluid sample after centrifugation is broken into broken samples with a preset particle size, and subjected to gradual centrifugation and nuclear magnetic resonance testing at different speeds, and the weight corresponding to each speed is recorded;

[0012] Based on the changes in the spectral peak morphology and the amount of nuclear magnetic resonance signals corresponding to the nuclear magnetic resonance test during the centrifugation process, the recoverable fluid and the adsorbed fluid are determined, and the corresponding contents are calculated based on the first preset formula.

[0013] Optionally, the step of determining the recoverable fluid and the adsorbed fluid further includes:

[0014] When the corresponding spectral peak shape and NMR signal amount remain unchanged in the NMR test of the saturated fluid sample, the fluid reduced during the centrifugation process is determined to be a movable fluid, and the corresponding speed at this time is recorded as R 1 ;

[0015] When the corresponding peak shape and NMR signal amount remain unchanged in the NMR test of the crushed sample, the fluid reduced during the centrifugation process is determined to be the bound fluid; the rest is the adsorbed fluid, and the corresponding speed at this time is recorded as R 2 .

[0016] Optionally, after calculating the corresponding content based on the first preset formula, the method further includes:

[0017] Based on the nuclear magnetic resonance test, the nuclear magnetic resonance T2 spectrum of the saturated fluid sample, the nuclear magnetic resonance T2 spectrum corresponding to the saturated fluid sample when centrifuged at a speed of R1, and the nuclear magnetic resonance T2 spectrum corresponding to the crushed sample when centrifuged at a speed of R2 are obtained;

[0018] Convert the NMR T2 spectra under different states into NMR cumulative spectra and put them in the same figure;

[0019] Select the speed corresponding to the unchanged peak shape and nuclear magnetic signal, and project it onto the T2 spectrum of the preset fluid to obtain the T2 cutoff value corresponding to each speed;

[0020] Based on the T2 cutoff value and / or the second preset formula, the industrial mining pore radius is calculated.

[0021] Optionally, the step of calculating the industrial mining pore radius further includes:

[0022] Calculate the displacement capillary pressure of the rock sample based on the length of the rock sample, the outer rotation radius of the rock sample and the corresponding centrifuge speed;

[0023] According to the algebraic relationship among surface tension, pore radius and capillary pressure of rock sample displacement, the corresponding pore radius is calculated.

[0024] Optionally, the step of calculating the industrial mining pore radius further includes:

[0025] Based on the NMR T2 time conversion coefficient and T2 cutoff value, the corresponding pore radius was calculated.

[0026] Optionally, the first preset formula includes:

[0027]

[0028]

[0029] V a =(1-V m -V b )×100%

[0030] Among them, V m 、V b and V a are the relative contents of movable fluid, bound fluid and adsorbed fluid; Q 0 is the saturated fluid sample signal; m 0 is the weight of the saturated fluid sample; Q 1 The saturated fluid sample is rotated at a speed R 1 Signal volume after centrifugation; m 1 The saturated fluid sample is rotated at a speed R 1 The weight after centrifugation corresponds to the T2 cutoff value of T 2c2 ;Q 2 The sample is crushed at a speed R 1 Signal volume after centrifugation; m 2 Q 2 Corresponding weight; Q 3 The sample is crushed at a speed R 2 Signal after centrifugation; m 3 The weight of the crushed sample at this time corresponds to the T2 cutoff value of T 2c1 ; T 2c1 It is the lower limit of aperture for industrial mining.

[0031] Optionally, the step of removing water from the standard plunger sample further includes:

[0032] Dry and evacuate the standard plunger samples.

[0033] In a second aspect, a system for classifying shale fluid occurrence types is provided, comprising:

[0034] A standard plunger sample making module is used to make typical samples from different lithofacies shales into standard plunger samples of preset sizes;

[0035] A dehydration module, used for dehydrating the standard plunger sample to obtain a dehydrated sample, and recording a first weight of the dehydrated sample;

[0036] A pressurizing module, pressurizing the dehydrated sample with a preset fluid to obtain a saturated fluid sample, and recording a second weight of the saturated fluid sample;

[0037] The first centrifugation module is used to perform gradual centrifugation on the saturated fluid sample at different speeds, and perform nuclear magnetic resonance testing accordingly, and record the weight corresponding to each speed;

[0038] The second centrifugation module is used to break the saturated fluid sample after centrifugation into broken samples with a preset particle size, perform gradual centrifugation and nuclear magnetic resonance testing at different speeds, and record the weight corresponding to each speed;

[0039] The calculation module determines the recoverable fluid and the adsorbed fluid based on the changes in the spectral peak morphology and the amount of nuclear magnetic resonance signals in the nuclear magnetic resonance test during the centrifugation process, and calculates the corresponding contents based on the first preset formula.

[0040] In a third aspect, an electronic device is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, steps corresponding to the method of the first aspect are implemented.

[0041] According to a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps corresponding to the method of the first aspect are implemented.

[0042] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0043] By combining plunger samples with crushed samples for experiments, the shale fluid storage characteristics, the lower limit of the production aperture, and the theoretical recoverable rate can be more accurately evaluated. This effectively solves the problems of difficulty in identifying the type of fluid storage and unclear lower limit of the industrial production aperture. At the same time, it has the advantages of being simple, easy to operate, widely applicable, and reliable, which is convenient for application and promotion in shale oil and gas exploration and development, and has guiding and reference significance for the optimization of favorable shale oil and gas areas and the design of development plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 A flow chart of a method for classifying shale fluid occurrence types provided by the present invention;

[0046] Figure 2 The nuclear magnetic T2 spectra of the saturated fluid sample at different centrifugal speeds in the present invention;

[0047] Figure 3 The NMR T2 spectra of the crushed samples at different centrifugal speeds in the present invention;

[0048] Figure 4 This is a schematic diagram of the T2 cutoff value division in the present invention;

[0049] Figure 5 A schematic diagram of the structure of a system for classifying shale fluid occurrence types provided by the present invention;

[0050] Figure 6 The present invention provides a schematic structural diagram of an electronic device. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0052] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0053] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0054] It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, rather than limitations of the technical solutions of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments may be combined with each other.

[0055] In addition, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0056] The technical solution of the embodiment of the present invention is to solve the above technical problems, and the overall idea is as follows:

[0057] Based on the two states of plunger samples (diameter 2.5cm) and crushed samples (particle size 1cm), the shale fluid types are classified by combining the nuclear magnetic resonance test of samples in different processing states, and their mining lower limit and theoretical recoverable rate are clarified. It can be applied to all shale reservoirs and provide theoretical guidance for shale oil and gas exploration and development.

[0058] In an embodiment of the present invention, there is provided Figure 1 A method for classifying shale fluid occurrence types is shown, the method comprising steps S101 to S106:

[0059] Step S101, typical samples from shales of different lithofacies are respectively made into standard plunger samples of preset sizes;

[0060] It should be noted that these typical samples were cut into standard plunger samples with a diameter of 2.5 cm by wire cutting.

[0061] Step S102, performing water removal treatment on the standard plunger sample to obtain a dehydrated sample, and recording a first weight of the dehydrated sample;

[0062] It should be noted that the selected plunger samples were dried in an oven at a temperature of 105°C for more than 24 h, and weighed after drying;

[0063] Step S103, pressurizing the dehydrated sample with a preset fluid to obtain a saturated fluid sample, and recording a second weight of the saturated fluid sample;

[0064] It should be noted that the dried sample is evacuated to remove the residual water in the sample using a vacuum pressurized saturated fluid device. The evacuation time is more than 12 hours. After the evacuation is completed, the preset fluid (kerosene or deionized water) is directly pressurized. The saturation pressure is about 20MPa and the saturation time is more than 36 hours. After the saturation pressurization is completed, the sample is weighed.

[0065] Step S104, subjecting the saturated fluid sample to gradual centrifugation at different rotation speeds, and performing a nuclear magnetic resonance test accordingly, and recording the weight corresponding to each rotation speed;

[0066] It should be noted that the saturated fluid sample was subjected to gradual centrifugation and nuclear magnetic resonance testing, and the centrifugal speed was 6000rpm, 8000rpm, 10000rpm, 11000rpm, 12000rpm, 13000rpm, 14000rpm, and 15000rpm. The centrifugal time was 30min, and the weight was recorded at each speed. In order to make the experimental phenomenon more obvious, centrifugation can be performed at each speed mentioned above. It is also possible to select a few speeds according to the specific conditions of the experiment, and the maximum speed must reach 15000rpm.

[0067] Step S105, breaking the saturated fluid sample after centrifugation into crushed samples with a preset particle size, performing gradual centrifugation treatment and nuclear magnetic resonance testing at different speeds, and recording the weight corresponding to each speed;

[0068] It should be noted that after the centrifugation of the saturated fluid sample, the sample is broken into broken samples with a particle size of about 1 cm. After weighing, the above-mentioned gradual centrifugation experimental process is repeated and the nuclear magnetic resonance test is performed. The rotation speed needs to be set to 500rpm, 1000rpm, 20000rpm, 4000rpm, 8000rpm, 12000rpm, 14000rpm, and 15000rpm respectively. The centrifugation time is 30min, and the weight is recorded at each speed. Among them, the centrifugal speed of the broken sample can also select some of the speeds or all of the above speeds according to the specific circumstances of the experiment, and the maximum speed needs to reach 15000rpm.

[0069] Step S106, based on the changes in the spectral peak morphology and the amount of nuclear magnetic resonance signals corresponding to the nuclear magnetic resonance test during the centrifugation process, the recoverable fluid and the adsorbed fluid are determined, and the corresponding contents are calculated based on the first preset formula.

[0070] The specific contents of judging recoverable fluid and adsorbed fluid are as follows:

[0071] When the corresponding spectral peak shape and NMR signal amount remain unchanged in the NMR test of the saturated fluid sample, the fluid reduced during the centrifugation process is determined to be a movable fluid, and the corresponding speed at this time is recorded as R 1 ;

[0072] When the corresponding peak shape and NMR signal amount remain unchanged in the NMR test of the crushed sample, the fluid reduced during the centrifugation process is determined to be the bound fluid; the rest is the adsorbed fluid, and the corresponding speed at this time is recorded as R 2 .

[0073] The specific calculation formula is as follows:

[0074]

[0075]

[0076] V a =(1-V m -V b )×100% (3)

[0077] Among them, V m 、V b and V a are the relative contents of movable fluid, bound fluid and adsorbed fluid, in %; Q 0 is the signal of saturated fluid sample, unit is au; m 0 is the weight of the saturated fluid sample, in g; Q 1 The saturated fluid sample is rotated at a speed R 1 Signal volume after centrifugation, unit: au; m 1 The saturated fluid sample is rotated at a speed R 1 The weight after centrifugation, in g; the corresponding T2 cutoff value is T 2c2 ;Q 2 The sample is crushed at a speed R 1 Signal volume after centrifugation, unit: au; m 2 Q 2 Corresponding weight, unit g; Q 3 The sample is crushed at a speed R 2 Signal volume after centrifugation, unit: au; m 3 This is the weight of the crushed sample at this time, in g, and the corresponding T2 cutoff value is T 2c1 ; T 2c1 It is the lower limit of aperture for industrial mining.

[0078] Further, after calculating the corresponding content based on the first preset formula, the method further includes:

[0079] like Figure 2 and Figure 3 As shown, based on the nuclear magnetic resonance test, the nuclear magnetic resonance T2 spectrum of the saturated fluid sample, the nuclear magnetic resonance T2 spectrum corresponding to the saturated fluid sample when centrifuged at a speed R1, and the nuclear magnetic resonance T2 spectrum corresponding to the crushed sample when centrifuged at a speed R2 are obtained;

[0080] Convert the NMR T2 spectra under different states into NMR cumulative spectra and put them in the same figure; Figure 4 shown.

[0081] Select the speed corresponding to the unchanged peak shape and nuclear magnetic signal, and project it onto the T2 spectrum of the preset fluid to obtain the T2 cutoff value corresponding to each speed; Figure 4 The T2 cutoff value corresponding to the lower limit of the medium mining aperture is T 2c1 .

[0082] Based on the T2 cutoff value and / or the second preset formula, the industrial mining pore radius is calculated.

[0083] The detailed calculation process is as follows:

[0084] Calculate the displacement capillary pressure of the rock sample based on the length of the rock sample, the outer rotation radius of the rock sample and the corresponding centrifuge speed;

[0085] The specific calculation formula is as follows:

[0086]

[0087] Among them, p ci is the capillary pressure of rock sample displacement, unit is MPa; L is the length of rock sample, unit is cm; R e is the outer rotation radius of the rock sample, in cm. Δρ is the density difference between the two phases, in g / mL; n is the centrifuge speed, in r / min.

[0088] According to the algebraic relationship among surface tension, pore radius and capillary pressure of rock sample displacement, the corresponding pore radius is calculated.

[0089]

[0090] Wherein, δ is the surface tension (480 mN / m), θ is the wetting contact angle (140°), and r is the pore radius in μm.

[0091] Furthermore, the step of calculating the industrial mining pore radius also includes:

[0092] Based on the NMR T2 time conversion coefficient and T2 cutoff value, the corresponding pore radius is calculated.

[0093] T 2 =C*r (6)

[0094] Where C is the NMR T2 time conversion coefficient. 2 is the T2 cutoff value.

[0095] It should be noted that the calculation of pore radius is aimed at calculating the lower limit of industrial mining aperture. That is, mining is impossible below the lower limit, which improves the numerical support for shale mining.

[0096] Furthermore, the step of removing water from the standard plunger sample also includes:

[0097] Dry and evacuate the standard plunger samples.

[0098] It should be noted that a drying oven may be used for drying, and the use of a vacuum and pressurized saturated fluid device for vacuuming and pressurizing integrates the two steps into one operation, thereby improving convenience.

[0099] Based on the same inventive concept, an embodiment of the present invention provides a system for classifying shale fluid occurrence types, such as Figure 5 As shown, including:

[0100] The standard plunger sample making module 201 is used to make typical samples from shales of different lithofacies into standard plunger samples of preset sizes;

[0101] A dehydration module 202 is used to perform a dehydration process on the standard plunger sample to obtain a dehydrated sample, and record a first weight of the dehydrated sample;

[0102] A pressurizing module 203 pressurizes the dehydrated sample with a preset fluid to obtain a saturated fluid sample, and records a second weight of the saturated fluid sample;

[0103] The first centrifugation module 204 is used to perform gradual centrifugation treatment on the saturated fluid sample at different speeds, and perform nuclear magnetic resonance testing accordingly, and record the weight corresponding to each speed;

[0104] The second centrifugation module 205 is used to break the saturated fluid sample after centrifugation into broken samples with a preset particle size, perform gradual centrifugation and nuclear magnetic resonance testing at different speeds, and record the weight corresponding to each speed;

[0105] The calculation module 206 determines the recoverable fluid and the adsorbed fluid based on the changes in the spectral peak morphology and the amount of nuclear magnetic resonance signals in the nuclear magnetic resonance test during the centrifugation process, and calculates the corresponding contents based on the first preset formula.

[0106] Based on the same inventive concept, an embodiment of the present invention provides an electronic device, such as Figure 6 As shown, it includes: a memory 302, a processor 301, and a computer program stored in the memory 302 and executable on the processor 301. When the processor 301 executes the computer program, a method for classifying shale fluid occurrence types is implemented.

[0107] Based on the same inventive concept, this embodiment provides a computer-readable storage medium on which a computer program is stored, characterized in that when the program is executed by a processor, a method for classifying shale fluid occurrence types is implemented.

[0108] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0109] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0110] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for classifying shale fluid occurrence types, characterized in that: The method comprises: Typical samples from shales of different lithofacies are made into standard plunger samples of preset sizes; Dehydrating the standard plunger sample to obtain a dehydrated sample, and recording a first weight of the dehydrated sample; Using a preset fluid to pressurize the dehydrated sample to obtain a saturated fluid sample, and recording a second weight of the saturated fluid sample; The saturated fluid sample is subjected to gradual centrifugation at different rotation speeds, and a nuclear magnetic resonance test is performed accordingly, and the weight corresponding to each rotation speed is recorded; The saturated fluid sample after centrifugation is broken into broken samples with a preset particle size, and subjected to gradual centrifugation and nuclear magnetic resonance testing at different speeds, and the weight corresponding to each speed is recorded; Based on the changes in the spectral peak morphology and the amount of nuclear magnetic resonance signals corresponding to the nuclear magnetic resonance test during the centrifugation process, the recoverable fluid and the adsorbed fluid are determined, and the corresponding contents are calculated based on the first preset formula.

2. The method according to claim 1, characterized in that The step of determining the recoverable fluid and the adsorbed fluid further includes: When the corresponding spectrum peak shape and nuclear magnetic resonance signal amount remain unchanged in the nuclear magnetic resonance test of the saturated fluid sample, the fluid reduced in the centrifugal process is determined to be a movable fluid, and the corresponding rotation speed at this time is recorded as R1; When the corresponding spectral peak shape and nuclear magnetic signal amount remain unchanged in the nuclear magnetic resonance test of the crushed sample, it is determined that the fluid reduced in the centrifugal process is bound fluid; the rest is adsorbed fluid, and the corresponding rotation speed at this time is recorded as R2.

3. The method according to claim 2, characterized in that After calculating the corresponding content based on the first preset formula, the method further includes: Based on the nuclear magnetic resonance test, the nuclear magnetic resonance T2 spectrum of the saturated fluid sample, the nuclear magnetic resonance T2 spectrum corresponding to the saturated fluid sample when centrifuged at a speed R1, and the nuclear magnetic resonance T2 spectrum corresponding to the crushed sample when centrifuged at a speed R2 are obtained; Convert the NMR T2 spectra under different states into NMR cumulative spectra and put them in the same figure; Selecting a rotation speed corresponding to when the spectrum peak shape and the nuclear magnetic signal amount remain unchanged, and projecting it onto the T2 spectrum of the preset fluid to obtain a T2 cutoff value corresponding to each rotation speed; Based on the T2 cutoff value and / or the second preset formula, the industrial mining pore radius is calculated.

4. The method according to claim 3, characterized in that The step of calculating the industrial mining pore radius also includes: Calculate the displacement capillary pressure of the rock sample based on the length of the rock sample, the outer rotation radius of the rock sample and the corresponding centrifuge speed; According to the algebraic relationship among the surface tension, the pore radius and the capillary pressure of the rock sample displacement, the corresponding pore radius is calculated.

5. The method according to claim 3, characterized in that The step of calculating the industrial mining pore radius also includes: Based on the NMR T2 time conversion coefficient and T2 cutoff value, the corresponding pore radius was calculated.

6. The method according to claim 2, characterized in that The first preset formula includes: V a =(1-V m -V b )×100% Among them, V m 、V b and V a are the relative contents of movable fluid, bound fluid and adsorbed fluid respectively; Q0 ​​is the signal of saturated fluid sample; m0 is the weight of saturated fluid sample; Q1 is the signal of saturated fluid sample after centrifugation at speed R1; m1 is the weight of saturated fluid sample after centrifugation at speed R1, and the corresponding T2 cutoff value is T 2c2 ; Q2 is the signal of the broken sample after centrifugation at a speed of R1; m2 is the weight corresponding to Q2; Q3 is the signal of the broken sample after centrifugation at a speed of R2; m3 is the weight of the broken sample at this time, and the corresponding T2 cutoff value is T 2c1 ; T 2c1 It is the lower limit of aperture for industrial mining.

7. The method according to claim 1, characterized in that The step of removing water from the standard plunger sample further includes: The standard plunger sample was dried and vacuumed.

8. A system for classifying shale fluid occurrence types, characterized in that: The system comprises: A standard plunger sample making module is used to make typical samples from different lithofacies shales into standard plunger samples of preset sizes; a dehydration module, used for dehydrating the standard plunger sample to obtain a dehydrated sample, and recording a first weight of the dehydrated sample; a pressurizing module, for pressurizing the dehydrated sample with a preset fluid to obtain a saturated fluid sample, and recording a second weight of the saturated fluid sample; The first centrifugation module is used to perform gradual centrifugation on the saturated fluid sample at different rotation speeds, and perform nuclear magnetic resonance testing accordingly, and record the weight corresponding to each rotation speed; The second centrifugation module is used to break the saturated fluid sample after centrifugation into broken samples with a preset particle size, perform gradual centrifugation and nuclear magnetic resonance testing at different speeds, and record the weight corresponding to each speed; The calculation module determines the recoverable fluid and the adsorbed fluid based on the changes in the spectral peak morphology and the amount of nuclear magnetic resonance signals corresponding to the nuclear magnetic resonance test during the centrifugation process, and calculates the corresponding contents based on the first preset formula.

9. An electronic device, characterized in that: The electronic device comprises: a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the method steps described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps corresponding to the method according to any one of claims 1 to 7 are implemented.

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