Shale porosity determination method, device, system, medium and equipment

Abstract

The invention discloses a shale porosity measuring method, device, system, medium and equipment, the method comprises the steps that two-dimensional nuclear magnetic resonance distribution of fluid signals in a rock sample is obtained, the nuclear magnetic resonance porosity is calculated according to the two-dimensional nuclear magnetic resonance distribution, and the fluid signals comprise clay bound fluid signals; the helium porosity of the rock sample is obtained, and the total porosity is calculated according to the helium porosity and the nuclear magnetic resonance porosity; the change of two-dimensional nuclear magnetic resonance distribution of each fluid signal in the heating process is obtained, and the porosity of the clay bound fluid is determined according to the change rule; and determining the effective porosity of the shale according to the porosity of the clay bound fluid and the total porosity. According to the technical scheme provided by the invention, the effective porosity of the rock sample can be determined by utilizing the two-dimensional nuclear magnetic resonance distribution change of the shale sample in the heating state, so that the subsequent reserve calculation is more accurate.

Description

Background Art

[0002] Shale porosity is an important parameter for reserve calculation. Since it is difficult to clean the crude oil in the small pores by oil washing treatment, it is difficult to accurately obtain the porosity of the core by conventional helium method. Nuclear magnetic resonance has certain advantages in fluid distribution and porosity measurement. Currently, only nuclear magnetic resonance under fully saturated fluid state can reflect the total porosity, but it is still difficult to accurately reflect the porosity of clay-bound fluid. Summary of the invention

[0003] The embodiments of the present application provide a shale porosity determination method, device, system, medium and equipment, thereby determining the effective porosity of the rock sample by utilizing the change in the two-dimensional nuclear magnetic resonance distribution of the shale sample in the heated state at least to a certain extent, so as to make subsequent reserve calculations more accurate.

[0004] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0005] According to a first aspect of an embodiment of the present application, a shale porosity determination method is provided, comprising:

[0006] Obtaining the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample, and calculating the nuclear magnetic resonance porosity based on the two-dimensional nuclear magnetic resonance distribution;

[0007] Obtaining the helium porosity of the rock sample, and calculating the total porosity based on the helium porosity and the nuclear magnetic resonance porosity;

[0008] Obtain the changes in the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determine the porosity of the clay-bound fluid based on the change law;

[0009] The effective porosity of the shale is determined based on the porosity of the clay-bound fluid and the total porosity.

[0010] In some embodiments of the present application, based on the above scheme, the process of generating the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample is as follows:

[0011] Acquire several groups of echo signals of the rock sample, invert the echo signals based on the inversion algorithm, and obtain the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample;

[0012] Among them, several groups of echo signals are signals obtained by scanning the rock samples with a low-field nuclear magnetic resonance instrument using several groups of T1-T2 two-dimensional pulse sequences with different waiting times.

[0013] In some embodiments of the present application, based on the aforementioned scheme, the T1-T2 two-dimensional pulse sequence includes 30 groups of different waiting times.

[0014] In some embodiments of the present application, based on the above scheme, before calculating the NMR porosity according to the two-dimensional NMR distribution, the method further includes:

[0015] The hydrogen index of each fluid signal in the two-dimensional NMR distribution is normalized and corrected.

[0016] In some embodiments of the present application, based on the above scheme, the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process is obtained, and the porosity of the clay-bound fluid is determined according to the change law, including:

[0017] Obtain the changes in the NMR distribution of each fluid signal during the heating process, and detect the critical temperature of the clay-bound fluid during the change process;

[0018] The clay-bound fluid signal at the critical temperature is taken as the porosity of the clay-bound fluid.

[0019] In some embodiments of the present application, based on the above scheme, determining the effective porosity of shale according to the porosity of the clay-bound fluid and the total porosity includes:

[0020] The effective porosity is determined based on the difference between the total porosity and the porosity of the clay-bound fluid.

[0021] According to a second aspect of an embodiment of the present application, a shale porosity measuring device is provided, comprising:

[0022] The first calculation module is used to obtain the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample, and calculate the nuclear magnetic resonance porosity according to the two-dimensional nuclear magnetic resonance distribution;

[0023] A second calculation module is used to obtain the helium porosity of the rock sample and calculate the total porosity based on the helium porosity and the nuclear magnetic resonance porosity;

[0024] A porosity determination module is used to obtain the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determine the porosity of the clay-bound fluid according to the change law;

[0025] The third calculation module is used to determine the effective porosity of the shale according to the porosity of the clay-bound fluid and the total porosity.

[0026] According to the third aspect of the embodiment of the present application, a shale porosity measurement system is provided, comprising the device as described in the second aspect, and also comprising a low-field nuclear magnetic resonance instrument, wherein the low-field nuclear magnetic resonance instrument is used to adopt several groups of T1-T2 two-dimensional pulse sequences with different waiting times to respectively collect echo signals of rock samples in their original state and during the heating process.

[0027] According to a fourth aspect of an embodiment of the present application, a computer-readable storage medium is provided, in which at least one program code is stored. The at least one program code is loaded and executed by a processor to implement the operations performed by any method described in the first aspect.

[0028] According to the fifth aspect of an embodiment of the present application, an electronic device is provided, comprising one or more processors and one or more memories, wherein at least one program code is stored in the one or more memories, and the at least one program code is loaded and executed by the one or more processors to implement the operations performed by any of the methods described in the first aspect.

[0029] The technical solution proposed in the present application calculates the total porosity through nuclear magnetic resonance porosity and helium porosity; obtains the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determines the porosity of the clay-bound fluid according to the change law; and then determines the effective porosity of the shale according to the porosity of the clay-bound fluid and the total porosity, so that the subsequent reserve calculation is more accurate.

[0030] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0032] Figure 1 A flow chart of a shale porosity determination method according to an embodiment of the present application is shown;

[0033] Figure 2 A two-dimensional nuclear magnetic resonance pulse sequence according to an embodiment of the present application is shown;

[0034] Figure 3 The figure shows the T1-T2 two-dimensional nuclear magnetic resonance fluid distribution of a rock sample in an original state according to an embodiment of the present application;

[0035] Figure 4 The figure shows the T1-T2 two-dimensional nuclear magnetic resonance fluid distribution of a rock sample during a heating process according to an embodiment of the present application;

[0036] Figure 5 A structural block diagram of a shale porosity measuring device according to an embodiment of the present application is shown;

[0037] Figure 6 A structural block diagram of a shale porosity measurement system according to an embodiment of the present application is shown;

[0038] Figure 7 A schematic diagram of a computer-readable storage medium according to an embodiment of the present application is shown;

[0039] Figure 8 A schematic diagram of the structure of a computer system suitable for implementing an electronic device of an embodiment of the present application is shown. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0042] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0043] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0044] It should also be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those shown or described.

[0045] See also Figure 1 , showing a flow chart of a shale porosity determination method according to an embodiment of the present application.

[0046] like Figure 1 As shown, the shale porosity determination method includes but is not limited to being implemented by steps S1 to S4:

[0047] Step S1. Obtaining the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample, and calculating the nuclear magnetic resonance porosity based on the two-dimensional nuclear magnetic resonance distribution;

[0048] It should be noted that the embodiment of the present application uses a nuclear magnetic resonance instrument to scan and collect rock sample signals. Preferably, the nuclear magnetic resonance instrument uses a nuclear magnetic resonance instrument of model MARAN Ultra. Specifically, when the nuclear magnetic resonance instrument tests the shale core, it obtains fluid information according to the relaxation process of the hydrogen nucleus in the rock pore fluid, which is a non-destructive and environmentally friendly core analysis test method. Among them, the relaxation process of the hydrogen nucleus in the rock pore refers to the process of energy transfer and conversion that occurs due to the interaction between the hydrogen nucleus and the pore wall under the action of an external magnetic field. This process is related to the boundary conditions of the hydrogen nucleus relaxation and the spatial size of the relaxation. In small pores, there are many fluids of different properties, such as clay bound water, capillary bound water and oil, and the longitudinal relaxation and transverse relaxation times of the hydrogen nuclei of different fluids are different, so the two-dimensional distribution of the longitudinal relaxation time and the transverse relaxation time can be used to identify the fluid properties. Using the signal data obtained by the nuclear magnetic resonance test, the porosity, permeability, bound water saturation and rock pore structure parameters of the shale can be further calculated. In practical applications, such as in the oil industry, reservoir parameters can be quantitatively calculated based on core data measured by nuclear magnetic resonance imaging, so as to formulate reasonable oil and gas exploration and development plans, thereby improving the efficiency of oil and gas exploration and development.

[0049] See also Figure 2 , Figure 2 A two-dimensional nuclear magnetic resonance pulse sequence according to an embodiment of the present application is shown.

[0050] See also Figure 3 , Figure 3 The figure shows the T1-T2 two-dimensional nuclear magnetic resonance fluid distribution of a rock sample in its original state according to one embodiment of the present application.

[0051] Combination Figure 2 and Figure 3 As shown, based on the above, in some embodiments of step S1, the process of generating the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample is as follows:

[0052] Acquire several groups of echo signals of the rock sample, invert the echo signals based on the inversion algorithm, and obtain the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample;

[0053] Among them, several groups of echo signals are signals obtained after the low-field nuclear magnetic resonance instrument uses several groups of T1-T2 two-dimensional pulse sequences with different waiting times to scan the rock sample; preferably, the T1-T2 two-dimensional pulse sequence includes 30 groups with different waiting times.

[0054] Specifically, a low-field (2MHz-6MHz) nuclear magnetic resonance instrument is used to measure the nuclear magnetic resonance fluid distribution information of the shale oil plunger sample in the original state (i.e., at room temperature), wherein, Figure 2 As shown, a T1-T2 two-dimensional pulse sequence is used to obtain two-dimensional NMR measurement information during NMR measurement. Since the pore size of shale oil is small, in order to ensure the acquisition of accurate oil and gas signals, the waiting time of the T1-T2 two-dimensional pulse sequence is mainly based on small hole acquisition. Preferably, the NMR pulse sequence of the embodiment of the present application includes 30 groups of different waiting times. The two-dimensional NMR distribution of the shale oil sample is obtained by performing two-dimensional data inversion on the 30 groups of echo train signals. The two-dimensional NMR distribution of each fluid signal can be visualized by a rendering model, so that the signal can be intuitively displayed in the form of an image. For example, in Figure 3 The distribution of fluid signals such as clay-adsorbed oil, movable oil and clay-bound water can be observed. The inversion algorithm preferably adopts the SVD (Singular Value Decomposition) inversion algorithm.

[0055] In some embodiments of the present application, based on the above scheme, before calculating the NMR porosity according to the two-dimensional NMR distribution, the method further includes:

[0056] The hydrogen index of each fluid signal in the two-dimensional NMR distribution is normalized and corrected.

[0057] It should be noted that since the porosity calculation requires the calculation of the pore volume, that is, the sum of the volumes of each medium in the pore, it is known that the signal measured by nuclear magnetic resonance comes from hydrogen atoms, and the hydrogen atom content of the same volume of fluid may be different, for example, the hydrogen atom content of the same volume of oil and water is different, that is, the hydrogen index of the same volume of oil and water is different. Therefore, if no correction is performed, subsequent calculations may be inaccurate. Based on this, the embodiment of the present application performs normalization correction processing on the hydrogen index of each fluid signal in the two-dimensional nuclear magnetic resonance distribution, so that the corrected fluid signal can be used for porosity calculation later to improve the accuracy of the calculation results.

[0058] Step S2. Obtaining the helium porosity of the rock sample, and calculating the total porosity based on the helium porosity and the nuclear magnetic resonance porosity;

[0059] It should be noted that the helium porosity in the embodiment of the present application is measured by the existing helium method. Specifically, this method is based on the results obtained by measuring the core sample in its original state. Since the pore structure of shale oil samples is mainly micro-nano porosity, and the lamination and cracks are developed, the conventional helium method can only measure the porosity of non-fluid in the rock sample.

[0060] Based on the above, the porosity of each fluid in the rock sample is obtained through step S1, and the porosity of the non-fluid in the rock sample is obtained through step S2. Then, the total porosity of the core can be obtained by summing the fluid porosity and the non-fluid porosity.

[0061] See also Figure 4 , shows the T1-T2 two-dimensional nuclear magnetic resonance fluid distribution of a rock sample during a heating process according to an embodiment of the present application.

[0062] Step S3. Obtain the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determine the porosity of the clay-bound fluid according to the change law;

[0063] In some embodiments of the present application, in step S3, based on the above scheme, the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process is obtained, and the porosity of the clay-bound fluid is determined according to the change law, including:

[0064] Obtain the changes in the NMR distribution of each fluid signal during the heating process, and detect the critical temperature of the clay-bound fluid during the change process;

[0065] The clay-bound fluid signal at the critical temperature is taken as the porosity of the clay-bound fluid.

[0066] Specifically, a shale plunger sample is placed in a core holder, the shale plunger sample is heated, and the signal of the shale sample during the heating process is scanned and collected by a nuclear magnetic resonance instrument. It is worth noting that the rock sample used in step S3 should be the same as that in step S1, and the scanning and collection operation of the rock sample signal by the nuclear magnetic resonance instrument should also be the same as that in step S1, so as to ensure that the signal changes of the same rock sample in the original state and the heated state can be obtained.

[0067] It should be noted that during the rock sample heating process, due to the different critical volatilization temperatures of various fluids, the critical volatilization temperature of the clay-bound fluid is higher than that of other fluids, that is, the clay-bound fluid is the fluid with the highest critical volatilization temperature in the rock sample. Based on this characteristic, by monitoring the changes in the nuclear magnetic resonance distribution of the fluid signal, the critical temperature of the remaining clay-bound fluid after all other fluids have volatilized can be obtained, and the clay-bound fluid signal at the critical temperature is used as the porosity of the clay-bound fluid.

[0068] like Figure 4 As shown, the changes in the nuclear magnetic resonance distribution of fluid signals in the original state and during the temperature increase from 60°C to 180°C are shown. It can be seen from the figure that with the increase in temperature, the total porosity Por of the core gradually decreases, indicating that fluid volatilization has occurred in this process. When it is monitored that other fluids have been volatilized and the clay-bound fluid has reached the critical temperature of volatilization, it can be determined that the current fluid signal is only the clay-bound fluid signal, and the clay-bound fluid signal at this time is used as the porosity of the clay-bound fluid.

[0069] Step S4: determining the effective porosity of the shale according to the porosity of the clay-bound fluid and the total porosity.

[0070] In some embodiments of the present application, in step S4, based on the above scheme, the effective porosity of shale is determined according to the porosity of the clay-bound fluid and the total porosity, including:

[0071] The effective porosity is determined based on the difference between the total porosity and the porosity of the clay-bound fluid.

[0072] Based on the above disclosed content, the embodiment of the present application calculates the total porosity through nuclear magnetic resonance porosity and helium porosity; obtains the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determines the porosity of the clay-bound fluid according to the change law; and then determines the effective porosity of the shale according to the porosity of the clay-bound fluid and the total porosity, so that the subsequent reserve calculation is more accurate, thereby being able to objectively evaluate the reservoir characteristics of the shale oil reservoir and provide a parameter basis for formulating a reasonable shale oil exploration and development plan.

[0073] Application Examples

[0074] The method is further described below through a specific application of the method.

[0075] Six pieces of plunger samples after wire cutting were used. For each sample, a 2MHz nuclear magnetic resonance instrument was used to obtain two-dimensional nuclear magnetic resonance measurement information using a T1-T2 two-dimensional pulse sequence. Due to the small size of shale oil pores, in order to ensure accurate signal acquisition, the waiting time of the T1-T2 two-dimensional pulse sequence was mainly based on small hole acquisition, and 30 groups of waiting times were set for signal scanning and acquisition. For example, 30 groups of echo trains as shown in Table 1 were used to scan and acquire the plunger sample:

[0076] Table 1 Multi-wait inversion recovery NMR two-dimensional measurement mode parameters

[0077]

[0078] It should be noted that, in Table 1, NO. represents the echo string number, RD represents the waiting time, TE represents the echo time interval, and NS represents the number of scans.

[0079] After the echo signals are collected by the above 30 sets of parameters, the two-dimensional nuclear magnetic resonance distribution containing the signals of each fluid is obtained by performing two-dimensional data inversion on the 30 sets of echo train signals, and fluid signals such as clay bound water, capillary bound water and oil are obtained. The nuclear magnetic resonance porosity including the above fluid signals is calculated, and the hydrogen index of the fluid is corrected before calculation.

[0080] The helium porosity of the shale oil core was measured, and the nuclear magnetic resonance porosity of fluids including clay bound water, capillary bound water and oil was summed with the helium porosity to obtain the total porosity of the core; the shale oil plunger sample was placed in the core holder, and the T1-T2 two-dimensional nuclear magnetic resonance signal was measured during the heating process to determine the change law of fluid signals such as clay bound water, capillary bound water and oil, determine the critical temperature of clay bound water change, and obtain the clay bound fluid nuclear magnetic resonance porosity. The total porosity and clay bound fluid porosity were used to determine the effective porosity, as shown in Table 2 below, which shows the measurement results of the porosity of each of the six shale samples.

[0081] Table 2 Porosity measurement results of shale samples

[0082]

[0083] The following describes an embodiment of the device of the present application, which can be used to execute the method in the above embodiment of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the above embodiment of the method of the present application.

[0084] See also Figure 5 , shows a structural block diagram of a shale porosity measuring device according to an embodiment of the present application.

[0085] like Figure 5 As shown, according to the second aspect of the embodiment of the present application, a shale porosity measuring device 100 is provided, comprising:

[0086] The first calculation module 101 is used to obtain the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample, and calculate the nuclear magnetic resonance porosity according to the two-dimensional nuclear magnetic resonance distribution;

[0087] A second calculation module 102 is used to obtain the helium porosity of the rock sample and calculate the total porosity based on the helium porosity and the nuclear magnetic resonance porosity;

[0088] The porosity determination module 103 is used to obtain the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determine the porosity of the clay-bound fluid according to the change law;

[0089] The third calculation module 104 is used to determine the effective porosity of the shale according to the porosity of the clay-bound fluid and the total porosity.

[0090] See also Figure 6 , shows a structural block diagram of a shale porosity measurement system according to an embodiment of the present application.

[0091] like Figure 6 As shown, according to the third aspect of the embodiment of the present application, a shale porosity measurement system is provided, comprising the device 100 as described in the second aspect, and also comprising a low-field nuclear magnetic resonance instrument 200, wherein the low-field nuclear magnetic resonance instrument 200 is used to adopt several groups of T1-T2 two-dimensional pulse sequences with different waiting times to respectively collect echo signals of rock samples in the original state and in the heating process.

[0092] like Figure 7 As shown, based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium 300, in which at least one computer program instruction is stored, and the at least one computer program instruction is loaded and executed by a processor to implement the operations performed by the method described in any one of the third aspects.

[0093] The computer readable storage medium 300 may be a portable compact disk read-only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the computer readable storage medium 300 of the present application is not limited thereto. In the present application, the computer readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0094] The readable storage medium 300 may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any combination thereof. More specific examples (a non-exhaustive list) of the readable storage medium 300 include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0095] Program code for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0096] As another aspect, the present application also provides an electronic device 400 capable of implementing the above method.

[0097] Those skilled in the art will appreciate that various aspects of the present application may be implemented as a system, method or program product. Therefore, various aspects of the present application may be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software, which may be collectively referred to as "circuit", "module" or "system" herein.

[0098] Refer to the following Figure 8 The electronic device 400 according to this embodiment of the present application is described. Figure 8 The electronic device 400 shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0099] like Figure 8 As shown, the electronic device 400 is in the form of a general computing device. The components of the electronic device 400 may include but are not limited to: at least one processing unit 410, at least one storage unit 420, and a bus 430 connecting different system components (including the storage unit 420 and the processing unit 410).

[0100] The storage unit stores program codes, which can be executed by the processing unit 410, so that the processing unit 410 executes the steps described in the above “Example Method” section of this specification according to various exemplary implementations of the present application.

[0101] The storage unit 420 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 421 and / or a cache memory unit 422 , and may further include a read-only memory unit (ROM) 423 .

[0102] The storage unit 420 may also include a program / utility 424 having a set (at least one) of program modules 425, such program modules 425 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0103] Bus 430 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0104] The electronic device 400 may also communicate with one or more external devices 500 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 400, and / or communicate with any device that enables the electronic device 400 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface 450. Furthermore, the electronic device 400 may also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter 460. As shown, the network adapter 460 communicates with other modules of the electronic device 400 via a bus 430. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 400, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0105] The above description is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for measuring shale porosity, characterized in that: include: Obtaining the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample, and calculating the nuclear magnetic resonance porosity based on the two-dimensional nuclear magnetic resonance distribution, the fluid signal includes a clay-bound fluid signal; Obtaining the helium porosity of the rock sample, and calculating the total porosity based on the helium porosity and the nuclear magnetic resonance porosity; Obtain the changes in the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determine the porosity of the clay-bound fluid based on the change law; The effective porosity of the shale is determined based on the porosity of the clay-bound fluid and the total porosity.

2. The method according to claim 1, characterized in that The generation process of the two-dimensional NMR distribution of each fluid signal in the rock sample is as follows: Acquire several groups of echo signals of the rock sample, invert the echo signals based on the inversion algorithm, and obtain the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample; Among them, several groups of echo signals are signals obtained by scanning the rock samples with a low-field nuclear magnetic resonance instrument using several groups of T1-T2 two-dimensional pulse sequences with different waiting times.

3. The method according to claim 2, characterized in that The T1-T2 two-dimensional pulse sequence includes 30 groups of different waiting times.

4. The method according to claim 1, characterized in that: Before calculating the NMR porosity according to the two-dimensional NMR distribution, the method further comprises: The hydrogen index of each fluid signal in the two-dimensional NMR distribution is normalized and corrected.

5. The method according to claim 1, characterized in that: Obtain the changes in the 2D NMR distribution of each fluid signal during the heating process, and determine the porosity of the clay-bound fluid based on the change law, including: Obtain the changes in the NMR distribution of each fluid signal during the heating process, and detect the critical temperature of the clay-bound fluid during the change process; The clay-bound fluid signal at the critical temperature is taken as the porosity of the clay-bound fluid.

6. The method according to claim 1, characterized in that The effective porosity of shale is determined based on the porosity of clay-bound fluid and the total porosity, including: The effective porosity is determined based on the difference between the total porosity and the porosity of the clay-bound fluid.

7. A shale porosity measuring device, characterized in that: include: The first calculation module is used to obtain the two-dimensional nuclear magnetic resonance distribution of each fluid signal in the rock sample, and calculate the nuclear magnetic resonance porosity according to the two-dimensional nuclear magnetic resonance distribution; A second calculation module is used to obtain the helium porosity of the rock sample and calculate the total porosity based on the helium porosity and the nuclear magnetic resonance porosity; A porosity determination module is used to obtain the change of the two-dimensional nuclear magnetic resonance distribution of each fluid signal during the heating process, and determine the porosity of the clay-bound fluid according to the change law; The third calculation module is used to determine the effective porosity of the shale according to the porosity of the clay-bound fluid and the total porosity.

8. A shale porosity measurement system, characterized in that: The device comprises the device as claimed in claim 7, and also comprises a low-field nuclear magnetic resonance instrument, wherein the low-field nuclear magnetic resonance instrument is used to use several groups of T1-T2 two-dimensional pulse sequences with different waiting times to respectively collect echo signals of rock samples in the original state and during the heating process.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one program code, and the at least one program code is loaded and executed by the processor to implement the operations performed by any one of the methods according to claims 1-6.

10. An electronic device, characterized in that: The method comprises one or more processors and one or more memories, wherein at least one program code is stored in the one or more memories, and the at least one program code is loaded and executed by the one or more processors to implement the operations performed by the method according to any one of claims 1 to 6.

Images