Low-field and ultralow-field nuclear magnetic resonance sample detection system

Abstract

The embodiment of the invention provides a low-field and ultralow-field nuclear magnetic resonance sample detection system, and belongs to the technical field of nuclear magnetic resonance. The system comprises a driving assembly, a detection piece, a guide piece and a pre-polarization piece, wherein the detection piece and the pre-polarization piece are both located on the side of the guide piece; the guide part is horizontally arranged and is used for accommodating a nuclear magnetic resonance sample, the driving assembly is used for driving the nuclear magnetic resonance sample to move in the guide part, so that the nuclear magnetic resonance sample moves from a magnetization treatment position to a detection position, the magnetization treatment position corresponds to the pre-polarization part, and the detection position corresponds to the detection part; the pre-polarization part is used for carrying out magnetization treatment on the nuclear magnetic resonance sample, and the detection part is used for detecting the physical properties of the nuclear magnetic resonance sample in low-field and ultra-low-field environments. According to the scheme, the measurement precision of nuclear magnetic resonance of the sample can be improved.

Description

Technical Field

[0001] The present application relates to the field of nuclear magnetic resonance technology, and in particular to a low-field and ultra-low-field nuclear magnetic resonance sample detection system. Background Art

[0002] In the NMR detection experiment, the transmission of the NMR sample is one of the key links for the success of the experiment. Especially in the NMR core detection experiment based on low field and ultra-low field environment, the transmission of the core sample has an important impact on the success of the experiment.

[0003] In the prior art, nuclear magnetic resonance core detection experiments based on low-field and ultra-low-field environments usually adopt a free-fall sampling method.

[0004] However, the above method makes it impossible for the core sample to fall on the detection device steadily. In addition, when the core sample falls on the detection device, it will cause vibration, which will lead to relaxation phenomenon, thereby affecting the experimental measurement accuracy of nuclear magnetic resonance. Summary of the invention

[0005] The embodiment of the present application provides a low-field and ultra-low-field nuclear magnetic resonance sample detection system, which can improve the measurement accuracy of sample nuclear magnetic resonance.

[0006] The embodiments of the present application provide the following technical solutions to solve the above technical problems:

[0007] An embodiment of the present application provides a low-field and ultra-low-field nuclear magnetic resonance sample detection system, comprising: a driving component, a detection component, a guide component and a prepolarization component, wherein the detection component and the prepolarization component are both located on the side of the guide component; the guide component is horizontally arranged, and the guide component is used to accommodate the nuclear magnetic resonance sample, and the driving component is used to drive the nuclear magnetic resonance sample to move in the guide component so that the nuclear magnetic resonance sample moves from a magnetization processing position to a detection position, the magnetization processing position corresponds to the prepolarization component, and the detection position corresponds to the detection component, the prepolarization component is used to magnetize the nuclear magnetic resonance sample, and the detection component is used to detect the physical properties of the nuclear magnetic resonance sample in a low-field and ultra-low-field environment.

[0008] Low-field NMR usually refers to NMR detection experiments conducted under relatively low magnetic field strength. Here, "low field" refers to systems with magnetic field strengths below 1 Tesla (T). Ultra-low-field NMR refers to NMR detection experiments with further reduced magnetic field strengths. Here, "ultra-low field" refers to systems with magnetic field strengths far below 0.1 Tesla (T). That is, the magnetic field strength of ultra-low-field NMR is much lower than that of low-field NMR.

[0009] In a possible embodiment, the driving assembly includes a driving member and a transmission member, the guide member is provided with a positioner, the driving member is connected to the positioner through the transmission member, and the driving member is used to drive the nuclear magnetic resonance sample to move in the guide member through the transmission member and the positioner.

[0010] In a possible implementation, the transmission member is a transmission belt, and the positioner is a positioning wheel; the driving member is a motor, and the driving assembly also includes a driving wheel, which is sleeved on the output shaft of the motor, and the transmission member is wrapped around the driving wheel and the positioner.

[0011] In a possible implementation, it further includes a mounting seat, which is located in the guide member, and is used to accommodate the nuclear magnetic resonance sample, and the driving assembly is used to drive the mounting seat to move in the guide member.

[0012] In a possible embodiment, the mounting base includes a shell, an inner cylinder and two sealing covers. The inner cylinder is arranged in the shell. A cavity for accommodating the nuclear magnetic resonance sample is provided in the inner cylinder. The two sealing covers are respectively arranged at two ends of the shell, and the sealing covers are used to seal the inner cylinder.

[0013] In a possible embodiment, the mounting seat is provided with a pressurizing port, a temperature measuring port, a liquid inlet pipe and a liquid outlet pipe, the pressurizing port, the temperature measuring port and the liquid inlet pipe are arranged on one of the sealing covers, the liquid inlet pipe passes through the inner cylinder to communicate with the cavity, the liquid outlet pipe is arranged on the other sealing cover, and the liquid outlet pipe passes through the inner cylinder to communicate with the cavity.

[0014] In a possible implementation, a guide is further included, wherein the guide is disposed inside the guide, the guide is located between the detection position and the magnetization processing position, and the guide is used to maintain the magnetization state of the nuclear magnetic resonance sample.

[0015] In a possible implementation manner, a magnetic field shielding member is further included, wherein the detection member and a portion of the guide member are arranged inside the magnetic field shielding member, and one end of the guide member passes through the magnetic field shielding member.

[0016] In a possible implementation, a pulse coil is further included. The pulse coil is disposed in the magnetic field shielding component. The detection component is disposed in the pulse coil. The pulse coil is used to apply a pulse magnetic field to the nuclear magnetic resonance sample.

[0017] In a possible implementation manner, a compensation coil is further included. The compensation coil is disposed in the magnetic field shielding component, the compensation coil is disposed between the magnetic field shielding component and the pulse coil, and the compensation coil is used to compensate for interference of an external magnetic field.

[0018] Beneficial effects of the embodiments of the present application: The low-field and ultra-low-field NMR sample detection system provided by the embodiments of the present application can guide the NMR sample into the detection position in the horizontal direction through the horizontally arranged guide piece, and by setting the driving component, the NMR sample can reach the detection position in the horizontal direction via the magnetization treatment position in the guide piece, and the NMR sample is driven in the horizontal direction by the driving component, so that the NMR sample can be smoothly moved to the detection position, ensuring the stability of the NMR sample during the transmission process, and avoiding the instability caused by the free fall sampling method. By setting the guide piece, the NMR sample can accurately reach the detection position and correspond to the detection piece, thereby improving the measurement accuracy of the sample NMR, and avoiding the experimental error caused by the position deviation of the NMR sample.

[0019] In addition to the technical problems solved by the present application, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the core detection system and method provided by the present application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0021] Figure 1 A schematic diagram of the structure of a low-field and ultra-low-field nuclear magnetic resonance sample detection system provided in an embodiment of the present application;

[0022] Figure 2 A schematic diagram of the structure of a mounting base in a low-field and ultra-low-field nuclear magnetic resonance sample detection system provided in an embodiment of the present application;

[0023] Figure 3 This is a schematic diagram of the structure of the compensation coil in the low-field and ultra-low-field nuclear magnetic resonance sample detection system provided in the embodiment of the present application.

[0024] Description of reference numerals:

[0025] 10. Nuclear magnetic resonance samples;

[0026] 100. Driving assembly;

[0027] 110. Driving parts;

[0028] 120. Transmission parts;

[0029] 130, driving wheel;

[0030] 200. Inspection parts;

[0031] 300, guide member;

[0032] 400, prepolarization element;

[0033] 500, locator;

[0034] 600, mounting seat;

[0035] 610, housing;

[0036] 611, boss;

[0037] 620, inner tube;

[0038] 630, sealing cover;

[0039] 640, pressurization port;

[0040] 650, temperature measuring port;

[0041] 670, liquid inlet pipe;

[0042] 680, liquid outlet pipe;

[0043] 681, flow limiting valve;

[0044] 690, Fixer;

[0045] 700, guide;

[0046] 800, magnetic field shielding parts;

[0047] 810, magnetic leakage sleeve;

[0048] 910, pulse coil;

[0049] 920. Compensation coil.

[0050] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0051] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0052] NMR sample testing generally refers to a method of using Nuclear Magnetic Resonance (NMR) technology to analyze the chemical structure, purity or other physical properties of a sample. NMR technology is a powerful analytical tool that is widely used in fields such as chemistry, biochemistry, medicine and materials science. NMR testing is based on the phenomenon that atomic nuclei absorb electromagnetic waves of a specific frequency in a strong magnetic field. When a sample is placed in a strong magnetic field, the spin state of the atomic nuclei in the sample will split to form different energy levels. When a radio frequency pulse that matches these energy level differences is applied to the sample, the atomic nuclei will absorb energy and transition to a higher energy level. Subsequently, these atomic nuclei will release energy to return to the ground state, and the released energy can be captured and recorded by the detector to form an NMR spectrum.

[0053] Specifically, NMR sample testing includes core sample testing. Core sample testing is usually carried out in low-field and ultra-low-field environments. Low-field and ultra-low-field NMR testing of core samples is an advanced rock physics analysis method, mainly used to evaluate key parameters such as the pore structure, fluid properties and permeability of the core. Ultra-low-field NMR technology uses the magnetic moment characteristics of atomic nuclei in an ultra-low magnetic field environment to excite and detect the relaxation signals of atomic nuclei through radio frequency pulses, thereby achieving non-destructive testing of the internal structure and fluid distribution of core samples.

[0054] Low-field and ultra-low-field nuclear magnetic resonance technology is widely used in core testing, mainly including the following aspects. 1. Porosity measurement: By detecting the hydrogen nuclear resonance signal of water molecules in the core sample, the porosity of the core can be accurately measured. This method is non-destructive, fast and highly sensitive. 2. Fluid property analysis: Ultra-low-field nuclear magnetic resonance technology can be used to distinguish between movable fluid and bound fluid in the core. By measuring the T 1 and T 2 Relaxation time can be used to calculate the properties and distribution of fluids. This is of great significance for evaluating the oil and water distribution and exploitation potential of the reservoir. 3. Permeability estimation: Combining the porosity and fluid property information measured by low-field and ultra-low-field nuclear magnetic resonance technology, the permeability of the core can be estimated. Permeability is an important parameter for evaluating the flow capacity of reservoir fluids and is crucial for the formulation of oil and gas field development plans.

[0055] In the related art, in order to conduct nuclear magnetic resonance core detection experiments in low-field and ultra-low-field environments, a free-fall sampling method is usually adopted. The above-mentioned free-fall sampling method makes it impossible for the core sample to fall smoothly onto the detection device. In addition, when the core sample falls on the detection device, it will cause vibration, thereby affecting the experimental measurement accuracy of nuclear magnetic resonance.

[0056] In view of this, the embodiment of the present application can guide the nuclear magnetic resonance sample into the detection position in the horizontal direction through the horizontally arranged guide piece, and by setting the driving component, the nuclear magnetic resonance sample can reach the detection position in the horizontal direction through the magnetization treatment position in the guide piece, and the driving component drives the nuclear magnetic resonance sample in the horizontal direction, so that the nuclear magnetic resonance sample can be smoothly moved to the detection position, ensuring the stability of the nuclear magnetic resonance sample during the transmission process, and avoiding the instability caused by the free fall sampling method. By setting the guide piece, the nuclear magnetic resonance sample can accurately reach the detection position and correspond to the detection piece, thereby improving the measurement accuracy of the sample nuclear magnetic resonance, and avoiding the experimental error caused by the position deviation of the nuclear magnetic resonance sample.

[0057] 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.

[0058] Figure 1 This is a schematic diagram of the structure of the low-field and ultra-low-field nuclear magnetic resonance sample detection system provided in the embodiment of the present application. Figure 1 As shown, an embodiment of the present application provides a low-field and ultra-low-field NMR sample detection system, including a driving component 100, a detection piece 200, a guide piece 300 and a prepolarization piece 400, wherein the detection piece 200 and the prepolarization piece 400 are both located on the side of the guide piece 300; the guide piece 300 is horizontally arranged, and the guide piece 300 is used to accommodate the NMR sample 10, and the driving component 100 is used to drive the NMR sample 10 to move in the guide piece 300, so that the NMR sample 10 moves from the magnetization treatment position to the detection position, the magnetization treatment position corresponds to the prepolarization piece 400, and the detection position corresponds to the detection piece 200, the prepolarization piece 400 is used to magnetize the NMR sample 10, and the detection piece 200 is used to detect the physical properties of the NMR sample 10 in a low-field and ultra-low-field environment.

[0059] That is to say, in the process of detecting the NMR sample 10 by the low-field and ultra-low-field NMR sample detection system provided by the present embodiment, the driving component 100 first pushes the NMR sample 10 in the horizontal direction so that it passes through the prepolarization component 400. In this process, the prepolarization component 400 will magnetize the NMR sample 10, so that the NMR sample 10 can be magnetized by the magnetic field to form a specific magnetization state. Secondly, the magnetized NMR sample 10 will continue to be pushed by the driving component 100 until it reaches the detection position in the guide member 300. Among them, the detection position corresponds to the detection member 200 arranged on the side of the guide member 300, so as to ensure that the detection member 200 can accurately and effectively detect the physical properties of the NMR sample 10.

[0060] In a possible design, when the NMR sample 10 is a core sample, the low-field and ultra-low-field NMR sample detection system can detect the pore structure characteristics of the core sample. The pore structure characteristics can include the pore size and distribution of the core sample and the pore connectivity of the core sample. When detecting the pore size and distribution of the core sample, the pore size and distribution of the core sample and the T 2 The larger the pore size of the core sample, the longer the corresponding relaxation time, T 2 The distribution curve is closer to the right; the smaller the pore size of the core sample, the shorter the corresponding relaxation time, T 2 The distribution curve is closer to the left. Therefore, by measuring the T 2 The relaxation time distribution can be used to infer the pore size and distribution range of the core sample. When testing the pore connectivity of the core sample, the relaxation characteristics of the core sample can also reveal the connectivity between the pores. A well-connected pore structure indicates that the core sample has a high fluid transport capacity.

[0061] The low-field and ultra-low-field NMR sample detection system provided in this embodiment can guide the NMR sample 10 into the detection position in the horizontal direction through the horizontally arranged guide member 300, and by setting the driving component 100, the NMR sample 10 can reach the detection position in the horizontal direction through the magnetization treatment position in the guide member 300, and the NMR sample 10 is driven in the horizontal direction by the driving component 100, so that the NMR sample 10 can be smoothly moved to the detection position, ensuring the stability of the NMR sample 10 during the transmission process, and avoiding the instability caused by the free fall sampling method. Through the design of the guide member 300, the NMR sample 10 can accurately reach the detection position and correspond to the detection member 200, thereby improving the measurement accuracy of the NMR experiment and avoiding the experimental error caused by the position deviation of the NMR sample 10.

[0062] In a possible embodiment, the driving assembly 100 includes a driving member 110 and a transmission member 120, and a positioner 500 is provided on the guide member 300. The driving member 110 is connected to the positioner 500 through the transmission member 120. The driving member 110 is used to drive the nuclear magnetic resonance sample 10 to move in the guide member 300 through the transmission member 120 and the positioner 500.

[0063] That is to say, the structure of the driving assembly 100 can realize the precise movement of the nuclear magnetic resonance sample 10 in the horizontal direction. Specifically, the driving member 110 acts as a power source, and drives the transmission member 120 through the force or torque generated by it. The transmission member 120 is closely connected with the driving member 110 to ensure the effective transmission of power. Among them, the guide member 300 not only provides a stable moving path for the transmission member 120, but also ensures the stability and accuracy of the nuclear magnetic resonance sample 10 during the movement. The positioner 500 in the guide member 300 further enhances the stability of the nuclear magnetic resonance sample 10 during the movement. The positioner 500 ensures that the transmission member 120 can remain on a predetermined track when moving, thereby avoiding deviation or shaking. When the driving member 110 is started, the power generated by it is transmitted to the nuclear magnetic resonance sample 10 through the transmission member 120, thereby moving the nuclear magnetic resonance sample 10 in the horizontal direction. Through the above design, the movement of the nuclear magnetic resonance sample 10 is more stable and controllable.

[0064] In a possible implementation, the transmission member 120 is a transmission belt, and the positioner 500 is a positioning wheel; the driving member 110 is a motor, and the driving assembly 100 also includes a driving wheel 130, which is sleeved on the output shaft of the motor, and the transmission member 120 surrounds the driving wheel 130 and the positioner 500.

[0065] That is to say, the output shaft of the motor can drive the driving wheel 130 to rotate synchronously, and the driving wheel 130 can drive the transmission member 120 to move while rotating, thereby moving the nuclear magnetic resonance sample 10 in the guide member 300. The positioner 500 is fixed at an appropriate position of the guide member 300, which can support the transmission member 120 and ensure its smooth operation. Further, the motor can be set on one side of the guide member 300. The motor can be set on a motor seat, and the motor seat can be fixed on the frame of the low-field and ultra-low-field nuclear magnetic resonance sample detection system, thereby ensuring the stability of the motor.

[0066] In a possible embodiment, the low-field and ultra-low-field NMR sample detection system also includes a mounting seat 600, which is located in the guide member 300, and the mounting seat 600 is used to accommodate the NMR sample 10, and the drive assembly 100 is used to drive the mounting seat 600 to move in the guide member 300.

[0067] Optionally, the transmission member 120 can also be a traction rope. The positioner 500 can also be a screw made of PEEK (polyetheretherketone), which has excellent chemical corrosion resistance, high temperature stability and good mechanical properties. The positioner 500 can be fixed on the inner wall of the guide member 300 to ensure its stability and reliability during the injection of the nuclear magnetic resonance sample 10. The transmission member 120 can pass through the screw structure of the positioner 500 and be closely connected to the mounting seat 600.

[0068] In this way, the transmission member 120 can be driven by the motor and can achieve horizontal movement of the mounting seat 600 in the guide member 300 through the conduction of the driving wheel 130. In addition, the positioner 500 made of PEEK also has good wear resistance and self-lubricating properties, thereby reducing the friction and wear that may be generated when the transmission member 120 passes through the positioner 500, further improving the stability of the low-field and ultra-low-field nuclear magnetic resonance sample detection system. Through the design of the positioner 500, the transmission member 120 and the mounting seat 600, the precise and stable movement of the nuclear magnetic resonance sample 10 in the horizontal direction is achieved.

[0069] Optionally, the guide member 300 can be a tubular structure. The guide member 300 of the tubular structure can provide stable guiding and supporting functions. Optionally, the guide member 300 is a circular injection tube. Optionally, the guide member 300 can be made of glass, the inner diameter of the guide member 300 is 1 inch, and the inner wall of the guide member 300 is coated with a coating to prevent the mounting seat 600 from causing wear on the inner wall of the guide member 300.

[0070] Figure 2 This is a schematic diagram of the structure of the mounting base in the low-field and ultra-low-field nuclear magnetic resonance sample detection system provided in the embodiment of the present application. Figure 2 The structure of the mounting base is further described.

[0071] In a possible embodiment, the mounting base 600 includes a shell 610, an inner cylinder 620 and two sealing covers 630. The inner cylinder 620 is arranged in the shell 610. A cavity for accommodating the nuclear magnetic resonance sample 10 is provided in the inner cylinder 620. The two sealing covers 630 are respectively arranged at both ends of the shell 610, and the sealing covers 630 are used to seal the inner cylinder 620.

[0072] That is, the housing 610 can serve as the main supporting structure of the mounting base 600, providing a protective barrier to prevent external mechanical shocks and environmental factors from damaging the inner cylinder 620 and the nuclear magnetic resonance sample 10. The inner cylinder 620 can accommodate the nuclear magnetic resonance sample 10, and the inner cylinder 620 has a cavity for storing the nuclear magnetic resonance sample 10. Two sealing covers 630 can be respectively disposed at both ends of the housing 610 to seal the inner cylinder 620 to prevent external air, moisture or other impurities from entering the inner cylinder 620.

[0073] Optionally, the shell 610 can be designed to be cylindrical. The shell 610 can be made of non-magnetic material and have a bionic super-slip coating on the surface. The material of the inner cylinder 620 includes graphene or carbon composite material, and is coated with an insulation layer. The material of the sealing cover 630 includes non-magnetic metal, zirconia ceramic, carbon-ceramic composite material or basalt fiber material. At least two rollers are provided on the shell 610, and the rollers are in rolling contact with the inner wall of the guide member 300. The design of the rollers helps to achieve smooth movement of the mounting seat 600 in the guide member 300. It helps to reduce the impact of vibration and impact on the nuclear magnetic resonance sample 10 during movement, and ensure the accuracy and stability of detection.

[0074] In a possible embodiment, the mounting base 600 is provided with a pressurizing port 640, a temperature measuring port 650, a liquid inlet pipe 670 and a liquid outlet pipe 680. The pressurizing port 640, the temperature measuring port 650 and the liquid inlet pipe 670 are arranged on one of the sealing covers 630, and the liquid inlet pipe 670 passes through the inner cylinder 620 to communicate with the cavity. The liquid outlet pipe 680 is arranged on the other sealing cover 630, and the liquid outlet pipe 680 passes through the inner cylinder 620 to communicate with the cavity.

[0075] That is, in experiments involving specific pressure treatment of core samples or simulation of formation pressure conditions, the pressure port 640 allows high-pressure gas or liquid to be injected into the inner tube 620 to achieve pressure loading of the core samples. This helps to evaluate the physical response of core samples under different pressure environments, such as permeability, pore pressure changes, etc. At the same time, pressure pulse testing can also be performed through the pressure port 640 to study the dynamic response characteristics of the core samples. The temperature measuring port 650 is also arranged on the sealing cover 630, so as to facilitate cooperation with the pressure port 640. The temperature measuring port 650 is used to monitor the temperature change of the core sample during the experiment in real time. Since the core sample may be heated, cooled or otherwise treated with temperature during the experiment, the presence of the temperature measuring port 650 ensures that the experimenter can accurately grasp the temperature change inside the core product, so as to better analyze the thermal physical parameters of the core sample. At the same time, combined with the pressure data, the pressure-temperature sensitivity of the core product can be further studied. The liquid inlet pipe 670 is a channel for injecting fluid (such as water, oil or other experimental media) into the cavity during the experiment.

[0076] Optionally, the liquid inlet pipe 670 can be connected to the core sample through the liquid inlet on the sealing cover 630. The flow state of the underground fluid can be simulated through the liquid inlet pipe 670, so that the key parameters such as the fluid transmission characteristics, wettability, and adsorption of the core sample can be studied. The liquid outlet pipe 680 is arranged on another sealing cover 630, and the liquid outlet pipe 680 is also connected to the cavity. The liquid outlet pipe 680 is responsible for collecting the fluid flowing out of the core sample, which is convenient for subsequent analysis of the composition and properties of the effluent. By comparing the difference between the inflow and outflow liquids, the filtering performance, adsorption capacity, etc. of the core sample can be further evaluated. In addition, when a circulating flow experiment is required, the liquid outlet pipe 680 can also re-inject the collected fluid into the mounting seat 600 to form a circulation loop.

[0077] Optionally, a flow limiting valve 681 is also provided on the liquid outlet pipe 680. The flow limiting valve 681 can adjust and control the outflow rate of the fluid. In the core detection experiment, different experimental conditions may require different fluid flow rates. By providing the flow limiting valve 681, the outflow of the fluid can be accurately adjusted to meet the experimental requirements and ensure the accuracy of the experimental data. In addition, a sealing ring is also provided at the connection between the liquid inlet pipe 670 and the liquid outlet pipe 680 and the sealing cover 630. A fixer 690 is also provided on the sealing cover 630 to ensure that the sealing cover 630 can be tightly connected to the housing 610.

[0078] In a possible design, bosses 611 are further provided at the openings at both ends of the housing 610 to form a stepped structure. A corresponding groove is provided on the sealing cover 630 to ensure that the sealing cover 630 can fit closely with the bosses 611 to form a stable sealing interface. This design not only increases the structural strength of the housing 610, but also facilitates the connection of the sealing cover 630. The bosses 611 are symmetrically distributed along the axis of the housing 610, thereby ensuring the consistency of the two ends. Specifically, the sealing cover 630 is used to cover the openings at both ends of the housing 610, and achieves sealing by fitting closely with the bosses 611.

[0079] In a possible embodiment, the low-field and ultra-low-field NMR sample detection system also includes a guide 700, which is arranged inside the guide 300. The guide 700 is located between the detection position and the magnetization processing position. The guide 700 is used to maintain the magnetization state of the NMR sample 10.

[0080] In a possible design, the guide 700 can be a guide coil. The guide 700 can be tightly wound around the inner wall of the guide 300, and the guide 700 is adjacent to the prepolarizer 400 until the detection position. Among them, a weak current passes through the guide 700, which can generate a finely regulated magnetic field to maintain the magnetization state of the nuclear magnetic resonance sample 10 and resist interference from the external magnetic field. By setting the guide 700, it is possible to provide a stable magnetic field environment for the nuclear magnetic resonance sample 10, ensuring that the magnetization state of the nuclear magnetic resonance sample 10 will not be affected by changes in the external magnetic field during the process from the magnetization treatment position to the detection position of the nuclear magnetic resonance sample 10. The current in the guide 700 can be used to fine-tune the magnetic field strength to maintain the stability and consistency of the magnetic properties of the nuclear magnetic resonance sample 10.

[0081] In a possible design, the prepolarizer 400 can be arranged at the entrance of the guide 300. The prepolarizer 400 can be composed of two circular magnets arranged opposite to each other, which are made of high-performance iron-negium-boron material and have strong magnetization ability and good stability. The two circular magnets are arranged at the upper and lower ends of the guide 300, that is, the starting point where the NMR sample 10 enters the guide 300, thereby forming an efficient magnetization area.

[0082] In the core detection experiment, the prepolarizer 400 can pre-magnetize the core sample. When the core sample is located between two circular magnets, the core sample will be subjected to a uniform magnetic field of 1T strength, thereby making the magnetic particles inside the core sample reach a higher magnetization level, and the spatial uniformity of the magnetic field reaches about 90%, ensuring that the magnetization effect of the core sample is consistent throughout the prepolarization process, providing good initial conditions for subsequent detection.

[0083] In a possible embodiment, the low-field and ultra-low-field nuclear magnetic resonance sample detection system also includes a magnetic field shielding member 800, in which the detection member 200 and a portion of the guide member 300 are arranged, and one end of the guide member 300 passes through the magnetic field shielding member 800. Optionally, the magnetic field shielding member 800 is composed of five layers of Permalloy. In other words, the function of the magnetic field shielding member 800 is to form a low-field or ultra-low-field environment, thereby protecting the detection member 200 and a portion of the guide member 300 inside the magnetic field shielding member 800 from external magnetic field fluctuations. The design of the five-layer structure not only enhances the shielding effect, but also ensures the uniformity of the shielding, and can keep the magnetic field of the internal space stable even in a strong magnetic field environment.

[0084] In a possible design, the detection member 200 can be a magnetometer, which is arranged below the detection position and closely fits with the guide member 300. The detection member 200 can directly detect various physical or chemical properties of the nuclear magnetic resonance sample 10. Under the protection of the magnetic field shielding member 800, the detection member 200 can more accurately capture the slight changes of the nuclear magnetic resonance sample 10, such as magnetic susceptibility, resistivity, etc., so as to provide high-quality raw data for subsequent data analysis.

[0085] In a possible design, a magnetic flux leakage sleeve 810 is provided at the contact position between the guide member 300 and the magnetic field shielding member 800. The magnetic flux leakage sleeve 810 can effectively absorb or disperse the trace magnetic flux leakage transmitted from the guide member 300, thereby preventing the magnetic flux leakage from interfering with the low magnetic field environment inside the magnetic field shielding member 800. In this way, even if the guide member 300 needs to penetrate the magnetic field shielding member 800, the magnetic flux leakage sleeve 810 can maintain the low field and ultra-low field environment inside the magnetic field shielding member 800. In other words, the magnetic field shielding member 800, the detection member 200, the guide member 300 and the magnetic flux leakage sleeve 810 together constitute a closed low field and ultra-low field detection environment. In low-field and ultra-low-field detection environments, the magnetic field shielding component 800 provides basic magnetic isolation and an interference-free working space for the detection component 200; the detection component 200 is responsible for measuring various parameters of the nuclear magnetic resonance sample 10; the guide component 300 not only supports the detection component 200, but also achieves a safe connection with the outside world through the leakage magnetic sleeve 810; the leakage magnetic sleeve 810 serves as a buffer device to ensure the magnetic shielding effect and mechanical stability of the entire system.

[0086] In a possible embodiment, the low-field and ultra-low-field nuclear magnetic resonance sample detection system also includes a pulse coil 910, which is disposed in the magnetic field shielding component 800, and the detection component 200 is disposed in the pulse coil 910, and the pulse coil 910 is used to apply a pulse magnetic field to the nuclear magnetic resonance sample 10.

[0087] In a possible embodiment, the low-field and ultra-low-field nuclear magnetic resonance sample detection system also includes a compensation coil 920, which is disposed in the magnetic field shielding member 800, and between the magnetic field shielding member 800 and the pulse coil 910, and the compensation coil 920 is used to compensate for the interference of the external magnetic field.

[0088] That is, the pulse coil 910 can apply a short pulse magnetic field to the NMR sample 10 when the mounting base 600 carries the NMR sample 10, thereby stimulating the magnetic properties inside the NMR sample 10, so that the detection element 200 can capture and analyze these properties. The compensation coil 920 is arranged between the magnetic field shielding element 800 and the pulse coil 910, and can play a role in magnetic field compensation.

[0089] During the core detection experiment, although the magnetic field shielding member 800 can significantly reduce the interference of the external magnetic field on the detection area, it is difficult to completely eliminate it. The compensation coil 920 can effectively neutralize the external interference magnetic field by generating a magnetic field in the opposite direction to the external interference magnetic field, ensuring that the magnetic field environment of the core sample during the detection process is not disturbed by the outside world, thereby improving the accuracy of the detection data.

[0090] Figure 3 This is a schematic diagram of the structure of the compensation coil in the low-field and ultra-low-field nuclear magnetic resonance sample detection system provided in the embodiment of the present application. Figure 3 The structure of the compensation coil is further described.

[0091] In a possible design, the compensation coil 920 is a cubic structure, and the guide 300 passes through the compensation coil 920. Circular coils adapted to the guide 300 are arranged on the two surfaces of the compensation coil 920 in contact with the guide 300, and square coils are arranged on the other four surfaces of the compensation coil 920. Among them, each group of coils is passed with the same current, and is responsible for generating a compensation magnetic field in different directions. The above design ensures the uniformity of the compensation magnetic field through the symmetry of the coil, thereby improving the accuracy of the detection data. In particular, two groups of square Helmholtz coils are arranged in the direction parallel to the guide 300, which can further enhance the shielding effect. On the two surfaces perpendicular to the guide 300, circular Helmholtz coils are used so that the guide 300 can pass smoothly while maintaining efficient magnetic field shielding. Compared with the traditional saddle coil, the rectangular coil requires less current, so that the entire low-field and ultra-low-field nuclear magnetic resonance sample detection system can operate at lower energy consumption, while achieving excellent performance of a residual magnetic field less than 1nT, which is conducive to improving the sensitivity and accuracy of the detection.

[0092] In this embodiment, the low-field and ultra-low-field nuclear magnetic resonance sample detection method based on the above-mentioned low-field and ultra-low-field nuclear magnetic resonance sample detection system includes:

[0093] S1. Performing magnetization treatment on the NMR sample 10 through the prepolarization element 400.

[0094] In the specific implementation process, before the NMR sample 10 is magnetized, the NMR sample 10 is also installed. Specifically, the NMR sample 10 is placed in the inner cylinder 620 of the mounting seat 600, and two sealing covers 630 are used to seal the two ends of the mounting seat 600, thereby ensuring the stability and sealing of the NMR sample 10 during the detection process. Then check whether the magnetic field shielding member 800 forms a closed low field or ultra-low field environment, and check whether the pulse coil 910 and the compensation coil 920 are connected correctly.

[0095] The method of magnetizing the NMR sample 10 by the prepolarizer 400 includes: transferring the NMR sample 10 to the magnetization processing position by the drive assembly 100. The NMR sample 10 is magnetized by the prepolarizer 400. The NMR sample 10 is magnetized according to a preset time so that the NMR sample 10 is fully polarized. Optionally, the preset time is 3-5T. 1 .

[0096] S2. The driving assembly 100 drives the NMR sample 10 to move in the guide member 300 until it reaches the detection position.

[0097] In the specific implementation process, the driving assembly 100 is started, specifically, the driving wheel 130 is driven to rotate by the motor, and then the mounting seat 600 moves horizontally with the NMR sample 10 through the cooperation of the transmission member 120 and the positioner 500. In the above process, the NMR sample 10 can pass through the guide member 700 when moving in the guide member 300, and the guide member 700 can provide a precession magnetic field for the NMR sample 10, help the sample to smoothly enter the detection position, and shield the influence of the earth's magnetic field.

[0098] S3. Within a preset detection period, the NMR sample 10 is detected by the detection component 200.

[0099] When the nuclear magnetic resonance sample 10 reaches the detection position in the guide 300, the detection part 200 starts to detect the nuclear magnetic resonance sample 10. In the core detection experiment, when the core sample reaches the detection position in the guide 300, the pulse coil 910 can apply a calibrated pulse magnetic field to the core sample, and the pulse time is 1 second to stimulate the magnetic properties of the core sample. The compensation coil 920 is responsible for compensating for the interference of the external magnetic field during the detection process to ensure the purity of the detection environment. Within the preset detection cycle, the detection part 200 continues to detect the core sample and collect relevant data. After the detection is completed, wait for 5 seconds for the low-field and ultra-low-field nuclear magnetic resonance sample detection system to resume working state and prepare for the next experimental detection. Repeat the above steps of sampling, detection and data acquisition, and obtain high signal-to-noise ratio spectra through multiple acquisitions to improve the accuracy and reliability of the detection results.

[0100] It should be noted that: in this application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0101] In addition, in this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0102] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A low-field and ultra-low-field nuclear magnetic resonance sample detection system, characterized in that: It comprises a driving component (100), a detection component (200), a guide component (300) and a prepolarization component (400), wherein the detection component (200) and the prepolarization component (400) are both located on the side of the guide component (300); The guide member (300) is arranged horizontally, and the guide member (300) is used to accommodate the nuclear magnetic resonance sample (10). The driving component (100) is used to drive the nuclear magnetic resonance sample (10) to move in the guide member (300), so that the nuclear magnetic resonance sample (10) moves from a magnetization processing position to a detection position, the magnetization processing position corresponds to the prepolarization member (400), and the detection position corresponds to the detection member (200). The prepolarization member (400) is used to magnetize the nuclear magnetic resonance sample (10), and the detection member (200) is used to detect the physical properties of the nuclear magnetic resonance sample (10) in a low field or ultra-low field environment.

2. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to claim 1, characterized in that: The driving assembly (100) comprises a driving member (110) and a transmission member (120); a positioner (500) is provided on the guide member (300); the driving member (110) is connected to the positioner (500) via the transmission member (120); the driving member (110) is used to drive the nuclear magnetic resonance sample (10) to move in the guide member (300) via the transmission member (120) and the positioner (500).

3. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to claim 2, characterized in that: The transmission member (120) is a transmission belt, and the positioner (500) is a positioning wheel; The driving member (110) is a motor, and the driving assembly (100) further comprises a driving wheel (130), wherein the driving wheel (130) is sleeved on an output shaft of the motor, and the transmission member (120) surrounds the driving wheel (130) and the positioner (500).

4. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to any one of claims 1 to 3, characterized in that: It also includes a mounting seat (600), the mounting seat (600) is located in the guide member (300), the mounting seat (600) is used to accommodate the nuclear magnetic resonance sample (10), and the driving component (100) is used to drive the mounting seat (600) to move in the guide member (300).

5. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to claim 4, characterized in that: The mounting base (600) comprises a shell (610), an inner cylinder (620) and two sealing covers (630); the inner cylinder (620) is arranged in the shell (610); a cavity for accommodating the nuclear magnetic resonance sample (10) is arranged in the inner cylinder (620); the two sealing covers (630) are respectively arranged at two ends of the shell (610); and the sealing covers (630) are used to seal the inner cylinder (620).

6. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to claim 5, characterized in that: The mounting seat (600) is provided with a pressurizing port (640), a temperature measuring port (650), a liquid inlet pipe (670) and a liquid outlet pipe (680); the pressurizing port (640), the temperature measuring port (650) and the liquid inlet pipe (670) are arranged on one of the sealing covers (630); the liquid inlet pipe (670) passes through the inner cylinder (620) and is communicated with the cavity; the liquid outlet pipe (680) is arranged on the other sealing cover (630); the liquid outlet pipe (680) passes through the inner cylinder (620) and is communicated with the cavity.

7. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to claim 4, characterized in that: It also includes a guide member (700), which is arranged inside the guide member (300), and the guide member (700) is located between the detection position and the magnetization processing position, and the guide member (700) is used to maintain the magnetization state of the nuclear magnetic resonance sample (10).

8. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to any one of claims 1 to 3, characterized in that: It also comprises a magnetic field shielding member (800), wherein the detection member (200) and part of the guide member (300) are arranged inside the magnetic field shielding member (800), and one end of the guide member (300) passes through the magnetic field shielding member (800).

9. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to claim 8, characterized in that: It also includes a pulse coil (910), wherein the pulse coil (910) is arranged in the magnetic field shielding component (800), the detection component (200) is arranged in the pulse coil (910), and the pulse coil (910) is used to apply a pulse magnetic field to the nuclear magnetic resonance sample (10).

10. The low-field and ultra-low-field nuclear magnetic resonance sample detection system according to claim 9, characterized in that: It also includes a compensation coil (920), which is arranged in the magnetic field shielding component (800), and the compensation coil (920) is arranged between the magnetic field shielding component (800) and the pulse coil (910), and the compensation coil (920) is used to compensate for the interference of the external magnetic field.

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