Nuclear magnetic probe relay mounting bracket assembly and nuclear magnetic probe

Abstract

The invention discloses a nuclear magnetic probe relay mounting bracket assembly and a nuclear magnetic probe, and belongs to the technical field of oil exploration and development, the nuclear magnetic probe relay mounting bracket assembly comprises an electrical connection assembly, a sealing assembly and a frequency adjusting assembly, the electrical connection assembly comprises an upper joint, a lower joint and a transition rod, and the upper joint and the lower joint are respectively connected to two ends of the transition rod; the sealing assembly comprises a sealing plug body, a pressure-bearing sealing plug and a sealing plug contact pin, the sealing plug contact pin penetrates through and is connected to the middle of the sealing plug body in a sealing mode, the sealing plug contact pin is electrically connected with the lower connector, the pressure-bearing sealing plug is connected to the sealing plug body, and the sealing face of the pressure-bearing sealing plug protrudes out of the outer diameter side of the sealing plug body; the frequency adjusting assembly comprises an installation disc used for installing a relay, and the installation disc is connected to the side, close to the upper connector, of the sealing plug body. The sealing assembly is used for sealing, the frequency adjusting assembly is used for frequency adjusting, the sealing performance in the ultrahigh-pressure well hole environment can be improved, and the frequency adjusting precision is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil exploration and development, in particular to a nuclear magnetic probe relay mounting bracket assembly and a nuclear magnetic probe. BACKGROUND

[0002] In the field of oil exploration and development, accurate acquisition of reservoir information is of great significance to oil and gas reservoir evaluation, resource estimation and development plan formulation. Traditional logging technology cannot meet the complex exploration needs. Nuclear magnetic resonance imaging logging (NMR) plays an irreplaceable key role in oil and gas exploration due to its direct detection capability of reservoir fluids. By analyzing the nuclear magnetic resonance signals of fluids in the formation pores, this technology can provide multi-dimensional reservoir parameters and accurately describe the reservoir characteristics, providing a core basis for oil and gas reservoir evaluation, resource estimation and development plan formulation.

[0003] Nuclear magnetic resonance logging measurement information is not affected by the rock skeleton, and the logging data is accurate and consistent, which plays an irreplaceable role in oil and gas exploration, reservoir evaluation and oil and gas exploitation.

[0004] Nuclear magnetic resonance imaging logging instrument is a high-precision instrument and equipment used for oil exploration. It detects the relaxation characteristics of hydrogen nuclei in formation pore fluids to obtain important formation information parameters such as reservoir permeability, porosity, oil saturation and pore size distribution. Its core components include nuclear magnetic electronic circuit, nuclear magnetic capacitor energy storage short circuit and nuclear magnetic probe, which work together to realize high-resolution magnetic resonance data acquisition in complex downhole environments.

[0005] Currently, in the field of oil exploration, especially in extreme environments such as deep oil and gas exploration and deep sea exploration, there are problems of sealing failure and insufficient frequency modulation accuracy in ultra-high pressure wellbore environments. SUMMARY

[0006] The purpose of the present application is to provide a nuclear magnetic probe relay mounting bracket assembly and a nuclear magnetic probe to solve the above-mentioned problems of the prior art. The sealing assembly is used for sealing, and the frequency adjustment assembly is used for frequency modulation, which can improve the sealing performance in ultra-high pressure wellbore environments and improve the frequency modulation accuracy.

[0007] To achieve the above-mentioned purpose, the present application provides the following solutions:

[0008] The application provides a nuclear magnetic probe relay mounting bracket assembly, which comprises an electrical connection assembly, a sealing assembly and a frequency adjustment assembly, the electrical connection assembly comprises an upper joint, a lower joint and a transition rod, the upper joint and the lower joint are connected to two ends of the transition rod respectively; the sealing assembly comprises a sealing plug body, a pressure-bearing sealing plug and a sealing plug pin, the sealing plug pin penetrates through and is sealingly connected to the middle part of the sealing plug body, the sealing plug pin is electrically connected with the lower joint, the pressure-bearing sealing plug is connected to the sealing plug body, and the sealing surface of the pressure-bearing sealing plug protrudes from the outer diameter side of the sealing plug body; the frequency adjustment assembly comprises a mounting disc, the mounting disc is used for mounting a relay, and the mounting disc is connected to one side of the sealing plug body close to the upper joint.

[0009] In an embodiment, the transition rod comprises a rod sleeve and a wire passing rod, a first end of the rod sleeve is connected to the upper joint, a second end of the rod sleeve is sleeved with a first end of the wire passing rod, and a second end of the wire passing rod is connected to the lower joint.

[0010] In an embodiment, the transition rod further comprises a spring, an inner diameter side of the rod sleeve is provided with a first step, an outer diameter side of the wire passing rod is provided with a second step, the spring is sleeved on the wire passing rod, a first end of the spring abuts against the first step, and a second end of the spring abuts against the second step.

[0011] In an embodiment, the wire passing rod is provided with a wire passing channel for a straight-through wire to penetrate, and the upper joint and the lower joint are electrically connected through the straight-through wire.

[0012] In an embodiment, the pressure-bearing sealing plug is provided with annular grooves, at least two annular grooves are arranged at intervals, the annular grooves are used for mounting sealing rings, and outer diameter sides of the sealing rings are provided with check rings.

[0013] In an embodiment, the sealing rings are made of fluororubber material, which can withstand a temperature of-20 DEG C to 260 DEG C, the check rings are made of PEEK material, which has a hardness of 90HRB to 95HRB and can inhibit the deformation of the sealing rings to be less than or equal to 0.1 mm under a pressure of 170 MPa.

[0014] In an embodiment, the pressure-bearing sealing plug is made by using a glass metal sintering process, when sintering at a temperature of 500 DEG C to 700 DEG C, borosilicate glass and a metal alloy surface are atomically diffused to form a transition layer with a thickness of 5 μm to 10 μm, and the interface bonding strength is greater than 200 MPa.

[0015] In an embodiment, the sealing plug body and the sealing plug pin are both made of nickel-based alloy, the two are connected by melting, and the surface of the sealing plug pin is plated with a nickel-gold plating layer system.

[0016] The application also provides a nuclear magnetic probe, which comprises the nuclear magnetic probe relay mounting support assembly as described above, a relay is mounted on the mounting disc, an input end of the relay is electrically connected to a nuclear magnetic electronic circuit through a control line, and a high-voltage end of the relay is connected to a nuclear magnetic probe frequency modulation circuit.

[0017] In an embodiment, four relays are provided, three groups of control lines are provided, and relay control signals output by the nuclear magnetic electronic circuit are used to control the on / off actions of the four relays through the control lines, wherein the first group of control lines is used to control the simultaneous actions of the first relay and the second relay, the second group of control lines is used to control the action of the third relay, and the third group of control lines is used to control the action of the fourth relay.

[0018] Three groups of six high-voltage lines output from the high-voltage ends of the first relay, the third relay and the fourth relay are respectively connected to C3 of a frequency modulation capacitor plate, capacitor C1 and capacitor C7, two high-voltage ends of the second relay are respectively connected to capacitor C6 on a fixed capacitor plate and 1TURN of a transmitting antenna, and the other end of capacitor C6 is connected to 2TURN of the transmitting antenna.

[0019] Four high-voltage lines output by the nuclear magnetic electronic circuit are respectively connected to C2, fixed capacitor C4, the transmitting antenna and fixed capacitor C5 of the nuclear magnetic probe frequency modulation circuit.

[0020] The application has the following technical effects relative to the prior art:

[0021] The application realizes the electrical connection between the nuclear magnetic electronic circuit and the nuclear magnetic probe frequency modulation circuit through the electrical connection assembly, realizes conduction and effective sealing by using the sealing plug pin in the inside of the sealing plug body, realizes sealing by using the pressure-bearing sealing plug in the outside of the sealing plug body, can guarantee the sealing performance of the sealing assembly, installs the relay by using the mounting disc, can realize frequency modulation by using the relay, and thus the application realizes sealing by using the sealing assembly and realizes frequency modulation by using the frequency adjustment assembly, can improve the sealing performance in the super-high-pressure wellbore environment, and improve the frequency modulation precision. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0023] Figure 1 It is an exploded structural schematic view of the nuclear magnetic probe relay mounting support assembly in the embodiments of the application.

[0024] Figure 2 It is the axial section schematic view of the nuclear magnetic probe relay mounting bracket assembly in the embodiment of the present application.

[0025] Figure 3 It is the electrical connection and control principle schematic view in the embodiment of the present application.

[0026] Figure 4 It is the single relay control principle schematic view in the embodiment of the present application.

[0027] Wherein, 1, upper joint; 2, rod sleeve; 3, wire passing rod; 4, relay; 5, mounting disc; 6, lower joint; 7, pressure-bearing sealing plug; 8, sealing plug body; 9, spring; 10, control line; 11, sealing plug pin; 12, straight-through line; 21, first step; 31, second step. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0029] The purpose of the present application is to provide a nuclear magnetic probe relay mounting bracket assembly and a nuclear magnetic probe, so as to solve the problems in the prior art. The sealing is performed by using a sealing assembly, and the frequency adjustment is performed by using a frequency adjustment assembly. The sealing performance in the ultra-high pressure wellbore environment can be improved, and the frequency adjustment precision can be improved.

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0031] As Figures 1-4As shown, the present application provides a nuclear magnetic probe relay mounting bracket assembly, which comprises an electrical connection assembly, a sealing assembly and a frequency adjustment assembly. The electrical connection assembly comprises an upper joint 1, a lower joint 6 and a transition rod. The upper joint 1 and the lower joint 6 are respectively connected to the two ends of the transition rod. The transition rod supports and fixes the upper joint 1 and the lower joint 6. The upper joint 1 is used to be connected to the lower joint of the nuclear magnetic electronic circuit. The lower joint 6 is used to be connected to the frequency modulation circuit of the nuclear magnetic probe. The transition rod can be a single rod structure or a multi-rod combined structure. The sealing assembly comprises a sealing plug body 8, a pressure-bearing sealing plug 7 and a sealing plug pin 11. The sealing plug pin 11 penetrates and is sealingly connected to the middle part of the sealing plug body 8. The sealing plug pin 11 is electrically connected to the lower joint 6. The pressure-bearing sealing plug 7 is connected to the sealing plug body 8. The sealing surface of the pressure-bearing sealing plug 7 protrudes from the outer diameter side of the sealing plug body 8. The pressure-bearing sealing plug 7 realizes sealing with the installed structure. The frequency adjustment assembly comprises a mounting disc 5. The mounting disc 5 is used to mount the relay 4. The mounting disc 5 is connected to the side of the sealing plug body 8 close to the upper joint 1. The mounting disc 5 can be annularly sleeved on the outer diameter side of the transition rod. There can be a gap between the mounting disc 5 and the transition rod. The gap is used for the arrangement of the circuit.

[0032] The present application realizes the electrical connection between the lower joint of the nuclear magnetic electronic circuit and the frequency modulation circuit of the nuclear magnetic probe through the electrical connection assembly. The sealing plug pin 11 is used for conduction and effective sealing in the inside of the sealing plug body 8. The pressure-bearing sealing plug 7 is used for sealing in the outside of the sealing plug body 8. The sealing performance of the sealing assembly can be guaranteed. The relay 4 is mounted by the mounting disc 5. The frequency modulation can be realized by the relay 4. Therefore, the present application realizes sealing by the sealing assembly and realizes frequency modulation by the frequency adjustment assembly. The sealing performance in the ultra-high pressure well environment can be improved. The frequency modulation accuracy can be improved.

[0033] In an embodiment, the mounting disc 5 (aluminum alloy 7075-T6, anodized conductive yellow treatment) is provided with a U-shaped mounting groove. The relay 4 is fixed in the U-shaped mounting groove by M3 hexagonal screws. RTV silicone rubber (Shore hardness 50A) is used to fill the gap. The impact resistance can be realized. The problems such as the increase of contact resistance caused by vibration and the damage of the relay 4 can be prevented. The reliable operation of the instrument can be ensured.

[0034] In an embodiment, as shown in Figure 1 and Figure 2 The transition rod comprises a rod sleeve 2 and a wire passing rod 3. The rod sleeve 2 is a hollow structure. The first end of the rod sleeve 2 is connected to the upper joint 1. The upper joint 1 can be inserted into the first end of the rod sleeve 2 to realize the mounting and fixation of the upper joint 1 and the rod sleeve 2. The second end of the rod sleeve 2 is sleeved and connected to the first end of the wire passing rod 3 to realize the mounting and fixation of the rod sleeve 2 and the wire passing rod 3. The second end of the wire passing rod 3 is connected to the lower joint 6.

[0035] In this example, the transition rod adopts a sleeve structure combined with a rod sleeve 2 and a wire passing rod 3 (material: aluminum alloy 7075-T6), an internal wire passing channel for 19-core straight-through wires 12 is provided, and 6 control wires 10 and 4 high-voltage pulse wires (16G red / white twisted wires) are fixed outside through an insulating tape. The insulating tape (temperature resistance 175°C) is wound and reinforced, and after a certain time of vibration test, there is no phenomenon such as skin breakage and wear, and the perfect rate of the wire insulation layer is 100%.

[0036] In this example, the control wires 10 are used to transmit 27-30VDC relay on / off driving signals, and four K40-P relays are controlled through differential wiring (twisted pair) design, and the switch response time is less than 10ms, which ensures real-time transmission of frequency modulation commands.

[0037] In an embodiment, as shown in Figure 1 and Figure 2 , the transition rod further comprises a spring 9, a first step 21 is arranged on the inner diameter side of the rod sleeve 2, a second step 31 is arranged on the outer diameter side of the wire passing rod 3, and the first step 21 and the second step 31 have a spacing after the rod sleeve 2 and the wire passing rod 3 are inserted, the spring 9 is sleeved on the wire passing rod 3, the first end of the spring 9 abuts against the first step 21, and the second end of the spring 9 abuts against the second step 31. Through the arrangement of the spring 9, the rod sleeve 2 and the wire passing rod 3 can slide relatively in the axial direction and have a certain elasticity, so that the upper joint 1 has a buffer amount when the upper joint 1 is installed, and damage caused by hard connection is avoided.

[0038] In an embodiment, as shown in Figure 1 and Figure 2 , the wire passing rod 3 is provided with a wire passing channel for the straight-through wires 12 to penetrate, which facilitates the arrangement of the straight-through wires 12, and the upper joint 1 and the lower joint 6 are electrically connected through the straight-through wires 12.

[0039] In this example, the upper joint 1 is a joint of 18-core straight-through wires 12, and the straight-through wires 12 are designed to provide power supply (such as 120Vac instrument main power and auxiliary power) and bidirectional communication (downlink command and measurement data upload) interface for lower instruments when the nuclear magnetic instrument is connected to other logging instrument devices. If there is no need to connect to the instrument, the straight-through wires 12 can be removed, and only the plug and the plug-in insulating sleeve (polytetrafluoroethylene material, temperature resistance 200°C) are reserved to avoid the risk of circuit short circuit.

[0040] In this example, the straight-through wires 12 adopt 19 high-temperature wires (polyimide insulation layer, temperature resistance 260°C), which realize electrical penetration through the lower joint 6.

[0041] In an embodiment, as shown in Figure 1 and Figure 2As shown, the pressure-bearing sealing plug 7 is provided with annular grooves, at least two annular grooves are arranged at intervals, the annular grooves are used to install sealing rings, and the outer diameter side of the sealing ring is provided with a retainer. The sealing ring further improves the sealing performance, and the retainer can inhibit the maximum deformation of the sealing ring and protect the sealing ring. Through the arrangement of the sealing ring and the retainer, the pressure resistance of the pressure-bearing sealing plug 7 is improved, which can withstand ≥170MPa wellbore mud pressure (traditional products are only 140MPa), prevent mud from entering the instrument, protect the relay 4, the frequency modulation capacitor plate and other elements from corrosion and short circuit risk of ultra-high pressure mud, and is suitable for ultra-deep well operation of well depth 7000m-10000m.

[0042] In this example, the lower connector 6 installed inside the pressure-bearing sealing plug 7 is a 37-core plug, the outer ring 18-core is a nuclear magnetic instrument signal channel, and the inner ring 19-core is a straight-through line 12 channel. The insulation resistance is >1000MΩ (the traditional product is about 500MΩ), and the voltage resistance is 2000V, which ensures the transmission of high-frequency high-voltage transmission signals.

[0043] In an embodiment, the sealing ring is made of fluororubber material with a temperature resistance of -20℃ to 260℃; the retainer is made of PEEK material with a hardness of 90HRB-95HRB, and the deformation amount of the sealing ring is ≤0.1mm under 170MPa pressure, which can effectively prevent the sealing ring from being extruded and damaged, and significantly improve the sealing method compared with the traditional scheme.

[0044] In an embodiment, the pressure-bearing sealing plug 7 adopts a glass metal sintering process. When sintering at 500℃-700℃, atomic-level diffusion occurs between borosilicate glass and the surface of the metal alloy, forming a transition layer with a thickness of 5μm-10μm, and the interfacial bonding strength is >200MPa, which is much higher than the design pressure of 175MPa. The glass phase is in an amorphous state after cooling, and the internal micro-porosity is <0.1%, which can block the fluid penetration path. Glass-to-Metal Sealing (GTMS) is a process of forming airtight sealing between glass and metal through high-temperature sintering. This process is widely used in electronic packaging, aerospace, oil exploration (such as pressure sealing of nuclear magnetic resonance logging instruments), medical devices and other fields to achieve high reliability, high pressure resistance and corrosion resistance. Through the cross-border innovation of material science and mechanics design, the glass metal sintering sealing breaks through the bottleneck of traditional sealing technology in ultra-high pressure and wide temperature range scenes, and provides a core sealing solution for extreme environments such as deep oil and gas exploration and deep sea exploration. Compared with the traditional design, the glass-metal sintering layer has insulation properties, which can avoid the interference of high-voltage and high-current emission pulse leakage current, ensure the capacitance switching of the LC frequency modulation circuit and the stable transmission of the nuclear magnetic resonance signal, and provide strong guarantee for the quality of nuclear magnetic logging in extreme environments (high temperature and high pressure).

[0045] In an embodiment, the sealing plug body 8 and the sealing plug pin 11 are both made of a nickel-based alloy, and the two are connected by melting to ensure the connection strength. The surface of the sealing plug pin 11 is plated with a nickel-gold plating system. The nickel-gold plating (Electroless Nickel / Immersion Gold, ENIG) is a high-performance surface treatment technology widely used in electronic packaging, PCB (printed circuit board), semiconductors, aerospace, and other fields. The system consists of a chemical nickel (Ni) layer + chemical immersion gold (Au) layer, and has excellent weldability, conductivity, corrosion resistance, and oxidation resistance.

[0046] In this example, the sealing plug body 8 and the sealing plug pin 11 are both made of Inconel X-750 nickel-based alloy (Ni≥70%, Cr 14-17%, Ti 2.25-2.75%), which is subjected to double aging treatment, has high tensile strength, and is resistant to corrosion in H2S-containing mud with a corrosion rate of ≤0.05 mm / year. The surface of the sealing plug pin 11 is plated with a "nickel (75±25 μm) + gold (75±15 μm)" plating system, the contact resistance is <1 Ω, the oxidation resistance is strong at 200°C, and the electrical connection reliability in extreme environments (high temperature and high pressure) is ensured.

[0047] The nuclear magnetic detection relay mounting bracket assembly of the application has the following effects:

[0048] Electrical connection: connects the upper nuclear magnetic electronic circuit and the lower nuclear magnetic probe frequency modulation circuit (frequency modulation capacitor plate and fixed capacitor plate, etc.), and realizes the through line of the instrument.

[0049] Frequency modulation: under the control of the relay control signal transmitted from the upper nuclear magnetic electronic circuit, the four relays 4 switch their on / off states, change the capacitance value of the probe antenna, and form five frequency band high-voltage transmission pulses according to the mechanism of the LC frequency modulation circuit.

[0050] Pressure sealing: the sealing assembly has a 19-core channel to realize signal transmission between the mounting disc 5 and the nuclear magnetic probe frequency modulation circuit; a glass-metal sintering sealing structure is used to withstand ≥175 MPa wellbore mud pressure, avoid mud intrusion into the instrument under high pressure, protect the relays 4, circuit boards and other electrical components from corrosion and short circuit risk, and ensure safe operation of well logging in ultra-deep wells (such as depths below 8000 m).

[0051] Relay 4 installation, control line 10, high-voltage transmission pulse connection, etc.

[0052] As Figures 1-4As shown, the present invention also provides a nuclear magnetic probe, including the nuclear magnetic probe relay mounting bracket assembly as described above, a relay 4 is installed on the mounting plate 5, the input end of the relay 4 is electrically connected to the nuclear magnetic electronic circuit through the control line 10, and the high-voltage end of the relay 4 is connected to the nuclear magnetic probe frequency modulation circuit. The nuclear magnetic probe frequency modulation circuit includes a frequency modulation capacitor plate and a fixed capacitor plate, etc. By switching the on / off position, the capacitance value connected to the probe transmitting / receiving antenna is changed, and according to the principle of the LC circuit (inductor-capacitor circuit), 5 transmission pulses of different frequency bands are formed.

[0053] like Figure 4 The figure shows the control schematic for a single relay. E1 and E2 connect to control line 10. Relay 4 has two on / off control lines, each with a 26VDC-30VDC DC voltage signal. The voltages (+ and -) on these two control lines 10 differ, indicating different current directions. After passing through the diodes shown, the current flowing through the relay's closing and opening coils has different directions, controlling the closing and opening of the circuit between relay 4's high-voltage output terminals A1 and A2. The voltages across control line 10 are 30V, or +15VDC and -15VDC, respectively, indicating the direction of the current applied to control line 10.

[0054] When E1 is + and E2 is -, D2 and D1 are turned on, diode D5 is turned off, the current flowing through the coil is from right to left, relay 4 is energized, and A1 and A2 are turned on; when E1 is - and E2 is +, diodes D5 and D6 are turned on, D4 is turned off, the current flowing through the coil is from left to right, relay 4 is open, and A1 and A2 are disconnected.

[0055] Mechanism: The "on / off" states of A1 and A2 are different, and the capacitance values ​​connected to the transmitting antenna are different.

[0056] In one embodiment, it also includes red / white high-voltage wires. There are two groups of red / white high-voltage wires, two groups of 16G conductors (silver-plated copper core, current carrying capacity of 20A), which are connected to the lower connector Pin26 / 27 and Pin28 / 29 of the nuclear magnetic electronic circuit, transmit 500=1500V high-voltage transmission pulses, and are connected to the frequency modulation capacitor board at the bottom. The temperature and voltage resistance meet the high voltage and large current requirements of nuclear magnetic transmission.

[0057] In one embodiment, if Figure 3 As shown, four relays 4 are provided, and three groups of control lines 10 are provided. The relay control signals output by the nuclear magnetic electronic circuit respectively control the on / off actions of the four relays 4 through the control lines 10. Among them, the first group of control lines controls the simultaneous action of the first relay and the second relay; the second group of control lines controls the action of the third relay, and the third group of control lines controls the action of the fourth relay;

[0058] The 3 groups of 6 high-voltage lines output from the high-voltage ends of the first, third and fourth relays are connected to the C3 of the frequency modulation capacitor plate, the capacitor C1 and the capacitor C7 respectively, the 2 high-voltage ends of the second relay are connected to the capacitor C6 on the fixed capacitor plate and the 1 TURN of the transmitting antenna respectively, and the other end of the capacitor C6 is connected to the 2 TURN of the transmitting antenna.

[0059] The 4 high-voltage lines output from the nuclear magnetic electronic circuit are connected to the C2 of the frequency modulation capacitor plate, the fixed capacitor C4, the transmitting antenna and the fixed capacitor C5 respectively, and the 4 K40-P type high-voltage relays 4 (with a temperature resistance of 175℃ and a contact resistance of <1Ω) are switched by the matrix switch logic (as shown in Table 1) to switch the 81nF-55nF capacitor to realize the 590kHz-770kHz frequency band adjustment, and the frequency error is ≤0.5%.

[0060] In this example, as shown in Figure 3 The relay control signals output from the lower joint of the nuclear magnetic electronic circuit are controlled by the 3 groups of 6 control lines 10, i.e. 24, 25, 20, 21, 22, 23, on the mounting bracket 5, to control the on / off actions of the four relays 4, i.e. K11, K12, K13, K14 respectively. Among them, the two control lines 10, i.e. 24, 25, control the simultaneous actions of K11 and K12; the control lines 20, 21 control K13, and the control lines 22, 23 control K14.

[0061] Figure 3 The 3 groups of 6 high-voltage lines output from the high-voltage ends of K11, K13 and K14 at the relay mounting bracket assembly are connected to the C3, C1 and C7 of the frequency modulation capacitor plate respectively, the 2 high-voltage output ends of K12 are connected to the capacitor C6 on the fixed capacitor plate and the 1 TURN of the transmitting antenna (probe transmitting / receiving antenna) respectively, and the other end of the capacitor C6 is connected to the 2 TURN of the transmitting antenna (probe transmitting / receiving antenna). The 4 high-voltage lines 26, 27, 28, 20 output from the lower joint of the nuclear magnetic electronic circuit are connected to the C2 of the frequency modulation capacitor plate, the fixed capacitor C4, the transmitting antenna and the fixed capacitor C5 respectively.

[0062] The relay control signals from the nuclear magnetic electronic circuit control the on / off states of the 4 relays according to different measurement modes, continuously change the capacitance value connected to the transmitting antenna L in the high-voltage pulse transmitting loop, and form 5 frequency bands of transmitting pulses according to the principle of LC oscillation circuit. The transmitting frequency bands are 590±5Khz, 616±5Khz, 640±5Khz, 680±5Khz and 770±5Khz.

[0063] As shown in Figure 3As shown, the relay control signals output by the nuclear magnetic resonance electronic circuitry control four relays, K11, K12, K13, and K14, respectively, via three groups of six control lines 10. Lines 24 and 25 simultaneously control K11 and K12, so the on / off states of these two relays 4 are identical. Lines 20 and 21 control K13, while lines 22 and 23 control K14. When K11 and K12 are closed, capacitors C3 (4.8nF) and C6 (10nF) are connected to the transmitting antenna; when open, they are disconnected. When K13 is closed, capacitor C13 (6nF) is connected to the antenna transmitting circuit; when open, it is disconnected. When K14 is closed, capacitor C7 is connected to the antenna transmitting circuit; when open, it is disconnected.

[0064] Table 1: Capacitor values ​​for each frequency band of relay control and transmitter circuits

[0065]

[0066] In Table 1, +15 and -15 indicate the current direction of the relay control signal. The capacitance values ​​represent the capacitance values ​​connected to the transmit antenna at different frequency bands. As can be seen from Table 1, the coordinated switching of the four relays 4 determines the five capacitance values ​​connected to the transmit antenna at five frequency bands, thereby adjusting the frequency range of the transmitted pulse.

[0067] Table 2: Capacitance values ​​for each frequency band

[0068]

[0069] In Table 2, the inductance value of the nuclear magnetic transmitting antenna is L≈0.90uH. The frequency value of a certain frequency band is calculated according to the calculation formula of the LC circuit:

[0070] For example: BAND 0, inductance L≈0.90uH, capacitance C=81.2nF,

[0071] According to the formula The frequency f≈590Khz is calculated.

[0072] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A nuclear magnetic probe relay mounting bracket assembly, characterized in that: include: An electrical connection assembly, comprising an upper joint, a lower joint, and a transition rod, wherein the upper joint and the lower joint are respectively connected to two ends of the transition rod; A sealing assembly comprising a sealing plug body, a pressure-bearing sealing plug, and a sealing plug pin, wherein the sealing plug pin penetrates and is sealingly connected to the middle portion of the sealing plug body, the sealing plug pin is electrically connected to the lower connector, the pressure-bearing sealing plug is connected to the sealing plug body, and the sealing surface of the pressure-bearing sealing plug protrudes from the outer diameter side of the sealing plug body; And a frequency regulating component, the frequency regulating component includes a mounting plate, the mounting plate is used to mount the relay, and the mounting plate is connected to a side of the sealing plug body close to the upper joint.

2. The nuclear magnetic field probe relay mounting bracket assembly according to claim 1, characterized in that: The transition rod includes a rod sleeve and a wire-passing rod, the first end of the rod sleeve is connected to the upper joint, the second end of the rod sleeve is sleeved and connected to the first end of the wire-passing rod, and the second end of the wire-passing rod is connected to the lower joint.

3. The nuclear magnetic probe relay mounting bracket assembly according to claim 2, characterized in that: The transition rod also includes a spring, a first step is provided on the inner diameter side of the rod sleeve, a second step is provided on the outer diameter side of the wire-passing rod, the spring is sleeved on the wire-passing rod, the first end of the spring abuts against the first step, and the second end of the spring abuts against the second step.

4. The nuclear magnetic field probe relay mounting bracket assembly according to claim 2, characterized in that: The wire rod is provided with a wire passage for a straight-through wire to pass through, and the upper connector and the lower connector are electrically connected via the straight-through wire.

5. The nuclear magnetic probe relay mounting bracket assembly according to claim 1, characterized in that: The pressure-bearing sealing plug is provided with an annular groove, and at least two of the annular grooves are arranged at intervals. The annular groove is used to install a sealing ring, and a retaining ring is provided on the outer diameter side of the sealing ring.

6. The nuclear magnetic field probe relay mounting bracket assembly according to claim 5, characterized in that: The sealing ring is made of fluororubber and has a temperature resistance of -20°C to 260°C; the retaining ring is made of PEEK and has a hardness of 90HRB to 95HRB, and can suppress the deformation of the sealing ring to ≤0.1mm under a pressure of 170MPa.

7. The nuclear magnetic field probe relay mounting bracket assembly according to claim 1, characterized in that: The pressure-bearing sealing plug adopts a glass-metal sintering process. When sintered at 500°C to 700°C, atomic-level diffusion occurs between the borosilicate glass and the metal alloy surface to form a transition layer with a thickness of 5μm to 10μm, and the interface bonding strength is greater than 200MPa.

8. The nuclear magnetic field probe relay mounting bracket assembly according to claim 1, characterized in that: The sealing plug body and the sealing plug pin are both made of nickel-based alloy, and the two are connected by fusion. The surface of the sealing plug pin is coated with a nickel-gold coating system.

9. A nuclear magnetic probe, characterized in that: It comprises a nuclear magnetic probe relay mounting bracket assembly as described in any one of claims 1 to 8, wherein a relay is mounted on the mounting plate, the input end of the relay is electrically connected to the nuclear magnetic electronic circuit through a control line, and the high-voltage end of the relay is connected to the nuclear magnetic probe frequency modulation circuit.

10. The nuclear magnetic probe according to claim 9, characterized in that: There are four relays and three groups of control lines. The relay control signals output by the nuclear magnetic resonance electronic circuit control the on / off actions of the four relays respectively through the control lines. The first group of control lines controls the simultaneous action of the first relay and the second relay; the second group of control lines controls the action of the third relay; and the third group of control lines controls the action of the fourth relay. Three groups of six high-voltage wires are output from the high-voltage terminals of the first, third, and fourth relays, and are connected to capacitors C3, C1, and C7 of the FM capacitor board, respectively. The two high-voltage terminals of the second relay are connected to capacitor C6 on the fixed capacitor board and 1TURN of the transmitting antenna, respectively. The other end of capacitor C6 is connected to 2TURN of the transmitting antenna. The four high-voltage wires output by the nuclear magnetic electronic circuit are respectively connected to C2 of the frequency modulation capacitor plate, the fixed capacitor C4, the transmitting antenna, and the fixed capacitor C5.

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