Far detection nuclear magnetic resonance logging instrument probe

Abstract

The invention discloses a far detection nuclear magnetic resonance logging instrument probe, which relates to the technical field of petroleum logging, and comprises a protective shell, a support piece, a magnet assembly, a magnetic core assembly and a detection antenna, a protection cavity is formed in the protection shell; the magnet assembly comprises a main magnet and two sets of auxiliary magnets which extend in the axial direction of the protection cavity. The main magnet is arranged in the middle of the protection cavity and is symmetrical about the supporting piece, and at least part of the outer wall surface of the main magnet is a convex arc surface; the two sets of auxiliary magnets are arranged on the two sides of the main magnet in the axial direction of the protection cavity, and the sets of auxiliary magnets are symmetrically arranged relative to the supporting piece. The magnetic core assembly is arranged in the protection cavity and extends in the axial direction of the protection cavity, and the magnetic core assembly is arranged on the outer side of the main magnet and is symmetrical about the supporting piece. The detection antenna is arranged on one side in the protection cavity and fixedly attached to the outer wall face of the magnetic core assembly on the two sides of the supporting piece, and the detection antenna is electrically connected with an external detector. According to the probe of the far detection nuclear magnetic resonance logging instrument, the detection depth can be increased.

Description

Technical Field

[0001] This invention relates to the field of oil well logging technology, and in particular to a remote detection nuclear magnetic resonance logging probe. Background Technology

[0002] Nuclear magnetic resonance logging utilizes the nuclear magnetic resonance signals generated when hydrogen nuclei in hydrogen-rich liquids (oil, water) and gases (natural gas) in formation pores are excited. Through logging interpretation, it can be used to quantitatively determine parameters such as effective porosity, free fluid porosity, bound water porosity, pore size distribution, permeability, and crude oil viscosity and wettability.

[0003] However, existing nuclear magnetic resonance logging has a shallow radial detection depth (mostly 6~10cm), making it susceptible to the influence of wellbore mud intrusion, which causes significant interference in reservoir evaluation. Summary of the Invention

[0004] The purpose of this invention is to provide a remote detection nuclear magnetic resonance logging probe to solve the problems existing in the prior art and improve the detection depth.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a remote-detection nuclear magnetic resonance logging probe, comprising a protective shell, a support member, a magnet assembly, a magnetic core assembly, and a detection antenna. The protective shell contains a protective cavity. The support member is axially disposed within the protective cavity. The magnet assembly is disposed within the protective cavity and fixedly connected to the support member. The magnet assembly includes a main magnet extending axially along the protective cavity and two sets of auxiliary magnets. The main magnet is located in the middle of the protective cavity and symmetrically arranged about the support member, with at least a portion of its outer wall surface being a convex arc surface. The two sets of auxiliary magnets are axially disposed on both sides of the main magnet and symmetrically arranged about the support member. The magnetic core assembly is disposed within the protective cavity and extends axially along the protective cavity, positioned outside the main magnet and symmetrically arranged about the support member. The detection antenna is disposed within the protective cavity and fixedly attached to the outer wall surface of the magnetic core assembly on both sides of the support member, and the detection antenna is used for electrical connection to an external detector.

[0006] Preferably, the support member is a metal sheet, and the magnet assembly is magnetically fixed to the metal sheet; and the long edge of the magnet assembly does not extend beyond the long edge of the support member in the width direction.

[0007] Preferably, the main magnets on both sides of the support member and the two sets of auxiliary magnets are all covered with a shell; the inner wall of the magnetic core assembly is attached to the outer wall of the shell on the outside of the main magnet.

[0008] Preferably, the main magnet and the auxiliary magnet are magnetized in the same direction, both perpendicular to the central axial section of the protective cavity; and the outer wall surface of the lower half of the main magnet is set as a convex arc surface; the cross-section of the auxiliary magnet is set as a rectangle.

[0009] Preferably, the magnetic core assemblies on both sides of the support member each include a first magnetic core and a second magnetic core that are separately arranged. The outer and inner walls of the first and second magnetic cores are respectively used to fit against the inner wall of the protective shell and the outer wall of the magnet assembly. The first magnetic core is close to the detection antenna, and the detection antenna is fixedly attached to the outer wall surface of the first magnetic core on both sides of the support member.

[0010] Preferably, the detection antenna includes a first main antenna, which is fixedly attached to the outer wall surface of the first magnetic core on both sides of the support member.

[0011] Preferably, the detection antenna includes a second main antenna and a spoiler antenna. The second main antenna is fixedly attached to the outer wall surface of the first magnetic core on both sides of the support member, and the spoiler antenna is fixedly attached to the outer wall surface of the second magnetic core on both sides of the support member. The magnetic fields generated by the second main antenna and the spoiler antenna are in opposite directions.

[0012] Preferably, the assembly further includes positioning hoops disposed at both axial ends of the magnetic core assembly. The positioning hoops are sleeved on the outside of the magnet assembly and can form a detachable fixed connection with the support member.

[0013] Preferably, the protective cavity is further provided with a filler, which is placed between the two positioning clamps and extends along an axis parallel to the protective cavity. The filler is used to fill the circumferential gap between the magnetic core assembly and the support member, and the filler is connected to the magnetic core assembly and the support member.

[0014] Preferably, it further includes a spoiler antenna, which is disposed in the protective cavity on the side opposite to the detection antenna and is fixedly attached to the outer wall of the magnetic core assembly on both sides of the support member, and the spoiler antenna is used to electrically connect to an external detector.

[0015] Preferably, the protective shell includes a middle outer shell, side outer shells, and a support shell; the middle outer shell has the side outer shell and the support shell on both axial sides; the middle outer shell is detachably coaxially connected to the side outer shell on both axial sides, and the middle outer shell is used to detachably fit over the magnetic core assembly; the auxiliary magnets on both sides of the magnetic core assembly are respectively disposed in the two support shells, and the support shell is detachably connected to the support member, and a wire passage is provided in one side of the support shell; the two side outer shells are detachably coaxially fitted over the two support shells respectively.

[0016] The present invention achieves the following technical effects compared to the prior art: The remote-detection nuclear magnetic resonance logging probe provided by this invention is supported and protected by a protective shell and support components. Furthermore, the magnet assembly within the protective shell is configured as a three-section structure: an auxiliary magnet, a main magnet, and an auxiliary magnet, all extending axially. This not only enhances the local static magnetic field strength of the probe but also effectively extends the uniform region length of the axial static magnetic field, improving the longitudinal coverage and signal stability of the detection. In addition, by providing a convex arc surface on the outer wall of the main magnet, the spatial distribution of the static magnetic field can be further optimized, significantly increasing the static magnetic field strength within the working area, thereby enhancing the detection signal strength and signal-to-noise ratio, and ultimately improving the detection depth. A magnetic core assembly is installed outside the magnet assembly, effectively guiding and concentrating magnetic lines of force, optimizing the magnetic field path, and significantly suppressing eddy current generation under the action of the alternating magnetic field generated by the detection antenna, reducing useless heat loss, improving energy efficiency, and further increasing the detection depth. Thus, with the improved detection strength, the detection antenna can be electrically connected to an external detector to achieve the excitation and signal reading of hydrogen nuclei in the formation, revealing information such as formation porosity and fluid properties. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an axial view of the support member provided in Embodiment 1 of the present invention; Figure 2 This is an axial side view of the main magnet provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the magnetization direction of the main magnet provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the cooperation between the support member and the main magnet provided in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the outer casing of the main magnet provided in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the structure of the auxiliary magnet provided in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the magnetization direction of the auxiliary magnet provided in Embodiment 1 of the present invention; Figure 8 for Figure 4 Schematic diagram of the interaction with the auxiliary magnet; Figure 9This is a schematic diagram of the outer casing of the auxiliary magnet provided in Embodiment 1 of the present invention; Figure 10 A schematic diagram of the first magnetic core provided in Embodiment 1 of the present invention; Figure 11 A schematic diagram of the second magnetic core provided in Embodiment 1 of the present invention; Figure 12 This is a side view of the magnetic core assembly and magnet assembly in cooperation according to Embodiment 1 of the present invention; Figure 13 for Figure 8 Axial side schematic diagram of the magnetic core assembly; Figure 14 This is an axial side view of the filler provided in Embodiment 1 of the present invention; Figure 15 This is a side view of the filling material, magnetic core assembly, and magnet assembly provided in Embodiment 1 of the present invention. Figure 16 This is an axial side view of the positioning hoop provided in Embodiment 1 of the present invention; Figure 17 for Figure 12 Diagram showing the fit with the positioning clamp; Figure 18 This is an axial view of a support shell provided in Embodiment 1 of the present invention; Figure 19 for Figure 18 A schematic diagram showing the fit between the provided support shell and the support components; Figure 20 This is an axial view of the other side support shell provided in Embodiment 1 of the present invention; Figure 21 This is an axial side view of one side of the outer casing provided in Embodiment 1 of the present invention; Figure 22 for Figure 18 The provided support shell and Figure 21 A schematic diagram showing the fit of the side shell; Figure 23 This is an axial view of the other side of the outer casing provided in Embodiment 1 of the present invention; Figure 24 for Figure 20 The provided support shell and Figure 23 A schematic diagram showing the fit of the side shell; Figure 25 This is an axial side view of the fixing ring provided in Embodiment 1 of the present invention; Figure 26 This is an axial view of the probe (with the middle outer shell removed) of the remote detection nuclear magnetic resonance logging tool provided in Embodiment 1 of the present invention; Figure 27This is an axial view of the probe of the remote detection nuclear magnetic resonance logging tool provided in Embodiment 1 of the present invention; Figure 28 for Figure 27 A schematic diagram of the cross-section of the probe of the remote detection nuclear magnetic resonance logging tool; Figure 29 This is a schematic diagram of the static magnetic field direction of the magnet assembly provided in Embodiment 1 of the present invention; Figure 30 This is a schematic diagram of the radio frequency magnetic field direction of the probe antenna provided in Embodiment 1 of the present invention; Figure 31 This is a schematic diagram of the first main antenna provided in Embodiment 1 of the present invention; Figure 32 This is an axial view of the probe (with the middle outer shell removed) of the remote detection nuclear magnetic resonance logging tool provided in Embodiment 2 of the present invention; Figure 33 This is a schematic diagram of the second main antenna in Embodiment 2; Figure 34 This is a schematic diagram of the scrambling antenna in Example 2.

[0019] In the diagram: 1-Protective shell; 11-Middle shell; 12-Side shell; 13-Support shell; 131-Wire passage; 2-Support component; 3-Magnet assembly; 31-Main magnet; 32-Auxiliary magnet; 33-Shell; 4-Magnetic core assembly; 41-First magnetic core; 42-Second magnetic core; 5-Detection antenna; 51-First main antenna; 52-Second main antenna; 53-Disturbance antenna; 6-Positioning clamp; 7-Filling material; 8-Fixing ring; 9-Disturbance antenna. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The purpose of this invention is to provide a remote detection nuclear magnetic resonance logging probe to solve the problems existing in the prior art and improve the detection depth.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Example 1 This embodiment provides a remote detection nuclear magnetic resonance logging tool probe. Please refer to [link to relevant documentation]. Figures 1-30The system includes a protective shell 1, a support member 2, a magnet assembly 3, a magnetic core assembly 4, and a detection antenna 5. The protective shell 1 has a protective cavity inside. The support member 2 is axially positioned within the protective cavity. The magnet assembly 3 is located within the protective cavity and fixedly connected to the support member 2. The magnet assembly 3 includes a main magnet 31 extending axially along the protective cavity and two sets of auxiliary magnets 32. The main magnet 31 is located in the middle of the protective cavity and symmetrically arranged about the support member 2, with at least a portion of its outer wall surface being a convex arc surface. The two sets of auxiliary magnets 32 are axially positioned on both sides of the main magnet 31, and each set of auxiliary magnets 32 is symmetrically arranged about the support member 2. The magnetic core assembly 4 is located within the protective cavity and extends axially along the protective cavity, positioned outside the main magnet 31 and symmetrically arranged about the support member 2. The detection antenna 5 is located within the protective cavity and fixedly attached to the outer wall surface of the magnetic core assembly 4 on both sides of the support member 2, and the detection antenna 5 is used for electrical connection to an external detector.

[0024] The system is supported and protected by a protective shell 1 and a support member 2. The magnet assembly 3 within the protective shell 1 is designed as a three-section structure: an auxiliary magnet 32, a main magnet 31, and an auxiliary magnet 32, all extending axially. This not only enhances the local static magnetic field strength of the probe but also effectively extends the uniform area length of the axial static magnetic field, improving the longitudinal coverage and signal stability of the detection. Furthermore, by providing a convex arc surface on the outer wall of the main magnet 31, the spatial distribution of the static magnetic field is further optimized, significantly increasing the static magnetic field strength within the working area, thereby enhancing the detection signal strength and signal-to-noise ratio, and ultimately improving the detection depth. A magnetic core assembly 4 is installed outside the magnet assembly 3, effectively guiding and concentrating magnetic lines of force, optimizing the magnetic field path. Simultaneously, under the action of the alternating magnetic field generated by the detection antenna 5, it significantly suppresses eddy current generation, reduces useless heat loss, improves energy efficiency, and further enhances the detection depth. Thus, with the improved detection strength, the detection antenna 5 can be electrically connected to an external detector to excite hydrogen nuclei in the formation and read signals, revealing information such as the porosity and fluid properties of the formation.

[0025] In the optional scheme of this embodiment, more preferably, the support member 2 is a metal sheet, and the magnet assembly 3 is magnetically fixed to the metal sheet; and the long edge of the magnet assembly 3 does not extend beyond the long edge of the support member 2 in the width direction.

[0026] By setting the support member 2 as a metal sheet such as an iron sheet, the overall strength can be ensured. In addition, the support member 2 can be directly fixed to the magnet assembly 3 by magnetic attraction, simplifying the assembly structure. Moreover, the long edge of the magnet assembly 3 does not extend beyond the long edge of the support member 2 in the width direction. Specifically, the long edge of the magnet assembly 3 is flush with the long edge of the support member 2 in the width direction, reducing eddy current losses.

[0027] In the optional scheme of this embodiment, more preferably, the main magnets 31 on both sides of the support member 2 and the two sets of auxiliary magnets 32 are covered with shells 33; the inner wall of the magnetic core assembly 4 is attached to the outer wall of the shells 33 on the outside of the main magnets 31.

[0028] The outer shell 33 covering the main magnet 31 and the auxiliary magnet 32 ​​has the same shape as the corresponding main magnet 31 and auxiliary magnet 32. It covers the outside of the magnet assembly 3 and can effectively limit and protect the main magnet 31 and auxiliary magnet 32, preventing the magnet assembly 4 from being deformed and damaged. Furthermore, the outer shell 33 is made of steel and has sufficient protective strength.

[0029] In the optional scheme of this embodiment, it is more preferred that the magnetization direction of the main magnet 31 and the auxiliary magnet 32 ​​is the same, both perpendicular to the central axial section of the protective cavity.

[0030] Among them, the magnet components 3 are magnetized in the same direction, and the magnetic fields can be superimposed and enhanced together, thereby forming a strong static magnetic field outside the probe and further improving the detection intensity.

[0031] In the optional scheme of this embodiment, more preferably, the outer wall surface of the main magnet 31 on the lower half of the first main antenna 51 away from the detection antenna 5 is set as a convex arc surface; the cross-section of the auxiliary magnet 32 ​​is set as a rectangle.

[0032] Specifically, the lower half of the main magnets 31 on both sides of the support member 2 is set as a convex arc surface, and the upper half is set as a plane, and they are symmetrically arranged to optimize the spatial distribution of the static magnetic field, significantly improve the static magnetic field strength in the working area, and thus enhance the detection signal strength. In addition, each auxiliary magnet 32 ​​on both sides of the support member 2 is set as an axially extending rectangular body, which not only enhances the local static magnetic field strength, but also effectively expands the uniform area length of the axial static magnetic field, thereby improving the longitudinal coverage and signal stability of the detection. Moreover, the rectangular body setting is conducive to maximizing the volume of the magnet material and the total magnetic energy product within the outer diameter envelope of the entire cylindrical probe. Combined with the shape of the main magnet 31 and the setting of the three-segment magnet assembly 3, the detection intensity and detection depth are fully improved.

[0033] In the optional scheme of this embodiment, more preferably, the magnetic core assemblies 4 on both sides of the support member 2 include a first magnetic core 41 and a second magnetic core 42 that are separately arranged. The outer wall and inner wall of the first magnetic core 41 and the second magnetic core 42 are respectively used to fit the inner wall of the protective shell 1 and the outer wall of the magnet assembly 3.

[0034] The first magnetic core 41 and the second magnetic core 42 are separately arranged and attached to the inner wall of the protective shell 1 and the outer wall of the magnet assembly 3. The separate arrangement facilitates independent processing and assembly, and can effectively guide the magnetic circuit distribution, improve the antenna inductance, and thus provide support for achieving a longer detection distance. Moreover, the first magnetic core 41 and the second magnetic core 42 adopt an irregular geometric configuration with an arc shape, which effectively guides and concentrates the magnetic field lines, optimizes the magnetic field path, and can significantly suppress the generation of eddy currents under the action of alternating magnetic field, reduce useless heat loss, and improve energy efficiency.

[0035] More preferably, the magnet assembly 3 is made of neodymium iron boron or samarium cobalt, the core assembly 4 is made of iron powder core, the initial permeability is 24, and the relative permeability is 34.

[0036] In the optional scheme of this embodiment, more preferably, the detection antenna 5 includes a first main antenna 51, a first magnetic core 41 close to the first main antenna 51, and the first main antenna 51 is fixedly attached to the outer wall surface of the first magnetic core 41 on both sides of the support member 2.

[0037] More preferably, such as Figure 31 As shown, the first main antenna 51 is formed by winding a single-turn multi-strand insulated wire, and is divided into 3 layers, namely a copper coil structure, an FR4 spacer structure, and a copper coil structure. The two copper coil structures are identical.

[0038] By configuring only the first main antenna 51 to be bent along the surface of the magnetic core assembly 4 and to maintain close contact with the outer wall of the first magnetic core 41 and the filler 7, the circuit structure is simplified and the system complexity and cost are reduced while ensuring long-distance detection function, and no additional turbulence antenna is required. The first main antenna 51 adopts a single-turn design, with each turn made of 16 independent insulated wires wound together, which cooperates with the magnetic core assembly 4. The magnetic core assembly 4 guides the magnetic circuit and suppresses the generation of eddy currents, reducing iron loss caused by alternating magnetic field. The single-turn multi-strand parallel design of the first main antenna 51 effectively reduces ohmic loss while maintaining the required inductance. The two work together to greatly improve the radiation efficiency.

[0039] In the optional scheme of this embodiment, more preferably, the remote detection nuclear magnetic resonance logging tool probe provided in this embodiment also includes positioning hoops 6 disposed at both ends of the magnetic core assembly 4. The positioning hoops 6 are sleeved on the outside of the magnet assembly 3 and can form a detachable fixed connection with the support member 2.

[0040] The positioning clamp 6 is made of aluminum alloy to ensure sufficient strength. The positioning clamp 6 is composed of two opposing half buckles. The inner wall shape of the half buckle matches the outer wall shape of the outer shell 33 of the main magnet 31 of the magnet assembly 3. The half buckle can be fastened to the outside of the main magnet 31 and clamped to the support member 2 and then connected and fixed by bolts, thereby constraining and fixing the position of the magnetic core assembly 4.

[0041] In the optional scheme of this embodiment, more preferably, a filler 7 is also provided in the protective cavity. The filler 7 is placed between the two positioning clamps 6 and extends along the axis parallel to the protective cavity. The filler 7 is used to fill the circumferential gap between the magnetic core assembly 4 and the support member 2, and the filler 7 is connected to the magnetic core assembly 4 and the support member 2.

[0042] In order to reduce the eddy current loss generated by the magnetic core assembly 4, the magnetic core assembly 4 needs to maintain a gap in the circumferential direction to form an insulating seam. Therefore, in order to keep the magnetic core assembly 4 stable in the protective cavity, a filler 7 is provided at the gap for filling and fixing. That is, the gap between the opposing first magnetic cores 41 and between the second magnetic core 42 and the magnet assembly 3 is filled to form a complete internal support structure. The two ends of the filler 7 between the first magnetic cores 41 can also be fitted and connected with the support member 2 to further improve stability. Specifically, the filler 7 is made of resin material.

[0043] As shown in the radial cross-section of the probe, the direction of the static magnetic field generated by the magnet assembly 3 is as follows: Figure 29 As shown, the radio frequency magnetic field generated by the first main antenna 51 is as follows: Figure 30 As shown.

[0044] In the optional embodiment, more preferably, the protective shell 1 includes a middle shell 11, side shells 12, and a support shell 13; the middle shell 11 has side shells 12 and support shells 13 on both axial sides; the middle shell 11 is detachably coaxially connected to the side shells 12 on both axial sides, and the middle shell 11 is used to detachably fit over the magnetic core assembly 4; the auxiliary magnets 32 on both sides of the magnetic core assembly 4 are respectively disposed in the two support shells 13, and the support shells 13 are detachably connected to the support member 2, and a wire passage 131 is provided in one side of the support shell 13; the two side shells 12 are detachably coaxially fitted over the two support shells 13.

[0045] The two side support shells 13 further enhance internal stability. Specifically, the auxiliary magnet 32 ​​and the support member 2 can be embedded and fixed inside the support shell 13. The inner end of the support shell 13 in the axial direction abuts against the positioning hoop 6, and the support shell 13 and the support member 2 are fixed by bolts. Furthermore, the side shells 12 on both sides can be detachably and coaxially nested outside the corresponding support shell 13 for protection. In addition, in order to ensure that the detection antenna 5 can transmit signals, a wire passage 131 needs to be set on the support shell 13 near the signal end of the detection antenna 5. This passage can accommodate a capacitor. The wire passage 131 is formed by the notch set on the support shell 13 and the inner wall of the side shell 12. The capacitor communicates with the detection antenna 5. The capacitor and the detection antenna 5 together form a "resonant circuit". The communication cable between the detection antenna 5 and the capacitor is set in the gap reserved inside the protective shell 1.

[0046] Furthermore, the intermediate shell 11 comprises two axially distributed sections, which are spliced ​​and fixed together for easy assembly. The end of the intermediate shell 11 near the capacitor is connected to the side shell 12 via a fixing ring 8, and one side of the fixing ring 8 is nested inside one side of the side shell 12. The intermediate shell 11 is formed by two half-shells that are fastened together for easy assembly. The side shell 12, the intermediate shell 11, and the fixing ring 8 can be spliced ​​and fixed by edge nesting. Moreover, the inner wall of the outer side of the side shell 12 can be provided with a stepped groove, and the corresponding position of the support shell 13 is provided with a protrusion. The protrusion can cooperate with the stepped groove for limiting, and the stepped groove is provided with a notch that communicates with the inner cavity. The protrusion can be separated from the support shell 13 and the side shell 12 through the notch.

[0047] Furthermore, the support shell 13 and the side shell 12 are both made of aluminum alloy, while the middle shell 11 is made of resin. As an insulator, the resin material can further reduce eddy current losses.

[0048] Thus, the protective shell 1 provided in this embodiment adopts a modular design, which can encapsulate the internal magnet assembly 3, the magnetic core assembly 4 and other components into an integrated structure. This design not only facilitates assembly and maintenance, but also provides reliable mechanical protection and environmental isolation for the internal precision components, ensuring the long-term stable operation of the probe under complex downhole conditions.

[0049] Example 2 This embodiment provides a remote detection nuclear magnetic resonance logging probe, which differs from Embodiment 1 in that: the detection antenna 5 includes a second main antenna 52 and a turbulence antenna 53. The second main antenna 52 is fixedly attached to the outer wall of the first magnetic core 41 on both sides of the support member 2, and the turbulence antenna 53 is fixedly attached to the outer wall of the second magnetic core 42 on both sides of the support member 2; the magnetic fields generated by the second main antenna 52 and the turbulence antenna 53 are in opposite directions.

[0050] like Figure 32 As shown, a turbulence antenna 53 is also provided on the side opposite to the second main antenna 52. The turbulence antenna 53 is bent along the surface of the magnetic core assembly 4 and keeps in close contact with the outer wall of the second magnetic core 42 and the filler 7. The capacitor is communicatively connected to the turbulence antenna 53.

[0051] The core function of the second main antenna 52 is to transmit detection signals and receive echo signals from the formation, primarily used for long-distance detection. The disturbance antenna 53 is used to eliminate mud interference from the back of the probe. The disturbance antenna 53 transmits an electromagnetic field with the opposite direction and amplitude to that of the second main antenna 52 to suppress noise generated by near-field interference sources such as metal casing and drilling fluid within the wellbore, thereby improving the signal-to-noise ratio of the signal received by the second main antenna 52 and reducing the influence of wellbore environmental factors on the signal coupling process. Through the coordinated operation of the second main antenna 52 and the disturbance antenna 53, the probe can achieve high-precision and high-stability measurements of formation parameters under complex downhole conditions.

[0052] Specifically, the spoiler antenna 53 can be detachably attached to the surface, making it easy to set according to the detection depth requirements. For example, if only long-distance detection is required, only the main antenna can be set. If long-distance or short-distance detection is required, the spoiler antenna 52 can be installed on the curved surface.

[0053] The other structures of the remote-detection nuclear magnetic resonance logging tool probe provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here. The specific structures of the second main antenna 52 and the spoiler antenna 53 can be determined according to actual needs; for example... Figure 33 and Figure 34 As shown, the second main antenna 52 has a 2-turn structure, with each turn using 16 strands of winding, and the spoiler antenna 53 has an 8-turn structure; both antenna coils are divided into 3 layers, namely a copper coil structure, an FR4 partition and an upper and lower layer connection structure, and a copper coil structure. The two copper coil structures are connected through the partition through-hole.

[0054] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A remote detection nuclear magnetic resonance logging tool probe, characterized in that: include: The protective shell (1) has a protective cavity inside; The support member (2) is disposed in the protective cavity along the axial direction of the protective cavity; A magnet assembly (3) is disposed within the protective cavity and fixedly connected to the support member (2); the magnet assembly (3) includes a main magnet (31) extending along the axial direction of the protective cavity and two sets of auxiliary magnets (32); the main magnet (31) is disposed in the middle of the protective cavity and symmetrically arranged about the support member (2), and at least part of the outer wall surface of the main magnet (31) is configured as a convex arc surface; the two sets of auxiliary magnets (32) are disposed on both sides of the main magnet (31) along the axial direction of the protective cavity, and each set of auxiliary magnets (32) is symmetrically arranged about the support member (2); A magnetic core assembly (4) is disposed within the protective cavity and extends axially along the protective cavity. The magnetic core assembly (4) is positioned outside the main magnet (31) and symmetrically arranged about the support member (2). The detection antenna (5) is disposed in the protective cavity and fixedly attached to the outer wall of the magnetic core assembly (4) on both sides of the support member (2), and the detection antenna (5) is used to electrically connect to an external detector.

2. The remote detection nuclear magnetic resonance logging probe according to claim 1, characterized in that: The support member (2) is a metal sheet, and the magnet assembly (3) is magnetically fixed to the metal sheet; and the long side of the magnet assembly (3) does not extend beyond the long side of the support member (2) in the width direction.

3. The remote detection nuclear magnetic resonance logging probe according to claim 1, characterized in that: The main magnets (31) on both sides of the support member (2) and the two sets of auxiliary magnets (32) are covered with shells (33); the inner wall of the magnetic core assembly (4) is attached to the outer wall of the shells (33) on the outside of the main magnets (31).

4. The remote detection nuclear magnetic resonance logging probe according to claim 1, characterized in that: The main magnet (31) and the auxiliary magnet (32) are magnetized in the same direction, both perpendicular to the central axial section of the protective cavity; and the outer wall surface of the lower half of the main magnet (31) is set as a convex arc surface; the cross section of the auxiliary magnet (32) is set as a rectangle.

5. The remote detection nuclear magnetic resonance logging probe according to claim 1, characterized in that: The magnetic core assemblies (4) on both sides of the support member (2) each include a first magnetic core (41) and a second magnetic core (42) that are separately arranged. The outer and inner walls of the first magnetic core (41) and the second magnetic core (42) are respectively used to fit the inner wall of the protective shell (1) and the outer wall of the magnet assembly (3).

6. The remote detection nuclear magnetic resonance logging probe according to claim 5, characterized in that: The detection antenna (5) includes a first main antenna (51), which is fixedly attached to the outer wall of the first magnetic core (41) on both sides of the support member (2).

7. The remote detection nuclear magnetic resonance logging probe according to claim 5, characterized in that: The detection antenna (5) includes a second main antenna (52) and a turbulence antenna (53). The second main antenna (52) is fixedly attached to the outer wall of the first magnetic core (41) on both sides of the support member (2), and the turbulence antenna (53) is fixedly attached to the outer wall of the second magnetic core (42) on both sides of the support member (2). The magnetic fields generated by the second main antenna (52) and the turbulence antenna (53) are in opposite directions.

8. The remote detection nuclear magnetic resonance logging probe according to claim 1, characterized in that: It also includes positioning hoops (6) disposed at both ends of the magnetic core assembly (4), the positioning hoops (6) being sleeved on the outside of the magnet assembly (3) and being able to form a detachable fixed connection with the support member (2).

9. The remote detection nuclear magnetic resonance logging probe according to claim 8, characterized in that: The protective cavity is also provided with a filler (7), which is placed between the two positioning hoops (6) and extends along the axis parallel to the protective cavity. The filler (7) is used to fill the circumferential gap between the magnetic core assembly (4) and the support member (2), and the filler (7) is connected to the magnetic core assembly (4) and the support member (2).

10. The remote detection nuclear magnetic resonance logging probe according to claim 1, characterized in that: The protective shell (1) includes an inner shell (11), a side shell (12) and a support shell (13). The intermediate outer shell (11) is provided with side outer shells (12) and support shells (13) on both axial sides; the intermediate outer shell (11) is detachably coaxially connected to the side outer shells (12) on both axial sides, and the intermediate outer shell (11) is used to detachably fit over the magnetic core assembly (4); the auxiliary magnets (32) on both sides of the magnetic core assembly (4) are respectively disposed in the two support shells (13), and the support shells (13) are detachably connected to the support member (2), and a wire passage (131) is provided in one side of the support shell (13); the two side outer shells (12) are detachably coaxially fitted over the two support shells (13).

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