CN111290038A - Horizontal component induction type coil structure and magnetic field sensor - Google Patents

Abstract

The invention provides a horizontal component inductive coil structure and a magnetic field sensor to solve the technical problem that the horizontal component magnetic field sensor needs an amplifier with a larger magnification under a certain effective area and has a small signal-to-noise ratio. A horizontal component induction type coil structure includes a magnetic conductive component and a plurality of coil components; the plurality of coil components are connected in series and arranged in a straight line; the magnetic conductive component passes through the plurality of coil components. A horizontal component inductive magnetic field sensor includes a sensor outer tube, an interface and a horizontal component inductive coil structure; the horizontal component inductive coil structure is electrically connected with the interface. A horizontal component inductive magnetic field sensor includes a sensor outer tube, an interface and two horizontal component inductive coil structures; the two horizontal component inductive coil structures are both electrically connected with the interface. The invention makes the magnification of the amplifier required by the magnetic field sensor smaller, and meanwhile the signal-to-noise ratio is also improved.

Description

Horizontal Component Inductive Coil Structure and Magnetic Field Sensor

technical field

The invention relates to the technical field of induction coils, in particular to a horizontal component induction type coil structure and a magnetic field sensor.

Background technique

Transient electromagnetic method, also known as Time domain electromagnetic methods, referred to as TEM, is a method that uses an ungrounded return line or a grounded line source to launch a pulsed magnetic field underground. A method of observing the secondary eddy current field with a magnetic probe or ground electrode.

In the ground-well TEM system, the three-component magnetic field sensor in the well is one of the key components. The design of the three-component magnetic sensor in the well usually adopts the 1+2 method, that is, the acquisition of the three-component magnetic field signal is realized by one vertical component (Hz) and one horizontal component (Hx, Hy). The horizontal component requires the simultaneous transmission of the magnetic field signals in the X and Y directions of the downhole to the receiver. Each of the three component inductive magnetic field sensors includes a bobbin, coil, and preamplifier.

The existing horizontal component magnetic field sensor in a well is shown in FIG. 1 , the coil bobbin 01 is a cuboid magnetic core, and an annular groove is formed on its surface for winding the receiving coil 02 . However, in the existing horizontal component magnetic field sensor in a well, due to the relatively small length and diameter of the magnetic core, the effective area of the receiving coil 02 is small, and the magnetic field sensor needs an amplifier with a large magnification under a certain effective area, and the signal noise smaller.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a horizontal component inductive coil structure and a magnetic field sensor, so as to solve the technical problem that the horizontal component magnetic field sensor in the existing well needs an amplifier with a large magnification under a certain effective area, and the signal-to-noise ratio is small. .

In a first aspect, the present invention provides a horizontal component inductive coil structure, the horizontal component inductive coil structure includes a magnetic conductive component and a plurality of coil components;

A plurality of the coil assemblies are connected in series and spaced along a straight line, and the axes of the plurality of coil assemblies are parallel;

The magnetic conductive assembly passes through a plurality of the coil assemblies in turn in a bent form.

As a further solution of the first aspect of the present invention, the magnetically conductive component includes a plurality of magnetic cores and a plurality of magnetic sheets;

One of the magnetic cores is installed in each of the coil assemblies;

Two ends of the magnetic sheet are respectively connected with the ends of two adjacent magnetic cores, so that the magnetic conductive component forms a "bow" shape.

As a further solution of the first aspect of the present invention, the coil assembly includes a bobbin and a coil;

The skeleton is installed on the magnetic conductive component, and the coil is wound on the outside of the skeleton.

As a further solution of the first aspect of the present invention, the coil is wound into a circle, a rectangle or a square.

As a further solution of the first aspect of the present invention, the winding directions of the plurality of coils are the same.

As a further solution of the first aspect of the present invention, the magnetic core is cylindrical or rectangular parallelepiped.

In a second aspect, the present invention provides a horizontal component inductive magnetic field sensor, the horizontal component inductive magnetic field sensor includes a sensor outer tube, an interface, and the horizontal component inductive coil structure provided in the first aspect;

Both the interface and the horizontal component inductive coil structure are installed in the outer tube of the sensor, and the horizontal component inductive coil structure is electrically connected to the interface.

As a further solution of the second aspect of the present invention, a component amplifier is also included, and the horizontal component inductive coil structure is electrically connected to the interface through the component amplifier.

In a third aspect, the present invention provides a horizontal component inductive magnetic field sensor, the horizontal component inductive magnetic field sensor includes a sensor outer tube, an interface, and two horizontal component inductive coil structures provided in the first aspect;

The interface and the two horizontal component inductive coil structures are installed in the outer tube of the sensor;

The axes of the coil components of the two horizontal component inductive coil structures are at 90°, and both are electrically connected to the interface.

As a further solution of the third aspect of the present invention, the horizontal component inductive magnetic field sensor further includes an Hx component amplifier and a Hy component amplifier;

The two horizontal component inductive coil structures are electrically connected to the interface through the Hx component amplifier and the Hy component amplifier, respectively.

In conjunction with the above technical solutions, the beneficial effects brought by the present invention are analyzed as follows:

The invention provides a horizontal component inductive coil structure, a plurality of coil assemblies are connected in series and arranged at intervals along a straight line, the axes of the plurality of coil assemblies are parallel, and the magnetic conductive assembly passes through the plurality of coil assemblies in sequence. The magnetic conductive component of the horizontal component induction coil structure runs through each coil component, and the long-diameter ratio of the magnetic conductive component located inside the coil component is relatively large, so that the effective magnetic permeability of the magnetic conductive component is high, thereby improving the coil component. Effective area. Under the same effective area, the magnetic field sensor using the horizontal component inductive coil structure needs a smaller magnification of the amplifier, and the signal-to-noise ratio is also improved.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

1 is a schematic diagram of an existing horizontal component magnetic field sensor;

2 is a schematic diagram of a horizontal component inductive coil structure provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a horizontal component inductive magnetic field sensor provided by an embodiment of the present invention.

Icon: 01-coil bobbin; 02-receiving coil; 10-horizontal component induction coil structure; 10a-Hx component induction coil structure; 10b-Hy component induction coil structure; 11-magnetic conductive component; 111-magnetic core; 112-magnetic sheet; 12-coil assembly; 121-skeleton; 122-coil; 20-sensor outer tube; 30-interface; 40-Hx component amplifier; 50-Hy component amplifier.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the orientations or positional relationships shown in the accompanying drawings, only for the purpose of It is convenient to describe the present invention and to simplify the description, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integrated connection. Ground connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

In the ground-well TEM system, the three-component magnetic field sensor in the well is one of the key components. The design of the three-component magnetic sensor in the well usually adopts the 1+2 method, that is, the acquisition of the three-component magnetic field signal is realized by one vertical component (Hz) and one horizontal component (Hx, Hy). The horizontal component requires the simultaneous transmission of the magnetic field signals in the X and Y directions of the downhole to the receiver. Each of the three component inductive magnetic field sensors includes a bobbin 121, a coil 122 and a preamplifier.

The working principle of the inductive magnetic field sensor is Faraday's law of electromagnetic induction, which converts the changing magnetic field into a voltage output.

The initial sensitivity of the induction coil 122 with the magnetic core 111 is:

e/B=-jωμ _app NS (1)

The initial sensitivity of the hollow induction coil 122 is the value without _μapp in the formula (1), and the initial sensitivity is defined as the value when the magnification of the preamplifier is not included.

In formula (1), e represents the induced voltage across the coil 122, B represents the magnetic flux of the measured magnetic field, ω represents the angular frequency of the measured magnetic field, _μapp represents the effective permeability of the magnetic core 111, and N represents the coil 122 The number of turns, S represents the cross-sectional area of the magnetic core 111 .

In formula (1), the product of μ _app , N and S is defined as the effective area S ₀ of the coil 122 (S ₀ = μ _app ×N×S), and the size of the effective area is usually used to determine the sensitivity of the inductive magnetic field sensor and the magnetic field. The formula for calculating the effective area S of the sensor is:

S=S ₀ ×K (2)

S ₀ is the effective area of the coil 122 , K is the magnification of the preamplifier, and μ _app =1 of the air-core coil 122 .

It can be seen from the formula (2) that in order to obtain the maximum sensitivity of the sensor, it is necessary to increase the effective area S ₀ of the coil 122 and increase the magnification K. Increasing the magnification of the amplifier circuit is prone to oscillation, limiting the frequency bandwidth, and cannot improve the signal-to-noise ratio of the sensor.

The existing horizontal component magnetic field sensor in a well is shown in FIG. 1 , the coil bobbin 01 is a rectangular parallelepiped magnetic core 111 , and an annular groove is formed on its surface for winding the receiving coil 02 . The effective magnetic permeability _μapp of the magnetic core 111 is related to its initial magnetic permeability and aspect ratio. The higher the initial magnetic permeability is and the larger the aspect ratio is, the higher the effective magnetic permeability of the magnetic core 111 is. However, in the existing horizontal component magnetic field sensor in the well, due to the relatively small length and diameter of the magnetic core 111, the effective area of the receiving coil 02 is small, so that the magnetic field sensor needs a larger magnification amplifier under a certain effective area, and the signal-to-noise ratio smaller.

This embodiment provides a horizontal component inductive coil structure 10 , please refer to FIG. 2 .

The horizontal component induction coil structure 10 includes a magnetic conductive component 11 and a plurality of coil components 12 . Wherein, the plurality of coil assemblies 12 are arranged in series and spaced along a straight line, and the axes of the plurality of coil assemblies 12 are parallel. When the inductive coil structure 10 having the horizontal component is placed in the well, the plurality of coils 122 are arranged in the height direction. The magnetic conductive component 11 passes through the plurality of coil components 12 in a bent form in sequence.

The magnetic conductive component 11 of the horizontal component induction coil structure 10 runs through each coil component 12 . Compared with the existing horizontal component magnetic field sensor, the magnetic conductive component 11 of the horizontal component induction coil structure 10 is located in the coil component 12 . The long-diameter ratio of the part is relatively large, so that the effective magnetic permeability of the magnetic conductive component 11 is relatively high, thereby increasing the effective area of the coil component 12 . Under the same effective area, the magnetic field sensor using the horizontal component inductive coil structure 10 needs a smaller magnification of the amplifier, and the signal-to-noise ratio is also improved.

FIG. 2 shows a specific structural form of the magnetic conductive assembly 11 , and the magnetic conductive assembly 11 includes a plurality of magnetic cores 111 and a plurality of magnetic sheets 112 . A magnetic core 111 is installed in each coil assembly 12 . Two ends of the magnetic sheet 112 are respectively connected with the ends of two adjacent magnetic cores 111 , so that the magnetic conductive component 11 forms a "bow" shape. The magnetic sheet 112 in the magnetic conductive component 11 can guide the magnetic field lines, so that a plurality of magnetic cores 111 are connected in series to form a continuous magnetic circuit.

Taking the orientation shown in FIG. 2 as an example, the plurality of magnetic sheets 112 are alternately arranged up and down. Referring to the two magnetic conductive sheets 112 in the middle of FIG. 2 , the two ends of the magnetic conductive sheet 112 on the left are The lower ends of the magnetic cores 111 are connected, and the two ends of the magnetic conductive sheet 112 on the right side are respectively connected with the upper ends of the two adjacent magnetic cores 111 . Wherein, the magnetic core 111 and the magnetic sheet 112 may be connected by bonding, riveting or the like.

FIG. 2 also shows the specific structural form of the coil assembly 12 . The coil assembly 12 includes a bobbin 121 and a coil 122 . The frame 121 is installed on the magnetic conductive assembly 11 , and the frame 121 provides support for the coil 122 . The coils 122 are wound on the outside of the bobbin 121 , and the end of one coil 122 is connected to the beginning of an adjacent coil 122 . Each coil 122 is wound individually, and ends of adjacent coils 122 are welded.

The winding directions of the plurality of coils 122 are the same, and each coil 122 has the same function and can generate induced voltages in the same direction. If the induced voltage across the first coil 122 is e1, the induced voltage across the second coil 122 is e2, until the induced voltage across the n-th coil 122 is en, then the induced voltage of the entire horizontal component inductive coil structure 10 is E=e1+e2+...+en.

The coil 122 can be wound into various shapes, for example, the coil 122 can be wound into a circle, a rectangle or a square.

The magnetic core 111 can be in various shapes, for example, the magnetic core 111 is in a cylindrical shape or a rectangular parallelepiped shape.

This embodiment also provides a horizontal component inductive magnetic field sensor, please refer to FIG. 2 and FIG. 3 .

The horizontal component inductive magnetic field sensor includes a sensor outer tube 20 , an interface 30 and two above-mentioned horizontal component inductive coil structures 10 . The interface 30 and the two horizontal component inductive coil structures 10 are installed in the sensor outer tube 20 , and the two horizontal component inductive coil structures 10 are the Hx component inductive coil structure 10a and the Hy component inductive coil structure 10b respectively.

The axis of the coil component 12 of the Hx component inductive coil structure 10a and the axis of the coil component 12 of the Hy component inductive coil structure 10b are at 90°, and both the Hx component inductive coil structure 10a and the Hy component inductive coil structure 10b are connected to the interface 30 electrical connections. When the horizontal component inductive magnetic field sensor is placed in the well, the Hx component inductive coil structure 10a can detect the Hx direction magnetic field, and the Hy component inductive coil structure 10b can detect the Hy direction magnetic field.

The magnetic conductive component 11 included in the horizontal component inductive magnetic field sensor runs through each coil component 12. Compared with the existing horizontal component magnetic field sensor, the magnetic conductive component 11 of the horizontal component inductive sensor is located inside the coil component 12. The length-diameter ratio of the horizontal component induction coil structure 10 requires a smaller magnification of the amplifier required for the magnetic field sensor of the horizontal component inductive coil structure 10. The signal-to-noise ratio has also been improved.

Referring to FIG. 3 , the horizontal component inductive magnetic field sensor further includes an Hx component amplifier 40 and a Hy component amplifier 50 . The two horizontal component inductive coil structures 10 are electrically connected to the interface 30 through the Hx component amplifier 40 and the Hy component amplifier 50, respectively. Specifically, the Hx component inductive coil structure 10 a is electrically connected to the interface 30 through the Hx component amplifier 40 , and the Hy component inductive coil structure 10 b is electrically connected to the interface 30 through the Hy component amplifier 50 . The Hx component amplifier 40 and the Hy component amplifier 50 can respectively amplify the electrical signals on the two horizontal component inductive coil structures 10 , and then transmit them to the outside through the interface 30 .

Of course, when the aspect ratio of the magnetic conductive component 11 inside the coil component 12 is large enough, the horizontal component inductive magnetic field sensor can also meet the actual needs without installing the Hx component amplifier 40 and the Hy component amplifier 50 .

This embodiment also provides another horizontal component inductive magnetic field sensor, which is similar to the horizontal component inductive magnetic field sensor shown in FIG. 3 .

The horizontal component inductive magnetic field sensor includes a sensor outer tube 20 , an interface 30 and an above-mentioned horizontal component inductive coil structure 10 . The interface 30 and the horizontal component inductive coil structure 10 are both installed in the sensor outer tube 20 , and the horizontal component inductive coil structure 10 is electrically connected to the interface 30 .

When the horizontal component inductive magnetic field sensor is placed in the well, the horizontal component inductive coil structure 10 can detect the magnetic field in the Hx direction or the Hy direction. When the Hx and Hy directions need to be detected at the same time, two horizontal component inductive magnetic field sensors can be used. In the two component inductive magnetic field sensors, the axis of the coil assembly 12 of the horizontal component inductive coil structure 10 is at 90°, and one of the sensors is used. To detect the Hx direction, another sensor is used to detect the Hy.

Similarly, the magnetic conductive component 11 included in the horizontal component inductive magnetic field sensor runs through each coil component 12. Compared with the existing horizontal component magnetic field sensor, the magnetic conductive component 11 of the horizontal component inductive sensor is located in the coil component. The length-diameter ratio of the inner part of 12 is relatively large, so that the effective magnetic permeability of the magnetic permeable component 11 is higher, thereby increasing the effective area of the coil component 12, and making the magnetic field sensor of the horizontal component inductive coil structure 10 need a higher magnification of the amplifier. small, and the signal-to-noise ratio is also improved.

In addition, the horizontal component inductive magnetic field sensor includes a component amplifier, the horizontal component inductive coil structure 10 is electrically connected to the interface 30 through the component amplifier, and the component amplifier amplifies the electrical signal on the horizontal component inductive coil structure 10, and the amplified electrical The signal is transmitted outward through the interface 30 .

Of course, when the length-diameter ratio of the part of the magnetic conductive component 11 located inside the coil component 12 is sufficiently large, the horizontal component inductive magnetic field sensor can also meet the actual needs without installing a component amplifier.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some or all of the technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A horizontal component induction type coil structure, characterized in that it comprises a magnetic conductive assembly (11) and a plurality of coil assemblies (12); A plurality of the coil assemblies (12) are connected in series and arranged at intervals along a straight line, and the axes of the plurality of the coil assemblies (12) are parallel; The magnetic conductive assembly (11) passes through the plurality of coil assemblies (12) in turn in a bent form. 2 . The horizontal component induction coil structure according to claim 1 , wherein the magnetic conductive component ( 11 ) comprises a plurality of magnetic cores ( 111 ) and a plurality of magnetic sheets ( 112 ); 2 . A magnetic core (111) is installed in each of the coil assemblies (12); Two ends of the magnetic sheet (112) are respectively connected with the ends of two adjacent magnetic cores (111), so that the magnetic conductive component (11) forms a "bow" shape. 3. The horizontal component inductive coil structure according to claim 1, wherein the coil assembly (12) comprises a bobbin (121) and a coil (122); The frame (121) is installed on the magnetic conductive component (11), and the coil (122) is wound on the outside of the frame (121). 4. The horizontal component induction coil structure according to claim 3, wherein the coil (122) is wound into a circle, a rectangle or a square. 5. The horizontal component inductive coil structure according to claim 3, wherein the winding directions of the plurality of coils (122) are the same. 6. The horizontal component induction coil structure according to claim 2, wherein the magnetic core (111) is cylindrical or rectangular. 7. A horizontal component inductive magnetic field sensor, characterized in that it comprises a sensor outer tube (20), an interface (30) and the horizontal component inductive coil structure (10) according to any one of claims 1 to 6; Both the interface (30) and the horizontal component inductive coil structure (10) are installed in the sensor outer tube (20), and the horizontal component inductive coil structure (10) is connected to the interface (30) electrical connection. 8 . The horizontal component inductive magnetic field sensor according to claim 7 , further comprising a component amplifier, and the horizontal component inductive coil structure ( 10 ) is electrically connected to the interface ( 30 ) through the component amplifier. 9 . . 9. A horizontal component inductive magnetic field sensor, characterized in that it comprises a sensor outer tube (20), an interface (30) and two horizontal component inductive coil structures (10) according to any one of claims 1 to 6 ; The interface (30) and the two horizontal component inductive coil structures (10) are both installed in the sensor outer tube (20); The axes of the coil components (12) of the two horizontal component inductive coil structures (10) are at 90°, and both are electrically connected to the interface (30). 10. The horizontal component inductive magnetic field sensor according to claim 9, characterized in that, further comprising an Hx component amplifier (40) and a Hy component amplifier (50); The two horizontal component inductive coil structures (10) are electrically connected to the interface (30) through the Hx component amplifier (40) and the Hy component amplifier (50), respectively.

Images