Electric field orientation device for magnetotelluric method

Abstract

The utility model relates to the field of geophysical exploration, in particular to an electric field orienting device for a magnetotelluric method, which comprises a disc, a gradienter and a directional compass are integrated on the disc, and four external notches are arranged on the edge of the disc in an orthogonal direction; the four telescopic batten sets are connected to the four external interfaces respectively, each telescopic batten set is formed by cascading a plurality of battens which are partially connected in an overlapped mode, and the adjacent battens can slide relatively to increase the overall length; and the telescopic batten group is configured in a way that the position of the batten at the tail end of the telescopic batten group indicates the arrangement position of the electric field measuring electrode after the whole telescopic batten group is stretched to a specified length through the sliding of the plurality of battens. According to the orientation device, the orthogonality of the magnetotelluric method electric field signal acquisition process can be remarkably improved, and the orientation device has excellent terrain adaptability and electrode distance expandability.

Description

Technical Field

[0001] The utility model relates to the field of geophysical exploration, in particular to an electric field orientation device used for magnetotelluric method. Background Art

[0002] Geophysical exploration is a method of detecting geological conditions such as stratum lithology and geological structure by measuring and studying the changes in various physical fields of the earth. Among the many geophysical exploration technologies, medium-deep magnetotelluric method has become a research hotspot in the field of geophysical exploration in recent years due to its unique advantages.

[0003] The core of magnetotelluric method is the measurement of earth electric field and magnetic field. In the process of earth electric field measurement, it is necessary to collect earth electric field signals in two mutually perpendicular directions, such as Figure 1 As shown in the figure, the data acquisition of magnetotelluric exploration includes two channels, Ex (electrode 1 and electrode 2) and Ey (electrode 3 and electrode 4). To collect the signals of the two channels Ex and Ey, four electrodes (electrodes 1-4) need to be buried. It must be ensured that the Ex channels formed by electrodes 1-2 and the Ey channels formed by electrodes 3-4 are perpendicular to each other, and the Ex channel needs to be along the survey line direction, and the Ey channel needs to be perpendicular to the survey line direction. Since the weak signals of the underground electromagnetic field are collected, high-precision ground collection construction is particularly important. Usually, when collecting electric field data in two directions, the direction is determined by a compass, and the collection wires and electrodes are laid out in the specified direction. Due to human factors and the influence of mountainous terrain, the laid Ex and Ey channels are usually difficult to achieve mutual perpendicularity, the error is large, and the operation efficiency is low, which affects the quality and accuracy of the collected data. Utility Model Content

[0004] It is expected to provide an electric field orientation device for magnetotelluric method, which can significantly improve the verticality and efficiency of the layout of Ex and Ey channels for earth electric field measurement, thereby improving the quality and accuracy of raw data acquisition in magnetotelluric exploration.

[0005] An electric field orientation device for magnetotelluric method comprises: a disk on which a level and a direction compass are integrated, and the edge of which has four external notches arranged in orthogonal directions; four telescopic strip plate groups respectively connected to the four external interfaces, wherein each telescopic strip plate group is composed of a cascade of several partially overlapped and connected strip plates, and adjacent strip plates can slide relative to each other to increase the overall length; the telescopic strip plate group is configured so that after the strip plate group is stretched to a specified length as a whole through the sliding of several strip plates, the position of the end strip plate indicates the layout position of the electric field measurement electrode.

[0006] As a preferred implementation, the number of strips constituting each of the telescopic strip groups is the same or different to meet the exploration requirements of different electrode distances.

[0007] As an optional implementation, the telescopic strip group is cascaded in a telescopic manner.

[0008] As a preferred embodiment, the telescopic slat group is cascaded in a sliding and telescopic manner, and each of the slats is provided with a sliding groove along its length direction; a sliding block is fixed to the end of the second slat in the adjacent stacking relationship, and the sliding block is configured to slide in the sliding groove of the first slat in the adjacent stacking relationship.

[0009] The telescopic strip plate group serves as a medium for the current measuring point to reach the measuring points of the four measuring electrodes. It ensures that the vertical directions of the two vertical channels Ex and Ey are transmitted from the disk to the end of the electrode measuring point through linear indication, avoiding the direction error introduced by the previous estimation based on manual experience. Such vertical channel directional characteristic transmission can be achieved by using the sliding telescopic strip plate group provided in the present application, or by injecting a stacked telescopic plate / tube group, a folding telescopic plate group, etc. However, the sliding telescopic plate group has many conveniences in use, storage, manufacturing, etc., and is especially easier to realize the function of adjustable angle rotation between the plate groups.

[0010] The plate surface of each strip of the telescopic strip group is perpendicular to the horizontal plane, and the head end strip is connected to the external notch in a direction perpendicular to the horizontal plane. The slider is cylindrical, so that the second strip can slide in the slide groove and rotate around the slider to change the direction of the second strip relative to the first strip.

[0011] The telescopic slat groups are arranged vertically, and the overlapping of adjacent slats is achieved by sliding connection, so that the telescopic slat groups give the directional device terrain adaptability. Preferably, the lengths of the slats of each telescopic slat group are the same or different, and the flexible and adjustable length of the slats can further increase the terrain adaptability of the device.

[0012] A through hole is arranged at the head end of the head end strip along the width direction, and the head end strip is connected to the external notch via a rotating shaft passing through the through hole.

[0013] The telescopic strip set also includes a storage and fixing device.

[0014] A retractable bracket is arranged at the bottom of the disc.

[0015] The strips are made of aluminum alloy or a material with a density lower than that of aluminum alloy.

[0016] Beneficial effects of the utility model:

[0017] According to the electric field orientation device provided by the utility model, the previous extensive manual estimation method of electrode burial is changed. The medium between the current measuring point and the electrode measurement point is directly established through the telescopic strip plate group, the orthogonal directions of the two measuring electric paths are ensured, and the electrode burial point is indicated quickly and accurately. The electric field measurement electrodes measure the electric field data in two orthogonal directions at the same time, and the collected data is more reliable, which provides a basic guarantee for the high-precision original data quality of the earth's electric field measurement.

[0018] Based on the flexible structural design of the telescopic strip group, the directional device can rotate along the terrain without changing the specified measurement electric field direction. It can quickly bury the specified direction electric field measurement electrodes in the complex mountainous terrain, and ensure that the four electrodes are accurately positioned and the measurement paths are perpendicular to each other. In addition, the telescopic strip group with different electrode spacing requirements can be customized according to the needs of the actual engineering project. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The schematic diagram of vertical channel measurement in magnetotelluric exploration is shown;

[0020] Figure 2 A half-section view of the components of the orientation device is shown;

[0021] Figure 3 A half-section view of the telescopic slat assembly is shown;

[0022] Figure 4 A half-section view of the orientation device in an unopened state is shown;

[0023] Figure 5 A top view of the orientation device in an unopened state is shown;

[0024] Figure 6 An enlarged schematic diagram of a disk viewed from above is shown;

[0025] Figure 7 A schematic diagram of the orientation device in the open use state is shown;

[0026] Markings in the figure: 1-slat, 2-cylindrical nail, 3-cylindrical shaft, 4-telescopic tripod, 5-disc, 6-direction compass, 7-level, 8-measuring electrode, 9-telescopic slat group.

[0027] The various aspects and features of various embodiments of the present invention are described with reference to the above drawings. The above drawings are merely illustrative and non-restrictive. Without departing from the subject matter of the present invention, the distribution, numbering, or appearance of the various units in the above drawings may be changed, and are not limited to those shown in the drawings of the specification. DETAILED DESCRIPTION

[0028] The utility model is described in detail below in conjunction with the accompanying drawings.

[0029] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model. The up, down, left and right in the embodiments all refer to the positional relationship of the utility model in the use state.

[0030] Provide a geoelectric field orientation device, refer to Figure 2-6 , comprising: a disk 5 on which a level 7 and a compass 6 are integrated, and whose edge has four outward notches arranged in orthogonal directions; four telescopic strip groups 9 respectively connected to the four interfaces, wherein each telescopic strip group 9 is composed of a plurality of partially overlapped and connected strips 1, and adjacent strips 1 can slide relative to each other to increase the overall length; the telescopic strip group 9 is configured so that after the telescopic strip group 9 is stretched to a specified length as a whole through the sliding of a plurality of strips 1, the position of the end strip 1 indicates the layout position of the measuring electrode 8.

[0031] Each strip 1 in the telescopic strip group 9 is provided with a slide groove along its length direction; a slider is fixed to the end of the second strip 1 in the adjacent stacking relationship, and the slider is configured to slide in the slide groove of the first strip 1 in the adjacent stacking relationship.

[0032] As a specific implementation, the telescopic strip set 9 can be manufactured in the following manner:

[0033] A light and hard material aluminum alloy is selected to process 40 strips 1 with a length of 100 cm, a width of 10 cm, and a thickness of 1 cm; a strip hole with a length of 90 cm and a width of 2.5 cm is opened in each strip 1 as a slide groove;

[0034] refer to Figure 2-3 , select lightweight and hard aluminum alloy to process 36 cylindrical nails 2 with a length of 2 cm, a lower cylindrical diameter of 2 cm, and an upper cylindrical diameter of 3 cm; first, pass the lower part of the cylindrical nail 2 through the strip hole of the adjacent first strip 1, and then weld the lower part of the cylindrical nail 2 to the end of the adjacent second strip 1; in this cyclic method, connect 10 strips through 9 cylindrical nails 2 to form a telescopic strip group 9, and make a total of 4 telescopic strip groups 9.

[0035] It can be seen that the partial overlap between the strips 1 means that the second strip 1 as the main body of the relative movement overlaps with the first strip 1 as the movement path of the relative movement only within the movement range allowed by the slide slot. Figure 3Take the top two strips 1 in the example: when the ball nail 2 of the lower strip 1 is at the leftmost end, it maintains the longest overlapping distance with the upper strip 1 (the length of the entire chute); when the ball nail 2 of the lower strip 1 is at the rightmost end, it maintains the shortest overlapping distance with the upper strip 1, that is, the lower strip 1 is extended to the maximum distance. This cycle is repeated, taking 10 100cm cascaded telescopic strip groups 9 as an example, the system can achieve orthogonal directional measurement with a maximum electrode distance of 20 meters.

[0036] The sliding telescopic strip set 9 has many conveniences in use, storage, manufacturing and other links, especially it is easier to realize the angle rotation and adjustable function between the strip sets. The ball nail 2 as a slider can guide the movement in the slide slot to realize the extension of the overall length of the telescopic strip set 9, and on the other hand, it can also be used as a rotating shaft to point the strip 1 fixedly connected to it to provide a rotation function.

[0037] The telescopic slat group 9 also includes a storage fixing device, which is used to bind all the slats 1 when the slats 9 are kept in a contracted state, that is, when the maximum overlapping range is maintained, so as to facilitate the storage of the telescopic slat group 9. For example, the storage and fixation of the telescopic slat group 9 can be achieved by setting a binding rope from the end slat 1 to the head slat 1.

[0038] refer to Figure 5-6 In order to further adapt to the undulating terrain of the mountainous area, the surface of each slat 1 of the telescopic slat group 9 is perpendicular to the horizontal plane, and the head slat 1 is connected to the interface of the disc 5 in a direction perpendicular to the horizontal plane. The head end of the head slat 1 is provided with a through hole in the width direction, and the head slat 1 is connected to the interface via a rotating shaft passing through the through hole. Since the cross-sectional shape of the ball nail 2 is circular, the second slat 1 can rotate in the vertical plane around the ball nail 2 relative to the first slat 1. The telescopic slat group 9 is arranged vertically, and the overlapping between adjacent slats is achieved by a sliding connection method, so that the telescopic slat group 9 gives the directional device terrain adaptability.

[0039] As a specific implementation, the disc 5 is manufactured and connected to the telescopic strip set 9 as follows:

[0040] A light and hard aluminum alloy is used to process a disc-shaped disk 5 with a diameter of 20 cm and a height of 2 cm; four orthogonal positions of the disk 5 are respectively opened with external notches of 1.5 cm in width and 2.5 cm in length;

[0041] Select a lightweight hard material aluminum alloy to process four cylindrical shafts 3 with a diameter of 1 cm and a length of 1.5 cm; open a transverse through hole with a diameter of 1.5 cm in the head end strip 1 of the telescopic strip group 9, and then pass the cylindrical shaft 3 through the transverse through hole, and weld the two ends of the cylindrical shaft 3 to the outer notches of the disc 5, so that the telescopic strip group 9 can rotate around the cylindrical shaft 3 in the vertical plane. In this way, the four telescopic strip groups 9 are connected to the four outer notches of the disc 5 through the four cylindrical shafts 3;

[0042] Select lightweight and rigid aluminum alloy to process three telescopic legs 4, with a maximum telescopic length of 50 cm and a minimum telescopic length of 30 cm; then weld and fix the three telescopic legs 4 to the bottom of the disc 5 to support the disc 5 to be horizontal;

[0043] The direction compass 6 and the level 7 are fixed to the upper part of the disc respectively.

[0044] The method for using the electric field orientation device provided in this embodiment includes:

[0045] S1, move the system equipment to the current measuring point, and adjust its four interfaces to the direction of the electric field to be measured according to the indication information of the disk 5. Specifically, the disk 5 is adjusted to the level by the level meter 7 and the telescopic tripod 4 thereon, and then the direction of the electric field to be measured is determined by the direction compass 6 thereon, and finally fixed to the ground.

[0046] S2, stretch the corresponding telescopic strip group along the four directions to the specified length required for measuring the electrode point. Due to the restriction of the external notch of the disk 5, the telescopic strip group 9 cannot rotate left and right, but can only rotate in pitch, so the telescopic strip group 9 can rotate up and down along the terrain without changing the stretching direction, and the specified electric field direction will not change.

[0047] S3, burying four measuring electrodes at the tail end indicated positions of the end strips of the four telescopic strip groups. After the telescopic strip group 9 is stretched, bury the measuring electrode 8 under the end strip 1 of the device, and then connect the four electrodes to the magnetotelluric instrument through copper cables, so that the earth electric field data in the specified direction can be accurately collected.

[0048] In summary, the electric field orientation device solves the problems of large electric field direction control error, difficulty in verticality of Ex and Ey directions, and low construction efficiency in the acquisition of earth electric field data, and standardizes the order of field acquisition of earth electric field. The orientation device can be used not only in various types of magnetotelluric exploration operations, but also in all geophysical and other geological work that requires measurement and burial of specified directions, and is widely used.

[0049] The device of the present invention is described above with reference to various embodiments, wherein the embodiments mentioned may include specific features, structures or characteristics, but not every embodiment necessarily includes the specific features, structures or characteristics. In addition, some embodiments may have some or all of the features described for other embodiments or none of the features described for other embodiments.

[0050] As used in the claims, unless otherwise indicated, the use of ordinal adjectives "first," "second," "third," etc. to describe common elements merely indicates that different instances of similar elements are mentioned, and is not intended to imply that the elements so described must be in a given order, whether in time, space, ranking, or any other manner.

[0051] The various features of different embodiments or examples can be combined in a variety of ways with some of the features included and other features excluded to adapt to a variety of different applications. The accompanying drawings and the foregoing description provide examples of embodiments. It will be appreciated by those skilled in the art that one or more of the elements described can be combined into a single functional element. Alternatively, some elements can be divided into multiple functional elements. Elements from one embodiment can be added to another embodiment. The scope of the embodiments is by no means limited by these specific examples. Whether or not clearly provided in the specification, many variations such as differences in product composition and structure are possible.

Claims

1. An electric field orientation device for magnetotelluric method, characterized in that: include: A circular disk, on which a level and a compass are integrated, and whose edge has four outward notches arranged in orthogonal directions; Four telescopic strip groups connected to the four external notches respectively, wherein each telescopic strip group is composed of a cascade of several partially overlapped strips, and adjacent strips can slide relative to each other to increase the overall length; The telescopic strip group is configured such that after the strip group is stretched to a specified length as a whole through the sliding of a plurality of strips, the position of the end strip indicates the arrangement position of the electric field measurement electrode.

2. The device according to claim 1, characterized in that: The number of slats constituting each of the telescopic slat groups is the same or different.

3. The device according to claim 2, characterized in that: The lengths of the strips in each telescopic strip group are the same or different.

4. The device according to claim 3, characterized in that: The telescopic strip board group is formed by cascading in a telescopic manner.

5. The device according to claim 3, characterized in that: Each strip in the telescopic strip group is provided with a slide groove along its length direction; A slider is fixed to the end of the second strip in the adjacent stacking relationship, and the slider is configured to slide in the slide groove of the first strip in the adjacent stacking relationship.

6. The device according to claim 5, characterized in that: The plate surface of each strip of the telescopic strip group is perpendicular to the horizontal plane, and the head end strip is connected to the external notch in a direction perpendicular to the horizontal plane.

7. The device according to claim 6, characterized in that: The slider is cylindrical, so that the second strip can slide in the slide groove and rotate around the slider to change the direction of the second strip relative to the first strip.

8. The device according to claim 6, characterized in that: A through hole is arranged at the head end of the head end strip along the width direction, and the head end strip is connected to the external notch via a rotating shaft passing through the through hole.

9. The device according to any one of claims 5 to 8, characterized in that: The telescopic strip set also includes a storage and fixing device.

10. The device according to any one of claims 5 to 8, characterized in that: The strips are made of aluminum alloy or a material with a density lower than that of aluminum alloy.

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