CN-122014221-A - Well magnetic three-component measuring device

Abstract

The invention discloses a well magnetic three-component measuring device, which relates to the technical field of metal mineral drilling investigation and comprises a sealing tube, a swinging mechanism which can be arranged in the sealing tube in a swinging way and comprises a swinging block, a horizontal holding mechanism which is connected with the swinging mechanism and comprises a holding piece and a magnetic sensor assembly arranged on the holding piece, wherein the holding piece is connected with the swinging block through a rotating shaft, so that the surface of the holding piece can be automatically kept horizontal under the action of gravity when the swinging mechanism swings. According to the device for measuring the magnetic three components in the well, no matter how the inclination angle and the azimuth of the sealing tube change, the swinging block and the retainer assembly can dynamically and automatically calibrate the measuring reference plane of the retainer to a local horizontal plane through continuous swinging and rotation, the real-time output of the magnetic sensor assembly, namely, the horizontal magnetic field component and the vertical magnetic field component under a geographic coordinate system at the measuring point, so that conversion errors caused by inaccurate inclination angle measurement are eliminated, and the precision is ensured.

Inventors

• ZHANG XUHUI
• SU YONGJUN
• SONG YAODONG
• CHEN RENCAI
• XIANG MIN
• AN RAN

Assignees

• 新疆工程学院

Dates

Publication Date

20260512

Application Date

20260330

Claims (10)

1. 1. A downhole magnetic three component measurement apparatus comprising: a sealing tube (1); The swinging mechanism is arranged in the sealing tube (1) in a swinging way and comprises a swinging block (2); the horizontal holding mechanism is connected with the swinging mechanism and comprises a holding piece (3) and a magnetic sensor assembly arranged on the holding piece (3), wherein the holding piece (3) is connected with the swinging block (2) through a rotating shaft (4) so that the surface of the holding piece (3) can automatically keep horizontal under the action of gravity when the swinging mechanism swings; Wherein the magnetic sensor assembly comprises sensors for sensing magnetic fields in three mutually orthogonal directions, and when the surface of the holder (3) is kept horizontal, wherein the sensing directions of two sensors are located in a horizontal plane, and the sensing direction of the third sensor is perpendicular to the horizontal plane.
2. 2. The device for measuring three components of magnetism in a well according to claim 1, characterized in that an inner cavity (21) is provided in the swinging block (2), the holder (3) is connected to two side walls of the inner cavity (21) of the swinging block (2) through two rotating shafts (4), and the axis of the rotating shafts (4) coincides with the rotation axis of the holder (3).
3. 3. The device for measuring three components of magnetism in a well according to claim 1, wherein the magnetic sensor assembly comprises three independent magnetic sensors for respectively sensing a first horizontal magnetic field, a second horizontal magnetic field and a vertical magnetic field, the three magnetic sensors are fixedly arranged on the surface of the holder (3), and the sensing direction of the sensor for sensing the first horizontal magnetic field is consistent with the direction of the rotation axis of the holder (3).
4. 4. The downhole magnetic three component measurement apparatus of claim 1, wherein the swing mechanism further comprises: The adjusting piece (5) is arranged at the bottom of the sealing tube (1), and the bottom of the swinging block (2) is supported on the adjusting piece (5); The collecting ring (6) is used for realizing the electric connection between the magnetic sensor assembly and an external measuring circuit and comprises a fixing part (61) at the upper end and a rotating part (62) at the lower end, wherein the fixing part (61) is fixedly arranged on the sealing tube (1), and the rotating part (62) is connected with the upper part of the swinging block (2).
5. 5. A downhole magnetic three-component measurement device according to claim 4, wherein the adjusting member (5) is an adjusting screw screwed to the bottom centre of the sealing tube (1).
6. 6. The device for measuring three components of magnetism in well according to claim 4, characterized in that a cover plate (9) is fixedly arranged at the top of the sealing tube (1), and the fixing part (61) of the collecting ring (6) is in sealing connection with the cover plate (9).
7. 7. The downhole magnetic three component measurement device according to claim 4, wherein the magnetic sensor assembly is mounted on a circuit board (7), the circuit board (7) being fixed to the surface of the holder (3), the circuit board (7) being connected to the slip ring (6) by means of a signal connector (8).
8. 8. The device according to claim 4, characterized in that the rotation axis of the collector ring (6) is on the same axis as the support point of the bottom of the oscillating block (2) on the adjusting member (5).
9. 9. The device according to claim 8, characterized in that the bottom center of the swinging block (2) extends to one side of the adjusting member (5) to form a protruding portion (22), and the swinging block (2) is supported on the adjusting member (5) through the protruding portion (22).
10. 10. The device according to claim 1, characterized in that the sealing tube (1) is filled with damping fluid.

Description

Well magnetic three-component measuring device Technical Field The invention relates to the technical field of metal mineral drilling investigation, in particular to a device for measuring magnetic three components in a well. Background In the exploration of metal minerals, particularly magnetite, in wells, magnetic measurement is an important geophysical method. It is essentially the analysis and inference of mineral occurrence, production, and detection of blind minerals beside or at the bottom of a borehole by measuring the geomagnetic field vectors at different depth points within the borehole (typically resolved into three mutually perpendicular components, i.e., magnetic three components X, Y, Z). Of these, the horizontal component X, Y is mainly used to analyze the change in the horizontal direction of the magnetic field, while the vertical component Z is particularly sensitive to identifying vertical magnetized bodies. By processing the original magnetic component data, a vector diagram can be drawn, and a key basis is provided for geological interpretation. In addition, in weakly magnetic formations, the horizontal component X, Y of the magnetic field is sometimes also used to aid in analyzing the dip orientation of the borehole itself. Currently, most of well magnetic three-component sensors in wide application are axial magnetic three-component sensors. The working principle is that the sensor measures magnetic field values in three directions in the borehole, but the three directions are relative to a coordinate system of the sensor body (usually related to the axis of the probe). Since the borehole is not perfectly vertical, there are inclination angles and inclination orientations, and the attitude (inclination angle, azimuth angle) of the sensor body varies with depth. Thus, the directly measured X, Y, Z values are not the true horizontal and vertical components relative to the horizontal and earth's position required for geologic interpretation. In order to obtain geologically significant truth values, the prior art must perform complex data scaling. The specific flow is that the attitude (inclination angle and azimuth angle) of a sensor in a well must be measured in real time by using an inclination sensor and the like while measuring the magnetic three components. Then, in the later data processing stage, the measured values in the sensor coordinate system are converted into the horizontal geographic coordinate system by using these attitude measurement data through a coordinate rotation transformation formula or the like, and the true horizontal component (X, Y) and the vertical component (Z) are obtained. This process is severely dependent on the accuracy of the tilt angle measurement. However, in an actual well operation environment, the probe is very prone to sloshing, collision or rotation during lifting or lowering, especially at irregular well sections or when encountering obstructions. Such motion disturbances can seriously affect the accuracy of the tilt measurement, resulting in errors in the attitude angle data. Errors in attitude angles are transmitted and amplified in the coordinate conversion process, and finally the converted true magnetic three-component (X, Y, Z) data are distorted. Such distortion can directly affect the reliability of subsequent vector map drawings and geologic interpretation, potentially leading to ore body positioning errors, reservoir estimation bias, and even leakage. Therefore, the prior art still has the defects and shortcomings, and the measuring device capable of directly acquiring the real horizontal and vertical magnetic field components from the physical measurement layer is urgently needed in the art, so that the dependence on real-time and high-precision attitude measurement is eliminated, the process is simplified, the error sources are reduced, and the reliability of the final interpretation result is improved. Disclosure of Invention The invention aims to provide an in-well magnetic three-component measuring device, which solves the technical problems that when the existing in-well magnetic three-component sensor measures magnetic three-components, the posture of the sensor in the well must be measured in real time, the measured value can be converted into real magnetic three-components through a coordinate rotation transformation formula, the flow is complex, and the measurement accuracy cannot be ensured. To achieve the above object, the present invention provides a downhole magnetic three-component measurement apparatus comprising: Sealing the tube; The swinging mechanism is arranged in the sealing tube in a swinging way and comprises a swinging block; The horizontal holding mechanism is connected with the swinging mechanism and comprises a holding piece and a magnetic sensor assembly arranged on the holding piece, and the holding piece is connected with the swinging block through a rotating shaft, so that when the swinging mechanism s