A small-bore MWD mud pulse signal transmission device

Abstract

The utility model discloses a kind of for small-bore measurement while drilling mud pulse signal transmission device, including probe, probe rod, bionic ear sound wave amplifier, pressure sensor, male joint, female joint, noise reduction floppy disc pipe, connecting pipe, mud pump and ground receiving device;Probe and probe rod are threadedly connected, probe rod lateral wall is set bionic ear sound wave amplifier, pressure sensor and bionic ear sound wave amplifier are threadedly connected;Male joint and female joint are threadedly connected, realize the transition of probe rod rigid pipe to noise reduction floppy disc pipe flexible pipe, noise reduction floppy disc pipe is connected mud pump through connecting pipe;By simulating human outer ear and ear canal structure to realize the low amplitude pulse signal generated under the focusing and expansion small displacement, and signal is transmitted to pressure sensor again by pressure sensor, and signal is transmitted to ground receiving equipment by pressure sensor.

Description

Technical Field

[0001] This utility model belongs to the field of small-diameter geological core drilling technology, specifically relating to a mud pulse signal transmission device for small-diameter drilling measurement. Background Technology

[0002] Traditional high-volume mud pulse (MWD) products are mature in the large-diameter oil drilling market, but they require large mud flow rates, typically 9 L / s to 55 L / s, and large in-hole instrument dimensions. For small-diameter geological core drilling, where mud flow rates and drill string diameters are small, existing oil drilling MWD products cannot meet the real-time transmission requirements of bottom hole signals at low pump volumes. In small-diameter geological core drilling, the in-hole space severely restricts instrument size; many conventional sensors and structural components simply cannot be installed in such limited spaces. Insertion of instruments into drill strings that require sufficient mud flow is particularly difficult.

[0003] Under low flow rate (typically below 50 L / min), the mud flow exhibits laminar characteristics, leading to a significant attenuation of the pressure wave amplitude generated by the pulse generator (e.g., the actual intensity of a pulse signal designed for 2 MPa may decrease to less than 50% of its original value). Simultaneously, the reduced inner diameter of the drill string (commonly drill pipes with a diameter of φ73 mm or less) exacerbates fluid friction resistance, further weakening the signal energy. Increased viscosity of low-flow-rate mud (particularly noticeable when the dynamic shear force exceeds 6 Pa) increases the signal transmission attenuation coefficient (α can reach 0.126 × 10⁻³ m⁻¹), and turbulent disturbances at drill pipe joints cause pulse waveform distortion. Furthermore, differences in formation permeability (such as alternating sandstone and shale layers) can trigger signal reflection and transmission, causing phase shift issues. Ground noise can also interfere with the receiving system, such as mechanical noise: pump pressure fluctuations caused by insufficient pressure stabilization of the mud pump air compressor (amplitude can reach 0.5-1 MPa), and low-frequency vibrations generated by the contact between the drill bit and the rock formation (frequency band concentrated in 10-100 Hz); electromagnetic noise: power frequency harmonics (50 Hz and its multiples) generated by equipment such as generators and frequency converters at the well site, and induced currents caused by metal particles in the drilling fluid.

[0004] Therefore, it is necessary to provide a mud pulse signal transmission device for small-diameter drilling measurement to solve the above-mentioned problems. Utility Model Content

[0005] This invention provides a mud pulse signal transmission device for small-diameter drilling measurement, which can solve the problems existing in the prior art.

[0006] To solve the above problems, the technical solution provided by this utility model is as follows:

[0007] This utility model embodiment provides a mud pulse signal transmission device for small-diameter drilling measurement, including a probe (1), a probe rod (2), a bionic ear acoustic amplifier (3), a pressure sensor (4), a male connector (5), a female connector (6), a noise-reducing soft coil (7), a connecting pipe (8), a mud pump (9), and a ground receiving device;

[0008] The probe (1) is connected to the probe rod (2) by a thread. A bionic ear sound wave amplifier (3) is provided on the side wall of the probe rod (2). The pressure sensor (4) is connected to the bionic ear sound wave amplifier (3) by a thread. The pressure sensor (4) receives the signal transmitted by the bionic ear sound wave amplifier (3) and then transmits the pressure signal to the ground receiving device.

[0009] The male connector (5) and the female connector (6) are connected by threads to transfer the mud in the probe (2) to the noise-reducing flexible coil (7); the female connector (6) is connected to the noise-reducing flexible coil (7) to realize the conversion from the rigid tube of the probe (2) to the flexible tube of the noise-reducing flexible coil (7); the noise-reducing flexible coil (7) is connected to the connecting pipe (8), and the connecting pipe (8) is connected to the mud pump (9).

[0010] In one optional embodiment of this utility model, the noise-reducing soft coil (7) has 3 turns of winding coil, the diameter of the first turn of winding coil (7-1) is larger than that of the second turn of winding coil (7-2), and the diameter of the second turn of winding coil (7-2) is larger than that of the third turn of winding coil (7-3).

[0011] In one optional embodiment of this utility model, the mud pump (9) is connected to a generator (11) and a frequency converter (10).

[0012] Compared with the prior art, this utility model provides a mud pulse signal transmission device for small-diameter drilling measurement, which has the following effects: (1) A noise-reducing soft coil is added to the mud transmission pipeline. Its annular structure reduces electromagnetic interference and mechanical vibration noise generated by equipment such as mud pumps and drilling rigs, so that the bottom hole signal transmission is clearer and external interference is reduced. (2) A bionic human ear sound wave amplifier is installed on the outer wall of the probe to amplify the bottom hole sound wave signal. By imitating the structure of the human auricle and ear canal, the sound wave is focused to strengthen the signal, solving the problem of insufficient signal wave amplitude caused by low pump volume. (3) The device is small in size and can be placed in a small-diameter geological core drilling hole, solving the problem that many conventional sensing devices and structural components cannot be installed in a small space. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of a device for transmitting mud pulse signals for small-diameter drilling measurement, provided in an embodiment of this application.

[0015] Figure 2 A schematic diagram of the structure of the bionic ear acoustic amplifier and pressure sensor provided in the embodiments of this application.

[0016] Figure 3 This is a schematic diagram of the structure of the noise-reducing floppy disk tube provided in the embodiments of this application.

[0017] Figure 4 This is a schematic diagram showing the mud being introduced into a noise-reducing floppy disk via a connecting pipe, as provided in an embodiment of this application.

[0018] Figure 5 This is a schematic diagram showing the mud flowing into the hole from the bottom of the probe, as provided in an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The terms "upper," "lower," "front," "rear," "left," and "right," etc., used when describing the installation position or direction of the structure or components in this embodiment are based on the orientation shown in the accompanying drawings. They are merely for convenience of description, used to distinguish the relative positions of various components or directions, and do not represent the orientation of the device or functional component in this embodiment during use.

[0020] like Figures 1-5 As shown in the figure, this utility model embodiment provides a mud pulse signal transmission device for small-diameter drilling measurement, including a probe 1, a probe rod 2, a bionic ear acoustic amplifier 3, a pressure sensor 4, a male connector 5, a female connector 6, a noise-reducing flexible coil 7, a connecting pipe 8, a mud pump 9, and a ground receiving device. The probe 1 and the probe rod 2 are connected by threads. The bionic ear acoustic amplifier 3 is installed on the side wall of the probe rod 2, and the pressure sensor 4 is connected to the bionic ear acoustic amplifier 3 by threads. The pressure sensor 4 receives the signal transmitted by the bionic ear acoustic amplifier 3 and then transmits the pressure signal to the ground receiving device. The ground receiving device is a ground digital receiver. Figure 3 Combination Figure 1 The noise-reducing floppy coil 7 has 3 turns of winding coil. The diameter of the first turn of winding coil 7-1 is larger than that of the second turn of winding coil 7-2, and the diameter of the second turn of winding coil 7-2 is larger than that of the third turn of winding coil 7-3.

[0021] The probe 2 serves to transmit the mud pulse signal. The bionic ear acoustic amplifier 3 receives the acoustic signal from the probe 1 and enhances the acoustic signal by focusing the sound wave through the structure of the human external ear. The enhanced signal is then transmitted to the pressure sensor 4. The pressure sensor 4 receives the signal transmitted by the bionic ear acoustic amplifier 3 and then transmits the pressure signal to the ground receiving device.

[0022] Male connector 5 and female connector 6 are connected by threads to transfer the mud inside probe 2 to noise-reducing flexible coil 7. Female connector 6 connects to noise-reducing flexible coil 7, converting the rigid tube of probe 2 to the flexible tube of noise-reducing flexible coil 7. Noise-reducing flexible coil 7 is connected to connecting pipe 8. Connecting pipe 8 is connected to mud pump 9, transmitting mud pulses. Mud pump 9 is connected to generator 11 and frequency converter 10. This allows the liquid output from mud pump 9 to pass through the noise-reducing flexible coil 7, reducing pump pressure fluctuations caused by pump pressure instability and power frequency harmonics generated by generator 11 and frequency converter 12.

[0023] The working principle of a mud pulse signal transmission device for small-diameter drilling measurement is as follows: After assembling the device, first lower the probe 1 and probe rod 2 into the hole, leaving the noise-reducing flexible coil 7 on the ground, and then start the mud pump 9. Figure 4 As shown, the mud is introduced into the noise-reducing coil 7 through the connecting pipe 8. Its annular structure reduces the mechanical noise caused by pump pressure fluctuations due to pump pressure instability, and the power frequency harmonic electromagnetic noise generated by the generator 11 and frequency converter 10. For example... Figure 5 As shown, the noise-reduced mud is then introduced into the probe rod 2, and finally flows into the borehole from the bottom of the probe 1. During the mud return process, the mud enters the device from the bottom of the probe 1, flows into the ear-proof acoustic amplifier 3 through the probe rod 2, and achieves the effect of focusing the sound waves to enhance the signal by mimicking the structure of the human ear canal. The sound wave signal enhanced by the ear-proof acoustic amplifier 3 is transmitted to the pressure sensor 4, and then the pressure sensor 4 transmits it to the ground receiving equipment to complete the bottom hole signal collection.

[0024] This invention employs a ring-shaped noise-reducing coil design. This coil reduces noise from various external factors as the mud pump output passes through the ring, improving the clarity of the mud pulse signal transmission and enhancing signal penetration under low-displacement conditions. Simultaneously, a biomimetic human ear acoustic amplifier is added near the probe's tail end. By mimicking the structure of the human external ear and ear canal, it focuses and amplifies the low-amplitude pulse signal generated under low-displacement conditions, transmitting the signal to a pressure sensor, which then transmits it to the ground receiving equipment. This solves the problem that traditional mud pulse products are unsuitable for small-diameter geological core drilling and addresses the practical challenge of coring from permafrost layers in high-altitude regions.

[0025] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A device for transmitting mud pulse signals in small-diameter drilling measurements, characterized in that, Includes a probe (1), a probe rod (2), a bionic ear sound wave amplifier (3), a pressure sensor (4), a male connector (5), a female connector (6), a noise-reducing floppy coil (7), a connecting pipe (8), a mud pump (9), and a ground receiving device; The probe (1) is connected to the probe rod (2) by a thread. A bionic ear sound wave amplifier (3) is provided on the side wall of the probe rod (2). The pressure sensor (4) is connected to the bionic ear sound wave amplifier (3) by a thread. The pressure sensor (4) receives the signal transmitted by the bionic ear sound wave amplifier (3) and then transmits the pressure signal to the ground receiving device. The male connector (5) and the female connector (6) are connected by threads to transfer the mud in the probe (2) to the noise-reducing flexible coil (7); the female connector (6) is connected to the noise-reducing flexible coil (7) to realize the conversion from the rigid tube of the probe (2) to the flexible tube of the noise-reducing flexible coil (7); the noise-reducing flexible coil (7) is connected to the connecting pipe (8), and the connecting pipe (8) is connected to the mud pump (9).

2. The device for transmitting mud pulse signals for small-diameter drilling measurement according to claim 1, characterized in that, The noise-reducing floppy coil (7) has 3 turns of winding coil. The diameter of the first turn of winding coil (7-1) is larger than that of the second turn of winding coil (7-2), and the diameter of the second turn of winding coil (7-2) is larger than that of the third turn of winding coil (7-3).

3. The device for transmitting mud pulse signals for small-diameter drilling measurement according to claim 1, characterized in that, The mud pump (9) is connected to a generator (11) and a frequency converter (10).

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