CN113266342B - A wireless signal transmitter - Google Patents

Abstract

The invention discloses a signal wireless transmitting device, and belongs to the field of signal wireless communication. Comprises a signal generator, a coil-shaped conductor, an insulating medium, a first transmission line and a second transmission line; the signal generator is cylindrical and is nested and arranged outside the drill rod; the coil type conductor comprises two sections of conductors which are circumferentially arranged on the outer side of the drill rod, wherein the first section is a cylindrical conductor, and the second section is a solenoid-shaped conductor; the solenoid-shaped conductor comprises a plurality of turns of coils, and gaps exist among the turns of coils; insulating media are filled between the coil-shaped conductor and the drill rod and in each coil gap of the solenoid-shaped conductor; the signal generator is connected with the drill rod through a first transmission line and connected with the coil-shaped conductor through a second transmission line. According to the invention, by optimizing the structure of the transmitting device and using the slurry-drill rod as a signal transmission channel, the swelling of the underground device and the interference of drilling operation are avoided, the structure is simple, the installation is convenient, the installation and the descending difficulty of the device are reduced to a certain extent, and the equipment cost is reduced.

Description

A wireless signal transmitter

technical field

The present invention belongs to the field of signal wireless communication, and more particularly, relates to a signal wireless transmitting device.

Background technique

Surface-downhole communication is a key component to realize oilfield informatization and intelligence. Since real-time near-bit data needs to be collected during drilling, and the drill is in a state of high-speed rotation during drilling, wired communication is unavailable. Therefore, short-distance wireless transmission of near-bit signals is the focus of current research. At present, the currently used technologies for MWD data transmission mainly include mud pulse and electromagnetic wave wireless technology.

The wireless transmission technology using mud pulses is relatively mature and widely used in production sites. There are also many manufacturers and research units in my country that have this technology and have the ability to produce commercial products. But the main defects of this technology include: low transmission rate, generally within 10bits/s; dependence on drilling fluid, that is, the drilling fluid used in production must be liquid. The lower data transmission rate will not be able to meet the needs of downhole multi-parameter and large data transmission, and the reliance on drilling fluid makes it unusable in situations where underbalanced drilling technologies such as air drilling technology and foam drilling technology are used. In addition, due to the large volume of the pressure pulse generating mechanism, it is almost impossible to use in the near-bit environment.

Using the wireless transmission technology of electromagnetic waves, many foreign companies have been able to provide commercial products. The main advantages of this technology are: no dependence on drilling fluid, its launch device has no moving parts, its structure is simple, and it can be used in a near-bit environment. The disadvantage is: there are requirements for the resistivity of the formation, that is, when the resistivity of the formation changes or does not meet the requirements, its transmission speed and transmission effect will be affected; in addition, its data transmission rate is not high, generally within 20bits/s .

SUMMARY OF THE INVENTION

In view of the defects of the related art, the purpose of the present invention is to provide a signal wireless transmission device, which aims to solve the problems of low wireless transmission rate of the existing near-drill short-pass signal and limited applicable occasions.

In order to achieve the above purpose, the present invention provides a signal wireless transmitting device, comprising: a signal generator, a coil-type conductor, an insulating medium, a first transmission line and a second transmission line; the signal generator is cylindrical, and is installed in a nest on the outside of the drill pipe; the coil-type conductor includes two conductors circumferentially arranged on the outside of the drill pipe, wherein the first section is a cylindrical conductor, and the second section is a solenoid-shaped conductor; the solenoid-shaped conductor It includes a multi-turn coil, and there is a gap between the coils; the insulating medium is filled between the coil-shaped conductor and the drill rod, and in the coil gap of each coil of the solenoid-shaped conductor; the signal generator The first transmission line is connected to the drill rod, and the signal generator is connected to the coil-type conductor through the second transmission line.

Further, the signal generator, the cylindrical conductor and the solenoid conductor are arranged in sequence along the direction away from the drill bit.

Further, the number of turns of the coil of the solenoid-shaped conductor is greater than or equal to 3.

Further, the inter-turn distance of each turn of the coil in the solenoid-shaped conductor

为所述螺线管形导体的螺旋半径，f为通讯频率，c为光速。in,

is the helix radius of the solenoid-shaped conductor, f is the communication frequency, and c is the speed of light.

。Further, the communication frequency

.

Further, the outer side of the insulating medium is cylindrical.

Further, the insulating medium is Peek material.

Through the above technical solutions conceived by the present invention, compared with the prior art, the structure of the transmitting device is optimized and designed, and the mud-drill pipe is used as the signal transmission channel, so as to avoid the bloated downhole device and interfere with the drilling operation, and at the same time, the structure is simple and the installation is convenient. , which not only reduces the difficulty of device installation and downhole to a certain extent, but also reduces equipment costs. In addition, the present invention improves the wireless transmission distance of the drill bit signal in the existing logging while drilling process, and increases the wireless transmission accuracy.

Description of drawings

FIG. 1 is a schematic cross-sectional view of the overall structure of the device according to the embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a coil-type conductor in an embodiment of the present invention.

Reference number:

1-drilling mud; 2-bit; 3-metal drill pipe; 4-signal generator; 5-coil type conductor; 6-insulating medium.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Since the refractive index of the mud is much higher than the surrounding soil, drill pipe coated with drilling mud can be used as a single conductor transmission line, which can support TM surface waves. This kind of surface wave propagates along the metal pipeline, and there is no spherical wave propagation path loss, which makes it possible to transmit electromagnetic signals using mud and metal drill pipes.

The invention provides a signal wireless transmitting device, comprising: a signal generator, a coil-type conductor, an insulating medium, a first transmission line and a second transmission line; the signal generator is cylindrical, and is nested and installed on the outside of a drill pipe; The coil-type conductor includes two conductors circumferentially arranged on the outside of the drill pipe, wherein the first section is a cylindrical conductor, and the second section is a solenoid-shaped conductor; the solenoid-shaped conductor includes a multi-turn coil, There is a gap between each turn of the coil; the insulating medium is filled between the coil-shaped conductor and the drill rod, and in the coil gap of each turn of the solenoid-shaped conductor; the signal generator passes through the first The transmission line is connected with the drill pipe, and the signal generator is connected with the coil-type conductor through the second transmission line.

Further, the signal generator, the cylindrical conductor and the solenoid conductor are arranged in sequence along the direction away from the drill bit.

Further, the number of turns of the coil of the solenoid-shaped conductor is greater than or equal to 3.

Further, the inter-turn distance of each turn of the coil in the solenoid-shaped conductor

为所述螺线管形导体的螺旋半径，f为通讯频率，c为光速。in,

is the helix radius of the solenoid-shaped conductor, f is the communication frequency, and c is the speed of light.

。Further, the communication frequency

.

Further, the outer side of the insulating medium is cylindrical.

Further, the insulating medium is Peek material.

The content involved in the above embodiment will be described below with reference to a preferred embodiment.

Aiming at the structure in which the outside of the metal drill pipe is wrapped with mud during drilling, an embodiment of the present invention provides a near-drilling short-pass signal wireless transmitting device based on a mud-metal drill pipe channel as shown in FIG. 1 , and the device includes: a signal Generator 4 , coil-type conductor 5 , transmission line (not shown in the figure) and insulating medium 6 .

The signal generator 4 is a cylindrical hollow device, which is nested and installed on the outside of the metal drill pipe.

In this embodiment, the signal generator 4 is installed on one end of the metal drill pipe 3 close to the drill bit 2, and is close to the sensor at the drill bit, so that it is convenient to receive the detection data near the drill bit side by means of cables, etc., and send the code to the outside.

As shown in Figure 2, the coil-type conductor 5 is formed by connecting a cylindrical conductor and a solenoid-type conductor, and is nested and installed on the outside of the metal drill pipe 3. In this embodiment, the cylindrical conductor is at the bottom during installation, and the spiral The tubular conductor is on top. Solenoid-type conductors include multiple turns of coils with gaps between each turn.

,匝间距离为

，通讯频率为f，光速为c。则可以计算获得，电磁波理论等效波长如下式：Write down the helix radius of the solenoid conductor as

, the distance between turns is

, the communication frequency is f, and the speed of light is c. Then it can be calculated and obtained, the theoretical equivalent wavelength of electromagnetic wave is as follows:

。Preferably, in order to achieve efficient axial propagation of electromagnetic waves,

.

Preferably, the inter-turn distance is taken as:

Preferably, in order to make the electromagnetic wave attenuate slowly, the communication frequency can be selected as 6Mhz.

略大于钻杆外径，留出一定空间用于钻杆与导体间绝缘介质6的填充。Solenoid Conductor Helix Radius

It is slightly larger than the outer diameter of the drill pipe, and a certain space is reserved for filling the insulating medium 6 between the drill pipe and the conductor.

Preferably, the number of turns N of the solenoid conductor is greater than or equal to 3.

In this embodiment, the signal generator 4 sends data through two transmission lines, one is connected to the metal drill pipe 3 , and the other is connected to the cylindrical conductor in the coil-type conductor 5 .

In this embodiment, the coil-shaped conductor 5 is installed above and adjacent to the signal generator 4, so that the signal generator 4 and the coil-shaped conductor 5 are connected through a transmission line.

In this embodiment, the insulating medium 6 is a cylindrical dielectric that wraps the coil-type conductor, and is filled between the coil-type conductor and the metal drill pipe and between turns of the solenoid-type conductor.

Preferably, the insulating medium is made of peek material, the inner lower end is aligned with the lower end of the cylindrical conductor, and the upper end is slightly higher than the solenoid conductor for stabilizing the coil conductor and achieving electrical isolation between the coil conductor and the drill rod.

The basic principle of the device is: supply power to the coil-type conductor 5 through the signal generator 4, generate an electric field through the inter-turn gap of the solenoid-type conductor, and generate a magnetic field through the current flowing on the solenoid-type conductor and the metal drill pipe 3, that is, The electromagnetic waves in the mixed TM and TE modes are emitted along the axial direction of the drill pipe, and then the electromagnetic waves in the TM mode are sent to the ground through the conductive line structure formed by the drilling mud 1 and the drill pipe.

The TE mode electromagnetic wave has a magnetic field component but no electric field component in the propagation direction; the TM mode electromagnetic wave has an electric field component but no magnetic field component in the propagation direction.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (6)

1. A wireless signal transmitting apparatus, comprising: the signal generator, the coil-type conductor, the insulating medium, the first transmission line and the second transmission line;

the signal generator is cylindrical and is nested and arranged on the outer side of the drill rod;

the coil type conductor comprises two sections of conductors which are circumferentially arranged on the outer side of the drill rod, wherein the first section is a cylindrical conductor, and the second section is a solenoid-shaped conductor; the solenoid-shaped conductor comprises a plurality of turns of coils, and gaps exist among the turns of coils;

the insulating medium is filled between the coil-shaped conductor and the drill rod and in each coil gap of the solenoid-shaped conductor;

the signal generator is connected with the drill rod through the first transmission line, and the signal generator is connected with the coil-type conductor through the second transmission line;

wherein the theoretical equivalent wavelength of the electromagnetic wave is

Wherein,

the spiral radius of the solenoid-shaped conductor, f is communication frequency, c is light speed, s is turn-to-turn distance, and the spiral radius and the electromagnetic wavelength satisfy

。

2. The wireless signal transmission device according to claim 1, wherein the signal generator, the cylindrical conductor and the solenoid-shaped conductor are arranged in this order in a direction away from the drill bit.

3. The wireless signal transmitting device of claim 1, wherein the number of coil turns of the solenoid-shaped conductor is 3 or more.

4. The wireless signal transmitting device as claimed in claim 3, wherein said communication frequency is set to

。

5. The signal wireless transmission apparatus of claim 1, wherein an outer side of the insulating medium is cylindrical.

6. The signal wireless transmitting device of claim 1 or 5, wherein the insulating medium is a Peek material.

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