Downhole electromagnetic wave signal relay receiving device and method based on layered interface reflection

Abstract

The application belongs to the technical field of downhole communication, and discloses a downhole electromagnetic wave signal relay receiving device and method based on layered interface reflection. The downhole electromagnetic wave signal relay receiving device based on layered interface reflection comprises a downhole casing, a transmitter and a relay. The downhole casing comprises a horizontal section and a vertical section which are connected with each other, and the vertical section penetrates through a water layer. The transmitter is arranged in the horizontal section. The relay is arranged in the vertical section, and comprises a transmitting end and a receiving end. The transmitting end is arranged above the water layer for communication with the ground, and the receiving end is arranged below the water layer for communication with the transmitter. In the application, the transmitting end and the receiving end of the relay are arranged above and below the water layer respectively, so that the communication link is not affected by the water layer, the electromagnetic wave is not greatly attenuated due to the water layer, and the downhole communication reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of downhole communication technology, and in particular to a downhole electromagnetic wave signal relay receiving device and method based on layered interface reflection. Background Technology

[0002] Currently, downhole electromagnetic wave communication is a widely applicable, relatively fast, and low-cost wireless communication method that can effectively achieve real-time uploading of downhole data, and has broad development prospects in the petroleum industry. However, its reliability and adaptability are currently limited by the short propagation distance and significant signal attenuation of electromagnetic waves in the complex downhole environment.

[0003] Currently, the main method to address the issues of poor communication reliability and adaptability is the use of signal repeaters. These repeaters receive and amplify signals that have attenuated during transmission, enabling relay transmission and thus increasing the depth of underground communication. However, the signal repeaters currently used in underground communication are not designed and used in accordance with geological conditions, leading to unstable signal reception. This is especially true when thick water layers are present in the strata. Some electromagnetic waves penetrate the water layer, causing severe signal attenuation, while others are reflected by the water layer and cannot be transmitted further upwards. Because water layers have a significant impact on electromagnetic wave communication, they can even cause repeaters to fail, thereby rendering the entire communication system unusable. Summary of the Invention

[0004] The purpose of this invention is to provide a downhole electromagnetic wave signal relay receiving device and method based on layered interface reflection, so as to solve the problem of the influence of water layer on electromagnetic wave communication.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A downhole electromagnetic wave signal relay receiving device based on layered interface reflection, comprising:

[0007] The downhole casing includes a vertical section and a horizontal section connected to each other, wherein the vertical section is installed through a water layer;

[0008] A transmitter, wherein the transmitter is disposed in the horizontal section of the downhole casing;

[0009] A repeater is provided in the vertical section of the downhole casing. The repeater includes a transmitter and a receiver. The transmitter is used to communicate with the ground, and the receiver is used to communicate with the transmitter. The transmitter is located above the water layer, and the receiver is located below the water layer.

[0010] Optionally, the transmitter is installed inside the downhole casing via a first centralizer, and the inclination angle of the transmitter relative to the downhole casing is adjustable.

[0011] Optionally, the receiving end is installed inside the downhole casing via a second centralizer, and the tilt angle of the receiving end relative to the downhole casing is adjustable.

[0012] Optionally, the transmitter is installed inside the downhole casing via a third centralizer, and the inclination angle of the transmitter relative to the downhole casing is adjustable.

[0013] Optionally, the first, second, and third centralizers are all elastic centralizers, each comprising a spring plate whose elastic height is adjustable.

[0014] Optionally, the spring sheet is made of metal.

[0015] Optionally, the receiving end is located in the direction of reflection of the lower surface of the water layer, where the direction of maximum power density of the transmitted signal from the transmitter is the direction of reflection.

[0016] A downhole electromagnetic wave signal relay receiving method based on layered interface reflection, according to the downhole electromagnetic wave signal relay receiving device based on layered interface reflection provided by the present invention, the downhole electromagnetic wave signal relay receiving method based on layered interface reflection includes the following steps:

[0017] The positional data of the upper and lower surfaces of the water layer are collected, and the inclination angle data of the lower surface of the water layer with respect to the horizontal plane are also collected.

[0018] The transmitter of the repeater is positioned above the water layer, and the receiver of the repeater is positioned below the water layer.

[0019] A transmitter is provided, which is communicatively connected to the receiver, and the transmitter is located below the water layer.

[0020] Optionally, the downhole electromagnetic wave signal relay receiving method based on layered interface reflection further includes the step of adjusting the tilt angle of the transmitter so that the direction of maximum power density of the transmitter's transmitted signal is reflected by the direction of reflection of the lower surface of the water layer through the receiving end of the repeater.

[0021] Optionally, the downhole electromagnetic wave signal relay receiving method based on layered interface reflection further includes the step of adjusting the tilt angle of the transmitting end so that the radiation direction of the transmitting end of the repeater is perpendicular to the antenna direction.

[0022] The beneficial effects of this invention are:

[0023] The downhole electromagnetic wave signal relay and receiving device based on layered interface reflection of the present invention, by placing the transmitter of the repeater above the water layer and the receiver below the water layer, facilitates communication between the receiver below the water layer and the transmitter, as well as communication between the transmitter above the water layer and the ground. Neither communication link is affected by the water layer, avoiding the large attenuation of electromagnetic waves caused by the water layer, which helps to improve the reliability of downhole communication.

[0024] The present invention provides a downhole electromagnetic wave signal relay receiving method based on layered interface reflection. According to the location of the water layer, the transmitter and receiver of the repeater are set above and below the water layer, respectively, and the transmitter is set below the water layer, thereby avoiding the influence of the water layer on electromagnetic wave communication and improving the reliability of downhole communication. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the downhole electromagnetic wave signal relay receiving device based on layered interface reflection provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the repeater structure of the downhole electromagnetic wave signal relay receiving device based on layered interface reflection provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the elastic centralizer in the downhole electromagnetic wave signal relay receiving device based on layered interface reflection provided in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the structure of the transmitter adjusting the tilt angle through an elastic centralizer in the downhole electromagnetic wave signal relay receiving device based on layered interface reflection provided in this embodiment of the invention.

[0029] In the picture:

[0030] 100, water layer; 200, signal receiver;

[0031] 1. Downhole casing; 11. Vertical section; 12. Horizontal section; 2. Transmitter; 3. Repeater; 31. Transmitter end; 32. Receiver end; 33. Repeater housing; 34. Control circuit board; 4. Elastic centralizer; 41. Spring plate. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0033] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0036] This invention provides a downhole electromagnetic wave signal relay receiving device based on layered interface reflection, such as... Figure 1 and Figure 2 As shown, the device includes a downhole casing 1, a transmitter 2, and a repeater 3. The downhole casing 1 includes a vertical section 11 and a horizontal section 12 connected to each other. The vertical section 11 is installed through the water layer 100. The transmitter 2 is installed in the horizontal section 12 of the downhole casing 1. The repeater 3 is installed in the vertical section 11 of the downhole casing 1. The repeater 3 includes a transmitter 31 and a receiver 32. The transmitter 31 is used to communicate with the ground, and the receiver 32 is used to communicate with the transmitter 2. The transmitter 31 is located above the water layer 100, and the receiver 32 is located below the water layer 100.

[0037] This invention relates to a downhole electromagnetic wave signal relay and receiving device based on layered interface reflection. The receiver 32 of the repeater 3 is a receiving coil, and the transmitter 31 is a transmitting coil. The transmitter 31 and receiver 32 amplify and forward signals via a control circuit board 34. The transmitter 31, receiver 32, and control circuit board 34 are all encapsulated within a repeater housing 33. By designing the length of the repeater housing 33, the receiver 32 of the repeater 3 is positioned below the water layer 100, effectively receiving electromagnetic wave signals reflected from the lower surface of the water layer 100, facilitating reliable communication between the receiver 32 and the transmitter 2 below. By positioning the transmitter 31 of the repeater 3 above the water layer 100, communication between the transmitter 31 and the signal receiver 200 on the surface is facilitated, allowing the electromagnetic wave signal to bypass interference from the water layer 100. In this invention, the electromagnetic wave signals of both communication links are not affected by the water layer 100, avoiding significant attenuation caused by the water layer 100 and improving the reliability of downhole communication.

[0038] Optionally, the transmitter 31 is installed inside the downhole casing 1 via a first centralizer, and the inclination angle of the transmitter 31 relative to the downhole casing 1 is adjustable.

[0039] It is understood that downhole electromagnetic wave communication uses the tubing string as a dipole antenna to transmit electromagnetic wave signals. Therefore, when the electromagnetic wave radiation direction is perpendicular to the antenna (tubing string) direction, the transmission and reception of electromagnetic wave signals are better. In this embodiment, by setting first centralizers at both ends of the transmitter 31, the tilt angle of the transmitter 31 can be adjusted by adjusting the two first centralizers. This optimizes the electromagnetic wave radiation direction of the transmitter 31 to a certain extent, ensuring that more electromagnetic wave energy is transmitted to the ground signal receiver 200, thereby improving the reliability of the ground signal reception.

[0040] Optionally, the receiver 32 is installed inside the downhole casing 1 via a second centralizer, and the tilt angle of the receiver 32 relative to the downhole casing 1 is adjustable.

[0041] The receiver 32 is equipped with a second centralizer at each end for mounting and fixing the upper and lower ends of the receiver 32. The tilt angle of the upper and lower ends of the receiver 32 can be adjusted by adjusting the two second centralizers. That is, the included angle between the upper and lower ends of the receiver 32 and the axis of the vertical section 11 of the downhole casing 1 is adjustable, so that the receiver 32 can make full use of the electromagnetic wave energy reflected by the water layer 100, and thus receive the transmitted signal of the transmitter 2, thereby improving the receiving efficiency.

[0042] Optionally, the transmitter 2 is installed inside the downhole casing 1 via a third centralizer, and the tilt angle of the transmitter 2 relative to the downhole casing 1 is adjustable.

[0043] In this embodiment, the transmitter 2 is installed in the horizontal section 12 of the downhole casing 1. Both ends of the transmitter 2 are installed and fixed to the horizontal section 12 via a third centralizer. By adjusting the two third centralizers, the tilt angle of the transmitter 2 can be adjusted; that is, the angle between the transmitter 2 and the axis of the horizontal section 12 is adjustable. By adjusting the tilt angles of the receiver 32 and the transmitter 2, the receiver 32 can ultimately be positioned in the direction of maximum power density of the transmitted signal from the transmitter 2, in the reflection direction of the lower surface of the water layer 100. Figure 1 As shown by the dashed arrow, the electromagnetic wave with the highest transmitted signal power density in direction A1 is reflected at the lower surface of the water layer 100, and the reflection direction is A2. The reflection direction A2 intersects with the vertical section 11 of the downhole casing 1 at point A. The receiving end 32 of the repeater 3 is set at the height of point A, and the receiving end 32 is adjusted to receive the electromagnetic wave signal in the reflection direction A2, which helps to improve the receiving efficiency of the repeater 3.

[0044] Optionally, the first, second, and third centralizers are all elastic centralizers 4, and the elastic centralizer 4 includes a spring plate 41, the elastic height of which is adjustable.

[0045] like Figure 3 and Figure 4 As shown, taking the tilt angle adjustment of transmitter 2 as an example, the tilt angle adjustment methods and structures of the transmitter end 31 and receiver end 32 of repeater 3 are the same as those of transmitter 2. Both ends of transmitter 2 are equipped with elastic centralizers 4. Each elastic centralizer 4 includes multiple spring plates 41. By setting the spring plates 41 of the elastic centralizer 4 to different elastic heights, and through the elastic abutment installation method between the spring plates 41 and the inner wall of the downhole casing 1 at their location, the elastic height of the spring plates 41 in the radial direction of the downhole casing 1 changes, i.e., the eccentricity of the elastic centralizer 4 changes, thereby obtaining the desired tilt angle of transmitter 2. For example... Figure 4 In the middle, the elastic height of the lower spring plate 41 of the elastic stabilizer 4 at the left end of the transmitter 2 decreases, and the left end of the transmitter 2 tilts downward and forms an angle B.

[0046] Optionally, the spring sheet 41 is made of metal, which has good elasticity and makes it easy to control the elastic modulus and adjust the elastic height.

[0047] The present invention also provides a downhole electromagnetic wave signal relay receiving method based on layered interface reflection. According to the downhole electromagnetic wave signal relay receiving device based on layered interface reflection provided in the above embodiments, the downhole electromagnetic wave signal relay receiving method based on layered interface reflection includes the following steps:

[0048] The positional data of the upper and lower surfaces of water layer 100 are collected, and the inclination angle data of the lower surface of water layer 100 with the horizontal plane are also collected.

[0049] The transmitter 31 of the repeater 3 is located above the water layer 100, and the receiver 32 of the repeater 3 is located below the water layer 100.

[0050] Transmitter 2 is configured to communicate with receiver 32, and transmitter 2 is located below water layer 100.

[0051] The downhole electromagnetic wave signal relay receiving method based on layered interface reflection of the present invention, by pre-collecting the position of the water layer 100, and accordingly setting the transmitter 31 and receiver 32 of the repeater 3 to be located above and below the water layer 100, respectively, thereby avoiding the influence of the water layer 100 on electromagnetic wave communication and improving the reliability of downhole communication.

[0052] Optionally, the downhole electromagnetic wave signal relay receiving method based on layered interface reflection also includes the step of adjusting the tilt angle of the transmitter 2, so that the direction A1 of the transmitter 2 with the maximum power density of the transmitted signal is reflected in the direction A2 of the lower surface of the water layer 100 through the receiving end 32 of the repeater 3.

[0053] In this step, the tilt angles of transmitter 2 and receiver 32 can be adjusted simultaneously until the requirements are met. It should be noted that when adjusting the tilt angles of transmitter 2 and receiver 32, attention should be paid to the tilt angle of water layer 100 relative to the horizontal plane, and adjustments should be made according to the principle of electromagnetic wave transmission, so that the direction A1 of the maximum power density of the transmitted signal of transmitter 2 (perpendicular to the direction of the transmitting antenna) satisfies the condition that the reflected electromagnetic wave A2 of the incident electromagnetic wave at the lower surface of water layer 100 passes through point A at the height of receiver 32.

[0054] Optionally, the downhole electromagnetic wave signal relay receiving method based on layered interface reflection also includes the step of adjusting the tilt angle of the transmitting end 31 so that the radiation direction of the transmitting end 31 of the repeater 3 is perpendicular to the antenna direction, that is, perpendicular to the vertical section 11 of the downhole casing 1, to ensure that more electromagnetic waves can be transmitted to the ground and improve the reliability of the ground receiving signal.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A downhole electromagnetic wave signal relay receiving device based on layered interface reflection, characterized in that, include: Downhole casing (1), the downhole casing (1) includes a vertical section (11) and a horizontal section (12) connected to each other, the vertical section (11) is arranged to penetrate the water layer (100); A transmitter (2) is disposed in the horizontal section (12) of the downhole casing (1); A repeater (3) is installed in the vertical section (11) of the downhole casing (1). The repeater (3) includes a transmitter (31) and a receiver (32). The transmitter (31) is used to communicate with the ground, and the receiver (32) is used to communicate with the transmitter (2). The transmitter (31) is located above the water layer (100), and the receiver (32) is located below the water layer (100).

2. The downhole electromagnetic wave signal relay receiving device based on layered interface reflection according to claim 1, characterized in that, The transmitter (31) is installed inside the downhole casing (1) via a first centralizer, and the inclination angle of the transmitter (31) relative to the downhole casing (1) is adjustable.

3. The downhole electromagnetic wave signal relay receiving device based on layered interface reflection according to claim 2, characterized in that, The receiving end (32) is installed inside the downhole casing (1) via a second centralizer, and the tilt angle of the receiving end (32) relative to the downhole casing (1) is adjustable.

4. The downhole electromagnetic wave signal relay receiving device based on layered interface reflection according to claim 3, characterized in that, The transmitter (2) is installed inside the downhole casing (1) via a third centralizer, and the inclination angle of the transmitter (2) relative to the downhole casing (1) is adjustable.

5. The downhole electromagnetic wave signal relay receiving device based on layered interface reflection according to claim 4, characterized in that, The first, second, and third centralizers all employ elastic centralizers (4), which include a spring plate (41) with an adjustable elastic height.

6. The downhole electromagnetic wave signal relay receiving device based on layered interface reflection according to claim 5, characterized in that, The spring sheet (41) is made of metal.

7. The downhole electromagnetic wave signal relay receiving device based on layered interface reflection according to claim 1, characterized in that, The receiving end (32) is located in the direction of reflection of the lower surface of the water layer (100) where the power density of the transmitted signal of the transmitter (2) is the greatest.

8. A method for relaying and receiving downhole electromagnetic wave signals based on layered interface reflection, characterized in that, The downhole electromagnetic wave signal relay receiving device based on layered interface reflection according to any one of claims 1-7, wherein the downhole electromagnetic wave signal relay receiving method based on layered interface reflection comprises the following steps: The position data of the upper and lower surfaces of the water layer (100) are collected, and the inclination angle data of the lower surface of the water layer (100) to the horizontal plane are collected. The transmitter (31) of the repeater (3) is located above the water layer (100), and the receiver (32) of the repeater (3) is located below the water layer (100). A transmitter (2) is provided, which is communicatively connected to the receiver (32), and the transmitter (2) is located below the water layer (100).

9. The downhole electromagnetic wave signal relay and receiving method based on layered interface reflection according to claim 8, characterized in that, It also includes the step of adjusting the tilt angle of the transmitter (2) so that the direction of the transmitter (2) with the maximum power density of the transmitted signal is reflected by the direction of the reflection of the lower surface of the water layer (100) through the receiver (32) of the repeater (3).

10. The downhole electromagnetic wave signal relay and receiving method based on layered interface reflection according to claim 9, characterized in that, It also includes the step of adjusting the tilt angle of the transmitter (31) so that the radiation direction of the transmitter (31) of the repeater (3) is perpendicular to the antenna direction.

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