Downhole deep electromagnetic wave detection method based on three-dimensional phased array technology

Abstract

Disclosed in the present invention is a downhole deep electromagnetic wave detection method based on three-dimensional phased array technology. The method comprises: a signal transmitting sub transmitting phased-array electromagnetic waves in an axial direction, a horizontal x direction and a horizontal y direction, and adjusting radiation phases of the phased-array electromagnetic waves to enhance signals, thereby increasing the penetration depth of the electromagnetic waves into a formation; and a receiving sub capturing signals reflected from the formation, and processing the signals to reveal formation information. In the present invention, phased array technology is used to significantly enhance the electromagnetic wave transmission and reception performance, thereby effectively counteracting formation-induced attenuation, and ensuring the signal strength and clarity during long-range detection. Thus, the accuracy and reliability of formation boundary detection are improved, and a detection range is also expanded, thereby providing extensive and accurate data support for petroleum exploration and drilling operations. In particular, a three-component antenna design significantly enhances the capability of an instrument to resolve complex formations, such that even under variable and heterogeneous geological conditions, precise discrimination of formation properties is enabled, so as to provide an important basis for the hydrocarbon reserve evaluation and drilling risk assessment, thereby significantly improving the exploration efficiency and safety.

Description

A Deep-Bottom Electromagnetic Wave Detection Method Using Three-Dimensional Phased Array Technology Technical Field

[0001] This invention relates to the fields of geophysical exploration and signal processing technology, and in particular to a method for deep downhole electromagnetic wave detection using three-dimensional phased array technology. Background Technology

[0002] In oil exploration and drilling operations, obtaining accurate formation information is crucial for effectively assessing geological conditions and ensuring the accuracy and safety of drilling.

[0003] Currently, electromagnetic wave logging technology is widely used in the industry to detect formation information. However, existing electromagnetic wave logging methods have significant limitations, especially in long-distance detection and formation boundary identification. For example:

[0004] 1. Traditional electromagnetic wave logging methods primarily rely on receiving electromagnetic wave signals reflected from the formation to analyze formation characteristics. However, due to the attenuation effect of electromagnetic waves propagating through the formation, the received signals are often very weak with a low signal-to-noise ratio, which severely affects the accuracy and reliability of long-distance detection. Especially when attempting to detect formation boundaries in front of and to the sides of the drill bit, the rapid signal attenuation makes it difficult for existing methods to provide clear and accurate formation information.

[0005] 2. Existing electromagnetic wave logging methods also face challenges when dealing with complex formation structures. Due to the heterogeneity and variability of formations, traditional detection methods often struggle to accurately distinguish the boundaries and characteristics of different formations, which further limits their application under complex geological conditions.

[0006] Therefore, how to improve the detection accuracy of long-distance stratigraphic information and the identification precision of stratigraphic boundaries has become the technical problem to be solved by this invention. Summary of the Invention

[0007] The technical problem solved by this invention is to address the deficiencies in the prior art by providing a three-dimensional phased array technology for deep downhole electromagnetic wave detection, thereby solving the problem of relatively low accuracy and precision of electromagnetic wave logging in long-distance detection and formation boundary identification mentioned in the background art.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] A method for deep subsurface electromagnetic wave detection in wells using three-dimensional phased array technology includes the following steps:

[0010] Step 1: Use the signal transmitting segment to transmit phased array electromagnetic wave signals in three directions, including the axial direction, the horizontal x-direction and / or the horizontal y-direction;

[0011] Step 2: Adjust the radiation phase of the phased array electromagnetic wave signal to enhance the interference of electromagnetic waves, thereby extending the propagation distance of electromagnetic waves in the strata.

[0012] Step 3: Use the signal receiving sub to receive electromagnetic wave signals reflected from the strata and process the received signals to obtain strata information;

[0013] Step 4: Determine the distances between the formation boundaries in front of and to the side of the drill bit by observing the data attenuation at different frequencies.

[0014] As a further aspect of the present invention, the signal transmitting sub-section is capable of transmitting phased array electromagnetic wave signals with a frequency range from 1 kHz to 100 kHz.

[0015] As a further aspect of the present invention, the method also includes freely combining and adjusting the distance between the signal transmitting section and the signal receiving section according to the detection requirements.

[0016] As a further aspect of the present invention, the method can detect the distance of the formation boundary in front of the drill bit up to 30m or more, and can also detect the distance of the lateral formation boundary up to 30m or more.

[0017] As a further aspect of the present invention, the method further includes using a signal transmitting device to transmit phased array electromagnetic wave signals in three directions, the directions including the axial direction, the horizontal x-direction and / or the horizontal y-direction.

[0018] As a further aspect of the present invention, the signal transmitting device includes multiple spiral antennas to achieve phase-controlled electromagnetic wave transmission.

[0019] As a further aspect of the present invention, a signal receiving device is used to receive electromagnetic wave signals reflected from the strata, and the received signals are processed to obtain strata information.

[0020] As a further aspect of the present invention, the distance between the signal transmitting device and the signal receiving device can be adjusted according to the detection requirements.

[0021] As a further aspect of the present invention, the method also includes using a data processing unit to determine the distance between the formation boundaries in front of and to the side of the drill bit by observing data attenuation at different frequencies.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. Phased array technology significantly enhances the transmission and reception capabilities of electromagnetic signals. Compared to traditional methods, it effectively resists the attenuation effect of strata on electromagnetic waves, thus maintaining signal strength and clarity during long-distance detection.

[0024] 2. Improved the accuracy and reliability of formation boundary detection in front of and to the side of the drill bit, expanded the effective detection range, and ensured that oil exploration and drilling operations obtained accurate formation information in a wider area.

[0025] 3. The three-component transmitting and receiving antenna design enhances the instrument's ability to resolve complex geological structures, enabling it to more precisely distinguish the boundaries and characteristics of different strata. Even under varying geological conditions and heterogeneous environments, it can provide detailed and accurate stratigraphic profiles. This is crucial for assessing oil and gas reserves and drilling risks in complex geological environments, significantly improving exploration efficiency and safety.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 is a schematic diagram of the working process of the phased array drilling electromagnetic wave remote detection instrument of the present invention;

[0029] Figure 2 is a schematic diagram of the structure of the launch section of the present invention;

[0030] Figure 3 is a schematic diagram of the receiving section of the present invention. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Please refer to Figure 1. In this embodiment of the invention, a method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology includes the following steps:

[0033] Step 1: Use the signal transmitting segment to transmit phased array electromagnetic wave signals in three directions, including the axial direction, the horizontal x-direction and / or the horizontal y-direction;

[0034] Step 2: Adjust the radiation phase of the phased array electromagnetic wave signal to enhance the interference of electromagnetic waves, thereby extending the propagation distance of electromagnetic waves in the strata.

[0035] Step 3: Use the signal receiving sub to receive electromagnetic wave signals reflected from the strata and process the received signals to obtain strata information;

[0036] Step 4: Determine the distances between the formation boundaries in front of and to the side of the drill bit by observing the data attenuation at different frequencies.

[0037] As a further aspect of the present invention, the signal transmitting sub-section is capable of transmitting phased array electromagnetic wave signals with a frequency range from 1 kHz to 100 kHz.

[0038] As a further aspect of the present invention, the method also includes freely combining and adjusting the distance between the signal transmitting section and the signal receiving section according to the detection requirements.

[0039] As a further aspect of the present invention, the method can detect the distance of the formation boundary in front of the drill bit up to 30m or more, and can also detect the distance of the lateral formation boundary up to 30m or more.

[0040] As a further aspect of the present invention, the method further includes using a signal transmitting device to transmit phased array electromagnetic wave signals in three directions, the directions including the axial direction, the horizontal x-direction and / or the horizontal y-direction.

[0041] As a further aspect of the present invention, the signal transmitting device includes multiple spiral antennas to achieve phase-controlled electromagnetic wave transmission.

[0042] As a further aspect of the present invention, a signal receiving device is used to receive electromagnetic wave signals reflected from the strata, and the received signals are processed to obtain strata information.

[0043] As a further aspect of the present invention, the distance between the signal transmitting device and the signal receiving device can be adjusted according to the detection requirements.

[0044] As a further aspect of the present invention, the method also includes using a data processing unit to determine the distance between the formation boundaries in front of and to the side of the drill bit by observing data attenuation at different frequencies.

[0045] Example 1:

[0046] Background and Application Scenarios: In oil exploration and drilling operations, traditional electromagnetic wave logging methods have significant limitations in long-distance detection and identification of complex formation structures. To address this issue, this embodiment proposes a downhole electromagnetic wave deep-layer detection method based on three-dimensional phased array technology, which can significantly improve the accuracy of formation information detection and the precision of formation boundary identification.

[0047] Implementation steps:

[0048] Step 1: Transmit phased array electromagnetic wave signals.

[0049] The signal transmitting section transmits phased array electromagnetic wave signals in three directions (axial, horizontal x-axis, and horizontal y-axis). The signal transmitting section can transmit phased array electromagnetic wave signals with frequencies ranging from 1 kHz to 100 kHz. By adjusting the distance between the signal transmitting and receiving sections, the sections can be flexibly combined and adjusted according to detection requirements to optimize the detection effect.

[0050] Step 2: Electromagnetic wave radiation phase adjustment.

[0051] The radiation phase of the phased array electromagnetic wave signal is adjusted to enhance electromagnetic wave interference, thereby extending the propagation distance of the electromagnetic wave in the strata. This step effectively improves signal strength and enhances the accuracy and reliability of long-distance detection.

[0052] Step 3: Electromagnetic wave signal reception and processing.

[0053] The signal receiving sub-section receives electromagnetic wave signals reflected from the formation and processes the received signals to obtain formation information. The coordinated use of the signal receiving sub-section and the signal transmitting sub-section ensures the integrity and reliability of the signal.

[0054] Step 4: Determine the stratigraphic boundary distance.

[0055] By observing data attenuation at different frequencies, the distances to formation boundaries in front of and to the sides of the drill bit are determined. This method can detect formation boundaries up to 30 meters in front of the drill bit and also up to 30 meters to the sides.

[0056] Specific applications and effects: In practical applications, this embodiment is particularly suitable for stratigraphic information detection in complex geological structures. By employing three-dimensional phased array technology, this method effectively solves the problems of severe signal attenuation and low signal-to-noise ratio in traditional electromagnetic wave logging at long distances, improving the accuracy of detection depth and boundary identification.

[0057] For example, during drilling, this method can accurately detect formation boundaries in front of and to the sides of the drill bit in advance, providing crucial data support for adjusting and optimizing the drilling path, thereby reducing drilling accidents and improving operational safety and efficiency. Furthermore, under varying geological conditions, the high sensitivity and accuracy of this method can significantly improve the accuracy of formation characteristic identification, contributing to a comprehensive assessment of geological conditions.

[0058] In summary, this embodiment demonstrates the application of a downhole electromagnetic wave deep detection method based on three-dimensional phased array technology in oil exploration and drilling operations. It significantly improves the accuracy of formation information detection and the precision of formation boundary identification, and has broad application prospects and practical significance.

[0059] Example 2:

[0060] This invention proposes a novel phased array electromagnetic wave remote sensing instrument for drilling, which enables precise detection of formation information ahead of the drill bit during oil drilling. The following are specific embodiments designed according to the technical solution of this invention.

[0061] In this embodiment, the phased array electromagnetic wave remote sensing instrument for drilling consists of a signal transmitting section and a signal receiving section. The transmitting section contains an array of electric dipole coils in three directions, used to radiate phased array electromagnetic waves in the axial, horizontal x-direction, and horizontal y-direction, respectively. Specifically, as shown in Figure 2, T1 represents the axial phased array transmitting coil, T2 represents the horizontal x-direction phased array transmitting coil, and T3 represents the horizontal y-direction phased array transmitting coil. These coils can transmit electromagnetic waves with frequencies ranging from 1 kHz to 100 kHz, ensuring comprehensive detection of different formation characteristics.

[0062] The receiving section is responsible for receiving electromagnetic wave signals reflected back from the strata. As shown in Figure 3, the receiving section includes an axial phased array coil (R1), a horizontal x-direction phased array coil (R2), and a horizontal y-direction phased array coil (R3), used to receive electromagnetic wave signals from different directions. These receiving coils can capture frequency domain signals, providing rich information for subsequent data processing.

[0063] In this embodiment, an instrument is used, consisting of one launch section and two receiver sections. This configuration allows the instrument to flexibly respond to different detection needs. The distance between the launch and receiver sections can be adjusted according to the formation detection requirements within different detection ranges in front of the drill bit, thereby optimizing the detection effect.

[0064] By observing the data attenuation of antennas in corresponding directions on two receiving sections at different frequencies, the instrument of this invention can accurately detect the distance to the formation boundary in front of the drill bit. Compared with the prior art, the detection range of this invention is significantly improved, with the detection distance to the formation boundary in front reaching more than 30m. Simultaneously, the instrument of this invention also demonstrates superior performance in detecting lateral formation boundaries, with a maximum detection distance also exceeding 30m, far surpassing the detection capabilities of current azimuth electromagnetic wave instruments.

[0065] Furthermore, the instrument of this invention is highly flexible. The relative positions of the transmitting and receiving antennas in the axial, horizontal x-direction, and horizontal y-direction can be interchanged to meet different detection requirements. Simultaneously, the positions of the transmitting and receiving sub-sections can also be adjusted as needed, either with the transmitting sub-section below and the receiving sub-section above, or vice versa.

[0066] In terms of observation methods, this embodiment uses signal attenuation within the observation frequency domain to detect the distance to the frontal or lateral stratigraphic boundaries. This method not only improves the accuracy and reliability of the detection but also provides more information for subsequent data processing and analysis.

[0067] In summary, the phased array electromagnetic wave remote sensing instrument for drilling of the present invention has demonstrated significant advantages and flexibility in practical applications, providing strong technical support for formation information detection during oil drilling.

[0068] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., 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 connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology, characterized in that, Includes the following steps: Step 1: Use the signal transmitting segment to transmit phased array electromagnetic wave signals in three directions, including the axial direction, the horizontal x-direction and / or the horizontal y-direction; Step 2: Adjust the radiation phase of the phased array electromagnetic wave signal to enhance the interference of electromagnetic waves, thereby extending the propagation distance of electromagnetic waves in the strata. Step 3: Use the signal receiving sub to receive electromagnetic wave signals reflected from the strata and process the received signals to obtain strata information; Step 4: Determine the distances between the formation boundaries in front of and to the side of the drill bit by observing the data attenuation at different frequencies.

2. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, The signal transmitting section is capable of transmitting phased array electromagnetic wave signals with a frequency range from 1 kHz to 100 kHz.

3. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, The method also includes the ability to freely combine and adjust the distance between the signal transmitting section and the signal receiving section according to detection requirements.

4. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, The method can detect the distance of the formation boundary in front of the drill bit up to 30m or more, and can also detect the distance of the formation boundary on the side up to 30m or more.

5. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, The method further includes using a signal transmitting device to transmit phased array electromagnetic wave signals in three directions, including the axial direction, the horizontal x-direction, and / or the horizontal y-direction.

6. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, in, The signal transmitting device includes multiple spiral antennas to achieve phase-controlled electromagnetic wave transmission.

7. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, in, A signal receiving device is used to receive electromagnetic wave signals reflected from the strata and process the received signals to obtain strata information.

8. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, in, The distance between the signal transmitting device and the signal receiving device can be adjusted according to the detection requirements.

9. The method for deep subsurface electromagnetic wave detection using three-dimensional phased array technology according to claim 1, characterized in that, The method also includes using a data processing unit to determine the distances to the formation boundaries in front of and to the sides of the drill bit by observing data attenuation at different frequencies.

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