A mud pulse transmission device and method

Abstract

The present application provides a kind of mud pulse transmission device, it includes: downhole equipment, system operating mode is determined based on mud pump switch state, and according to system operating mode, measured downhole measurement data is handled to generate mud pulse pressure wave signal;Surface equipment is used to obtain mud pulse pressure wave signal, and according to system operating mode, mud pulse pressure wave signal is decoded, and downhole measurement data is restored.The present application overcomes the problems of low transmission rate and inability to switch system operating mode in conventional mud pulse transmission.The present application has reasonable structure, easy to process, strong adaptability, can improve transmission rate in good well condition, and can ensure transmission reliability in poor well condition.

Description

Technical Field

[0001] This invention relates to the field of drilling engineering technology in oil and gas exploration and development, and more specifically, to a mud pulse transmission device and method. Background Technology

[0002] Mud pulse transmission is currently the most widely used data transmission method in oil drilling. Its principle is that downhole instruments use pulse generators to change the mud pressure in the drill string, forming pressure waves that transmit measurement data to the surface in the form of pulses. Mud pulse transmission can provide well site personnel with various downhole parameters in real time, such as well inclination, azimuth, and tool face. With the successful development and application of various new downhole measuring instruments, the amount of information that needs to be uploaded from downhole is increasing, thus transmission rate has gradually become a bottleneck for mud pulse transmission systems. There are two main solutions to improve the positive pulse transmission rate: reducing the pulse width and compressing the data. Regarding the pulse width reduction solution, recent advancements in mud pulse transmission technology have enabled mud pulse generators to produce signals with smaller pulse widths, laying the foundation for improving the mud pulse transmission rate. However, reducing the pulse width increases the attenuation of the mud pulse signal and makes it more susceptible to noise interference. For compressed data schemes, traditional pulse position modulation coding does not consider the data characteristics of the application environment. For example, the time taken to transmit data "0x0" is always less than the time taken to transmit data "0xF". This can lead to a significant waste of transmission bandwidth in certain situations (e.g., the data to be transmitted is always near "0xF"). Converting the transmitted data into a smaller value can effectively improve the mud pulse transmission rate. However, closer pulse spacing makes mutual interference more likely.

[0003] Traditional mud pulse transmission typically only offers one measurement method, which cannot be changed after the instrument is deployed into the well. During the same drilling run, variations in mud pump status, mud properties, and formation parameters mean that a single measurement scheme may not be suitable for all situations. Ensuring that measurement data is constantly transmitted to the surface, avoiding tripping operations, while maximizing the mud pulse transmission rate, remains a crucial issue that rapid mud pulse transmission must address.

[0004] To address the problems of existing technologies, this invention provides a rapid mud pulse transmission device and method that integrates multiple measurement methods. Summary of the Invention

[0005] To address the problems in the prior art, the present invention provides a mud pulse transmission device, the device comprising:

[0006] The downhole equipment determines the system operating mode based on the mud pump switch status, and processes the measured downhole measurement data to generate mud pulse pressure wave signals according to the system operating mode.

[0007] The surface equipment is used to acquire the mud pulse pressure wave signal and decode the mud pulse pressure wave signal according to the system working mode to restore the downhole measurement data.

[0008] According to one embodiment of the present invention, the downhole equipment is installed inside a non-magnetic drill collar connected to a drill string assembly, and is lowered to a predetermined downhole position along with the drill string assembly, comprising:

[0009] A measurement sensor module, used to continuously measure the downhole measurement data;

[0010] A flow switch module is used to continuously measure the on / off status of the mud pump;

[0011] The central controller module determines the system operating mode based on the mud pump switch status and encodes the downhole measurement data according to the system operating mode to obtain an encoded signal;

[0012] A mud pulse generator module, controlled by the coded signal, blocks or allows mud to pass through in order to generate the mud pulse pressure wave signal;

[0013] A battery module for providing power to electrical equipment within the downhole equipment;

[0014] A power management module is used to control the power distribution of the battery pack module.

[0015] According to one embodiment of the present invention, the central controller module includes a mode determination unit, which determines whether a mode transition condition is met based on the mud pump switching state, and determines the system operating mode, wherein:

[0016] Extract the pump start-up and pump stop-down times from the mud pump's on / off states;

[0017] Calculate the time difference between the pump shutdown time and the pump startup time, and record it as the first value;

[0018] Determine whether the first value is within the working mode conversion window. If it is not within the working mode conversion window, the mode conversion condition is not met, and the current system working mode is maintained.

[0019] If the working mode conversion window is in progress, the mode conversion condition is met. The difference between the first value and the preheating window length is calculated and recorded as the second value.

[0020] Determine the mode conversion sub-window where the second value is located, and convert the current system working mode to the system working mode pointed to by the mode conversion sub-window. The working mode conversion window contains multiple mode conversion sub-windows, and each mode conversion sub-window points to a system working mode.

[0021] According to one embodiment of the present invention, the central controller module includes an encoding unit, which encodes the downhole measurement data based on a preset pulse width reduction factor corresponding to the system operating mode and a preset parameter offset vector to obtain an encoded signal, wherein:

[0022] Read the preset pulse width reduction factor, the preset parameter offset vector, and the downhole measurement data;

[0023] Subtract the preset parameter offset vector from the downhole measurement data to obtain the parameter difference vector;

[0024] Divide the original pulse width by the preset pulse width reduction factor to obtain the current pulse width;

[0025] The parameter difference vector is encoded based on the current pulse width to obtain the encoded signal.

[0026] According to one embodiment of the present invention, the ground equipment comprises:

[0027] The riser line connects to the wellbore, mud pump, mud pit, and mud return line for circulating mud.

[0028] A pressure sensor, installed on the vertical pressure pipeline, is used to sense the mud pulse pressure wave signal and generate a mud pulse electrical signal.

[0029] A ground pressure wave acquisition module is used to acquire the mud pulse electrical signal to obtain the acquired signal;

[0030] A ground computer module is used to decode the acquired signals and reconstruct the downhole measurement data;

[0031] The mud pump is used to execute the pump switching operation command issued by the operator and generate the mud pump switching status.

[0032] The mud tank, which is connected to the mud pump, is used to store mud.

[0033] The mud return pipeline is connected to the vertical pressure pipeline and is used to return mud to the mud tank.

[0034] According to one embodiment of the present invention, the ground computer module includes a decoding unit, which decodes the acquired signal based on a preset pulse width reduction factor corresponding to the system operating mode and a preset parameter offset vector to reconstruct the downhole measurement data, wherein:

[0035] The acquired signal is decoded based on the preset pulse width reduction factor to obtain a parameter difference vector;

[0036] The downhole measurement data is obtained by adding the parameter difference vector to the preset parameter offset vector.

[0037] According to one embodiment of the present invention, when the pulse width of the mud pulse pressure wave signal exceeds a preset value, one of the pressure sensors is used to sense the mud pulse pressure wave signal, and the acquired signal is denoised using a median filtering algorithm and a bandpass filtering algorithm; when the pulse width of the mud pulse pressure wave signal does not exceed the preset value, at least two of the pressure sensors are used to sense the mud pulse pressure wave signal, and all the acquired signals are denoised using an adaptive filtering algorithm.

[0038] According to another aspect of the present invention, a mud pulse transmission method is also provided, performed by the apparatus described in any of the preceding claims, the method comprising the following steps:

[0039] The downhole equipment determines the system operating mode based on the mud pump switch status, and processes the measured downhole measurement data to generate the mud pulse pressure wave signal according to the system operating mode.

[0040] The mud pulse pressure wave signal is acquired by the ground equipment, and the mud pulse pressure wave signal is decoded according to the system working mode to restore the downhole measurement data.

[0041] According to an embodiment of the present invention, the system operating mode is determined by the following steps:

[0042] Extract the pump start-up and pump stop-down times from the mud pump's on / off states;

[0043] Calculate the time difference between the pump shutdown time and the pump startup time, and record it as the first value;

[0044] Determine whether the first value is within the working mode conversion window. If it is not within the working mode conversion window, the mode conversion condition is not met, and the current system working mode is maintained.

[0045] If the working mode conversion window is in progress, the mode conversion condition is met. The difference between the first value and the preheating window length is calculated and recorded as the second value.

[0046] Determine the mode conversion sub-window where the second value is located, and convert the current system working mode to the system working mode pointed to by the mode conversion sub-window. The working mode conversion window contains multiple mode conversion sub-windows, and each mode conversion sub-window points to a system working mode.

[0047] According to an embodiment of the present invention, the mud pulse pressure wave signal is generated through the following steps:

[0048] Read the preset pulse width reduction factor, the preset parameter offset vector, and the downhole measurement data, wherein the preset pulse width reduction factor and the preset parameter offset vector are preset parameters corresponding to the system working mode;

[0049] Subtract the preset parameter offset vector from the downhole measurement data to obtain the parameter difference vector;

[0050] Divide the original pulse width by the preset pulse width reduction factor to obtain the current pulse width;

[0051] The parameter difference vector is encoded based on the current pulse width to obtain the encoded signal.

[0052] According to an embodiment of the present invention, the downhole measurement data is obtained by restoring the data through the following steps:

[0053] The mud pulse pressure wave signal is sensed by a pressure sensor installed on the vertical pressure pipeline to form a mud pulse electrical signal;

[0054] The mud pulse electrical signal is acquired by the ground pressure wave acquisition module to obtain the acquired signal;

[0055] The acquired signal is decoded based on a preset pulse width reduction factor to obtain a parameter difference vector;

[0056] The downhole measurement data is obtained by adding the parameter difference vector to the preset parameter offset vector, wherein the preset pulse width reduction factor and the preset parameter offset vector are preset parameters corresponding to the system working mode.

[0057] According to another aspect of the invention, a storage medium is also provided, which includes a series of instructions for performing the steps of the method described in any of the preceding claims.

[0058] This invention provides a mud pulse transmission device and method, overcoming the problems of low transmission rate and inability to switch system operating modes in conventional mud pulse transmission. This invention has a reasonable structure, is easy to manufacture, and is highly adaptable, capable of improving the transmission rate under good well conditions while ensuring transmission reliability under poor well conditions.

[0059] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0060] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0061] Figure 1 A schematic diagram of the overall structure of a mud pulse transmission device according to an embodiment of the present invention is shown;

[0062] Figure 2 A schematic diagram of system operating mode switching according to an embodiment of the present invention is shown;

[0063] Figure 3 The diagram shows a waveform schematic of transmitting the same data using different system operating modes according to an embodiment of the present invention;

[0064] Figure 4 A flowchart of a mud pulse transmission method according to an embodiment of the present invention is shown.

[0065] In the accompanying drawings, the same parts use the same reference numerals. Also, the drawings are not drawn to scale.

[0066] The meanings of the reference numerals in the attached drawings are as follows: 1-Wellbore; 2-Non-magnetic drill collar; 10-Measurement sensor module; 20-Central controller module; 30-Power management module; 40-Battery pack module; 50-Flow switch module; 60-Mud pulse generator module; 70-Standing pressure pipeline; 81-First pressure sensor; 82-Second pressure sensor; 90-Surface pressure wave acquisition module; 100-Surface computer module; 110-Mud pump; 120-Mud pit; 130-Mud return pipeline. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0068] Prior art (201310154900.7) discloses a high-speed mud pulse generator. Prior art (201510566037.5) discloses a joint coding method for downhole source channels based on a wireless measurement-while-drilling system. Prior art (201910824639.4) discloses an encoding and decoding method based on combined codes for oil drilling. Prior art (201911064160.1) discloses a mud pulse data encoding method and transmission method. Prior art (Joint coding and modulation method for MWD remote transmission systems, Measurement and Control Technology, 2016.09) discloses a joint coding and modulation method for MWD remote transmission systems. Prior art (High-efficiency PPM drilling fluid pulse signal encoding with protected time slots, Petroleum Drilling Technology, 2018.06) discloses a high-efficiency PPM drilling fluid pulse signal encoding with protected time slots. However, none of the aforementioned existing technologies have been able to address the shortcomings of existing methods where a single measurement scheme may not be applicable to all situations due to changes in mud pump status, mud properties, and formation parameters during the same drilling run.

[0069] To address the aforementioned deficiencies in existing technologies, the present invention aims to overcome these shortcomings by providing a rapid mud pulse transmission device integrating multiple measurement modes. This device can switch between various measurement modes, such as conventional, reduced pulse width, compressed data, and reduced pulse width + compressed data, by controlling the on / off state of the mud pump. This allows for improved transmission speed under favorable well conditions while ensuring transmission reliability under poor well conditions.

[0070] Figure 1 A schematic diagram of the overall structure of a mud pulse transmission device according to an embodiment of the present invention is shown.

[0071] In one embodiment, a mud pulse transmission device includes: downhole equipment and surface equipment. The downhole equipment determines the system operating mode based on the mud pump's on / off state and, according to the system operating mode, processes the measured downhole measurement data to generate a mud pulse pressure wave signal. Specifically, the downhole equipment acquires the system operating mode and the actual measurement vector (downhole measurement data), combines the system operating mode and the actual measurement vector to obtain an encoded signal, and generates the mud pulse pressure wave signal based on the encoded signal. The surface equipment acquires the mud pulse pressure wave signal and decodes it according to the system operating mode to reconstruct the downhole measurement data. Specifically, the surface equipment sets the same system operating mode as the downhole equipment and decodes the acquired mud pulse pressure wave signal based on the system operating mode to obtain the actual measurement vector.

[0072] In one embodiment, the downhole equipment is installed inside the non-magnetic drill collar 2 connected to the drill string assembly and is lowered to a predetermined location downhole (e.g., the bottom of the well). Figure 1 As shown, the downhole equipment includes: a measurement sensor module 10, a central controller module 20, a power management module 30, a battery pack module 40, a flow switch module 50, and a mud pulse generator module 60.

[0073] The measurement sensor module 10 is used to continuously measure downhole measurement data. Specifically, the downhole measurement data includes, but is not limited to, well inclination, azimuth, tool face, etc. The flow switch module 50 is used to continuously measure the on / off status of the mud pump. Specifically, the flow switch module 50 continuously measures the on / off status of the mud pump 110.

[0074] The central controller module 20 determines the system operating mode based on the mud pump's on / off status and encodes the downhole measurement data according to the system operating mode to obtain an encoded signal. Specifically, the central controller module 20 periodically reads various downhole parameters measured by the measurement sensor module 10 and the mud pump's on / off status measured by the flow switch module 50. The central controller module 20 sets / changes the system operating mode by calculating the pump switching time interval and encodes the downhole measurement data based on the system operating mode to form an encoded signal.

[0075] The mud pulse generator module 60, controlled by coded signals, blocks or allows mud to pass through, thereby generating mud pulse pressure wave signals. The battery module 40 provides power to the electrical equipment within the downhole facility. The power management module 30 controls the power distribution of the battery module 40.

[0076] Existing mud pulse transmission technology can only preset the operating mode before the instrument is inserted into the well, and the operating mode cannot be changed after the instrument is inserted. With the downhole equipment of this invention, if it is necessary to modify the system operating mode after insertion, the surface operator can switch the system operating mode by changing the status of the mud pump switch.

[0077] In one embodiment, the central controller module 20 includes a mode determination unit that determines whether a mode transition condition is met based on the mud pump's on / off state, and determines the system operating mode. Specifically, the mode determination unit determines the system operating mode in the following manner:

[0078] First, extract the start-up and shut-down times from the mud pump's on / off status. Specifically, the mud pump's on / off status includes various operations performed by ground operators on mud pump 110, and it is necessary to extract the start-up and shut-down times from these operations.

[0079] Secondly, the time difference between the pump shutdown time and the pump startup time is calculated and recorded as the first value. Specifically, in order to avoid frequent changes in the system operating mode from interfering with normal downhole operations, this invention proposes an operating mode switching window, which only allows the system operating mode to be switched within the operating mode switching window. Therefore, it is necessary to calculate the time difference between the pump shutdown time and the pump startup time.

[0080] Then, it is determined whether the first value is within the working mode switching window. If it is not within the working mode switching window, the mode switching condition is not met, and the current system working mode is maintained. Specifically, the working mode switching window is set between the pump start-up time and the pulser start-up time. Further, a preheating window is set after the pump start-up time, and the working mode switching window is set after the preheating window. After the working mode switching window, the mud pulse pressure wave signal (pulser starts working) is displayed.

[0081] Next, if the system is in the operating mode conversion window, the mode conversion conditions are met. The difference between the first value and the preheating window length is calculated and recorded as the second value. Specifically, if the pump switching operation is in the operating mode conversion window, system operating mode conversion is allowed, and the converted system operating mode needs to be determined by the second value.

[0082] Finally, the mode conversion sub-window containing the second value is determined, and the current system operating mode is converted to the system operating mode pointed to by the mode conversion sub-window. The operating mode conversion window contains multiple mode conversion sub-windows, each pointing to a system operating mode. Specifically, this invention provides multiple system operating modes; within the operating mode conversion window, the current system operating mode can be converted to any of the specified system operating modes.

[0083] Existing mud pulse transmission technology requires a long time to transmit parameters from downhole to the surface if the parameters are large. Furthermore, it cannot guarantee data transmission efficiency and accuracy in poor well conditions. This invention can switch the system's operating mode in real time according to well conditions and, through various encoding methods corresponding to each operating mode, improve transmission speed under good well conditions while ensuring transmission reliability under poor well conditions.

[0084] In one embodiment, the central controller module 20 includes an encoding unit that encodes downhole measurement data based on a preset pulse width reduction factor corresponding to the system operating mode and a preset parameter offset vector to obtain an encoded signal. Specifically, the encoding unit obtains the encoded signal in the following manner:

[0085] First, the preset pulse width reduction factor, preset parameter offset vector, and downhole measurement data are read. Specifically, any system operating mode provided by this invention has at least three preset parameters: mode number, preset pulse width reduction factor, and preset parameter offset vector.

[0086] Secondly, the preset parameter offset vector is subtracted from the downhole measurement data to obtain the parameter difference vector. Specifically, the preset parameter offset vector can convert the parameter vector with a relatively large value to be transmitted into a parameter vector with a very small value, which can shorten the transmission time from downhole to the surface.

[0087] Then, the original pulse width is divided by a preset pulse width reduction factor to obtain the current pulse width. Specifically, the preset pulse width reduction factor can change the original pulse width, shorten the transmission time from downhole to the surface, and improve transmission efficiency.

[0088] Finally, the parameter difference vector is encoded based on the current pulse width to obtain the encoded signal. Specifically, the encoded signal can improve the transmission rate under good well conditions and ensure transmission reliability under poor well conditions.

[0089] In one embodiment, such as Figure 1 As shown, the ground equipment includes: a vertical pressure pipeline 70, a pressure sensor, a ground pressure wave acquisition module 90, a ground computer module 100, a mud pump 110, a mud tank 120, and a mud return pipeline 130.

[0090] The standpipeline 70 is connected to the wellbore 1, mud pump 110, mud tank 120, and mud return line 130 for circulating mud. A pressure sensor is installed on the standpipeline 70 to sense mud pulse pressure wave signals and generate mud pulse electrical signals. Specifically, the mud pulse pressure wave signal emitted by the downhole equipment is transmitted through the mud channel in the wellbore 1 to the standpipeline 70, where it is sensed by the pressure sensor and generates a mud pulse electrical signal.

[0091] In one embodiment, when the pulse width of the mud pulse pressure wave signal exceeds a preset value, a pressure sensor is used. Figure 1 The first pressure sensor 81 in the system senses the mud pulse pressure wave signal. When the pulse width of the mud pulse pressure wave signal does not exceed a preset value, processing only the mud pulse electrical signal acquired by a single pressure sensor is usually insufficient to remove noise interference; therefore, at least two pressure sensors need to be used in combination. Figure 1 The first pressure sensor 81 and the second pressure sensor 82 in the system sense the mud pulse pressure wave signal.

[0092] The surface pressure wave acquisition module 90 is used to acquire mud pulse electrical signals to obtain acquired signals. Specifically, the surface pressure wave acquisition module 90 acquires mud pulse electrical signals and transmits them to the surface computer module 100. The surface computer module 100 is used to decode the acquired signals and reconstruct downhole measurement data. Specifically, the surface computer module 100 decodes the acquired signals based on the current system operating mode and reconstructs them into various downhole parameters measured by the measurement sensor module 10. When the pulse width of the mud pulse pressure wave signal exceeds a preset value, the acquired signal is denoised using a median filtering algorithm and a bandpass filtering algorithm to effectively remove noise interference; when the pulse width of the mud pulse pressure wave signal does not exceed the preset value, the acquired signal is denoised using an adaptive filtering algorithm.

[0093] The mud pump 110 is used to execute the pump switching operation command issued by the operator and generate the mud pump switching status. The mud tank 120 is connected to the mud pump 110 and is used to store mud. The mud return pipe 130 is connected to the vertical pressure pipeline 70 and is used to return mud to the mud tank 120.

[0094] In one embodiment, the ground computer module includes a decoding unit that decodes the acquired signal based on a preset pulse width reduction factor corresponding to the system operating mode and a preset parameter offset vector to reconstruct the downhole measurement data. Specifically, the decoding unit reconstructs the downhole measurement data in the following manner: decoding the acquired signal based on the preset pulse width reduction factor to obtain a parameter difference vector; and adding the preset parameter offset vector to the parameter difference vector to obtain the downhole measurement data.

[0095] The mud pulse transmission device provided by this invention has a reasonable structure, is easy to process, and has strong adaptability. By controlling the on / off state of the mud pump 110, it can switch between various measurement modes such as conventional, reduced pulse width, compressed data, and reduced pulse width + compressed data. It can improve the transmission rate when the well condition is good and ensure the transmission reliability when the well condition is poor.

[0096] Figure 2 A schematic diagram illustrating the switching of system operating modes according to an embodiment of the present invention is shown.

[0097] like Figure 2 As shown, the mud pulse transmission method proposed in this invention adds a working mode switching window to the traditional mud pulse transmission method, allowing the system working mode to be switched only within the working mode switching window. Within the working mode switching window, ground operators can switch the system working mode by changing the on / off state of the mud pump 110, thus solving the shortcomings of the traditional mud pulse transmission method.

[0098] In one embodiment, such as Figure 2As shown, the present invention provides four system working modes, which are respectively numbered as Mode 1 (first system working mode), Mode 2 (second system working mode), Mode 3 (third system working mode) and Mode 4 (fourth system working mode).

[0099] like Figure 2 As shown, a preheating window (preset to 30s) is set after the pump starts, and a working mode switching window (preset to 60s) is set after the preheating window. The working mode switching window is divided into four mode switching sub-windows. In the first mode switching sub-window (30-45s after pump starts), the ground operator can perform a pump shutdown operation on the mud pump 110 to switch to the first system working mode.

[0100] When the pump switching time interval (first value) is within the first mode switching sub-window, the central controller module 20 switches to the first system operating mode and controls the mud pulse generator module 60 to generate mud pulse signals according to the first system operating mode encoding signal. When the system operating mode of the downhole equipment changes, it is necessary to ensure that the downhole equipment and the surface equipment are in the same system operating mode. That is, when the central controller module 20 is in the first system operating mode, the surface computer module 100 switches to the first system operating mode and decodes according to the first system operating mode decoding rules.

[0101] like Figure 2 As shown, within the second mode switching sub-window (a time window of 45-60 seconds after pump start-up), the surface operator can switch to the second system operating mode by performing a pump shut-off operation on the mud pump 110. Specifically, when the pump start-up / shutdown time interval is within the second mode switching sub-window, the central controller module 20 switches to the second system operating mode and controls the mud pulse generator module 60 to generate mud pulse signals according to the second system operating mode encoding signal. When the system operating mode of the downhole equipment changes, it is necessary to ensure that the downhole equipment and the surface equipment are in the same system operating mode. That is, when the central controller module 20 is in the second system operating mode, the surface computer module 100 is switched to the second system operating mode and decoded according to the second system operating mode decoding rules.

[0102] like Figure 2As shown, within the third mode switching sub-window (a time window of 60-75 seconds after pump startup), the surface operator can switch to the third system operating mode by performing a pump shutdown operation on the mud pump 110. Specifically, when the pump startup / shutdown time interval is within the third mode switching sub-window, the central controller module 20 switches to the third system operating mode and controls the mud pulse generator module 60 to generate mud pulse signals according to the third system operating mode encoding signal. When the system operating mode of the downhole equipment changes, it is necessary to ensure that the downhole equipment and the surface equipment are in the same system operating mode. That is, when the central controller module 20 is in the third system operating mode, the surface computer module 100 is switched to the third system operating mode and decoded according to the third system operating mode decoding rules.

[0103] like Figure 2 As shown, within the fourth mode switching sub-window (a time window of 75-90 seconds after pump startup), the surface operator can switch to the fourth system operating mode by performing a pump shutdown operation on the mud pump 110. Specifically, when the pump startup / shutdown time interval is within the fourth mode switching sub-window, the central controller module 20 switches to the fourth system operating mode and controls the mud pulse generator module 60 to generate mud pulse signals according to the fourth system operating mode encoding signal. When the system operating mode of the downhole equipment changes, it is necessary to ensure that the downhole equipment and the surface equipment are in the same system operating mode. That is, when the central controller module 20 is in the fourth system operating mode, the surface computer module 100 is switched to the fourth system operating mode and decodes according to the fourth system operating mode decoding rules.

[0104] During other time windows after pump startup, ground operators perform pump shutdown operations to maintain the current system operating mode. Specifically, when the pump startup / shutdown interval falls within other time periods, the central controller module 20 makes no changes.

[0105] Figure 3 A waveform diagram illustrating the transmission of the same data using different system operating modes according to an embodiment of the present invention is shown.

[0106] In one embodiment, the first system operating mode does not change the transmitted data or the transmitted pulse. Further, the preset parameter offset vector corresponding to the first system operating mode is set to 0, and the preset pulse width reduction factor is set to 1. For example... Figure 3 As shown, for the first system working mode, if the original pulse width is 1s, it will take 24.5s to transmit the data "89.98" with 12-bit precision. At this time, the transmission reliability can be guaranteed even under poor well conditions.

[0107] In one embodiment, the second system operating mode does not change the transmitted data, only the transmitted pulse. Further, the preset parameter offset vector corresponding to the second system operating mode is set to 0, and the preset pulse width reduction factor is set to an integer greater than 1. Compared to the first system operating mode, the second system operating mode can reduce the original pulse width, shorten the transmission time from downhole to the surface, and improve transmission efficiency. For example, if the preset pulse width reduction factor of the second system operating mode is set to 2, then the transmission pulse width of the second system operating mode is half that of the first system operating mode. If the transmission pulse width of the first system operating mode is 1s, then the transmission pulse width of the second system operating mode is 0.5s, which can shorten the transmission time by half compared to the first system operating mode.

[0108] like Figure 3 As shown, for the second system working mode, if the original pulse width is 1s, the preset parameter offset vector is set to 0, and the preset pulse width reduction factor is set to 2, then the current pulse width is 0.5s, and the time required to transmit the data "89.98" with 12-bit precision is 12.25s.

[0109] In one embodiment, the third system operating mode only changes the transmitted data and does not change the transmitted pulse. Furthermore, the preset parameter offset vector corresponding to the third system operating mode is set to the minimum value vector of each parameter for subsequent drilling of a preset length of wellbore, and the preset pulse width reduction factor is set to 1. Compared to the first system operating mode, the third system operating mode can convert the parameter vector with a relatively large value to be transmitted into a parameter vector with a very small value, which can shorten the transmission time from downhole to the surface.

[0110] For example, in the horizontal section, the well inclination is approximately 90°. Assuming the measured well inclination at a certain moment is 89.98°, and transmission is performed with 12-bit precision, when processed using the pulse position modulation encoding method of the first system operating mode, the corresponding hexadecimal number is "0x7FF". When processed using the encoding method of the third system operating mode, with the well inclination offset INC0 = 85°, the well inclination difference is INC2 = (89.98 - 85)° = 4.98°, and the corresponding hexadecimal number is "0x071".

[0111] like Figure 3As shown, for the third system working mode, if the original pulse width is 1s, the preset parameter offset vector is set to 85° (well deviation offset INC0 = 85°), and the preset pulse width reduction factor is set to 1, then the current pulse width is 1s. Converting the data "89.98" to "4.98" and transmitting the data "4.98" with 12-bit precision takes 10s. Compared with the first system working mode, the third system working mode can shorten the transmission time significantly.

[0112] In one embodiment, the fourth system operating mode modifies both the transmitted data and the transmitted pulses. Further, the preset parameter offset vector corresponding to the fourth system operating mode is set to the minimum value vector of each parameter for subsequent drilling of a preset length of wellbore, and the preset pulse width reduction factor is set to an integer greater than 1. Specifically, the fourth system operating mode is a combination of the second and third system operating modes, and compared to the first system operating mode, the fourth system operating mode can significantly shorten the transmission time.

[0113] For example, if the preset pulse width reduction factor for the fourth system operating mode is set to 2, then the transmission pulse width of the fourth system operating mode is half that of the first system operating mode. If the transmission pulse width of the first system operating mode is 1s, then the transmission pulse width of the fourth system operating mode is 0.5s. Furthermore, the fourth system operating mode can convert parameter vectors with larger actual transmission values ​​into parameter vectors with very small values. For instance, in the horizontal segment, the well inclination is approximately 90°. Assuming the measured well inclination at a certain moment is 89.98°, and transmission is performed with 12-bit precision, when processed using the pulse position modulation encoding method of the first system operating mode, the corresponding hexadecimal number is "0x7FF". When processed using the encoding method of the fourth system operating mode, setting the well inclination offset INC0 = 85°, then the well inclination difference is INC2 = (89.98 - 85)° = 4.98°, and the corresponding hexadecimal number is "0x071".

[0114] like Figure 3 As shown, for the fourth system working mode, if the original pulse is 1s, the preset parameter offset vector is set to 85° (well deviation offset INC0 = 85°), and the preset pulse width reduction factor is set to 2, then the current pulse width is 0.5s. It takes 5s to convert the data "89.98" to "4.98" and transmit the data "4.98" with 12-bit precision.

[0115] This invention can switch between multiple measurement modes, including conventional (first system working mode), reduced pulse width (second system working mode), compressed data (third system working mode), and reduced pulse width + compressed data (fourth system working mode). It can improve the transmission rate when the well conditions are good, and ensure the transmission reliability when the well conditions are poor.

[0116] Figure 4 A flowchart of a mud pulse transmission method according to an embodiment of the present invention is shown.

[0117] like Figure 4 As shown, in step S1, the system operating mode is determined by the downhole equipment based on the mud pump switch status, and the measured downhole measurement data is processed to generate mud pulse pressure wave signals according to the system operating mode.

[0118] In one embodiment, before the downhole equipment is lowered into the well, the ground engineer sets the initial system operating mode number and its corresponding preset parameter offset vector and preset pulse width reduction factor through the central controller module 20.

[0119] In one embodiment, in step S1, the downhole equipment enters the well bottom. The measurement sensor module 10 continuously measures downhole measurement data, the flow switch module 50 continuously measures the mud pump switching status, and the central controller module 20 reads the initial system operating mode number, the preset pulse width reduction factor M, the preset parameter offset vector X0, and the actual parameter measurement vector X1 (downhole measurement data). X1 is subtracted from X0 to obtain the parameter difference vector X2 (X2 is always greater than 0). The original pulse width is divided by the preset pulse width reduction factor M (M is an integer greater than or equal to 1) to obtain the current pulse width. The parameter difference vector X2 is encoded based on the current pulse width to obtain an encoded signal. The central controller module 20 controls the mud pulse generator module 60 to generate a mud pulse pressure wave signal according to the encoded signal and transmits it to the surface.

[0120] In one embodiment, in step S1, steps S11-S15 determine whether the mode transition condition is met based on the mud pump switching state, and determine the system operating mode:

[0121] In step S11, the start-up and shut-down times of the mud pump are extracted from its on / off state. Specifically, the mud pump's on / off state includes various operations performed by ground operators on the mud pump 110, and the start-up and shut-down times need to be extracted.

[0122] In step S12, the time difference between the pump shutdown time and the pump startup time is calculated and recorded as the first value. In one embodiment, if the pump startup time is 17:30:00 and the pump shutdown time is 17:31:20, then the time difference between the pump shutdown time and the pump startup time is 80s, that is, the first value is 80s.

[0123] In step S13, it is determined whether the first value is within the working mode conversion window. If it is not within the working mode conversion window, the mode conversion condition is not met, and the current system working mode is maintained. In one embodiment, such as... Figure 2 As shown, the working mode switching window is from 30s to 90s after the pump starts. If the first value is 100s, then it is not in the working mode switching window.

[0124] In step S14, if the system is in a working mode switching window, the mode switching condition is met. The difference between the first value and the preheating window length is calculated and recorded as the second value. In one embodiment, such as... Figure 2 As shown, the 0s-30s after the pump starts is the preheating window, and the 30s-90s is the working mode switching window. If the first value is 80s, it is in the working mode switching window and the mode switching condition is met. Calculate the difference between the first value 80s and the preheating window length 30s, that is, the second value is 50s.

[0125] In step S15, the mode conversion sub-window containing the second value is determined, and the current system operating mode is converted to the system operating mode pointed to by the mode conversion sub-window. The operating mode conversion window contains multiple mode conversion sub-windows, each pointing to a system operating mode. In one embodiment, such as... Figure 2 As shown, the first mode switching sub-window is for the period 30s to 45s after pump startup, pointing to the first system operating mode. The second mode switching sub-window is for the period 45s to 60s after pump startup, pointing to the second system operating mode. The third mode switching sub-window is for the period 60s to 75s after pump startup, pointing to the third system operating mode. The fourth mode switching sub-window is for the period 75s to 90s after pump startup, pointing to the fourth system operating mode. By comparison, if the second value of 50s falls within the second mode switching sub-window, then the current system operating mode is switched to the second system operating mode.

[0126] In one embodiment, in step S1, a mud pulse pressure wave signal is generated through steps S16-S20:

[0127] In step S16, the current system operating mode is determined, and the preset pulse width reduction factor, preset parameter offset vector, and downhole measurement data are read. The preset pulse width reduction factor and preset parameter offset vector are preset parameters corresponding to the system operating mode. Specifically, as follows... Figure 3As shown, the preset parameter offset vector for the first system operating mode is set to 0, and the preset pulse width reduction factor is set to 1. The preset parameter offset vector for the second system operating mode is set to 0, and the preset pulse width reduction factor is set to an integer greater than 1. The preset parameter offset vector for the third system operating mode is set to the minimum value vector of all parameters for subsequent drilling of a preset length of wellbore, and the preset pulse width reduction factor is set to 1. The preset parameter offset vector for the fourth system operating mode is set to the minimum value vector of all parameters for subsequent drilling of a preset length of wellbore, and the preset pulse width reduction factor is set to an integer greater than 1.

[0128] In step S17, the preset parameter offset vector is subtracted from the downhole measurement data to obtain the parameter difference vector. Specifically, the preset parameter offset vector X0 is subtracted from the actual parameter measurement vector X1 (downhole measurement data) to obtain the parameter difference vector X2 (X2 is always greater than 0).

[0129] In step S18, the original pulse width is divided by a preset pulse width reduction factor to obtain the current pulse width. Specifically, the original pulse width is divided by the preset pulse width reduction factor M (M is an integer greater than or equal to 1) to obtain the current pulse width.

[0130] In step S19, the parameter difference vector is encoded based on the current pulse width to obtain the encoded signal. Specifically, the parameter difference vector X2 is encoded based on the current pulse width to obtain the encoded signal.

[0131] In step S20, the mud pulse generator module 60, controlled by the coded signal, blocks or allows the mud to pass through, thereby generating a mud pulse pressure wave signal, which is transmitted to the ground along with the mud pulse.

[0132] like Figure 4 As shown, in step S2, mud pulse pressure wave signals are acquired through ground equipment, and the mud pulse pressure wave signals are decoded according to the system working mode to restore downhole measurement data.

[0133] In one embodiment, pressure data is acquired and sent to the ground computer module 100 by pressure sensors (e.g., first pressure sensor 81 and / or second pressure sensor 82) installed on the stand-up pressure line 70 in the ground equipment and the ground pressure wave acquisition module 90. The ground computer module 100 decodes the acquired signal based on the current system working mode number and its corresponding preset pulse width reduction factor M to obtain the parameter difference vector X2. By adding the preset parameter offset vector X0, the actual parameter measurement vector X1 can be obtained, and the downhole measurement data can be restored.

[0134] In one embodiment, in step S2, the downhole measurement data is restored through steps S21-S24:

[0135] In step S21, the mud pulse pressure wave signal is sensed by a pressure sensor installed on the vertical pressure line 70 to generate a mud pulse electrical signal. In one embodiment, when the pulse width of the mud pulse pressure wave signal exceeds a preset value, a pressure sensor ( Figure 1 The first pressure sensor 81 in the system senses the mud pulse pressure wave signal. When the pulse width of the mud pulse pressure wave signal does not exceed a preset value, processing only the mud pulse electrical signal acquired by a single pressure sensor is usually insufficient to remove noise interference; therefore, at least two pressure sensors need to be used in combination. Figure 1 The first pressure sensor 81 and the second pressure sensor 82 in the system sense the mud pulse pressure wave signal.

[0136] In step S22, the ground pressure wave acquisition module 90 acquires the mud pulse electrical signal to obtain the acquired signal. Specifically, the ground pressure wave acquisition module 90 acquires the mud pulse electrical signal and transmits it to the ground computer module 100.

[0137] In step S23, the acquired signal is decoded based on a preset pulse width reduction factor to obtain a parameter difference vector. Specifically, the ground computer module 100 decodes the acquired signal based on the current system operating mode number and its corresponding preset pulse width reduction factor M to obtain the parameter difference vector X2.

[0138] In step S24, the parameter difference vector is added to a preset parameter offset vector to obtain the downhole measurement data. The preset pulse width reduction factor and the preset parameter offset vector are preset parameters for the system's operating mode. Specifically, adding the parameter difference vector X2 to the preset parameter offset vector X0 yields the actual parameter measurement vector X1, thus restoring the downhole measurement data. When the pulse width of the mud pulse pressure wave signal exceeds a preset value, the acquired signal is denoised using a median filtering algorithm and a bandpass filtering algorithm to effectively remove noise interference. When the pulse width of the mud pulse pressure wave signal does not exceed the preset value, the acquired signal is denoised using an adaptive filtering algorithm.

[0139] The mud pulse transmission device and method provided by this invention can also be used in conjunction with a computer-readable storage medium. The storage medium stores a computer program, and executing the computer program runs a mud pulse transmission method. The computer program is capable of executing computer instructions, which include computer program code. The computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc.

[0140] Computer-readable storage media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0141] It should be noted that the contents of computer-readable storage media may be appropriately added to or subtracted from the contents according to the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media may not include electrical carrier signals and telecommunication signals.

[0142] In summary, this invention provides a mud pulse transmission device and method that overcomes the problems of low transmission rate and inability to switch system operating modes inherent in conventional mud pulse transmission. This invention has a reasonable structure, is easy to manufacture, and is highly adaptable, capable of improving transmission rate under good well conditions while ensuring transmission reliability under poor well conditions.

[0143] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0144] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0145] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0146] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0147] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

[0148] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A mud pulse transmission device, characterized in that, The device includes: The downhole equipment determines the system operating mode based on the mud pump switch status, and processes the measured downhole measurement data to generate mud pulse pressure wave signals according to the system operating mode. The surface equipment is used to acquire the mud pulse pressure wave signal and decode the mud pulse pressure wave signal according to the system working mode to restore the downhole measurement data; The downhole equipment includes: a central controller module, which determines the system operating mode through the mud pump switch status, and encodes the downhole measurement data according to the system operating mode to obtain an encoded signal; The central controller module includes a mode determination unit, which determines whether the mode conversion condition is met based on the mud pump's on / off state and determines the system's operating mode. The process includes: extracting the pump start-up and shut-down times from the mud pump's on / off state; calculating the time difference between the shut-down and start-up times, denoted as a first value; determining whether the first value is within the operating mode conversion window; if not, the mode conversion condition is not met, and the current system operating mode is maintained; if it is within the operating mode conversion window, the mode conversion condition is met, and the difference between the first value and the preheating window length is calculated, denoted as a second value; determining the mode conversion sub-window where the second value is located, and converting the current system operating mode to the system operating mode pointed to by the mode conversion sub-window; wherein the operating mode conversion window contains multiple mode conversion sub-windows, each pointing to a system operating mode. The central controller module further includes an encoding unit, which encodes the downhole measurement data based on a preset pulse width reduction factor and a preset parameter offset vector corresponding to the system operating mode to obtain the encoded signal, wherein: the preset pulse width reduction factor, the preset parameter offset vector, and the downhole measurement data are read; the preset parameter offset vector is subtracted from the downhole measurement data to obtain a parameter difference vector; the original pulse width is divided by the preset pulse width reduction factor to obtain the current pulse width; and the parameter difference vector is encoded based on the current pulse width to obtain the encoded signal.

2. The mud pulse transmission device as described in claim 1, characterized in that, The downhole equipment is installed inside the non-magnetic drill collar connected to the drill string assembly, and is lowered to a predetermined downhole position along with the drill string assembly. It also includes: A measurement sensor module, used to continuously measure the downhole measurement data; A flow switch module is used to continuously measure the on / off status of the mud pump; A mud pulse generator module, controlled by the coded signal, blocks or allows mud to pass through in order to generate the mud pulse pressure wave signal; A battery module for providing power to electrical equipment within the downhole equipment; A power management module is used to control the power distribution of the battery pack module.

3. The mud pulse transmission device as described in claim 1, characterized in that, The ground equipment includes: The riser line connects to the wellbore, mud pump, mud pit, and mud return line for circulating mud. A pressure sensor, installed on the vertical pressure pipeline, is used to sense the mud pulse pressure wave signal and generate a mud pulse electrical signal. A ground pressure wave acquisition module is used to acquire the mud pulse electrical signal to obtain the acquired signal; A ground computer module is used to decode the acquired signals and reconstruct the downhole measurement data; The mud pump is used to execute the pump switching operation command issued by the operator and generate the mud pump switching status. The mud tank, which is connected to the mud pump, is used to store mud. The mud return pipeline is connected to the vertical pressure pipeline and is used to return mud to the mud tank.

4. The mud pulse transmission device as described in claim 3, characterized in that, The ground computer module includes a decoding unit, which decodes the acquired signal based on the preset pulse width reduction factor corresponding to the system operating mode and the preset parameter offset vector, to reconstruct the downhole measurement data, wherein: The acquired signal is decoded based on the preset pulse width reduction factor to obtain the parameter difference vector; The downhole measurement data is obtained by adding the parameter difference vector to the preset parameter offset vector.

5. A mud pulse transmission device as described in any one of claims 3-4, characterized in that, When the pulse width of the mud pulse pressure wave signal exceeds a preset value, one of the pressure sensors is used to sense the mud pulse pressure wave signal, and the acquired signal is denoised using a median filtering algorithm and a bandpass filtering algorithm; when the pulse width of the mud pulse pressure wave signal does not exceed the preset value, at least two of the pressure sensors are used to sense the mud pulse pressure wave signal, and all the acquired signals are denoised using an adaptive filtering algorithm.

6. A mud pulse transmission method, characterized in that, Performed by the apparatus as described in any one of claims 1-5, the method comprises the following steps: The downhole equipment determines the system operating mode based on the mud pump switch status, and processes the measured downhole measurement data to generate the mud pulse pressure wave signal according to the system operating mode. The mud pulse pressure wave signal is acquired by the ground equipment, and the mud pulse pressure wave signal is decoded according to the system working mode to restore the downhole measurement data.

7. The mud pulse transmission method as described in claim 6, characterized in that, The system operating mode is determined by the following steps: Extract the pump start-up and pump stop-down times from the mud pump's on / off states; Calculate the time difference between the pump shutdown time and the pump startup time, and record it as the first value; Determine whether the first value is within the working mode conversion window. If it is not within the working mode conversion window, the mode conversion condition is not met, and the current system working mode is maintained. If the working mode conversion window is in progress, the mode conversion condition is met. The difference between the first value and the preheating window length is calculated and recorded as the second value. The mode conversion sub-window where the second value is located is determined, and the current system working mode is converted to the system working mode pointed to by the mode conversion sub-window. The working mode conversion window contains multiple mode conversion sub-windows, and each mode conversion sub-window points to a system working mode.

8. The mud pulse transmission method as described in claim 6, characterized in that, The mud pulse pressure wave signal is generated through the following steps: Read the preset pulse width reduction factor, the preset parameter offset vector, and the downhole measurement data, wherein the preset pulse width reduction factor and the preset parameter offset vector are preset parameters corresponding to the system working mode; Subtract the preset parameter offset vector from the downhole measurement data to obtain the parameter difference vector; Divide the original pulse width by the preset pulse width reduction factor to obtain the current pulse width; The parameter difference vector is encoded based on the current pulse width to obtain the encoded signal; The mud pulse generator module, controlled by the encoded signal, blocks or allows mud to pass through, thereby generating the mud pulse pressure wave signal.

9. A mud pulse transmission method according to any one of claims 6-8, characterized in that, The downhole measurement data is obtained by reconstructing the data through the following steps: The mud pulse pressure wave signal is sensed by a pressure sensor installed on the vertical pressure pipeline to form a mud pulse electrical signal; The mud pulse electrical signal is acquired by the ground pressure wave acquisition module to obtain the acquired signal; The acquired signal is decoded based on the preset pulse width reduction factor to obtain the parameter difference vector; The downhole measurement data is obtained by adding the parameter difference vector to the preset parameter offset vector, wherein the preset pulse width reduction factor and the preset parameter offset vector are preset parameters corresponding to the system working mode.

10. A storage medium, characterized in that, It includes a series of instructions for performing the method as described in any one of claims 6-9.

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