Continuous wave mud pulse code modulation method, device, equipment and storage medium

Abstract

The invention provides a continuous wave mud pulse code modulation method, device and equipment and a storage medium, and belongs to the technical field of oil and gas drilling. The method comprises the following steps: encoding detected target acquisition information into a multi-system code element; two code elements are taken as a group to form a code element group, and the code element group controls the rotating speed of a rotor together to form a modulated pressure wave signal for determining a phase delay degree and a phase switching position corresponding to the phase delay degree; wherein the phase switching position is a time period when the corresponding phase delay degree occurs in a modulation period of the code element group to the pressure wave signal. According to the invention, on the premise of not additionally occupying frequency band resources, the transmission information amount is doubled, so that the signal transmission rate based on the continuous wave mud pulse is doubled, and the defect of low transmission rate in the traditional code modulation mode for the continuous wave mud pulse is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling and production, in particular to the technical field of logging while drilling during oil and gas production, and specifically to a continuous wave mud pulse coding modulation method, device, equipment and storage medium. Background Art

[0002] In recent years, oil well extraction has continued to increase, and drilling environments have become increasingly complex. Logging while drilling (LWD) technology measures downhole geological and engineering parameters such as temperature, well deviation, georesistivity, and natural gamma ray data while drilling, transmitting this data to the surface in real time. This helps surface engineers understand downhole conditions, better determine formation characteristics, control drilling conditions, ensure drilling safety in harsh environments, improve drilling efficiency, and reduce drilling costs. Currently, the most widely used LWD technology is mud pulse telemetry. Mud pulse telemetry systems can be categorized by pulse type: positive pulse, negative pulse, and continuous wave (CW). Positive pulse technology is relatively mature and has been used the earliest, but its data transmission rate is relatively slow, typically between 1 and 2 bit / s. Negative pulse technology not only has a low transmission rate and high energy consumption, but is also susceptible to mud corrosion, resulting in limited application. Compared to positive and negative pulse technology, CW mud pulse technology emerged later, but its principles are more advanced. Due to its advantages of high transmission rate, reliability, and cost-effectiveness, it has become a major research focus in LWD technology.

[0003] The mud pulse telemetry system is a typical communication system. The downhole information processing unit encodes and modulates the information collected in real time by various sensors, drives the motor to control the valve opening, and generates a pressure wave signal. This signal is transmitted to the surface through the mud pipeline, and after a series of signal processing, the downhole information is obtained. The key technology of the continuous wave mud pulse telemetry system is signal modulation and demodulation. Currently, common modulation methods include ASK, FSK, and PSK. Phase shift keying modulation methods (i.e., phase delay degree modulation methods) include BPSK and MPSK. MPSK includes higher-order phase shift keying modulation methods such as QPSK and 8PSK. As we know, phase-shift keying (PSK) modulation signals are commonly generated using phase modulation. For example, a multiplier is used to modulate two strictly orthogonal carrier components to produce a QPSK signal. However, it is important to note that PSK modulation technology used in continuous-wave mud pulse telemetry systems differs from signal modulation methods implemented using high-performance integrated circuits. It is a purely mechanical signal generation method, and its phase variation depends on changes in the rotor's angular velocity and angular displacement, with its own unique adjustment rules. Therefore, increasing the base number makes it increasingly difficult for the mud pulse signal generator to produce an ideal waveform. Furthermore, the minimum phase unit variation of high-base PSK, such as π / 4 for 8PSK, is small, making ground detection susceptible to complex noise interference, making demodulation difficult. Therefore, BPSK and QPSK modulation methods are still commonly used in continuous-wave mud pulse telemetry systems. Compared to BPSK, QPSK modulation offers higher bandwidth utilization and information transmission rate at the same carrier frequency, as well as better noise immunity, making it the preferred method. However, to meet the requirements of efficient drilling operations, the data transmission rate of QPSK modulation still needs to be improved.

[0004] Through technical research, those skilled in the art have conducted extensive research to improve the data transmission rate of continuous-wave mud pulse systems. For example, Chinese patent application publication number CN104088628A, entitled "Continuous Phase-Shift Keying Modulation Method Based on a Four-Blade Triangular Valve," discloses a mud pulse generator with a four-blade triangular valve structure. Based on this structure, the one-to-one correspondence between the carrier phase and the representative code element, as well as the waveform generation rules, for BPSK and QPSK modulation schemes are clarified. However, this scheme does not clarify the specific relationship between BPSK and QPSK code elements and the carrier period, making the degree of data transmission rate improvement unknown. Another example is U.S. patent number US14625813, entitled "Modulation Scheme for High-Speed ​​Mud Pulse Telemetry With Reduced Power Requirements," which discloses an offset phase-shift keying (OQPSK) modulation technique. OQPSK is a constant envelope modulation technique improved upon QPSK, staggering the time between two code elements by half a code element period. Compared with QPSK, there is no 180° phase shift, which improves the complex frequency transition problem of the mud pulse generator. It also has the same data transmission rate and bit error rate under the same signal power and bandwidth, improving the reliability of system communication. However, this case did not further study the conversion rules and transition methods between waveforms of different phases.

[0005] In summary, how to improve the data transmission rate of continuous wave mud pulse has become a key research topic in the field of logging while drilling. Summary of the Invention

[0006] In view of this, the purpose of the embodiments of the present invention is to provide a continuous wave mud pulse code modulation method, device, equipment and storage medium to overcome the technical problem of low transmission rate in the existing technology based on the continuous wave mud pulse code modulation method.

[0007] In order to achieve the above-mentioned object, a first aspect of an embodiment of the present invention provides a continuous wave mud pulse code modulation method, the method comprising:

[0008] Encoding the detected target acquisition information into multi-binary code elements;

[0009] Two code elements are grouped into a code element group, and the rotor speed is jointly controlled to form a modulated pressure wave signal with a determined phase delay degree and a determined phase switching position corresponding to the phase delay degree;

[0010] The phase switching position is a time period in which the corresponding phase delay degree occurs within the modulation period of the pressure wave signal by the code element group.

[0011] Optionally, jointly controlling the rotor speed to form a modulated pressure wave signal that determines a phase delay degree and a phase switching position corresponding to the phase delay degree specifically includes:

[0012] pre-define a first control rule and a second control rule;

[0013] The rotor speed is controlled according to a first symbol value in the symbol group and a first control rule to form a pressure wave signal that determines a degree of phase delay, and a timing of a change in the rotor speed is determined according to a second symbol value in the symbol group and a second control rule, thereby generating a modulated pressure wave signal that determines a degree of phase delay and a phase switching position under the control of the symbol group;

[0014] Among them, the first control rule is the correspondence between the first code element value in the code element group, the rotor speed under the control of the first code element value and the degree of phase delay generated under the rotor speed; the second control rule is the correspondence between the second code element value in the code element group and the phase switching position.

[0015] Optionally, the multi-base system is quaternary, and the first control rule is specifically:

[0016] When the first symbol value in the symbol group is X0, the rotor speed under the control of this symbol value is 0, and the phase delay degree at this time is 0 degrees;

[0017] When the first symbol value of the symbol group is X1, the rotor speed under the control of this symbol value is V c / 4, the phase delay is 270 degrees;

[0018] When the first symbol value of the symbol group is X2, the rotor speed under the control of this symbol value is V c / 2, the phase delay is 180 degrees;

[0019] When the first symbol value of the symbol group is X3, the rotor speed under the control of this symbol value is 3V c / 4, the phase delay is 90 degrees;

[0020] Among them, V c It is the rotation speed value maintained when the rotor is working and no code element is sent. X0, X1, X2, and X3 can take any one of 0, 1, 2, and 3 and are different from each other.

[0021] Optionally, the modulation period includes multiple carrier periods, and the phase switching position is located in different carrier periods according to the different values ​​of the second code element in each code element group.

[0022] Optionally, the multi-base system is quaternary, and the second control rule is specifically:

[0023] The second code element value in the code element group is one of 0, 1, 2, and 3, and different second code element values ​​correspond to different phase switching positions one by one, and the phase switching position is within the first carrier cycle, or the second carrier cycle, or the third carrier cycle, or the fourth carrier cycle of the modulation period corresponding to the code element group.

[0024] Optionally, each modulation period is a reference period of the pressure wave signal, and the modulation period of the pressure wave signal by each code element group starts at least from the second reference period of the pressure wave signal. The waveform phase within the first reference period of the pressure wave signal is used as the reference phase, and the reference phase is used as a measurement reference for the phase delay when demodulating the modulated pressure wave signal.

[0025] Optionally, the target acquisition information includes first acquisition information and second acquisition information of different dimensions, and each code element group includes a first code element value encoded according to the first acquisition information and a second code element value encoded according to the second acquisition information.

[0026] A second aspect of an embodiment of the present invention provides a continuous mud pulse code modulation device, the device comprising:

[0027] The encoding module is used to encode the detected target acquisition information into multi-binary code elements;

[0028] a modulation module configured to form a code element group with two code elements as a group, and to jointly control the rotor speed to form a modulated pressure wave signal that determines a phase delay degree and a phase switching position corresponding to the phase delay degree;

[0029] The phase switching position is a time period in which the corresponding phase delay degree occurs within the modulation period of the pressure wave signal by the code element group.

[0030] A third aspect of an embodiment of the present invention provides a device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, a continuous wave mud pulse code modulation method as described in the first aspect of the embodiment of the present invention is implemented.

[0031] A fourth aspect of the embodiments of the present invention provides a storage medium having a computer program stored thereon. When the computer program is executed by a processor, the continuous wave mud pulse code modulation method according to the first aspect of the embodiments of the present invention is implemented.

[0032] It can be seen that within a reference period of the unmodulated pressure wave signal generated by the continuous wave mud pulse generator, when the pressure wave signal is phase-modulated by the traditional phase-shift keying modulation method, one reference period can only carry one code element, and the above-mentioned technical scheme controls the rotor speed change through two code elements, so that the flow of mud liquid through the valve changes within a reference period, thereby bringing about a change in the phase of the pressure wave signal. This phase change carries the information of one of the code elements through the degree of phase delay, and carries the information of another code element through the phase switching position. It can be seen that the above-mentioned technical scheme doubles the amount of transmitted information without occupying additional frequency band resources, thereby doubling the signal transmission rate based on the continuous wave mud pulse, overcoming the low transmission rate defect of the traditional coding modulation method for continuous wave mud pulses.

[0033] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0035] Figure 1 A schematic flow chart of a continuous wave mud pulse code modulation method provided by an embodiment of the present invention;

[0036] Figure 2 A waveform diagram of different phase delay degrees;

[0037] Figure 3 A waveform diagram of a modulated pressure wave signal;

[0038] Figure 4 A schematic diagram of the composition of a continuous wave mud pulse code modulation device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0040] In the description of the embodiments of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to indicate the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0041] In the embodiments of the present invention, the word "exemplary" is used to mean "serving as an example, illustration or description". Any embodiment described as "exemplary" in the embodiments of the present invention is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to implement and use the embodiments of the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the embodiments of the present invention can be implemented without using these specific details. In other examples, known structures and processes are not elaborated in detail to avoid obscuring the description of the embodiments of the present invention with unnecessary details. Therefore, the embodiments of the present invention are not intended to be limited to the embodiments shown, but are consistent with the widest scope consistent with the principles disclosed in the embodiments of the present invention.

[0042] To facilitate understanding of the contents of the following embodiments, some well-known principles and some technical features involved in the following embodiments are explained.

[0043] The basic principle of transmitting data through mud pulses is: the signal detected by the downhole sensor is encoded according to a preset coding rule. The encoded signal controls the operation of the cone valve, rotary valve, or rotor in the mud pulse generator through the driving control circuit of the mud pulse generator, producing a cutoff effect, thereby causing the mud pulse generator to generate a sine or cosine pressure wave signal. The pressure wave signal is transmitted to the ground through the mud in the drill string. The pressure sensor installed on the ground column receives the pressure wave signal. After filtering and shaping, it is decoded by the ground decoding system, so that the data signal transmitted from the downhole can be obtained. This method has the characteristics of mature technology, simple structure and reliable performance.

[0044] In a typical continuous-wave mud pulse generator, the rotor has four blades. Each rotation of the rotor generates four cycles of a sine or cosine wave, known as a carrier cycle. Therefore, in a traditional continuous-wave mud pulse modulation scheme, four carrier cycles constitute a reference cycle, and the modulation time slot of each symbol for a sine or cosine wave constitutes a reference cycle. This modulation time slot is referred to as a modulation period in the following embodiments. It can be seen that in engineering applications of continuous-wave mud pulse generators, the carrier frequency and modulation time slot can be flexibly adjusted as needed.

[0045] Method Example

[0046] See Figures 1 to 3 The present invention provides a continuous wave mud pulse code modulation method, which can be applied to data transmission in oil and gas drilling. This statement does not limit the application of the continuous wave mud pulse code modulation method provided by the present invention. It is known that it can also be used for data transmission in other types of drilling or other fields.

[0047] Specifically, a continuous wave mud pulse code modulation method includes the following implementation steps:

[0048] S100. Encode the detected target acquisition information into multi-binary code elements. It is known that in general drilling operations, the acquisition information detected downhole is typically one or more types of data information that needs to be transmitted to the surface. This can be downhole environmental parameter information or equipment operating parameter information. Downhole environmental parameter information can be downhole geological parameters and engineering parameter information, such as temperature, well deviation, geological resistivity, and natural gamma. Therefore, the target acquisition information can be determined to have a single dimension or multiple dimensions based on the acquisition information that needs to be transmitted in real time in the engineering application.

[0049] It should be understood that in order to encode the target acquisition information into multi-binary code elements, it is first necessary to determine which encoding rule to use for encoding. However, the encoding rule to use is not an improved technical point of the present invention and is not described in detail in this embodiment. Specifically, the preset encoding rule can adopt the encoding rule of the conventional embodiment.

[0050] S200. Two code elements are grouped together to form a code element group, which jointly controls the rotor speed to form a modulated pressure wave signal that determines the phase delay degree and the phase switching position corresponding to the phase delay degree.

[0051] The phase switching position is the period within the modulation cycle of the pressure wave signal by the symbol group where the corresponding phase delay occurs. It can be seen that after continuously changing the rotor speed for a period of time, the pressure wave waveform will produce a corresponding phase delay. The period where this phase delay appears in the pressure wave waveform is called the phase switching position. In other words, compared to before the rotor speed change, the phase delay causes the phase switch.

[0052] For example, the phase switching position is within a certain carrier cycle. The phase switching position at this time can be further interpreted as: when transmitting an information sequence composed of multiple code element groups, a modulation period corresponding to the number of code element groups is required. The modulation period includes multiple carrier cycles. For example, one modulation period includes four carrier cycles, and one modulation period is 4 seconds. Under the control of the second code element value in the code element group, the motor controls the rotor speed to change according to the first code element value in the code element group within a certain carrier cycle, so that the pressure wave waveform within the carrier cycle has a phase delay. The period of phase delay within the carrier cycle is the phase switching position of the pressure wave waveform under the control of the code element group.

[0053] It can be seen that the determination of the phase delay degree expressed in S200 refers to the phase delay degree corresponding to the specific code value of the code group obtained according to predefined rules or mapping relationships. Similarly, the determination of the phase switching position expressed in this step refers to the phase switching position corresponding to the specific code value of the code group obtained according to predefined rules or mapping relationships.

[0054] For example, in one embodiment, the specific implementation process of S200 is as follows:

[0055] S201. Form a symbol group with two symbols as a group. Specifically, for example, the multi-ary symbols obtained by encoding in S100 can be arranged in sequence, with the first symbol and the second symbol forming a first symbol group, the third symbol and the fourth symbol forming a second symbol group, and so on, to form multiple symbol groups.

[0056] S202. Predefine a first control rule and a second control rule. The first control rule is a correspondence between the first symbol value in the symbol group, the rotor speed under the control of the first symbol value, and the degree of phase delay generated under the rotor speed. The second control rule is a correspondence between the second symbol value in the symbol group and the phase switching position.

[0057] S203. The rotor speed is controlled according to the first code element value in the code element group and the first control rule to form a pressure wave signal that determines the degree of phase delay, and the moment of change of the rotor speed is determined according to the second code element value in the code element group and the second control rule, thereby generating a modulated pressure wave signal that determines the degree of phase delay and the phase switching position under the control of the code element group.

[0058] For example, when differential phase modulation is used, after a continuous segment of code elements is modulated onto a pressure wave signal, a reference phase needs to be set before the modulated pressure wave signal is transmitted. This reference phase serves as a measurement reference for the phase delay when demodulating the modulated pressure wave signal, thereby improving the phase demodulation accuracy of the ground terminal. For example, when a continuous segment of code elements modulates a pressure wave signal, the modulation period of each code element group on the pressure wave signal starts at least from the second reference period of the pressure wave signal, and the waveform phase within the first reference period of the pressure wave signal is used as the reference phase.

[0059] Exemplarily, in one embodiment, the phase switching position is located in different carrier cycles of the modulation cycle corresponding to the code group according to different values ​​of the second code group in the code group.

[0060] In the above embodiment, when the target acquisition information is encoded according to the preset encoding rule in S100, the obtained multi-ary code symbols may be quaternary code symbols.

[0061] Accordingly, the first control rule may be:

[0062] When the first symbol value in the symbol group is X0, the rotor speed under the control of this symbol value is 0, and the phase delay degree at this time is 0 degrees;

[0063] When the first symbol value of the symbol group is X1, the rotor speed under the control of this symbol value is V c / 4, the phase delay is 270 degrees;

[0064] When the first symbol value of the symbol group is X2, the rotor speed under the control of this symbol value is V c / 2, the phase delay is 180 degrees;

[0065] When the first symbol value of the symbol group is X3, the rotor speed under the control of this symbol value is 3V c / 4, the phase delay is 90 degrees;

[0066] Among them, V c It is the rotation speed value maintained when the rotor is working and no code element is sent. X0, X1, X2, and X3 can take any one of 0, 1, 2, and 3 and are different from each other.

[0067] For example, when X0=0, X1=1, X2=2, and X3=3, the first control rule is as shown in Table 1.

[0068] Table 1

[0069]

[0070] Accordingly, the second control rule can be:

[0071] The second code element value in the code element group is one of 0, 1, 2, and 3, and different second code element values ​​correspond to different phase switching positions one by one. The phase switching position is within the first carrier cycle, or the second carrier cycle, or the third carrier cycle, or the fourth carrier cycle of the modulation period corresponding to the code element group.

[0072] For example, as shown in Table 2, when the second code element value of the code element group is 0, the corresponding phase switching position is within the first carrier cycle of the modulation period corresponding to the code element group; when the second code element value of the code element group is 1, the corresponding phase switching position is within the second carrier cycle of the modulation period corresponding to the code element group; when the second code element value of the code element group is 2, the corresponding phase switching position is within the third carrier cycle of the modulation period corresponding to the code element group; when the second code element value of the code element group is 3, the corresponding phase switching position is within the fourth carrier cycle of the modulation period corresponding to the code element group.

[0073] Table 2

[0074] Quaternary code element Phase switching position 0 The first carrier cycle 1 The second carrier cycle 2 The third carrier cycle 3 The fourth carrier cycle

[0075] Under differential phase modulation, Figure 2 A waveform diagram of the phase delay degree under the control of the reference phase and different quaternary code values ​​is given. In order to facilitate the comparison of the waveform differences of different phase delay degrees, the second code value in each transmitted code group is 0, that is, the phase switching position is within the first carrier cycle, that is, Figure 2 It is actually the waveform of the modulated pressure wave signal when the code elements 00 10 20 30 are sent.

[0076] exist Figure 2 middle:

[0077] The reference phase pressure waveform is set in the reference period 0 to 1 on the time axis. The reference period includes four carrier periods.

[0078] The modulation period of time axis 1 to 2 carries the first code element value 0 in the quaternary code element group. At this time, the rotor speed under the control of the code element value (i.e., the rotor speed when the phase delay is generated) is 0, that is, the rotor does not rotate, and the corresponding phase delay degree is 0 degrees. When the rotor does not rotate, the valve opening remains the valve opening controlled by the previous code element, so the mud flow rate also remains unchanged. From the waveform at this time, it can be seen that in the first carrier cycle, the waveform amplitude remains constant at the beginning, and then the waveform remains in the same phase with the previous reference cycle (here is the reference phase). Therefore, it can be seen that the pressure wave waveform when no code element is sent and the pressure wave waveform when the rotor does not rotate when the first code element value is 0 can be well distinguished;

[0079] The modulation period of time axis 2 to 3 carries the first code element value 1 in the quaternary code element group. At this time, the rotor speed controlled by this code element value is V c / 4, the corresponding phase delay is 270 degrees, and the rotor speed is changed from the moment 2 on the time axis to the moment V c Adjust to V c / 4, and lasts for a period of time in the first carrier cycle, eventually causing the modulated pressure wave waveform to have a phase delay of 270 degrees compared to the previous reference cycle;

[0080] The modulation period from time axis 3 to 4 carries the first code element value 2 in the quaternary code element group. At this time, the rotor speed controlled by this code element value is V c / 2, the corresponding phase delay is 180 degrees, and the rotor speed is changed from time 3 on the time axis to V c Adjust to V c / 2, and lasts for a period of time in the first carrier cycle, eventually causing the modulated pressure wave waveform to have a 180-degree phase delay compared to the previous reference cycle;

[0081] The modulation period from time axis 4 to 5 carries the first code element value 3 in the quaternary code element group. At this time, the rotor speed controlled by this code element value is 3V. c / 4, the corresponding phase delay is 90 degrees, and the rotor speed is changed from time 4 on the time axis to V c Adjust to 3V c / 4, and lasts for a period of time within the first carrier cycle, eventually causing the modulated pressure wave waveform to have a 90-degree phase delay compared to the previous reference cycle.

[0082] In summary, the two quaternary symbols within the symbol group jointly control the phase variation of the pressure wave signal. The first quaternary symbol value controls the phase delay of the resulting pressure wave signal, while the second quaternary symbol value controls the phase switching position of the resulting pressure wave signal. The combination of the two quaternary symbols can be viewed as a single symbol based on the principles of QPSK-PPM (Quadrature Phase Shift Modulation - Pulse Phase Modulation). Combining the first and second control rules yields Table 3.

[0083] Table 3

[0084]

[0085] Under differential phase modulation, Figure 3 A waveform diagram under the control of reference phase and different symbol groups is given. Figure 3 The code elements sent are: 00 10 21 31 12 02 13 23.

[0086] exist Figure 3 middle:

[0087] Before sending the above code element sequence, a pressure wave waveform with a reference phase is set within the reference period 0 to 1 on the time axis. The reference period includes four carrier periods.

[0088] The modulation period of time axis 1 to 2 carries the symbol group 00. At this time, the rotor speed under the control of the symbol group is 0, and the corresponding phase delay is 0 degrees. The phase switching position is in the first carrier cycle. The rotor speed is changed from the first carrier cycle to the rotor speed of V c Adjust to 0 and last for a period of time in the first carrier cycle. The pressure wave waveform after modulation is in phase with the previous reference cycle.

[0089] The modulation period of time axis 2 to 3 carries the code element group 10. At this time, the rotor speed controlled by the code element group is V c / 4, the corresponding phase delay is 270 degrees, the phase switching position is in the first carrier cycle, and the rotor speed is changed from the moment 2 on the time axis to the moment V c Adjust to V c / 4, and lasts for a period of time in the first carrier cycle, eventually causing the modulated pressure wave waveform to have a phase delay of 270 degrees compared to the previous reference cycle;

[0090] The modulation period of time axis 3 to 4 carries the code element group 21. At this time, the rotor speed controlled by the code element group is V c / 2, the corresponding phase delay is 180 degrees, the phase switching position is within the second carrier cycle, and the rotor speed is changed from the beginning of the second carrier cycle to the rotor speed from V c Adjust to V c / 2, and lasts for a period of time in the second carrier cycle, eventually causing the modulated pressure wave waveform to have a 180-degree phase delay compared to the previous reference cycle;

[0091] The modulation period between time axis 4 and 5 carries code element group 31. At this time, the rotor speed controlled by this code element group is 3V. c / 4, the corresponding phase delay is 90 degrees, the phase switching position is within the second carrier cycle, and the rotor speed is changed from the beginning of the second carrier cycle to the rotor speed from V c Adjust to 3V c / 4, and lasts for a period of time in the second carrier cycle, eventually causing the modulated pressure wave waveform to have a 90-degree phase delay compared to the previous reference cycle;

[0092] The modulation period in time axis 5 to 6 carries code element group 12. At this time, the rotor speed controlled by this code element group is V c / 4, the corresponding phase delay is 270 degrees, the phase switching position is within the third carrier cycle, and the rotor speed is changed from the beginning of the third carrier cycle to the rotor speed from V c Adjust to V c / 4, and lasts for a period of time in the third carrier cycle, eventually causing the modulated pressure wave waveform to have a phase delay of 270 degrees compared to the previous reference cycle;

[0093] The modulation period from time axis 6 to 7 carries code element group 02. At this time, the rotor speed under the control of this code element group is 0, and the corresponding phase delay is 0 degrees. The phase switching position is in the third carrier period. From the beginning of the third carrier period, the rotor speed is changed from V c Adjust to 0 and keep for a period of time in the third carrier cycle. The pressure wave waveform after modulation is in phase with the previous reference cycle.

[0094] The modulation period between time axis 7 and 8 carries code element group 13. At this time, the rotor speed controlled by this code element group is V c / 4, the corresponding phase delay is 270 degrees, the phase switching position is in the fourth carrier cycle, and the rotor speed is changed from the beginning of the fourth carrier cycle to the rotor speed from V c Adjust to V c / 4, and lasts for a period of time within the fourth carrier cycle, eventually causing the modulated pressure wave waveform to have a phase delay of 270 degrees compared to the previous reference cycle;

[0095] The modulation period in time axis 8 to 9 carries the code element group 23. At this time, the rotor speed controlled by this code element group is V c / 2, the corresponding phase delay is 180 degrees, the phase switching position is in the fourth carrier cycle, and the rotor speed is changed from the beginning of the fourth carrier cycle to the rotor speed from V c Adjust to V c / 2, and lasts for a period of time within the fourth carrier cycle, eventually causing the modulated pressure wave waveform to have a phase delay of 180 degrees compared to the previous reference cycle.

[0096] For example, in one embodiment, the target acquisition information includes first acquisition information and second acquisition information of different dimensions, and each symbol group includes a first symbol value encoded based on the first acquisition information and a second symbol value encoded based on the second acquisition information. Thus, the first acquisition information of the first dimension is carried by the phase delay degree, and the second acquisition information of the second dimension is carried by the phase switching position. Compared to traditional continuous wave mud pulse code modulation methods, two symbols representing acquisition information of different dimensions are transmitted within a single modulation cycle, effectively meeting the real-time transmission requirements of acquisition information of two different dimensions during logging while drilling.

[0097] Device embodiment

[0098] See Figure 4 As shown, the present invention provides a continuous wave mud pulse code modulation device, which includes a coding module and a modulation module connected in sequence.

[0099] The encoding module is used to encode the detected target acquisition information into multi-binary code elements.

[0100] The modulation module is configured to control the rotor speed using two symbols in a group, forming a symbol group, to generate a modulated pressure wave signal with a predetermined phase delay and a phase switching position corresponding to the phase delay. The phase switching position is the time period within the modulation cycle of the pressure wave signal by the symbol group that corresponds to the phase delay.

[0101] Optionally, jointly controlling the rotor speed to form a modulated pressure wave signal that determines a phase delay degree and a phase switching position corresponding to the phase delay degree specifically includes:

[0102] pre-define a first control rule and a second control rule;

[0103] The rotor speed is controlled according to a first symbol value in the symbol group and a first control rule to form a pressure wave signal that determines a degree of phase delay, and a timing of a change in the rotor speed is determined according to a second symbol value in the symbol group and a second control rule, thereby generating a modulated pressure wave signal that determines a degree of phase delay and a phase switching position under the control of the symbol group;

[0104] Among them, the first control rule is the correspondence between the first code element value in the code element group, the rotor speed under the control of the first code element value and the degree of phase delay generated under the rotor speed; the second control rule is the correspondence between the second code element value in the code element group and the phase switching position.

[0105] Optionally, the multi-base system is quaternary, and the first control rule is specifically:

[0106] When the first symbol value in the symbol group is X0, the rotor speed under the control of this symbol value is 0, and the phase delay degree at this time is 0 degrees;

[0107] When the first symbol value of the symbol group is X1, the rotor speed under the control of this symbol value is V c / 4, the phase delay is 270 degrees;

[0108] When the first symbol value of the symbol group is X2, the rotor speed under the control of this symbol value is V c / 2, the phase delay is 180 degrees;

[0109] When the first symbol value of the symbol group is X3, the rotor speed under the control of this symbol value is 3V c / 4, the phase delay is 90 degrees;

[0110] Among them, V c It is the rotation speed value maintained when the rotor is working and no code element is sent. X0, X1, X2, and X3 can take any one of 0, 1, 2, and 3 and are different from each other.

[0111] Optionally, the modulation period includes multiple carrier periods, and the phase switching position is located in different carrier periods according to the different values ​​of the second code element in each code element group.

[0112] Optionally, the multi-base system is quaternary, and the second control rule is specifically:

[0113] The second code element value in the code element group is one of 0, 1, 2, and 3, and different second code element values ​​correspond to different phase switching positions one by one, and the phase switching position is within the first carrier cycle, or the second carrier cycle, or the third carrier cycle, or the fourth carrier cycle of the modulation period corresponding to the code element group.

[0114] Optionally, each modulation period is a reference period of the pressure wave signal, and the modulation period of the pressure wave signal by each code element group starts at least from the second reference period of the pressure wave signal. The waveform phase within the first reference period of the pressure wave signal is used as the reference phase, and the reference phase is used as a measurement reference for the phase delay when demodulating the modulated pressure wave signal.

[0115] Optionally, the target acquisition information includes first acquisition information and second acquisition information of different dimensions, and each code element group includes a first code element value encoded according to the first acquisition information and a second code element value encoded according to the second acquisition information.

[0116] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0117] On the other hand, the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, a continuous wave mud pulse code modulation method as described in the above method embodiment is implemented.

[0118] In another aspect, the present invention further provides a storage medium storing a computer program, wherein when the computer program is executed by a processor, the continuous wave mud pulse code modulation method as described in the above method embodiment is implemented.

[0119] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A continuous wave mud pulse code modulation method, characterized in that: include: Encoding the detected target acquisition information into multi-binary code elements; Two code elements are grouped into a code element group, and the rotor speed is jointly controlled to form a modulated pressure wave signal with a determined phase delay degree and a determined phase switching position corresponding to the phase delay degree; The phase switching position is a time period in which the corresponding phase delay degree occurs within the modulation period of the pressure wave signal by the code element group.

2. A continuous wave mud pulse code modulation method according to claim 1, characterized in that: The rotor speed is jointly controlled to form a modulated pressure wave signal that determines a phase delay degree and a phase switching position corresponding to the phase delay degree, specifically comprising: pre-define a first control rule and a second control rule; The rotor speed is controlled according to a first symbol value in the symbol group and a first control rule to form a pressure wave signal that determines a degree of phase delay, and a timing of a change in the rotor speed is determined according to a second symbol value in the symbol group and a second control rule, thereby generating a modulated pressure wave signal that determines a degree of phase delay and a phase switching position under the control of the symbol group; Among them, the first control rule is the correspondence between the first code element value in the code element group, the rotor speed under the control of the first code element value and the degree of phase delay generated under the rotor speed; the second control rule is the correspondence between the second code element value in the code element group and the phase switching position.

3. A continuous wave mud pulse code modulation method according to claim 2, characterized in that: The multi-base system is quaternary, and the first control rule is specifically: When the first symbol value in the symbol group is X0, the rotor speed under the control of this symbol value is 0, and the phase delay degree at this time is 0 degrees; When the first symbol value of the symbol group is X1, the rotor speed under the control of this symbol value is V c / 4, the phase delay is 270 degrees; When the first symbol value of the symbol group is X2, the rotor speed under the control of this symbol value is V c / 2, the phase delay is 180 degrees; When the first symbol value of the symbol group is X3, the rotor speed under the control of this symbol value is 3V c / 4, the phase delay is 90 degrees; Among them, V c It is the rotation speed value maintained when the rotor is working and no code element is sent. X0, X1, X2, and X3 can take any one of 0, 1, 2, and 3 and are different from each other.

4. A continuous wave mud pulse code modulation method according to claim 2, characterized in that: The modulation period includes multiple carrier periods, and the phase switching position is located in different carrier periods according to the different values ​​of the second code element in each code element group.

5. A continuous wave mud pulse code modulation method according to claim 4, characterized in that: The multi-base system is quaternary, and the second control rule is specifically: The second code element value in the code element group is one of 0, 1, 2, and 3, and different second code element values ​​correspond to different phase switching positions one by one, and the phase switching position is within the first carrier cycle, or the second carrier cycle, or the third carrier cycle, or the fourth carrier cycle of the modulation period corresponding to the code element group.

6. The continuous wave mud pulse code modulation method according to claim 1, characterized in that: Each modulation period is a reference period of the pressure wave signal. The modulation period of the pressure wave signal by each code element group starts at least from the second reference period of the pressure wave signal. The waveform phase within the first reference period of the pressure wave signal is used as the reference phase. The reference phase is used as a measurement reference for the phase delay when demodulating the modulated pressure wave signal.

7. The continuous wave mud pulse code modulation method according to claim 1, characterized in that: The target acquisition information includes first acquisition information and second acquisition information of different dimensions, and each code element group includes a first code element value obtained by encoding the first acquisition information and a second code element value obtained by encoding the second acquisition information.

8. A continuous mud pulse code modulation device, characterized in that: include: The encoding module is used to encode the detected target acquisition information into multi-binary code elements; a modulation module configured to form a code element group with two code elements as a group, and to jointly control the rotor speed to form a modulated pressure wave signal that determines a phase delay degree and a phase switching position corresponding to the phase delay degree; The phase switching position is a time period in which the corresponding phase delay degree occurs within the modulation period of the pressure wave signal by the code element group.

9. A device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, a continuous wave mud pulse code modulation method according to any one of claims 1 to 7 is implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a continuous wave mud pulse code modulation method according to any one of claims 1 to 7 is implemented.

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