Downhole double-source-driven while-drilling distributed power supply system and operation method therefor

Abstract

Provided in the present disclosure are a downhole double-source-driven while-drilling distributed power supply system and an operation method therefor. The system comprises: an outer housing extending in an axial direction; and a vortex street generation unit, piezoelectric vibration energy harvesting units and a distributed energy storage unit, which are arranged in the outer housing along the axial direction. Each piezoelectric vibration energy harvesting unit comprises an inner housing, a base beam and a piezoelectric strain gauge, wherein an outer wall of each inner housing is fixedly connected to an inner wall of the outer housing; fixed ends of the plurality of base beams are evenly fixed to the inner wall of the inner housing along the circumference, and there is an inclination angle between a free end and an axis so as to provide a circulation space for a drilling fluid; a piezoelectric strain gauge is loaded on each base beam; and during drilling of a drilling tool and impact of the drilling fluid, the base beams are configured to bear mechanical energy generated by drilling vibration and kinetic energy generated by vortex street disturbance, and the piezoelectric strain gauges are configured to convert the mechanical energy and the kinetic energy into electric energy. During drilling, the electric energy is continuously generated along with continuous vibration of the drilling tool and continuous impact of the drilling fluid, thus achieving distributed collection and continuous supply of downhole electric energy.

Description

A downhole dual-source driven distributed power supply system while drilling and its operation method Technical Field

[0001] The present invention relates to the technical field of downhole power supply, and in particular to a downhole dual-source driven while-drilling distributed power supply system and an operation method thereof. Background Art

[0002] Logging while drilling (LWD) technology plays a vital role in oil exploration and production, serving as the primary means of acquiring formation information and real-time drilling data. Given the complex underground environment of high temperature, high pressure, and strong vibration, ensuring safe oil production and the proper functioning of LWD equipment requires a power supply with excellent stability, adaptability, and long-lasting performance.

[0003] Currently, the main power supply methods include wired transmission, turbine generators, and high-temperature lithium batteries, which can meet the power requirements of different measuring instruments. However, all of the above power supply methods have certain limitations, which are summarized as follows:

[0004] Wired transmission power supply cables are easily tangled and broken when rotated, and cannot be used in ultra-deep wells and highly inclined wells;

[0005] The mud turbine generator power supply structure is complex and easily damaged, and cannot be used in the middle of drilling;

[0006] Lithium battery power supply has a short and unstable battery life, posing safety risks such as data loss and explosion. Technical issues

[0007] The above problems have become the main bottleneck restricting the development of logging while drilling technology, and have also brought many restrictions to the development of deep mining and deep earth exploration.

[0008] In addition, most existing power supply systems are integrated and have concentrated loads. They cannot flexibly adjust the power supply according to different occasions. Moreover, if a fault occurs, the entire power supply system will be paralyzed. At the same time, the plug-and-play power supply mode cannot meet the power demand under non-drilling conditions. Technical Solutions

[0009] To address the challenges of the existing technology, the present invention provides a dual-source downhole, distributed power-while-drilling system and its operating method. The system can be installed at any location on the drill pipe and used in conjunction with logging instruments. During the drilling process, it fully captures the energy generated by both drilling fluid impact and drill tool vibration, thereby providing stable and continuous power to the logging-while-drilling equipment. This extends the life of downhole power supply equipment and avoids frequent replacement. Furthermore, the multi-stage piezoelectric vibration energy harvesting unit and the multiple, differently sized base beams within the piezoelectric vibration energy harvesting unit expand the power generation capacity. Connection to a distributed energy storage unit ensures flexible storage and retrieval of electrical energy.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a downhole dual-source driven while-drilling distributed power supply system, comprising:

[0012] an outer shell extending along the axial direction;

[0013] A vortex generating unit, a piezoelectric vibration energy harvesting unit and a distributed energy storage unit are arranged in the external shell and arranged along the axial direction; the piezoelectric vibration energy harvesting unit includes an internal shell, a base beam and a piezoelectric strain gauge; the outer wall of the internal shell is fixedly connected to the inner wall of the external shell; the fixed ends of multiple base beams are evenly fixed to the inner wall of the internal shell along the circumference, and there is an inclination angle between the free ends and the axis, which is used to provide a circulation space for the drilling fluid; the piezoelectric strain gauge is loaded on the base beam; when the drill bit is drilling and the drilling fluid is impacting, the base beam is used to bear the mechanical energy generated by the drilling vibration and the kinetic energy generated by the vortex disturbance, and the piezoelectric strain gauge is used to convert the mechanical energy and kinetic energy into electrical energy.

[0014] Preferably, the vortex generating unit comprises a circumferential bluff body, a bluff body support frame and a bluff body connecting frame;

[0015] The overall shape of the flow-around bluff body is a combination structure of a sphere and a cylinder. The flow-around bluff body is fixedly connected to the inner side of the bluff body support frame, and the bluff body connecting frame is evenly distributed between the inner wall of the bluff body support frame and the flow-around bluff body; one end of the bluff body connecting frame is fixedly connected to the inner wall of the bluff body support frame, and the other end is fixedly connected to the inner wall of the external shell.

[0016] Preferably, the upstream mud flushes the vortex generating unit and forms a Karman vortex street downstream, and the Karman vortex street generates a vortex disturbance force perpendicular to the axial direction on the piezoelectric vibration energy capture unit.

[0017] Preferably, both ends of the outer shell are fixedly connected to upstream and downstream drilling tools, and generate axial vibration force along with the drilling tools under drilling conditions.

[0018] Preferably, the resultant force of the vortex disturbance force and the axial vibration force acts on the piezoelectric strain gauge of the base beam.

[0019] Preferably, there are multiple piezoelectric vibration energy harvesting units, and the multiple piezoelectric vibration energy harvesting units are connected in series along the axial direction to form a piezoelectric annular stack.

[0020] Preferably, the multiple base beams have different sizes and are arranged in sequence along the circumference of the internal shell according to the external excitation frequency; the upper surface of the base beam is loaded with a piezoelectric strain gauge, and the piezoelectric strain gauge is electrically connected to the distributed energy storage unit through a wire.

[0021] Preferably, the distributed energy storage unit includes an energy management circuit and an energy storage management module;

[0022] The energy management circuit includes a rectifier circuit and a voltage-doubling rectifier circuit. The rectifier circuit uses a multi-source input series synchronous switching circuit and a voltage-doubling rectifier circuit. The multi-source input series synchronous switching circuit is used to achieve real-time control and maximum power extraction of different piezoelectric vibration energy harvesting units at different times within a cycle. The voltage-doubling rectifier circuit is used to amplify the circuit voltage and play a voltage stabilization role.

[0023] The energy storage management module is used to provide power to the logging while drilling instrument.

[0024] Preferably, the downstream of the distributed energy storage unit is fixedly connected to a threaded end cap, and the threaded end cap is fixedly connected to a downstream drilling tool or a measuring short joint.

[0025] In a second aspect, the present invention provides an operating method for a downhole dual-source driven distributed power supply system while drilling, which uses the downhole dual-source driven distributed power supply system while drilling described in the first aspect, comprising:

[0026] During the drilling process, the drilling fluid impacts the vortex generating unit, generating a Karman vortex street, which generates a vortex disturbance force on the piezoelectric vibration energy harvesting unit; the drilling tool drives the external shell to vibrate, generating an axial vibration force on the piezoelectric vibration energy harvesting unit;

[0027] The piezoelectric vibration energy harvesting unit receives the resultant force of the vortex street disturbance force and the axial vibration force, converts it into electrical energy, and transmits the electrical energy to the distributed energy storage unit through a wire;

[0028] The distributed energy storage unit manages, coordinates, stores and integrates the received electrical energy to provide power for logging-while-drilling instruments and wireless repeaters. Beneficial effects

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a downhole dual-source driven, downhole distributed power supply system that can be applied in the field of oil drilling, such as logging while drilling technology, and used in conjunction with logging instruments to realize the collection and utilization of downhole energy. During the drilling process, multiple piezoelectric vibration energy capture units are used to convert the impact of drilling fluid and the vibration of drill pipe into usable electrical energy. Moreover, electrical energy can be continuously generated with the continuous vibration of the drill tool and the continuous impact of the drilling fluid during the drilling process, overcoming the shortcomings of the wired power supply method and realizing the continuous supply of downhole electrical energy. In this way, while ensuring the normal operation of the logging while drilling system, the energy potential of the downhole environment is fully utilized, a new green and low-carbon downhole power supply model is developed, and new ideas, new technologies and new methods are provided for solving the power supply problem of logging while drilling instruments.

[0031] The redundant design of dual energy sources, on the one hand, fully utilizes the existing resources provided by the drilling conditions themselves to ensure sufficient usable electricity and a certain amount of stored electricity; on the other hand, it effectively avoids the disadvantage of power supply being cut off when either energy source cannot be generated due to drill tool vibration or drilling fluid impact.

[0032] The present invention provides a downhole dual-source driven distributed power supply system while drilling, which can adjust the number level of the piezoelectric vibration energy harvesting units, as well as the structural dimensions and number of the base beams therein according to the power supply requirements of the measuring and sensing equipment, so that the piezoelectric annular stack they constitute can achieve the matching power of the measuring short section, thereby realizing real-time monitoring of drill pipe vibration conditions, stress status, formation information and other data.

[0033] The present invention provides a downhole dual-source driven distributed power supply system while drilling, in which the distributed energy storage unit is connected to each piezoelectric vibration energy harvesting unit to realize the management, coordination, storage and integration of the electric energy generated by the piezoelectric vibration energy harvesting unit; on the one hand, it provides electric energy for logging while drilling instruments and equipment and wireless repeaters, etc.; on the other hand, the stored electric energy can also provide continuous electric energy for measuring sensors under non-drilling conditions, avoiding the problem of regular replacement of lithium batteries.

[0034] The present invention provides a downhole dual-source driven distributed power supply system while drilling, which serves as the hardware support and data transmission platform for logging while drilling data. It has a simple structure and can be distributed and installed at appropriate positions on the drill pipe. Its usage position is not restricted and it can be moved to any position underground with the drill pipe to realize distributed collection and utilization of electric energy. It can be optionally installed near the intelligent drill pipe wireless relay to receive measurement sensor test signals, realize signal transmission between adjacent repeaters, improve downhole data transmission efficiency, and improve and enhance the downhole distributed power generation network. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which constitute a part of the present disclosure, are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure but do not constitute a limitation of the present disclosure.

[0036] FIG1 is a schematic diagram of a downhole dual-source driven while-drilling distributed power supply system provided by the present disclosure;

[0037] Figure 2 is a schematic diagram of a piezoelectric vibration energy harvesting unit;

[0038] Figure 3 is a schematic diagram of a vortex generating unit device

[0039] FIG4 is a schematic diagram of the force on the base beam under dual-source excitation;

[0040] FIG5 is a working principle diagram of a downhole dual-source driven while-drilling distributed power supply system provided by the present disclosure.

[0041] Among them, 1-vortex street generating unit; 2-piezoelectric vibration energy capture unit; 3-external shell; 4-distributed energy storage unit; 5-threaded end cover; 6-inner shell; 7-base beam; 8-piezoelectric strain gauge; 9-flow bluff body; 10-bluff body connecting frame; 11-bluff body support frame. Modes for Carrying Out the Invention

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0043] As shown in FIG1 , this embodiment discloses a downhole dual-source driven distributed power supply system while drilling, comprising: an outer shell 3 extending along an axial direction.

[0044] Both ends of the outer shell 3 can be threadedly connected to upstream and downstream drilling tools, allowing standardized installation at any position on the drill pipe and realizing a distributed power generation mode downhole. Inside the outer shell 3, a vortex generating unit 1, a piezoelectric vibration energy capture unit 2, and a distributed energy storage unit 4 are arranged axially.

[0045] The outer shell 3 is composed of two semi-cylindrical shells, the arc axes of the two semi-cylindrical shells coincide, the cross sections are aligned and fixedly connected, and the outer diameter size matches the size of the upstream and downstream drilling tools.

[0046] Multiple piezoelectric vibration energy harvesting units 2 are connected in series along the axis of the housing to form a piezoelectric annular stack, with the piezoelectric vibration energy harvesting units 2 electrically connected to each other. Multiple rectangular grooves are designed along the circumference of the inner wall of the outer housing 3 for secure connection to the piezoelectric vibration energy harvesting units 2. Specifically, the diameter of the rectangular grooves matches the outer diameter of the piezoelectric vibration energy harvesting unit 2, and the width of the rectangular grooves matches the width of the piezoelectric vibration energy harvesting unit 2.

[0047] As shown in Figure 2, the piezoelectric vibration energy capture unit 2 includes an internal shell 6, a base beam 7 and a piezoelectric strain gauge 8; the outer wall of the internal shell 6 is fixedly connected to the inner wall of the external shell 3; the fixed end of the multiple base beams 7 is the wider end, which is evenly fixed to the inner wall of the internal shell 6 along the circumference, and there is an inclination between the free end and the axis, which is used to provide a circulation space for the drilling fluid; the piezoelectric strain gauge 8 is loaded on the base beam 7; when the drill bit is drilling and the drilling fluid is impacting, the base beam 7 is used to bear the mechanical energy generated by the drilling vibration and the kinetic energy generated by the vortex street disturbance, and the piezoelectric strain gauge 8 is used to convert the mechanical energy and kinetic energy into electrical energy.

[0048] In this specific embodiment, as shown in FIG3 , the surface of the vortex generating unit 1 is designed with threads, which are fixedly connected to the upstream drill pipe via the threads. The vortex generating unit 1 includes a circumferential bluff body 9, a bluff body support frame 11, and a bluff body connecting frame 10. The overall shape of the circumferential bluff body 9 is a combination of a sphere and a cylinder. The circumferential bluff body 9 is fixedly connected to the inner side of the bluff body support frame 11. The bluff body connecting frames 10 are evenly distributed between the inner wall of the bluff body support frame 11 and the circumferential bluff body 9. One end of the bluff body connecting frame 10 is fixedly connected to the inner wall of the bluff body support frame 11, and the other end of the bluff body connecting frame 10 is fixedly connected to the inner wall of the outer shell 3. The outer wall of the bluff body support frame 11 is designed with threads, the upstream end of which is fixedly connected to the upstream drill pipe via threads, and the downstream end of which is fixedly connected to the outer shell 3. This realizes the functional positioning of the circumferential bluff body 9, thereby rationally controlling the effective distance between the circumferential bluff body 9 and the downstream piezoelectric vibration energy harvesting unit 2 to generate a Karman vortex street.

[0049] During the drilling process, the high-speed flowing drilling fluid or mud flushes the bluff body 9, generating vortex streets and eddies in its downstream direction, causing periodic velocity fluctuations, affecting the fluid properties of the drilling fluid behind the bluff body 9, and generating vortex street disturbances on the piezoelectric vibration energy capture unit 2 downstream thereof.

[0050] When a Karman vortex street appears, vortices are generated and shed alternately. According to the flow characteristics formula behind the object during the Karman vortex street:

[0051] in, is the Reynolds number, which indicates the flow characteristics behind the object; is the incoming flow velocity; is the cylinder diameter, which is related to the structural size of the vortex generating unit; is the kinematic viscosity of the mud. The vortex shedding frequency f (Hz) can be further calculated:

[0052] Therefore, in order to further improve the power generation efficiency, by optimizing the structural dimensions of the vortex generating unit and the structural dimensions of each base beam in the piezoelectric energy capture unit, the natural frequency and vortex shedding frequency of the base beam are made consistent with the external excitation frequency applied to the shell, that is, the frequency corresponding to the vibration generated during the rock breaking process of the drilling tool, so as to excite the system to resonate, thereby causing the base beam 7 to produce the maximum bending strain and improving the electromechanical conversion efficiency of the piezoelectric strain gauge 8.

[0053] The base beams 7 in the piezoelectric vibration energy harvesting unit 2 vary in structural dimensions (e.g., length), corresponding to different stiffnesses or natural frequencies. Based on the power requirements of the logging-while-drilling instrumentation and the load power requirements, a specific number and series of base beams are selected. These beams are then arranged circumferentially according to the external excitation frequency and fixedly mounted within the internal housing 6. Because these multiple, sequentially arranged beams have different natural or resonant frequencies, they can adapt to drilling conditions in different operating frequency bands, thereby broadening the operating frequency band through distributed power generation using multiple beams.

[0054] The piezoelectric strain gauge 8 is glued and fixed to the surface of the base beam 7 and installed close to the fixed end of the base beam 7 to ensure that the maximum strain generated by the free end of the base beam 7 after being stimulated can be directly transmitted to the piezoelectric strain gauge 8, so that it has the maximum electrical response.

[0055] The base beam 7 is excited by the coupling of vortex disturbance force and axial force of the drill bit to produce periodic vibration, which causes the piezoelectric strain gauge 8 attached to the surface of the base beam 7 to produce periodic strain. The kinetic energy of the high-speed flow of drilling fluid and the mechanical energy of the external shell caused by the strong vibration of the drill pipe are converted into electrical energy through the piezoelectric vibration energy capture unit 2; multiple piezoelectric vibration energy capture units 2 are stacked to form a piezoelectric annular stack, and their respective electrical energy is transmitted to the distributed energy storage unit 4 through wires for coordinated management, thereby improving the energy collection efficiency and power generation capacity of the system.

[0056] Specifically, there is a certain inclination angle α between the free end of the base beam 7 and the axis of the external shell 3, which is used to reserve a certain space to ensure that there is enough annular space in the middle of the internal shell 6 to provide a flow channel for the drilling fluid, ensuring that the multi-stage piezoelectric vibration energy capture unit 2 is excited to generate vibration.

[0057] As shown in Figure 4, the selection of the inclination angle α needs to comprehensively consider the influence of factors such as the drilling fluid flow rate, the inner diameter of the internal shell 6, the length of the base beam 7, the structural dimensions of the flow bluff body 9, etc. By reasonably selecting the inclination angle, the direction of the resultant force of the vortex disturbance force generated by the flow bluff body 9 and the axial force generated by the drill bit vibration can be perpendicular to the surface of the base beam 7, thereby achieving the optimal force-to-electricity conversion efficiency of the piezoelectric vibration energy capture unit 2 and improving the maximum power generation efficiency in the limited downhole space.

[0058] Upstream mud scours vortex generator unit 1, forming a Karman vortex street. The corresponding vortex disturbance force, F1, is perpendicular to the axial direction. Both inner and outer shells 6 and 3 are fixedly connected to the drill string, which vibrates strongly during drilling. The resulting axial vibration force, F2, is generated. The resultant force, F, of these two forces, F1, acts on the surface of base beam 7.

[0059] The piezoelectric strain gauge 8 is fixed to the upper surface of the base beam 7 and is used to receive vibration signals generated by the base beam 7 due to the force F, converting mechanical energy into electrical energy. The positive and negative electrodes of the piezoelectric strain gauge 8 are connected to wires. The internal housing 6 is provided with multiple wiring gaps and holes to protect and secure the wires. The wires are routed through the reserved holes in the internal housing 6 into the wiring gaps. The piezoelectric strain gauge 8 is electrically connected to the distributed energy storage unit 4 via the wires, transmitting electrical energy to the distributed energy storage unit 4.

[0060] The output electromechanical response characteristics of different piezoelectric strain gauges 8 vary greatly. In order to improve the overall electrical energy conversion efficiency of the piezoelectric vibration energy harvesting unit 2 and coordinately manage the electromechanical responses of different piezoelectric vibration energy harvesting units 2, the distributed energy storage unit 4 adopts a multi-source input series synchronous switching circuit, independently designs the maximum power point tracking control algorithm and the corresponding extreme value detection control unit circuit adapted to each input energy source, and controls the input of different piezoelectric strain gauges 8 in real time. The long open-circuit time working mode of the series synchronous switching inductor circuit is used to achieve maximum power extraction of different piezoelectric vibration energy harvesting units 2 at different times within a cycle.

[0061] Specifically, the distributed energy storage unit 4 includes an energy management circuit and an energy storage management module, which are integrated and fixed in the distributed energy storage unit 4 .

[0062] The energy management circuit includes a rectifier circuit and a voltage-doubling rectifier circuit. The rectifier circuit utilizes a multi-source input, series synchronous switching circuit and a voltage-doubling rectifier circuit. This multi-source input, series synchronous switching circuit enables real-time control and maximum power extraction from different piezoelectric vibration energy harvesting units at different times within a cycle. The voltage-doubling rectifier circuit amplifies the circuit voltage, providing voltage stabilization when external excitation is weak, such as when the drilling tool is operating at a low drilling speed.

[0063] The energy storage module provides electrical energy to logging-while-drilling instruments, such as measuring sensors, and adjusts the system's electrical energy output to the optimal state based on the maximum power point tracking algorithm, so that its actual output power is close to the maximum output power.

[0064] The other end of the distributed energy storage unit 4 is fixedly connected to the threaded end cover 5. The inner wall surface of one end of the threaded end cover 5 is threaded and fixedly connected to the external shell 3 through the thread. The outer wall surface of the other end is threaded and fixedly connected to the downstream drill pipe or measuring short section through the thread.

[0065] As shown in FIG5 , the working principle of this embodiment is as follows:

[0066] When the downhole dual-source driven distributed power supply system while drilling is working, the drilling fluid flows through the annular cavity inside the drill pipe at high speed. The rock breaking process of the drill tool causes complex vibration behavior at different positions of the drill pipe, resulting in periodic relative motion between the drill tool and the internal drilling fluid. The downhole dual-source driven distributed power supply system while drilling is fixedly connected to the drill pipe through the external shell 3 and the threaded end cover 5, so that the system carries a certain amount of vibration mechanical energy driven by the drill pipe.

[0067] As the drilling fluid flows through the internal cavity of the drill string, it first flushes the upstream vortex generating unit 1. After flowing through the circumferential bluff body 9, it forms a Karman vortex street. The vortex disturbance force generated by the shedding of the Karman vortex street periodically acts on the piezoelectric vibration energy capture unit 2. Under the coupled excitation of the vortex disturbance force generated by the drilling fluid flow and the axial force generated by the vibration of the external shell, the base beam 7 generates forced vibration under the action of dual-source drive, quickly reaches an equilibrium position, and then performs periodic reciprocating motion. The piezoelectric strain gauge 8 is fixed to the upper surface of the fixed end of the base beam 7, receives the vibration signal generated by the base beam 7, and converts the mechanical energy into AC electrical energy through the piezoelectric material. The distributed energy storage unit 4 receives the electrical energy transmitted by each piezoelectric vibration energy capture unit 2, manages, coordinates, stores, and integrates the electrical energy, and provides continuous power to the logging equipment and wireless repeaters while drilling according to different working conditions. It can be understood that the distributed energy storage unit's processing of electrical energy is achievable by existing technology.

[0068] Since the downhole dual-source driven distributed power supply system while drilling provided by this embodiment has the characteristics of being easy to install at will, and the piezoelectric vibration energy harvesting unit 2 can be selectively set to multiple. Therefore, the overall strategy of the downhole dual-source driven distributed power supply system while drilling provided by this embodiment applied to the downhole distributed power generation mode is summarized as follows:

[0069] Next: (1) Distributed power generation of a single piezoelectric vibration energy harvesting unit:

[0070] For a single piezoelectric vibration energy harvesting unit 2, base beams 7 of different lengths have different natural frequencies or resonant frequencies, adapting to multiple working frequency bands corresponding to drilling tool vibration. Using a linear array structure with multiple base beams 7 of different structural parameters evenly distributed along the circumference can achieve the superposition of its multiple resonant frequencies and modes, forming a distributed power generation solution for a single piezoelectric vibration energy harvesting unit 2. Among them, the open circuit voltage generated by a single base beam 7 is It can be calculated by the following formula:

[0071]

[0072] in, is the internal capacitance of the strain gauge; is the external resistance; is the electromechanical positive coupling coefficient, which is determined by the vibration mode of the base beam; is the r-th order mechanical modal coordinate of the base beam.

[0073] (2) Distributed power generation using multi-stage piezoelectric vibration energy harvesting units:

[0074] For the piezoelectric annular stack formed by the multi-stage piezoelectric vibration energy harvesting unit 2, the electrical response and electrical energy output between the different piezoelectric vibration energy harvesting units are transmitted to the distributed energy storage unit 4 via the positive and negative conductors of the piezoelectric strain gauge 8 for coordinated management, broadening the operating frequency band while achieving maximum power point tracking. The distributed energy storage unit 4 rectifies and manages the signal through its internal integrated circuit and stores it in the energy storage module of the distributed energy storage unit 4. The voltage stabilization circuit monitors the real-time output voltage and adjusts it to ensure that the output voltage remains stable at the designed state, thus solving the problem of instability of the electrical signal generated by the piezoelectric vibration.

[0075] When the logging while drilling equipment needs power supply, the distributed energy storage unit 4 supplies power to it through the power supply circuit and adjusts the output voltage in real time according to the maximum power point tracking algorithm to obtain the maximum output power.

[0076] At the same time, since the distributed energy storage unit 4 can store electrical energy, it can continue to supply electrical energy to related equipment even in non-drilling conditions.

[0077] (3) Distributed installation of power supply system:

[0078] By threading the threaded end cap 5 and the blunt body support frame 11 of the while-drilling distributed power supply system provided in this embodiment to the drill pipe, standardized installation at any position of the drill pipe downhole can be achieved. The system can be installed near the drill bit or drill collar, at any position in the middle of the drill pipe, or near the intelligent drill pipe wireless relay, etc. It can also be used in combination with the measuring short section of the while-drilling logging equipment, so as to achieve continuous power supply for related equipment by following the logging equipment to any position downhole.

[0079] Distributed power supply overcomes the drawback of centralized power supply that is susceptible to failures that may lead to the overall paralysis of the power supply system, thereby ensuring a stable supply of electricity. Moreover, the power supply system provided in this embodiment has no external wiring and will not interfere with normal drilling work. It is highly safe, occupies little space, has flexible installation locations, and is simple and convenient to operate.

[0080] This embodiment provides a downhole dual-source driven, distributed power-while-drilling system that can be applied in the field of oil drilling, such as logging-while-drilling technology, in conjunction with logging instruments to achieve downhole energy collection and utilization. During the drilling process, multiple piezoelectric vibration energy capture units are used to convert drilling fluid impact and drill pipe vibration into usable electrical energy. This electrical energy is continuously generated as the drill tool vibrates and the drilling fluid impacts the drilling process, overcoming the shortcomings of wired power supply methods and achieving distributed collection and continuous supply of downhole electrical energy. This addresses the significant shortcomings of existing downhole power supply methods and fills a gap in the basic theory of downhole mud-drill tool coupled excitation vibration.

[0081] Example 2

[0082] As shown in FIG5 , this embodiment provides an operating method of a downhole dual-source driven distributed power supply system while drilling, which uses the downhole dual-source driven distributed power supply system while drilling described in Example 1, including:

[0083] During the drilling process, the drilling fluid impacts the vortex sound generating unit, generating a Karman vortex street, which generates a vortex street disturbance force on the piezoelectric vibration energy harvesting unit; the drilling tool drives the external shell to vibrate, generating an axial vibration force on the piezoelectric vibration energy harvesting unit;

[0084] The piezoelectric vibration energy harvesting unit receives the resultant force of the vortex street disturbance force and the axial vibration force, converts it into electrical energy, and transmits the electrical energy to the distributed energy storage unit through a wire;

[0085] The distributed energy storage unit manages, coordinates, stores and integrates the received electrical energy to provide power for logging-while-drilling instruments and wireless repeaters.

[0086] This specific embodiment provides an operating method for a downhole dual-source driven distributed power supply system while drilling, which utilizes multiple piezoelectric vibration energy capture units connected in series to convert drilling fluid impact and drill pipe vibration into usable electrical energy. The electrical energy can be continuously generated with the continuous vibration of the drill tool and the continuous impact of the drilling fluid during the drilling process; the distributed energy storage unit is used to manage and store the electrical energy to ensure that electrical energy can still be provided under non-drilling conditions, thereby realizing a distributed and continuous supply of downhole power.

[0087] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A downhole dual-source-driven distributed power supply system for drilling, characterized in that, Comprising: An external housing extending in the axial direction; A vortex street generating unit, a piezoelectric vibration energy harvesting unit, and a distributed energy storage unit arranged axially within the external housing; the piezoelectric vibration energy harvesting unit includes an internal housing, a base beam, and a piezoelectric strain gauge; the outer wall of the internal housing is fixedly connected to the inner wall of the external housing; the fixed ends of multiple base beams are uniformly fixed to the inner wall of the internal housing along the circumference, and the free ends have an inclination angle with respect to the axis to provide a flow space for the drilling fluid; piezoelectric strain gauges are loaded on the base beams; when the drill string is drilling and the drilling fluid impacts, the base beams are used to receive the mechanical energy generated by the drilling vibration and the kinetic energy generated by the vortex street disturbance, and the piezoelectric strain gauges are used to convert the mechanical energy and kinetic energy into electrical energy.

2. The downhole dual-source-driven distributed power supply system while drilling according to claim 1, wherein The vortex street generating unit includes a flow-around bluff body, a bluff body support frame, and a bluff body connecting frame; The overall shape of the flow-around bluff body is a combined structure of a sphere and a cylinder. The flow-around bluff body is fixedly connected to the inside of the bluff body support frame, and the bluff body connecting frames are uniformly distributed between the inner wall of the bluff body support frame and the flow-around bluff body; one end of the bluff body connecting frame is fixedly connected to the inner wall of the bluff body support frame, and the other end is fixedly connected to the inner wall of the external housing.

3. The downhole dual-source-driven distributed power supply system while drilling according to claim 1, characterized in that After the upstream mud flushes the vortex street generating unit, a Karman vortex street is formed downstream, and the Karman vortex street generates a vortex street disturbing force perpendicular to the axis on the piezoelectric vibration energy harvesting unit.

4. The downhole dual-source-driven distributed power supply system while drilling according to claim 3, characterized in that, Both ends of the external housing are fixedly connected to the upstream and downstream drill strings, and an axial vibration force is generated during the drilling operation with the drill string.

5. A downhole dual-source-driven distributed power supply system while drilling, characterized in that, The resultant force of the vortex street disturbing force and the axial vibration force acts on the piezoelectric strain gauges of the base beams.

6. The downhole dual-source-driven distributed power supply system while drilling according to claim 1, characterized in that, There are multiple piezoelectric vibration energy harvesting units, and the multiple piezoelectric vibration energy harvesting units are connected in series along the axis to form a piezoelectric ring stack.

7. A downhole dual-source-driven distributed power supply system while drilling, characterized in that, The multiple base beams have different sizes and are arranged in sequence along the circumference of the internal housing according to the external excitation frequency; piezoelectric strain gauges are loaded on the upper surface of the base beams, and the piezoelectric strain gauges are electrically connected to the distributed energy storage unit through wires.

8. The downhole dual-source driven distributed power supply system while drilling according to claim 1, wherein The distributed energy storage unit includes an energy management circuit and an energy storage management module; The energy management circuit includes a rectifier circuit and a voltage multiplier rectifier circuit; the rectifier circuit adopts a multi-source input series synchronous switch circuit and a voltage multiplier rectifier circuit. The multi-source input series synchronous switch circuit is used to achieve real-time control and maximum power extraction of different piezoelectric vibration energy harvesting units at different times within a cycle; the voltage multiplier rectifier circuit is used to amplify the circuit voltage and play a voltage stabilizing role; The energy storage management module is used to provide electrical energy for the logging-while-drilling instrument.

9. The downhole dual-source driven distributed power supply system while drilling according to claim 1, characterized in that The downstream of the distributed energy storage unit is fixedly connected to a threaded end cap, and the threaded end cap is fixedly connected to the downstream drill string or the measurement sub.

10. A method for operating a downhole dual-source-driven distributed power supply system while drilling, which uses a downhole dual-source-driven distributed power supply system as described in claims 1-9, characterized in that, During the drilling process, the drilling fluid impacts the vortex street generating unit, generating a Karman vortex street, which generates a vortex street disturbing force on the piezoelectric vibration energy harvesting unit; the drill string drives the external housing to vibrate, generating an axial vibration force on the piezoelectric vibration energy harvesting unit; The piezoelectric vibration energy harvesting unit receives the resultant force of the vortex street disturbing force and the axial vibration force, converts it into electrical energy, and transmits the electrical energy to the distributed energy storage unit through wires; The distributed energy storage unit manages, coordinates, stores, and integrates the received electrical energy to provide electrical energy for the logging-while-drilling instrument equipment and the wireless repeater.

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