A self-driven along-the-drillstring measurement system based on a frictional nanogenerator

Abstract

The present application relates to the technical field of self-driven measurement-while-drilling tool, and particularly relates to a self-driven along-drill-string measurement system based on a friction nanogenerator. The technical scheme comprises a friction nanogenerator, an energy management unit, a low-power wireless communication relay node and a ground control terminal. The friction nanogenerator is used to collect the vibration energy of the drill pipe and convert it into electric energy. The friction nanogenerator adopts a sliding independent layer structure and comprises a rotor and a stator. The present application realizes distributed self-driving by deploying the friction nanogenerator at each communication node and utilizing the downhole vibration energy. The energy converted by the friction nanogenerator at the drill bit is enough to emit stronger communication signals, ensuring sufficient energy supply, rapid response of communication content and efficiency, developing information transmission technology with continuous power supply and low-power operation in the process of measurement-while-drilling, and realizing bidirectional communication of information, which has remarkable engineering value for difficult-to-exploit oil and gas resources.

Description

Technical Field

[0001] This invention relates to the field of self-driven measurement while drilling tools, and in particular to a self-driven measurement system along the drill string based on a triboelectric nanogenerator. Background Technology

[0002] In the exploration and development of oil and gas resources, Measurement While Drilling (MWD) technology is a key means of acquiring downhole parameters (such as inclination angle, azimuth angle, tool face angle, temperature, pressure, and formation information) in real time. Traditional MWD systems mainly rely on battery power, downhole turbine generators, or cable power, but these methods have significant drawbacks:

[0003] Battery powered: High temperature environments (>150℃) can easily cause battery capacity to degrade, requiring frequent replacement, increasing maintenance costs and the risk of work interruption;

[0004] Turbine power generation: relies on mud flow rate and viscosity, has a complex mechanical structure and is prone to wear, making it difficult to adapt to small-diameter wellbores or deep well environments;

[0005] Cable power supply: construction is complex and costly, and cables are susceptible to damage from bending, stretching and friction in the mine.

[0006] In recent years, self-powered technology has become a research hotspot for solving downhole power supply problems, mainly including:

[0007] Turbine generators: generate electricity by driving the flow of mud (Guo H et al., IET Electric Power Applications, 2013), but they are sensitive to fluid parameters and have poor long-term reliability;

[0008] Piezoelectric generators utilize vibration to drive piezoelectric materials (such as ZnO nanowires, Wang ZL, Science, 2006), but have low output power (μW to mW level) and the material properties are prone to degradation at high temperatures.

[0009] Electromagnetic induction power generation: relies on changes in magnetic field (Jiang D et al., Nano Energy, 2020), but requires large vibrations to drive it, has a complex structure, and is easily affected by metallic environments;

[0010] Thermoelectric power generation: Power generation using underground temperature difference (Schnatzmeyer MA et al., Journal of PowerSources, 2004), but the power density is low and the temperature difference is limited, making it difficult to meet the continuous power supply demand.

[0011] Although triboelectric nanogenerators (TENGs) have shown potential for harvesting energy from low-frequency vibrations (Wang Zhonglin, NanoEnergy, 2013), existing technologies such as the toroidal TENGs proposed by Du T et al. (Advanced Materials Technologies, 2022) still have the following problems:

[0012] Insufficient power supply stability: TENG output is affected by material interface conditions and ambient humidity, and lacks efficient energy management strategies;

[0013] Low system integration: Existing solutions do not incorporate wireless communication technology and still require an external power supply to support data transmission;

[0014] Limited power density: Low energy conversion efficiency under low-frequency vibration (1-10Hz), making it difficult to drive high-power sensors.

[0015] In summary, existing self-driven technologies cannot meet the requirements of downhole measurement systems for long-term stable power supply, high data transmission rate and low-cost deployment. Therefore, this application proposes a self-driven measurement system along the drill string based on a triboelectric nanogenerator. Summary of the Invention

[0016] The purpose of this invention is to address the problem that existing self-driven technologies cannot meet the requirements of downhole measurement systems for long-term stable power supply, high data transmission rate and low-cost deployment, and to propose a self-driven measurement system along the drill string based on a triboelectric nanogenerator.

[0017] The technical solution of this invention: A self-driven measurement system along a drill string based on a triboelectric nanogenerator, comprising:

[0018] A triboelectric nanogenerator is deployed inside the drill pipe wall cavity to convert high-frequency, high-energy vibration energy downhole into electrical energy. The triboelectric nanogenerator adopts a sliding independent layer structure, including a mover and a stator. The surface of the mover is covered with copper foil, and the stator is composed of a plasma-treated polytetrafluoroethylene layer and copper electrodes.

[0019] An energy management and storage module, connected to the triboelectric nanogenerator, includes a full-wave rectifier circuit, a high-temperature resistant capacitor energy storage unit, and a voltage regulator circuit, used to convert the high-voltage pulse electrical energy output by the triboelectric nanogenerator into a stable 3.3V DC power.

[0020] The low-power wireless communication relay node, each node independently integrates a triboelectric nanogenerator and an energy management storage module. The relay node is deployed on each drill pipe and includes a CC1101 RF module for wireless data transmission between adjacent drill pipes and an RS485 serial communication module for wired data transmission within the drill pipe. The CC1101 RF module adopts Gaussian Frequency Shift Keying (GFSK) modulation technology and supports a data transmission rate of 115kbps.

[0021] The gamma geological steering measurement module is integrated near the drill bit position to collect gamma values, well inclination angle and azimuth angle data at the drill bit in real time, and upload them to the ground control terminal through the relay node;

[0022] The ground control terminal receives and analyzes gamma data and wellbore trajectory parameters in real time, and dynamically adjusts the drilling direction to ensure that the drill bit is within the reservoir.

[0023] Optionally, the mover of the triboelectric nanogenerator is made of FR-4 epoxy glass cloth laminate substrate with a thickness of 1.5-1.7 mm, preferably 1.6 mm, and the surface copper foil thickness is 50 μm. The polytetrafluoroethylene layer is plasma treated.

[0024] Optionally, the high-temperature supercapacitor energy storage unit of the energy management storage module adopts a stacked structure and has an operating temperature range of -40℃ to 200℃. The high-frequency voltage regulator circuit is equipped with an undervoltage lockout mechanism, which automatically cuts off the load power supply when the input voltage is lower than 2.7V.

[0025] Optionally, the gamma geological steering measurement module includes a scintillation crystal detector and a photomultiplier tube, with a sampling frequency ≥10Hz, a measurement blind zone ≤0.5m, and the ability to identify mud interlayers in real time and trigger wellbore trajectory adjustment commands.

[0026] Optionally, the relay nodes are distributed at a density of 3-5 per drill pipe to form a redundant communication network.

[0027] Optionally, the ground control terminal has a built-in geological modeling algorithm that combines gamma data and well inclination angle to dynamically generate a three-dimensional wellbore trajectory map, and sends real-time adjustment commands to the downhole guidance tool through the relay node.

[0028] Optionally, the buffer layer of the triboelectric nanogenerator is made of 1.5mm thick foam tape to maintain interfacial contact pressure under high-frequency vibration.

[0029] Optionally, the data transmitted by the system includes near-bit gamma values, real-time well inclination angle, azimuth angle, and formation lithology identification results, with a data upload delay of ≤100ms, used for dynamic tracking of reservoir boundaries during horizontal drilling.

[0030] Compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0031] 1. By deploying triboelectric nanogenerators at each communication node, distributed self-driving is achieved using downhole vibration energy, eliminating reliance on traditional batteries or external power supplies and significantly improving the stability and continuity of energy supply. Sufficient energy support enables the communication system to respond quickly and transmit data efficiently, solving the communication delays and signal interruptions caused by insufficient energy in traditional measurement while drilling. Simultaneously, combined with optimized energy management and low-power communication technology, the system maintains real-time and reliable signal transmission in complex downhole environments, providing instant data support for dynamic wellbore trajectory adjustment and formation identification, greatly improving the accuracy and efficiency of drilling operations.

[0032] 2. TENG uses high-temperature resistant materials and an optimized structure, which can operate stably for a long time under high temperature, high pressure and strong vibration environment, with an output power attenuation rate of less than 5%.

[0033] 3. By combining the low-power CC1101 RF module with RS485 serial communication, a wireless-wired hybrid transmission network is constructed, which improves the data transmission rate by three orders of magnitude compared with traditional mud pulse telemetry, meeting the requirements of high-precision real-time monitoring.

[0034] 4. The modular design allows the TENG network to be expanded as needed and can be embedded in the drill pipe cavity without interfering with drilling operations; the distributed wireless relay nodes enable data cascading transmission and adapt to different well depths.

[0035] 5. TENG uses low-cost materials, and its manufacturing cost is far lower than that of turbine generators or cable power supply systems; the battery-free design reduces the risk of environmental pollution and is in line with the trend of green energy technology.

[0036] 6. The energy management unit converts the high-voltage, low-current output of TENG into stable DC power through supercapacitor energy storage, switching voltage regulation, and undervoltage lockout mechanisms, ensuring the continuous and reliable operation of sensors and communication modules under power supply fluctuations.

[0037] This communication utilizes a triboelectric nanogenerator that converts vibrations into energy far exceeding that of traditional power sources, and each communication node can deploy this triboelectric generator. Because the energy supply is sufficient, the communication content and efficiency are both relatively fast.

[0038] In summary, this invention utilizes downhole vibration energy to achieve distributed self-drive by deploying triboelectric nanogenerators at each communication node. The energy converted by the triboelectric nanogenerators at the drill bit is sufficient to transmit stronger communication signals, ensuring adequate energy supply and enabling rapid response in communication content and efficiency. This invention develops information transmission technology with continuous power supply and low power consumption during drilling measurement, and enables two-way communication, which has significant engineering value for difficult-to-extract oil and gas resources. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall architecture of a self-driven measurement system along a drill string based on a triboelectric nanogenerator.

[0040] Figure 2 This is an architecture diagram of a low-power wireless communication system.

[0041] Figure 3 This is a flowchart of downhole data transmission.

[0042] Figure 4 A summary diagram illustrating the characteristics of different measurement-while-drilling (MWD) information transmission technologies. Detailed Implementation

[0043] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments of the present invention are not limited thereto, and those skilled in the art can make reasonable adjustments within the scope of the technical concept of the present invention.

[0044] This embodiment provides a self-driven measurement system along a drill string based on a triboelectric nanogenerator. The following is a detailed description of each part of the system.

[0045] 1. System Overall Architecture

[0046] like Figure 1 As shown, the self-driven drill string measurement system of the present invention includes the following core modules:

[0047] Triboelectric nanogenerator (TENG): Deployed within the drill pipe wall cavity to convert drill pipe vibration energy into electrical energy;

[0048] Energy Management Unit (EMU): Connected to TENG, used for rectifying, storing and regulating electrical energy;

[0049] Low-power wireless communication relay node: integrated into each drill pipe, including CC1101 RF module and RS485 serial communication module;

[0050] Ground control terminal: Receives and processes data transmitted from downhole;

[0051] Distributed sensor network: Collects downhole parameters (tool face angle, well inclination angle, pressure, temperature, etc.).

[0052] 2. Specific Implementation of Triboelectric Nanogenerator (TENG)

[0053] 2.1 Structural Design

[0054] The TENG adopts a sliding independent layer structure, specifically including:

[0055] Moving part: High-temperature resistant FR-4 epoxy glass cloth laminate (0.5mm thick) is used as the substrate, and the surface is covered with copper foil (Cu) (50μm thick);

[0056] Stator (fixed part): It is composed of a polytetrafluoroethylene (PTFE) film (100μm thick) and copper electrodes. The PTFE film is plasma treated to enhance the surface roughness and increase the triboelectric charge density.

[0057] 2.2 Working Mode

[0058] The drill pipe vibration drives the mover to slide axially, causing the copper foil and PTFE film to periodically contact and separate, generating alternating current through triboelectric effect and electrostatic induction. Under low-frequency vibration of 1-10Hz, the open-circuit voltage of a single TENG can reach 300V, and the short-circuit current is 5μA.

[0059] 3. Specific implementation of the Energy Management Unit (EMU), such as... Figure 2 As shown.

[0060] 3.1 Circuit Design

[0061] The EMU includes the following functional modules:

[0062] Full-wave rectifier bridge: Composed of 4 Schottky diodes (model 1N5819), it converts the AC output of TENG into DC.

[0063] Energy storage circuit: It uses a 22mF supercapacitor (withstanding voltage 400V) to store electrical energy and smooths the output voltage through a parallel tantalum capacitor (100μF / 35V);

[0064] Voltage regulation circuit: A TPS62150 switching regulator is used to convert the voltage of the energy storage capacitor into a stable 3.3V DC power supply for the wireless communication module;

[0065] Undervoltage lockout (UVLO) mechanism: When the voltage of the energy storage capacitor is lower than 2.7V, the power supply is cut off to protect the system.

[0066] 4. Specific implementation of low-power wireless communication systems, such as... Figure 3 As shown.

[0067] 4.1 Hardware Configuration

[0068] CC1101 RF module: operates in the 433MHz band, supports GFSK modulation, maximum transmit power +10dBm, receive sensitivity -110dBm, data transmission rate 115kbps;

[0069] RS485 serial communication module: uses MAX3485 chip, supports full-duplex communication, and has a transmission rate of 9.6kbps to 1Mbps;

[0070] Microcontroller: The MSP430F5529 low-power MCU is used to handle data acquisition, caching, and routing management.

[0071] 4.2 Data Transmission Protocol

[0072] Time Division Multiple Access (TDMA): Each relay node is allocated a fixed time window (e.g., 10ms) and transmits data through CC1101 within the window period to avoid signal collisions;

[0073] Data hierarchical routing:

[0074] Downhole sensor data is transmitted to the relay node within the drill pipe via an RS485 bus;

[0075] The relay node transmits wirelessly to the relay node of the adjacent drill pipe via CC1101;

[0076] Data is uploaded to the ground control terminal level by level, forming a cascaded transmission network.

[0077] 5. System Deployment and Operation Examples

[0078] Taking a 3000-meter deep well as an example, the specific implementation steps are as follows:

[0079] TENG Deployment: Embed 3 sets of TENG modules into the wall cavity of each drill pipe (9.5m in length) (more sets can be placed as needed);

[0080] Integrated energy management unit: Each TENG group is connected to an independent EMU, outputting a stable 3.3V voltage;

[0081] Relay node configuration: One relay node is deployed in each drill pipe, including a CC1101 module and an RS485 bus interface;

[0082] Ground terminal connection: The ground control terminal receives data transmitted from the drill pipe at the wellhead wirelessly and displays parameters such as well inclination angle and tool face angle in real time.

[0083] 6. Verification of technical effectiveness

[0084] Through laboratory simulation testing (vibration frequency 5Hz, temperature 150℃), this system achieves the following performance:

[0085] Power supply stability: The TENG network has a total output power of 6mW, which can continuously power the wireless communication module;

[0086] Data transmission rate: The end-to-end data transmission rate is stable at 115kbps, and the bit error rate is less than 10⁻⁶.

[0087] Environmental adaptability: After 500 hours of continuous operation in a high temperature (200℃) and high pressure (100MPa) environment, the output power attenuation rate of TENG is <5%.

[0088] This invention is based on the TENG self-driven drilling communication system, which consists of self-driven drilling communication relay nodes deployed on each drill pipe. The number of nodes deployed is determined by the drill pipe specifications and drilling depth. Downhole data, such as tool face angle, inclination angle, azimuth angle, and formation information, are collected by downhole measurement and logging tools (MWD / LWD tools) and then transmitted to the surface control terminal through multiple self-driven drilling communication relay nodes. Each relay node acts as a bridge between the uphole and downhole systems. The surface control terminal then processes the data promptly and transmits commands back to the downhole system in the same manner.

[0089] This invention utilizes downhole vibration energy to achieve distributed self-driving communication by deploying triboelectric nanogenerators at each communication node. The energy converted by the triboelectric nanogenerators at the drill bit is sufficient to transmit a stronger communication signal, while other nodes, due to their lower performance, may only transmit a few kb of information. For example, the data rate of mud pulse telemetry technology commonly used in oil and gas extraction is only 5-40 bit / s. In contrast, the self-driving communication system based on triboelectric nanogenerators consists of triboelectric nanogenerators, an energy management unit, and a relay node. Multiple relay nodes are distributed on each drill pipe to form the self-driving communication system. During drilling, the self-driving communication system can transmit information bidirectionally, increasing the data transmission rate by three orders of magnitude compared to traditional methods, and achieving an energy transmission efficiency of 2.22 J / bit. The lower figure shows the transmission speeds of other drill pipes, such as... Figure 4 As shown, ensuring sufficient energy supply enables rapid response in communication content and efficiency. Developing information transmission technologies with continuous power supply and low power consumption during drilling measurement, as well as realizing two-way communication, has significant engineering value for oil and gas resources that are difficult to extract.

[0090] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A self-driven measurement system along a drill string based on a triboelectric nanogenerator, characterized in that, include: A triboelectric nanogenerator is deployed inside the drill pipe wall cavity to convert high-frequency, high-energy vibration energy downhole into electrical energy. The triboelectric nanogenerator adopts a sliding independent layer structure, including a mover and a stator. The surface of the mover is covered with copper foil, and the stator is composed of a plasma-treated polytetrafluoroethylene layer and copper electrodes. An energy management and storage module, connected to the triboelectric nanogenerator, includes a full-wave rectifier circuit, a high-temperature resistant capacitor energy storage unit, and a voltage regulator circuit, used to convert the high-voltage pulse electrical energy output by the triboelectric nanogenerator into a stable 3.3V DC power. Low-power wireless communication relay nodes, each node independently integrates a triboelectric nanogenerator and an energy management storage module. The relay nodes are deployed on each drill pipe and include a CC1101 radio frequency module for wireless data transmission between adjacent drill pipes and an RS485 serial communication module for wired data transmission within the drill pipe. The gamma geological steering measurement module is integrated near the drill bit position to collect gamma values, well inclination angle and azimuth angle data at the drill bit in real time, and upload them to the ground control terminal through the relay node; The ground control terminal receives and analyzes gamma data and wellbore trajectory parameters in real time, and dynamically adjusts the drilling direction to ensure that the drill bit is within the reservoir. The high-temperature supercapacitor energy storage unit of the energy management storage module adopts a stacked structure and has an operating temperature range of -40℃ to 200℃. The voltage regulation circuit is equipped with an undervoltage lockout mechanism, which automatically cuts off the load power supply when the input voltage is lower than 2.7V. The buffer layer of the triboelectric nanogenerator is made of 1.5 mm thick foam tape, which maintains the interfacial contact pressure under high-frequency vibration. The system transmits data including near-bit gamma values, real-time well inclination angle, azimuth angle, and formation lithology identification results. The data upload delay is ≤100 ms, and it is used for dynamic tracking of reservoir boundaries during horizontal drilling.

2. The self-driven drill string measurement system based on a triboelectric nanogenerator according to claim 1, characterized in that, The mover of the triboelectric nanogenerator is made of FR-4 epoxy glass cloth laminate substrate with a thickness of 1.5-1.7 mm and a surface copper foil thickness of 50 μm. The polytetrafluoroethylene layer is treated with argon plasma.

3. The self-driven drill string measurement system based on a triboelectric nanogenerator according to claim 1, characterized in that, The gamma geological steering measurement module includes a scintillation crystal detector and a photomultiplier tube, with a sampling frequency ≥10 Hz and a measurement blind zone ≤0.5 m. It can identify mud interlayers in real time and trigger wellbore trajectory adjustment commands.

4. The self-driven drill string measurement system based on a triboelectric nanogenerator according to claim 1, characterized in that, The relay nodes are distributed at a density of 3-5 per drill pipe, forming a redundant communication network.

5. The self-driven drill string measurement system based on a triboelectric nanogenerator according to claim 1, characterized in that, The ground control terminal has a built-in geological modeling algorithm that combines gamma data and well inclination angle to dynamically generate a three-dimensional wellbore trajectory map, and sends real-time adjustment commands to the downhole guidance tool through the relay node.

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