Gas extraction method and device for downhole bore hydraulic penetration

Abstract

The present disclosure relates to a gas extraction method and device for downhole hydraulic permeability enhancement. The method comprises: monitoring the gas concentration of the orifice area in real time during the drilling operation; identifying the gas emission risk working condition of the drilling operation based on the numerical value and variation trend of the gas concentration; adjusting the extraction negative pressure of the gas extraction system connected with the drilling hole according to the identified different risk working conditions to execute the extraction strategy matched with the current working condition. The present scheme improves the timeliness, pertinence and safety of the whole process of gas control.

Description

Technical Field

[0001] This disclosure relates to the field of gas extraction technology, and in particular to a gas extraction method and apparatus for hydraulic permeability enhancement of downholes. Background Technology

[0002] In coal seam gas control, hydraulic fracturing or hydraulic cavity creation via downhole drilling is an effective technology for improving the gas extraction efficiency of low-permeability coal seams. However, this process faces challenges in wellhead blowout prevention, drainage and slag removal, and the integration of extraction. Specifically, when operations stop or pressure is released, high-pressure water, a mixture of gas and coal dust, is easily ejected at high speed from the wellhead; large quantities of coal-water mixtures require efficient separation and discharge; in traditional processes, blowout prevention, drainage, and extraction systems are independent, resulting in cumbersome process transitions and safety risks. Existing technologies mostly employ single-function wellhead blowout preventers or baffles, making it difficult to achieve rapid coordination of drainage, slag removal, and extraction. An integrated and automated device is urgently needed to achieve safe, continuous, and efficient full-process control. Summary of the Invention

[0003] To overcome the problems existing in related technologies, this disclosure provides a method and apparatus for gas extraction using hydraulic permeability enhancement in downhole boreholes.

[0004] According to a first aspect of the present disclosure, a gas extraction method for hydraulically enhanced permeability of a downhole borehole is provided, comprising:

[0005] Real-time monitoring of methane concentration in the borehole area during drilling operations; the drilling operation process includes hydraulic disturbance and gas replacement; Based on the value and trend of the gas concentration, the gas outburst risk condition of the drilling operation is identified; Based on the identified different risk conditions, the negative pressure of the gas extraction system connected to the borehole is adjusted to execute an extraction strategy that matches the current conditions; the gas extraction system is used for borehole operations and for extracting the mixture within the borehole.

[0006] According to a second aspect of the present disclosure, a gas extraction device for hydraulically enhancing the permeability of a downhole is provided, comprising: The monitoring unit is used to monitor the gas concentration in the borehole area in real time during the drilling operation; the drilling operation includes hydraulic disturbance and gas replacement. The identification unit is used to identify the gas outburst risk condition in which the drilling operation is located based on the value and trend of the gas concentration. The extraction unit is used to adjust the extraction negative pressure of the gas extraction system connected to the borehole according to the identified different risk conditions, so as to execute an extraction strategy that matches the current conditions; the gas extraction system is used for drilling operations and extraction of mixtures in the borehole.

[0007] According to a third aspect of the present disclosure, an electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as described in any one of the first aspects.

[0008] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of the first aspects.

[0009] According to a fifth aspect of the present disclosure, a computer program product is provided, including a computer program that, when executed by a processor, implements the method as described in any one of the first aspects.

[0010] The technical solutions provided by the embodiments of this disclosure can include the following beneficial effects: by monitoring the gas concentration at the orifice in real time and automatically identifying the risk conditions of the operation based on the concentration value and the trend of change, and then dynamically adjusting the extraction negative pressure to execute the matching extraction strategy, the proactive perception and adaptive control of the risk of gas outburst during the hydraulic permeability enhancement operation of the downhole is realized, transforming gas extraction from a passive response to an intelligent response linked with the drilling operation, effectively improving the timeliness, pertinence and safety of the entire process of gas management.

[0011] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0012] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0013] Figure 1 This is a flowchart illustrating a gas extraction method for hydraulic permeability enhancement of a downhole according to an exemplary embodiment.

[0014] Figure 2 This is a schematic diagram of the integrated device structure proposed in the embodiments of this disclosure.

[0015] Figure 3 This is a schematic diagram of the rock drilling stage proposed in the embodiments of this disclosure.

[0016] Figure 4 This is a schematic diagram of the coal seam drilling stage proposed in the embodiments of this disclosure.

[0017] Figure 5 This is a schematic diagram of the high-pressure gas slag discharge stage proposed in the embodiments of this disclosure.

[0018] Figure 6 This is a block diagram illustrating a gas extraction device for hydraulic permeability enhancement of a downhole according to an exemplary embodiment.

[0019] Figure 7 This is a block diagram illustrating an apparatus for a gas extraction method using hydraulic permeability enhancement in a downhole, according to an exemplary embodiment.

[0020] Attached Figure Captions 1. Main extraction pipeline; 2. Switch; 3. Manifold; 4. Extraction branch pipeline; 5. Electromagnetic control valve; 6. Gas-liquid separator; 7. Casing; 8. Solidified borehole section; 9. Drill rod; 10. Water jet injector; 11. Drill bit; 12. PLC controller; 13. Methane concentration sensor; 14. Air-water linkage switching device; 15. Orifice blowout preventer; 16. Solid-liquid separation device; 17. Flow meter. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0022] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. The singular forms “a” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0023] It should be understood that although the terms first, second, third, etc., may be used to describe various information in embodiments of this disclosure, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of embodiments of this disclosure, and similarly, second information may also be referred to as first information. Depending on the context, the words “if” and “suppose” as used herein may be interpreted as “when”, “when”, or “in response to a determination”.

[0024] Furthermore, various forms of processes shown in the embodiments of this disclosure can be used to reorder, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and no limitation is imposed herein.

[0025] It should be noted that the collection, storage, use, processing, transmission, provision, and disclosure of user personal information involved in the technical solution disclosed herein all comply with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0026] Figure 1 This is a flowchart illustrating a gas extraction method for hydraulic permeability enhancement of a downhole borehole, according to an exemplary embodiment. Figure 1 As shown, it should be noted that the gas extraction method for hydraulic permeability enhancement of a downhole in this embodiment of the present disclosure is applied to a gas extraction device for hydraulic permeability enhancement of a downhole. For example... Figure 1 As shown, the method may include the following steps: Step 101: Monitor the gas concentration in the borehole area in real time during the drilling operation.

[0027] The drilling process includes hydraulic disturbance and gas replacement.

[0028] In this embodiment, the focus is on the borehole area, a key location connecting the borehole to the external tunnel, to capture real-time methane concentration data in the gas returning from the borehole. This monitoring covers various process stages, including hydraulic disturbances (such as low-pressure water drilling and high-pressure water jet permeability enhancement) and gas replacement (such as high-pressure gas slag removal), providing direct data input for subsequent automatic identification of gas outburst risk conditions.

[0029] It should be noted that hydraulic disturbance refers to the process of using water flows of different pressures to exert physical effects on coal (rock) masses during drilling operations to modify their structure. Specifically, this includes: using low-pressure water as the circulating medium and coolant for drilling; and switching to high-pressure water upon reaching the target coal seam, using jet impact or hydraulic fracturing to create cavities or fracture networks within the coal seam, thereby increasing its permeability and creating channels for gas desorption and migration. This process is the disturbance source that induces gas outbursts.

[0030] Furthermore, gas replacement refers to the process of actively cleaning residual media within boreholes and coal seam cavities using high-pressure gas after drilling or permeability enhancement operations. The high-speed injected gas mixes solid drill cuttings, coal dust, and liquid water accumulated in the borehole to form a multiphase flow, which is then carried to the borehole opening via the annulus between the drill pipe and the borehole wall. This effectively clears and dries the borehole, creating favorable conditions for subsequent continuous gas drainage operations. This process also involves controlling any residual gas that may escape.

[0031] In some embodiments of this application, the gas concentration is obtained by a concentration sensor located in the orifice area and / or inside the solid-liquid separation device.

[0032] In this embodiment, by directly placing the concentration sensor in the orifice area (e.g., the internal flow channel of the orifice blowout preventer) and / or the process flow channel inside the solid-liquid separation device, in-situ, real-time acquisition of gas concentration is achieved. This arrangement allows for direct and unrestricted contact with and analysis of the gas gushing from the borehole or after preliminary separation, ensuring the immediacy and accuracy of the monitoring data and providing a reliable data source for subsequent intelligent identification and rapid response to operating conditions.

[0033] Step 102: Based on the value and trend of the gas concentration, identify the gas outburst risk conditions in which the drilling operation is located.

[0034] In this embodiment of the application, the gas concentration data collected in real time in step 101 is used to analyze the specific numerical value and the trend of change over time (such as the rate of change), and intelligent judgment is automatically performed to classify the current complex drilling operation status into a preset risk condition level with clear extraction countermeasures.

[0035] For example, by comparing whether the concentration exceeds a specific threshold and whether the concentration rises sharply, different working conditions such as "rock drilling without gas risk", "normal coal seam drilling with stable gas outburst" or "blowout risk with abnormal and rapid gas outburst" can be automatically identified, thus realizing the proactive perception and accurate diagnosis of gas dynamics at the work site.

[0036] In some embodiments of this application, step 102 may specifically include the following steps: When the gas concentration remains less than or equal to the first concentration threshold for a preset period of time, the gas outburst risk condition in which the drilling operation is located is determined to be a low-risk condition. When the gas concentration is greater than the first concentration threshold and less than or equal to the second concentration threshold, and the absolute value of the first concentration change rate of the gas concentration is less than the preset change rate, the gas outburst risk condition in which the drilling operation is located is determined to be a standard risk condition. When the gas concentration rises from a state below the second concentration threshold to a state above the second concentration threshold within a preset time period at a second concentration change rate, the gas outburst risk condition in which the drilling operation is located is determined to be a high-risk condition; the second concentration change rate is greater than the preset concentration change rate.

[0037] In one embodiment, an automated diagnostic method based on both absolute concentration value and trend of change is constructed. By setting two key concentration thresholds (a first concentration threshold and a higher second concentration threshold) and a rate of change threshold, the continuous, analog concentration signal is transformed into a discrete, explicit risk level signal, thereby providing a direct decision basis for subsequent differentiated sampling control.

[0038] Specifically, the determination of low-risk working conditions is based on the stability of the concentration remaining below the basic threshold (first concentration threshold), which usually corresponds to a safe stage such as drilling in rock formations without gas outbursts. The determination of standard risk working conditions adopts a composite condition combining "concentration range" and "stability of change": the concentration must be between the first and second thresholds, and its rate of change must be lower than a preset limit, which corresponds to the typical operating state of normal and stable gas outbursts after coal seam exposure.

[0039] The core identifying characteristic of high-risk operating conditions is that the gas concentration not only exceeds a relatively high second concentration threshold within a short period of time, but its rate of increase (second concentration change rate) also exceeds the preset change rate warning line. This simultaneous occurrence of "ultra-high concentration" and "rapid change" is accurately identified as a precursor to or an ongoing state of abnormal outbursts such as "blowouts," thereby triggering the highest level of emergency extraction response.

[0040] In some embodiments of this application, the drilling process includes a low-pressure water drilling stage, a high-pressure water permeability enhancement stage, and a high-pressure gas slag removal stage; the method further includes: During the high-pressure water permeability enhancement stage or the high-pressure gas slag discharge stage, when the gas outburst risk condition is a high-risk condition, the solid-liquid separation device is controlled to perform solid-liquid separation operation on the mixture returned from the orifice; the solid-liquid separation device is connected to the gas extraction system.

[0041] In this embodiment, low-pressure water is used as the circulating medium and coolant during the low-pressure water drilling stage to drive the drill bit for conventional drilling operations. During this process, the methane concentration in the gas returning from the borehole is monitored in real time, and the risk conditions are intelligently determined based on the monitoring results: if the concentration remains extremely low, it is determined to be rock drilling, and no extraction operation is performed to save energy; if the concentration rises steadily to a certain range, it is determined to have entered the coal seam, and the extraction system is activated and operated at a basic negative pressure (e.g., -10 kPa) to achieve "drilling and extraction simultaneously" and prevent methane accumulation. In the high-pressure water permeability enhancement stage, after the borehole reaches the target coal seam, the system switches to high-pressure water mode. High-pressure water is injected into the coal seam through a water jet injector, using hydraulic impact and fracturing to create cavities or fracture networks within the coal seam, thereby significantly improving its permeability. This stage is a high-risk phase that can induce sudden and massive gas outbursts (blowouts). Once a sharp rise in gas concentration exceeding the high-risk threshold is detected, enhanced extraction is immediately and automatically initiated (e.g., increasing the negative pressure to -25 kPa) while ensuring the simultaneous operation of the solid-liquid separation device to forcefully extract the outburst gas and efficiently treat the accompanying coal-water mixture. The high-pressure gas slag removal stage occurs after the permeability enhancement operation is completed. The system switches to high-pressure gas mode, injecting a high-speed gas stream into the borehole to remove residual coal dust, rock powder, and accumulated water. The gas stream carries the remaining material into the borehole, forming a multiphase mixture that is then returned to the borehole opening. During this stage, the extraction negative pressure is dynamically adjusted based on the real-time gas concentration in the discharged gas: if gas is detected, extraction continues to ensure safety; if no gas is detected, extraction is stopped to conserve energy. Simultaneously, the solid-liquid separation and gas-water separation devices operate continuously to ensure a smooth slag removal process and protect the extraction pipeline.

[0042] In this embodiment of the application, when the system identifies a high-risk working condition, it controls the solid-liquid separation device to perform a forced solid-liquid separation operation on the multiphase mixture returning from the orifice, effectively separating the splashed or carried solid particles such as coal slag and rock powder from the liquid, preventing them from clogging the flow channel or damaging the equipment, thereby ensuring the smoothness and stability of the entire extraction pipeline system while implementing high-intensity gas extraction.

[0043] In one embodiment, the solid-liquid separation device can be an existing solid-liquid separation device, which will not be described in detail here.

[0044] In some embodiments of this application, the method further includes: While controlling the solid-liquid separation device to perform solid-liquid separation operation on the mixture returned from the orifice, the first gas-liquid separator is controlled to perform gas-liquid separation on the gas in the output pipeline of the solid-liquid separation device; the gas-liquid separator is connected to the output pipeline of the solid-liquid separation device.

[0045] In this embodiment, a two-stage linkage separation mechanism is employed. In the first stage, a solid-liquid separation device performs primary separation on the multiphase mixture returning from the orifice, removing solid particles. Then, in the second stage, a specially designed gas-liquid separator further purifies the gas output from the solid-liquid separation device, separating and removing entrained liquid water droplets. This ensures that the gas entering the subsequent gas extraction pipeline is as dry and pure as possible, effectively preventing equipment corrosion, pipeline blockage, or decreased extraction efficiency caused by the entry of liquid water, thus guaranteeing the long-term, stable, and efficient operation of the entire gas extraction system.

[0046] Step 103: Adjust the negative pressure of the gas extraction system connected to the borehole according to the identified different risk conditions, so as to implement an extraction strategy that matches the current conditions.

[0047] The gas extraction system is used for drilling operations and for extracting the mixture within the borehole.

[0048] In this embodiment, based on the diagnostic results of different working conditions such as "low risk," "standard risk," or "high risk," the negative pressure generated by the extraction system is automatically and dynamically adjusted to execute extraction strategies matched to different working conditions. This achieves a closed loop from risk perception to precise control, making gas extraction no longer a passive process with fixed intensity, but an active safety measure that adaptively adjusts according to real-time operational risks. While ensuring the safe and continuous operation of borehole drilling, it also optimizes the extraction efficiency and system energy consumption of the mixture returning from the borehole.

[0049] For example, in low-risk operating conditions, a stop-drainage or zero-negative-pressure strategy is implemented to save energy; in standard-risk operating conditions, a conventional drainage strategy is implemented to control gas; and in high-risk operating conditions, an enhanced drainage strategy is immediately switched to strongly suppress gas flow.

[0050] In some embodiments of this application, the gas outburst risk conditions include low-risk conditions, standard-risk conditions, and high-risk conditions, and step 103 may specifically include the following steps: When the gas outburst risk condition is a low-risk condition, the gas extraction system is controlled to maintain zero negative pressure or stop working; When the gas outburst risk condition is a standard risk condition, the gas extraction system is controlled to operate at the first level of negative pressure. When the gas outburst risk condition is a high-risk condition, the gas extraction system is controlled to operate at a second-level negative pressure higher than the first-level negative pressure.

[0051] In this embodiment, the identified risk level is transformed into specific and differentiated extraction action execution strategies. For low-risk conditions, energy saving is maximized by maintaining zero negative pressure or directly stopping extraction. For standard risk conditions, the system is started and stabilized at a preset first-level negative pressure to achieve regular and effective control of gas outbursts. Once a high-risk condition is determined (such as a pre-blown gas flow), the extraction intensity is automatically increased to a higher second-level negative pressure to form a strong suction effect, quickly suppressing abnormal outbursts. This ensures that the operating intensity of the extraction system is precisely matched with the real-time gas risk, thereby optimizing energy consumption and maximizing extraction efficiency while ensuring operational safety.

[0052] In some embodiments of this application, the method further includes: While adjusting the negative pressure of the gas extraction system connected to the borehole, the second gas-water separator is controlled to separate the gas entering the extraction system into gas and water; the second gas-water separator is connected to the gas extraction system.

[0053] In this embodiment, while dynamically adjusting the extraction negative pressure and changing the system airflow state, the second gas-water separator performs deep dehydration treatment on the gas about to enter the extraction main pipeline, separating and discharging the residual liquid water droplets or water mist carried therein. This can effectively prevent problems such as internal pipeline corrosion, water accumulation blockage, reduced efficiency or damage to extraction equipment caused by excessive gas humidity. Thus, at any time when the system actively adjusts the extraction intensity according to the risk conditions, the long-term safe, stable and efficient operation of the gas extraction pipeline network can be ensured.

[0054] In some embodiments, such as Figure 2 As shown in the figure, this integrated device constitutes a complete orifice blowout prevention, drainage, and gas extraction control system. The orifice blowout prevention device 15 directly seals and connects to the borehole opening. Its front end is connected to the tail of the drill rod 9 via a wind-water linkage switching device 14, responsible for switching between low-pressure water drilling, high-pressure water permeability enhancement, and high-pressure gas slag removal modes. The orifice blowout prevention device 15 is slidably connected to the drill rod 9. The end of the drill rod 9 furthest from the orifice blowout prevention device 15 is sequentially connected to a water jet injector 10 and a drill bit 11. The orifice blowout prevention device 15 integrates a methane concentration sensor 13 to monitor the gas in the flow channel in real time.

[0055] The returned mixture first enters the solid-liquid separation device 16 through the orifice blowout preventer 15 for primary separation. The separated gas then enters the extraction network. This network includes multiple extraction branches 4, each equipped with an electromagnetic control valve 5 and a gas-liquid separator 6 for independent control and deep purification. Each extraction branch 4 ultimately merges into the main extraction pipeline 1 via a manifold 3, completing the gas transportation. In addition, a switch 2 and a flow meter 17 for monitoring the flow rate can be installed on the manifold 3.

[0056] In some embodiments, a PLC controller 12 can be used to receive signals from the sensor 13, perform analysis and decision-making based on the embedded program, and output control commands to drive the air-water linkage switching device 14 and each electromagnetic control valve 5 to operate, thereby coordinating with other units such as the solid-liquid separation device 16 to achieve dynamic, adaptive, and integrated control of the entire process.

[0057] In one embodiment, the blowout preventer 15 can be fixed to the orifice through the sleeve 7, and the orifice can also be reinforced by the fixed section 8.

[0058] In one embodiment, the air-water linkage switching device 14 can be a multi-way valve.

[0059] As an example of a possible implementation, the air-water linkage switching device 14 can be installed at the tail end of the drill rod 9, and connected to the high-pressure and low-pressure water pipelines, the high-pressure air pipeline, and the control system. The system is initialized and set to low-pressure drilling mode.

[0060] Start the low-pressure pump for normal drilling operations. The drill cuttings are discharged through the annulus of the drill pipe 9 along with the circulating fluid. This stage is divided into two sub-steps of intelligent control according to the gas risk: rock layer drilling and coal seam drilling. Rock layer drilling: As Figure 3 shown, when the methane concentration sensor 13 embedded in the hole mouth blowout prevention and solid-liquid separation device 16 detects that the methane concentration continuously or for a long time approaches 0%, the system determines that the current is a rock layer section without gas risk, and there is no need to start the extraction function. Based on this, the PLC controller 12 controls the electromagnetic control valve 5 on the extraction branch 4 to close, so that the negative pressure of the corresponding extraction branch 4 is maintained at 0 kPa.

[0061] Coal seam drilling: As Figure 4 shown, when the methane concentration sensor 13 detects that the concentration shows a stable or slow upward trend and the methane concentration value is within the range of 0% < C ≤ 30%, the system determines that the coal seam has been exposed, which belongs to the working condition with gas outburst but within the normal range. It is necessary to start extraction to prevent gas accumulation. The PLC controller 12 controls the electromagnetic control valve 5 on the extraction branch 4 to open, so that the negative pressure of the corresponding extraction branch 4 is maintained at -10 kPa to achieve safe and efficient gas control; If the methane concentration rises sharply within a short time, C > 30%, the PLC controller 12 will immediately identify it as the "hole spraying risk" working condition and execute the following interlocking control: ① Enhanced extraction: Automatically increase the negative pressure of the corresponding extraction branch 4 to the preset higher level of -25 kPa to strongly suck the ejected gas; ② Drainage guarantee and protection of the extraction pipeline: The solid-liquid separation device 16 continuously operates to efficiently separate the ejected coal-water mixture. The separated liquid water is exported, and the solid particles are effectively intercepted, so as to maintain the annulus unobstructed and ensure the roadway cleanliness. At the same time, to prevent the high negative pressure formed in the hole mouth blowout prevention device 15 and the solid-liquid separation device 16 from sucking the liquid water into the extraction branch 4, a gas-liquid separator 6 is independently set on each extraction branch 4 to achieve effective gas-liquid separation and protect the safe and stable operation of the extraction pipeline and the gas extraction system.

[0062] High-pressure water permeability enhancement stage: As Figure 2 shown, when the drill hole enters the predetermined position of the target coal seam, switch to the high-pressure water permeability enhancement mode. Shut down the low-pressure pump and start the high-pressure pump. Adjust the drill pipe 9 channel to a high-pressure waterway through the air-water linkage switching device 14. The high-pressure water is transported to the bottom coal body of the hole through the drill pipe 9, and through the jet impact and hydraulic fracturing effects, a pressure relief cavity is formed in the coal seam, thereby greatly increasing the coal seam permeability.

[0063] The key safety control in this stage is to effectively suppress and divert the possible sudden gas outburst (hole spraying) and a large amount of coal-water mixture splashing. At the same time of starting the permeability enhancement operation, the methane concentration sensor 13 embedded in the hole mouth blowout prevention device 15 and the solid-liquid separation device 16 continuously monitors the composition of the ejected gas.

[0064] If the methane concentration rises sharply within a short period of time, with C > 30%, the PLC controller 12 will immediately identify it as a "nozzle risk" condition and execute the following linkage control: Enhanced extraction: Automatically increases the negative pressure of the corresponding extraction branch 4 to a preset higher level of -25kPa, powerfully extracting the ejected gas; Drainage protection and extraction pipeline protection: The solid-liquid separation device 16 operates continuously to efficiently separate the ejected coal-water mixture. The separated liquid is discharged while solid particles are effectively retained, thus maintaining unobstructed annulus flow and ensuring roadway cleanliness. Simultaneously, to prevent the high negative pressure generated within the orifice blowout preventer 15 and the solid-liquid separation device 16 from drawing liquid water into the extraction branch 4, the system independently installs a gas-liquid separator 6 on each extraction branch 4 to achieve effective gas-liquid separation and protect the extraction pipeline and gas extraction system for safe and stable operation.

[0065] High-pressure gas slag discharge stage: such as Figure 5 As shown, after drilling and cavity creation are completed, the system switches to high-pressure air slag removal mode to clean residual coal dust, rock powder, and accumulated water in the borehole and cavity. The air-water linkage switching device 14 switches the drill rod 9 channel from water path to high-pressure air path, injecting high-speed airflow into the hole.

[0066] During this stage, the airflow carries solid slag and liquid water accumulated in the borehole, forming a gas-solid-liquid multiphase mixture, which is then rapidly returned to the borehole opening via the annulus of drill pipe 9. The system implements the following coordinated controls to ensure efficient and safe slag removal: Blowout prevention and separation: The blowout preventer 15 at the orifice remains sealed, allowing the mixture to pass smoothly and be introduced into the solid-liquid separator 16. The device efficiently separates the return material: solid particles are intercepted and collected, liquid water is discharged through the drainage pipe, and gas enters the extraction branch 4.

[0067] Dynamic adjustment of extraction negative pressure: The PLC controller 12 automatically adjusts the extraction negative pressure based on the monitoring data from the embedded methane sensor. If an increase in methane concentration is detected (C>0%), the PLC controller 12 controls the electromagnetic control valve 5 group to increase the negative pressure to -10kPa; if the concentration remains at zero, the PLC controller 12 closes the electromagnetic control valve 5 on the extraction branch 4 to stop extraction and achieve energy-saving operation.

[0068] Gas-liquid separation and pipeline protection: The gas-liquid separator 6 installed on each extraction branch 4 can further separate liquid droplets carried in the gas, prevent liquid from entering the extraction pipeline, and ensure the safe and stable operation of the gas extraction system.

[0069] After drainage and slag removal are completed, close the high-pressure gas valve. The process can then proceed to the next cycle (such as continuing drilling or creating a cavity) or to the subsequent gas extraction process.

[0070] According to the gas extraction method for hydraulic permeability enhancement of downholes proposed in this disclosure, by real-time monitoring of gas concentration at the wellhead and automatic identification of operational risk conditions based on concentration values ​​and trends, the extraction negative pressure is dynamically adjusted to execute a matching extraction strategy. This achieves proactive perception and adaptive control of gas outburst risk during downhole hydraulic permeability enhancement operations, transforming gas extraction from a passive response to an intelligent response linked to drilling operations, effectively improving the timeliness, targeting, and overall safety of gas management.

[0071] Figure 6 This is a block diagram illustrating a gas extraction device for hydraulic permeability enhancement of a downhole borehole, according to an exemplary embodiment. (Refer to...) Figure 6 The device includes a monitoring unit 601, an identification unit 602, and a sampling unit 603.

[0072] The monitoring unit 601 is used to monitor the gas concentration in the borehole area in real time during the drilling operation; the drilling operation includes hydraulic disturbance and gas replacement. The identification unit 602 is used to identify the gas outburst risk condition in which the drilling operation is located based on the value and trend of the gas concentration. The extraction unit 603 is used to adjust the extraction negative pressure of the gas extraction system connected to the borehole according to the identified different risk conditions, so as to execute an extraction strategy that matches the current conditions; the gas extraction system is used for drilling operations and extraction of mixtures in the borehole.

[0073] In some embodiments of this application, the gas outburst risk conditions include low-risk conditions, standard-risk conditions, and high-risk conditions, and the extraction unit 603 can specifically be used for: When the gas outburst risk condition is a low-risk condition, the gas extraction system is controlled to maintain zero negative pressure or stop working; When the gas outburst risk condition is a standard risk condition, the gas extraction system is controlled to operate at the first level of negative pressure. When the gas outburst risk condition is a high-risk condition, the gas extraction system is controlled to operate at a second-level negative pressure higher than the first-level negative pressure.

[0074] In some embodiments of this application, the identification unit 602 may specifically be used for: When the gas concentration remains less than or equal to the first concentration threshold for a preset period of time, the gas outburst risk condition in which the drilling operation is located is determined to be a low-risk condition. When the gas concentration is greater than the first concentration threshold and less than or equal to the second concentration threshold, and the absolute value of the first concentration change rate of the gas concentration is less than the preset change rate, the gas outburst risk condition in which the drilling operation is located is determined to be a standard risk condition. When the gas concentration rises from a state below the second concentration threshold to a state above the second concentration threshold within a preset time period at a second concentration change rate, the gas outburst risk condition in which the drilling operation is located is determined to be a high-risk condition; the second concentration change rate is greater than the preset concentration change rate.

[0075] In some embodiments of this application, the drilling process includes a low-pressure water drilling stage, a high-pressure water permeability enhancement stage, and a high-pressure gas slag removal stage, and the apparatus further includes: A solid-liquid separation unit is used to control the solid-liquid separation device to perform solid-liquid separation operation on the mixture returned from the orifice when the gas emission risk condition is a high-risk condition during the high-pressure water permeability enhancement stage or the high-pressure gas slag discharge stage; the solid-liquid separation device is connected to the gas extraction system.

[0076] In some embodiments of this application, the apparatus further includes: The first gas-liquid separation unit is used to control the solid-liquid separation device to perform solid-liquid separation operation on the mixture returned from the orifice, and to control the first gas-liquid separator to perform gas-liquid separation on the gas in the output pipeline of the solid-liquid separation device; the gas-liquid separator is connected to the output pipeline of the solid-liquid separation device.

[0077] In some embodiments of this application, the apparatus further includes: The second gas-water separation unit is used to control the second gas-water separator to separate the gas entering the extraction system while adjusting the extraction negative pressure of the gas extraction system connected to the borehole; the second gas-water separator is connected to the gas extraction system.

[0078] In some embodiments of this application, the gas concentration is obtained by a concentration sensor located in the orifice area and / or inside the solid-liquid separation device.

[0079] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0080] According to the gas extraction device for hydraulic permeability enhancement of downholes proposed in this disclosure, by real-time monitoring of gas concentration at the orifice and automatically identifying operational risk conditions based on concentration values ​​and trends, the extraction negative pressure is dynamically adjusted to execute a matching extraction strategy. This achieves proactive perception and adaptive control of gas outburst risk during downhole hydraulic permeability enhancement operations, transforming gas extraction from a passive response to an intelligent response linked to drilling operations, effectively improving the timeliness, targeting, and overall safety of gas management.

[0081] Figure 7This is a block diagram illustrating an apparatus for a gas extraction method using hydraulic permeability enhancement in a downhole, according to an exemplary embodiment. For example, apparatus 700 may be an electronic device, such as a mobile phone, computer, digital broadcasting terminal, messaging device, game console, tablet device, medical device, fitness equipment, personal digital assistant, etc.

[0082] Reference Figure 7 The device 700 may include one or more of the following components: a processing component 702, a memory 704, a power component 706, a multimedia component 708, an audio component 710, an input / output (I / O) interface 712, a sensor component 714, and a communication component 716.

[0083] Processing component 702 typically controls the overall operation of device 700, such as operations associated with display, telephone calls, data communication, camera operation, and recording. Processing component 702 may include one or more processors 720 to execute instructions to complete all or part of the steps of the methods described above. Furthermore, processing component 702 may include one or more modules to facilitate interaction between processing component 702 and other components. For example, processing component 702 may include a multimedia module to facilitate interaction between multimedia component 708 and processing component 702.

[0084] Memory 704 is configured to store various types of data to support the operation of device 700. Examples of this data include instructions for any application or method operating on device 700, contact data, phonebook data, messages, pictures, videos, etc. Memory 704 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0085] The power supply component 706 provides power to the various components of the device 700. The power supply component 706 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power to the device 700.

[0086] Multimedia component 708 includes a screen that provides an output interface between the device 700 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touchscreen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors may sense not only the boundaries of the touch or swipe action but also the duration and pressure associated with the touch or swipe operation. In some embodiments, multimedia component 708 includes a front-facing camera and / or a rear-facing camera. When the device 700 is in an operating mode, such as a shooting mode or a video mode, the front-facing camera and / or the rear-facing camera may receive external multimedia data. Each front-facing camera and rear-facing camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0087] Audio component 710 is configured to output and / or input audio signals. For example, audio component 710 includes a microphone (MIC) configured to receive external audio signals when device 700 is in an operating mode, such as call mode, recording mode, and voice recognition mode. The received audio signals may be further stored in memory 704 or transmitted via communication component 716. In some embodiments, audio component 710 also includes a speaker for outputting audio signals.

[0088] I / O interface 712 provides an interface between processing component 702 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons.

[0089] Sensor assembly 714 includes one or more sensors for providing state assessments of various aspects of device 700. For example, sensor assembly 714 may detect the on / off state of device 700, the relative positioning of components such as the display and keypad of device 700, changes in the position of device 700 or a component of device 700, the presence or absence of user contact with device 700, the orientation or acceleration / deceleration of device 700, and temperature changes of device 700. Sensor assembly 714 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. Sensor assembly 714 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, sensor assembly 714 may also include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor.

[0090] Communication component 716 is configured to facilitate wired or wireless communication between device 700 and other devices. Device 700 can access wireless networks based on communication standards, such as WiFi, 2G, or 3G, or combinations thereof. In one exemplary embodiment, communication component 716 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 716 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0091] In an exemplary embodiment, the apparatus 700 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the methods described above.

[0092] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 704 including instructions, which can be executed by a processor 720 of the device 700 to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0093] In an exemplary embodiment, a computer program product is also provided, including a computer program that implements the above-described method when executed by the processor 720 of the device 700.

[0094] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0095] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for gas extraction using hydraulic permeability enhancement in downhole boreholes, characterized in that, include: Real-time monitoring of methane concentration in the borehole area during drilling operations; the drilling operation process includes hydraulic disturbance and gas replacement; Based on the value and trend of the gas concentration, the gas outburst risk condition of the drilling operation is identified; Based on the identified different risk conditions, the negative pressure of the gas extraction system connected to the borehole is adjusted to execute an extraction strategy that matches the current conditions. The gas extraction system is used for drilling operations and for extracting the mixture within the borehole.

2. The gas extraction method for hydraulic permeability enhancement of downholes according to claim 1, characterized in that, The gas outburst risk conditions include low-risk conditions, standard-risk conditions, and high-risk conditions; The step of adjusting the negative pressure of the gas extraction system connected to the borehole according to the identified different risk conditions, in order to execute an extraction strategy that matches the current conditions, includes: When the gas outburst risk condition is a low-risk condition, the gas extraction system is controlled to maintain zero negative pressure or stop working; When the gas outburst risk condition is a standard risk condition, the gas extraction system is controlled to operate at the first level of negative pressure. When the gas outburst risk condition is a high-risk condition, the gas extraction system is controlled to operate at a second-level negative pressure higher than the first-level negative pressure.

3. The gas extraction method for hydraulic permeability enhancement of downholes according to claim 1, characterized in that, The identification of gas outburst risk conditions in the drilling operation based on the gas concentration value and its changing trend includes: When the gas concentration remains less than or equal to the first concentration threshold for a preset time, the gas outburst risk condition in which the drilling operation is located is determined to be a low-risk condition. When the gas concentration is greater than the first concentration threshold and less than or equal to the second concentration threshold, and the absolute value of the first concentration change rate of the gas concentration is less than the preset change rate, the gas outburst risk condition in which the drilling operation is located is determined to be a standard risk condition. When the gas concentration rises from a state below the second concentration threshold to a state above the second concentration threshold within a preset time period at a second concentration change rate, the gas outburst risk condition in which the drilling operation is located is determined to be a high-risk condition; the second concentration change rate is greater than the preset concentration change rate.

4. The gas extraction method for hydraulic permeability enhancement of downholes according to claim 2, characterized in that, The drilling process includes a low-pressure water drilling stage, a high-pressure water permeability enhancement stage, and a high-pressure gas slag removal stage. The method further includes: During the high-pressure water permeability enhancement stage or the high-pressure gas slag discharge stage, when the gas outburst risk condition is a high-risk condition, the solid-liquid separation device is controlled to perform solid-liquid separation operation on the mixture returned from the orifice; the solid-liquid separation device is connected to the gas extraction system.

5. The gas extraction method for hydraulically enhanced permeability of a downhole as described in claim 4, characterized in that, The method further includes: While controlling the solid-liquid separation device to perform solid-liquid separation on the mixture returned from the orifice, the first gas-liquid separator is controlled to perform gas-liquid separation on the gas in the output pipeline of the solid-liquid separation device; the gas-liquid separator is connected to the output pipeline of the solid-liquid separation device.

6. The gas extraction method for hydraulic permeability enhancement of downholes according to claim 1, characterized in that, The method further includes: While adjusting the negative pressure of the gas extraction system connected to the borehole, the second gas-water separator is controlled to separate the gas entering the extraction system into gas and water; the second gas-water separator is connected to the gas extraction system.

7. The gas extraction method for hydraulic permeability enhancement of downholes according to claim 1, characterized in that, The gas concentration is obtained by a concentration sensor installed in the orifice area and / or inside the solid-liquid separation device.

8. A gas extraction device for hydraulic permeability enhancement in downhole boreholes, characterized in that, include: The monitoring unit is used to monitor the gas concentration in the borehole area in real time during the drilling operation; the drilling operation includes hydraulic disturbance and gas replacement. The identification unit is used to identify the gas outburst risk condition in which the drilling operation is located based on the value and trend of the gas concentration. The extraction unit is used to adjust the extraction negative pressure of the gas extraction system connected to the borehole according to the different risk conditions identified, so as to execute an extraction strategy that matches the current working conditions. The gas extraction system is used for drilling operations and for extracting the mixture within the borehole.

9. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 7.

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