"One hole, one policy" hole protection and sealing method for gas extraction drilling

Abstract

The present invention relates to a "one hole, one policy" hole protection and sealing method for gas extraction boreholes, belonging to the field of gas control. The present invention mainly discloses the following contents: First, in the process of withdrawing a drill bit equipped with a signal collection and emission device, the stress and strain parameters of the surrounding rock of the borehole wall and other parameters reflecting the morphology of the borehole wall are fed back in real time, and a visualization image of the borehole formation including the integrity of the borehole wall, the distribution of instability and collapse of the borehole, etc. is formed through digital signal-image conversion technology, and the position of the baffle plate of the borehole plugging section, the position and length of the grouting section, the length of the plugging section, and the position and length of the lower screen are automatically designed according to the image; second, targeted hole protection and sealing operations can be carried out based on the visualization image of the borehole formation, that is, targeted sealing is carried out for shallow hole sections that exceed the equivalent discharge width of the roadway by a certain distance, and targeted hole protection is carried out for deep hole sections that collapse and become unstable.

Description

Technical Field

[0001] The invention belongs to the field of gas management and relates to a "one hole one policy" hole protection and sealing method for gas extraction drilling holes. Background Art

[0002] Gas disasters are one of the main disasters that endanger the safe and efficient production of coal mines, and pre-extraction of coal seam gas by underground drilling is one of the most commonly used and relatively mature means of gas disaster management. The patency of the gas extraction drilling channel and the sealing of the borehole directly affect the gas extraction effect and extraction efficiency. At present, the main means to improve the patency of the gas extraction drilling channel and the sealing of the borehole are to optimize the drilling sealing process and the lowering of the screen pipe in the hole. However, the instability and collapse of the borehole are related to the occurrence of coal seams and the drilling construction process. There are differences in the instability and collapse sections of different boreholes. At this stage, the sealing and the lowering of the screen pipe in the hole do not take this difference into account. All borehole sealing depths and the screen pipe lowering depths use one parameter. This will cause the following problems: First, some boreholes are not sealed to the loose circle of the tunnel surrounding rock or the shallow hole collapse section, resulting in borehole leakage, which in turn affects the extraction effect; Second, some borehole sealing sections cover a large distance inside the loose circle of the tunnel surrounding rock or the shallow hole collapse section, which exceeds the tunnel pre-discharge equivalent width. On the one hand, the coal gas outside the tunnel pre-discharge equivalent width within the coverage of the sealing section cannot be effectively extracted, and on the other hand, reasonable, economical and effective sealing is not achieved, which increases the cost of drilling and sealing; Third, the collapse of the deep hole section of the borehole generally does not cause the collapse of the entire hole section, but only within the stress concentration range or the coal body is broken and the strength is low. At this stage, the lower screen pipe does not carry out targeted hole protection for the deep hole collapse section, and generally adopts the method of lowering the screen pipe in the entire hole section. On the one hand, it increases the single hole drilling and continuous extraction time, and on the other hand, it increases the cost of lowering the screen pipe. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a "one hole, one policy" hole protection and sealing method for gas extraction drilling. Firstly, during the process of withdrawing a drill bit equipped with a signal collection and transmission device, the position of the baffle plate of the drilling plugging section, the position and length of the grouting section, the length of the plugging section and the position and length of the lower screen pipe are automatically designed by utilizing the real-time feedback of the hole wall integrity, the distribution of instability and collapse of the drilling hole and other drilling visualization images; secondly, based on the drilling hole visualization image, targeted hole protection and sealing operations are carried out to improve the drilling efficiency, reduce the gas control cost, and improve the gas extraction effect; finally, the proposal of this method has positive significance for improving intelligent extraction and realizing refined management of gas extraction.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A "one hole one policy" hole protection and hole sealing method for gas extraction drilling comprises the following steps:

[0006] S1 signal reception and processing, using a drill bit equipped with a signal collection and transmission device, during the drill withdrawal process, real-time feedback reflects the borehole wall morphological parameters, and forms a visual image of the drilling hole through digital signal-image conversion technology, which at least includes the integrity of the borehole wall and the distribution of instability and collapse of the borehole;

[0007] The S2 terminal automatically determines the scope of the borehole instability and collapse section;

[0008] The S3 terminal automatically designs the parameters for sealing and protecting the borehole. Using the real-time feedback of the visualization image of the drilling hole and the range of the drilling instability and collapse section, the terminal automatically designs the baffle position of the drilling sealing section, the position and length of the grouting section, the length of the sealing section, and the position and length of the lower screen pipe.

[0009] Optionally, S4 may also carry out drilling hole sealing and hole protection work, and carry out the specific implementation work of drilling hole sealing and hole protection according to the sealing and hole protection parameters automatically designed by the terminal.

[0010] Optionally, the signal collecting and transmitting device is installed between the drill bit and the first section of the drill pipe, and performs real-time circular scanning of the borehole as the drill pipe rotates during the drilling withdrawal process.

[0011] Optionally, after the real-time circular scanning, the circular scanning data is transmitted to the signal processing terminal in real time via wireless transmission means, and the signal processing terminal inverts the drilling visualization image based on the obtained signal.

[0012] Optionally, the parameters reflecting the morphology of the borehole wall include stress and strain parameters of the surrounding rock of the borehole wall.

[0013] Optionally, S2 mainly determines the specific instability and collapse positions within the shallow hole section that exceeds the preset equivalent width of the tunnel, and the specific instability and collapse positions within the deep hole section within the predetermined sealing section.

[0014] Optionally, it also includes determining the basic design parameters of S0, estimating the emission time of coal wall gas in the tunnel according to the extraction-excavation-mining time, determining the tunnel pre-discharge equivalent width according to the emission time, and then determining the sealing depth in combination with the average loose zone range of the tunnel surrounding rock.

[0015] The beneficial effects of the present invention are:

[0016] (1) The present invention uses a drill bit equipped with a signal collection and transmission device to achieve real-time visual feedback of borehole wall integrity, borehole instability and collapse distribution and other hole formation information during the drill withdrawal process.

[0017] (2) The present invention utilizes the visualization image of the drilling hole to realize the automatic design technology of the baffle position of the drilling plugging section, the position and length of the grouting section, the length of the plugging section, and the position and length of the lower screen pipe.

[0018] (3) The present invention uses a "one hole, one policy" hole protection and sealing method to perform differentiated and precise hole sealing and hole protection, which can effectively improve the effect of drilling and gas extraction, save gas management costs to a large extent, and achieve the goal of economic disaster prevention. The proposal of this method has positive significance for improving intelligent extraction and realizing refined management of gas extraction.

[0019] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0021] Figure 1 It is a flow chart of the present invention;

[0022] Figure 2 Schematic diagram of sealing hole.

[0023] Figure numerals: extraction borehole 1, borehole collapse position 2, screen pipe 3, plugging section 4, grouting section 5, baffle 6, coal body 7, sealing pipe 8. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0025] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0026] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0027] See also Figure 1-2 This is a "one hole one policy" hole protection and sealing method for gas extraction drilling. Taking the coal quality as anthracite, the drilling depth of 100m, the average tunnel surrounding rock loosening zone as the range of 10m inside the tunnel coal wall, and the estimated tunnel coal wall gas emission time of 300d according to the extraction-digging-mining as an example, it includes the following steps:

[0028] (1) Determination of basic design parameters. According to the estimated time of coal wall gas emission in the tunnel according to the extraction-excavation-mining method, it is 300 days. Referring to the Interim Provisions on Compliance with Coal Mine Gas Extraction Standards, for anthracite with a coal wall gas emission time of 300 days or more, the tunnel pre-discharge equivalent width is 13m. Considering that the average loose zone of the tunnel surrounding rock is 10m inside the coal wall of the tunnel, the reasonable sealing depth of the design is comprehensively determined to be 15m.

[0029] (2) Signal reception and processing. During the drill withdrawal process, the drill bit equipped with a signal collection and transmission device can provide real-time feedback on the stress and strain parameters of the surrounding rock in the borehole wall and other parameters reflecting the morphology of the borehole wall. Through the digital signal-image conversion technology, a visual image of the drilling process including the integrity of the borehole wall and the distribution of instability and collapse of the borehole is formed and displayed on the terminal.

[0030] (3) The terminal automatically determines the scope of the borehole instability and collapse. The terminal will analyze and record the specific locations of instability and collapse within 15m and 15m to 100m from the coal wall. If the borehole instability and collapse occurs at 12m and 50m, the terminal will display it in the image and give the specific location parameters.

[0031] (4) The terminal automatically designs the parameters for sealing and protecting the borehole. Using the real-time feedback of the borehole wall integrity, the distribution of borehole instability and collapse, and other visual images of the borehole formation, as well as the range of the borehole instability and collapse section (borehole collapse position 2), the terminal automatically designs the position of the baffle 6 of the sealing section 4 of the extraction borehole 1 in the coal body 7, the position and length of the grouting section 5, the length of the sealing section 4, and the position and length of the lower screen 3. Based on this example: the terminal will display the following in the figure: Figure 2The grouting section 5 shown has a position (13.5m to 14.5m from the orifice) and a length (1m), a plugging section 4 has a length (1m), a sealing pipe 8 and a position (45m to 55m from the orifice) and a length (5m).

[0032] (5) Step 5: Carry out drilling hole sealing and hole protection work. Carry out drilling hole sealing and hole protection work according to the hole sealing and hole protection parameters automatically designed by the terminal.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A "one hole one policy" hole protection and sealing method for gas extraction drilling, characterized in that: The following steps are involved: The basic design parameters of S0 are determined, and the emission time of coal wall gas in the roadway is estimated according to the extraction-excavation-mining time. The equivalent width of the roadway pre-discharge is determined according to the emission time, and then the sealing depth is determined in combination with the average loose zone range of the roadway surrounding rock; S1 signal reception and processing, using a drill bit equipped with a signal collection and transmission device, during the drill withdrawal process, real-time feedback reflects the borehole wall morphological parameters, and forms a visual image of the drilling hole through digital signal-image conversion technology, which at least includes the integrity of the borehole wall and the distribution of instability and collapse of the borehole; The S2 terminal automatically determines the scope of the instability and collapse section of the borehole, mainly judging the specific instability and collapse location within the shallow hole section that exceeds the equivalent width of the tunnel pre-arrangement, and the specific instability and collapse location within the deep hole section within the established sealing section; The S3 terminal automatically designs the parameters for sealing and protecting the borehole, and performs differentiated and accurate sealing and protecting the borehole. By using the real-time feedback of the visualization image of the drilling hole and the range of the instability and collapse of the drilling hole, the terminal automatically designs the baffle position of the drilling plugging section, the position and length of the grouting section, the length of the plugging section, and the position and length of the lower screen pipe; The signal collecting and transmitting device is installed between the drill bit and the first section of the drill rod, and performs real-time circular scanning of the borehole as the drill rod rotates during the drilling withdrawal process.

2. The "one hole one policy" hole protection and sealing method for gas extraction drilling according to claim 1 is characterized in that: It also includes S4 carrying out drilling hole sealing and hole protection work, and carrying out the specific implementation work of drilling hole sealing and hole protection according to the sealing and hole protection parameters automatically designed by the terminal.

3. The "one hole one policy" hole protection and sealing method for gas extraction drilling according to claim 1 is characterized in that: After the real-time ring scan, the ring scan data is transmitted to the signal processing terminal in real time through wireless transmission means, and the signal processing terminal inverts the drilling visualization image according to the obtained signal.

4. The "one hole one policy" hole protection and sealing method for gas extraction drilling according to claim 1 is characterized in that: The parameters reflecting the morphology of the borehole wall include the stress and strain parameters of the surrounding rock of the borehole wall.

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