Integrated combined direct current protection and permeation enhancement combined drilling tool and construction process thereof

Abstract

The invention relates to an integrated combined direct-keeping and permeability-increasing combined drilling tool and a construction process thereof, and belongs to the technical field of coal mine safety. The combined drilling tool comprises a top drill bit, a straight keeping short section, a mechanical openable square hole drill bit, a hollow high-low pressure hydraulic punching device, a pressure-resistant large-drift-diameter deslagging sealing drill rod and a pressure-resistant fast-inserting water braid which are connected in sequence. An upsetting section with a spiral groove, a blade rib and a sealing male buckle are arranged on the straight keeping short section, the hollow high-low pressure hydraulic punching device comprises a reset disc spring and a large-drift-diameter inner cavity barrel, and a high-pressure water flow channel, a low-pressure water flow channel, a high-low pressure conversion device and a nozzle are arranged on the large-drift-diameter inner cavity barrel. The construction technology comprises the steps of drilling site preparation, hole opening and reaming, reverse hole reaming, punching, deslagging, gas extraction and the like. According to the method, the problems that the drilling track deviates, the coal washing amount is small, and the gas extraction amount is low are effectively solved, permeability increasing and permeability increasing of the low-permeability coal seam are achieved, efficient pressure relief extraction is achieved, and the extraction efficiency and safety are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine safety, and relates to an integrated combined straightening and permeability-increasing drill string and its construction technology. Background Technique

[0002] In coal mine areas in China, more than 50% of coal seams exhibit the characteristics of softness and low permeability. This geological condition poses many challenges to the safe production of coal. The characteristics of soft and low-permeability coal seams are remarkable. Not only is the coal body structure broken, but the permeability is also relatively low. At the same time, a large amount of gas is contained in these coal seams. These characteristics make the coordination and matching of production links such as coal extraction, excavation, and mining in terms of time and space particularly complex and difficult.

[0003] First of all, the broken coal body structure of soft and low-permeability coal seams means that the stability of the coal seams is poor, which increases the safety risks during the mining process. During the excavation and mining process, the broken coal body is prone to collapse, which not only affects production efficiency but also may pose a threat to the safety of workers. In addition, the low permeability means that the gas in the coal seams is difficult to discharge naturally, which increases the risk of gas accumulation. Gas is a flammable and explosive gas. If it accumulates to a certain extent, it may trigger an explosion once it encounters a fire source, posing a serious threat to the safety of the mine.

[0004] Regarding the gas control of soft and low-permeability coal seams, although the existing process technologies have achieved certain effects, there are still many problems. Borehole deviation is one of them. Due to the softness and instability of the coal seams, the borehole is prone to deviation during the drilling process, resulting in inaccurate borehole positions and affecting the extraction effect. In addition, the low utilization rate of boreholes is also a prominent problem. Due to the low permeability of the coal seams, the gas extraction volume after drilling is limited, making the utilization rate of boreholes not high.

[0005] The limited technical application scope is also a major challenge in the gas control of low-permeability coal seams. Due to the particularity of the coal seams, some advanced gas control technologies may not be directly applicable, or the application effect is greatly reduced. This limits the choice of control means and increases the control difficulty.

[0006] The low success rate of screen pipe lowering is another issue that needs attention. When lowering the screen pipe in soft and low-permeability coal seams, due to the softness and instability of the coal seams, the screen pipe is easily blocked or deformed, resulting in a reduced success rate of lowering. This not only affects the progress of gas control but also increases the control cost.

[0007] The small amount of coal washing is also a difficult problem in the gas control of low-permeability coal seams. Due to the low permeability of the coal seams, the coal body is difficult to be effectively broken and washed out during the coal washing process, resulting in a small amount of coal washing. This not only affects production efficiency but also may lead to gas accumulation and increase safety hazards.

[0008] In summary, the characteristics of soft and low-permeability coal seams pose many challenges to the safe production of coal. In response to these challenges, we need to continuously explore and innovate gas control technologies to improve the control effect and ensure the safety and efficiency of coal production. Summary of the Invention

[0009] In view of this, the purpose of the present invention is to provide an integrated combined straightness-preserving and permeability-increasing drill tool and its construction technology, which can solve problems such as difficult pipe laying, trajectory deviation, and low gas extraction volume, and achieve permeability enhancement and efficient pressure relief and extraction in low-permeability coal seams.

[0010] To achieve the above purpose, the present invention provides the following technical solutions:

[0011] An integrated combined straightness-preserving and permeability-increasing drill tool includes a top drill bit, a straightness-preserving short section, a mechanically expandable square-hole drill bit, a hollow high-low pressure hydraulic punching device, a pressure-resistant large-diameter slag-discharging and sealing drill pipe, and a pressure-resistant quick-insert water braid connected in sequence.

[0012] The straightness-preserving short section is used to prevent the deviation of the borehole trajectory. A number of upset sections are sequentially arranged on the straightness-preserving short section, and blade ribs are arranged between adjacent upset sections. One end of the straightness-preserving short section is connected to the top drill bit through a sealing male thread.

[0013] The mechanically expandable square-hole drill bit is used for reverse hole reaming operation.

[0014] The hollow high-low pressure hydraulic punching device is used for punching operation after drilling.

[0015] The pressure-resistant large-diameter slag-discharging and sealing drill pipe is used for slag-discharging operation after punching.

[0016] Optionally, the hollow high-low pressure hydraulic punching device includes a return disc spring and a large-diameter inner cavity cylinder body connected in sequence.

[0017] Optionally, high-pressure water channels and low-pressure water channels are arranged on the outer periphery of the large-diameter inner cavity cylinder body, and a high-low pressure conversion device is arranged between the high-pressure water channels and the low-pressure water channels; nozzles are arranged on the high-pressure water channels.

[0018] Optionally, a connecting male thread is also included, which is arranged at one end close to the mechanically expandable square-hole drill bit to play a connecting role.

[0019] Optionally, a channel for slag-discharging is arranged inside the pressure-resistant large-diameter slag-discharging and sealing drill pipe, and outer grooves are arranged at intervals on the outer periphery.

[0020] Optionally, the water pipe is quickly inserted and unplugged on the pressure-resistant large-diameter slag-discharging and sealing drill pipe through the pressure-resistant quick-insert water braid, so as to facilitate the pressure-bearing water in the water pipe to enter the pressure-resistant large-diameter slag-discharging and sealing drill pipe through the pressure-resistant quick-insert water braid.

[0021] Optionally, spiral grooves are provided on the outer periphery of the upsetting section.

[0022] A construction process for drilling holes using any one of the above integrated combined straightening and permeability-increasing drill tools includes the following steps:

[0023] S1, Drill site preparation and equipment installation and commissioning;

[0024] S2, Use the top drill bit to open and ream the hole to the designed depth;

[0025] S3, Lower the hole sealing casing and grout, and wait for it to set;

[0026] After the drilling reaches the designed depth, lower the hole sealing casing and grout to seal the hole, monitor the grouting pressure and setting time, and adjust in real time;

[0027] S4, Connect the components of the combined drill tool in sequence and drill to the designed hole depth;

[0028] Connect the components to the top drill bit in sequence. During drilling, monitor the state of the drill bit and drilling parameters in real time, judge the changes in the formation and make corresponding adjustments;

[0029] S5, Reverse drilling and reaming;

[0030] Open the mechanically expandable square hole drill bit to perform reverse drilling and reaming operations, and timely clean the debris at the bottom of the hole;

[0031] S6, Flushing the hole;

[0032] Open the hollow high-low pressure hydraulic flushing device, control the flow rate and pressure of the drilling flushing fluid, and perform flushing operations;

[0033] S7, Lower the screen pipe for the entire hole section;

[0034] S8, Connect to the gas drainage system for gas drainage;

[0035] After completing the drilling and flushing operations, use a pump to pump out the residual mud and water in the hole, and connect to the gas drainage system for gas drainage.

[0036] The beneficial effects of the present invention are as follows:

[0037] The steel screen pipe protected by the present invention compacts the coal body around the borehole for the second time to prevent caving, extends the service life of the borehole, shortens the gas drainage cycle, and improves the gas control level; the straightening short joint reduces the deviation and inclination of the borehole, ensures that the entire borehole is in the coal seam, and improves the utilization rate of the borehole; the mechanically expandable square-hole drill bit is used for reverse reaming to increase the slag discharge and gas exhaust channels, avoid borehole blockage, and prevent borehole accidents such as drill sticking and drill pressing. Moreover, the entire operation process does not require secondary downhole drilling, can be completed in one trip, reduces the workload, lowers the labor intensity, and improves work efficiency. It can effectively solve problems such as poor permeability of soft coal seams, borehole blockage, caving, and drill burial, and low borehole utilization rate. It can realize the secondary transformation, pressure relief, permeability enhancement, and seepage increase of the coal seam, and improve the gas drainage technology level of low-permeability coal seams in mines.

[0038] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Brief Description of the Drawings

[0039] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0040] Figure 1 is the connection schematic diagram of the combined drill tool of the present invention;

[0041] Figure 2 is the structural schematic diagram of the straightening short joint;

[0042] Figure 3 is the structural schematic diagram of the hollow high-low pressure hydraulic punching device;

[0043] Figure 4 is the structural schematic diagram of the pressure-resistant large-diameter slag-discharging and sealing drill pipe;

[0044] Figure 5 is Figure 4 the A-A sectional view of

[0045] Figure 6 is the process flow chart of the present invention.

[0046] Reference Signs:

[0047] 1 vane rib, 2 spiral groove, 3 upset section, 4 sealing male thread, 5 large-diameter inner cavity cylinder, 6 return disc spring, 7 high-pressure water flow channel, 8 low-pressure water flow channel, 9 high-low pressure conversion device, 10 nozzle, 11 connecting male thread, 12 channel, 13 outer groove. Detailed Description of the Embodiment

[0048] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0049] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams rather than physical diagrams, and should not be construed as a limitation on the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0050] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This 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 operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation on the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0051] Please refer to Figures 1 to 6 , which is an integrated combined straightness-preserving and permeability-increasing drilling tool, including a top drill bit, a straightness-preserving short section, a mechanically expandable square-hole drill bit, a hollow high-low pressure hydraulic punching device, a pressure-resistant large-diameter slag-discharging and sealing drill pipe, and a pressure-resistant quick-insert water braid connected in sequence.

[0052] The straightness-preserving short section is used to prevent the deviation of the drilling trajectory. The straightness-preserving short section is sequentially provided with a plurality of upset sections 3 with spiral grooves 2 on the outer periphery. A blade rib 1 is provided between adjacent upset sections 3. One end of the straightness-preserving short section is connected to the top drill bit through a sealing male thread 4.

[0053] The upset section 3 reduces the height and increases the cross-section of this part through the upsetting process, so as to enhance stability and load-bearing capacity. The straightening short section is responsible for keeping the drilling tool vertical and centered, ensuring the accuracy and efficiency of drilling; and setting the upset section 3 on the straightening short section can significantly improve the performance and reliability of the drilling tool. Specifically manifested as: through the upsetting process, the cross-section of the straightening short section increases, improving its anti-bending and anti-torsion capabilities, thus enhancing the stability of the drilling tool during the drilling process; the straightened short section after upsetting has higher strength and can withstand greater drilling pressure and torque, improving the load-bearing capacity of the drilling tool; the improvement of the stability and load-bearing capacity of the straightening short section helps to ensure that the drilling tool maintains the correct direction and angle during the drilling process, thus improving the accuracy of drilling.

[0054] And a spiral groove 2 is provided on the outer periphery of the upset section 3, so that the drill tool can better fit the hole wall during the drilling process, reducing shaking and deviation. The addition of the spiral groove 2 further increases the contact area between the drill tool and the hole wall, improves the stability of the drill tool in the hole, and helps to maintain the straightness of the drilling. The spiral groove 2 can also reduce the frictional resistance between the drill tool and the hole wall to a certain extent, making the drill tool more smooth when advancing, and can effectively reduce energy consumption and drill tool wear. The design of the spiral groove 2 helps to generate a pumping effect when the drill tool rotates and drills, carrying the cuttings to move upward along the spiral path, and finally discharging them out of the hole through the slag discharge system.

[0055] The blade rib 1 plays a role in enhancing the structural strength of the drill tool, optimizing the hydrodynamic performance, guiding the fluid (such as the flushing fluid) to flow in a specific direction, reducing the fluid resistance, improving the flushing efficiency, and assisting the drill tool in guiding, maintaining the straightness of the drilling, providing additional stability support, and reducing the deviation of the drill tool caused by uneven stress.

[0056] The mechanically expandable square hole drill bit is used for reverse hole reaming operations;

[0057] The hollow high-low pressure hydraulic flushing device is used for the flushing operation after drilling. The hollow high-low pressure hydraulic flushing device includes a reset disc spring 6 and a large-diameter inner cavity cylinder body 5 connected in sequence. A high-pressure water flow channel 7 and a low-pressure water flow channel 8 are provided on the outer periphery of the large-diameter inner cavity cylinder body 5, and a high-low pressure conversion device 9 is provided between the high-pressure water flow channel 7 and the low-pressure water flow channel 8; a nozzle 10 is provided on the high-pressure water flow channel 7; the hollow high-low pressure hydraulic flushing device also includes a connecting male thread 11 provided at one end close to the mechanically expandable square hole drill bit for connection.

[0058] When the device is deformed under external force, the reset disc spring 6 can use its own elastic restoring force to make the device automatically return to the initial state or the preset position after a specific operation.

[0059] The large diameter inner cavity cylinder 5 provides a spacious channel 12 for water to flow through, ensuring that the water can flow smoothly through the device, and also ensuring the structural strength and stability of the device, providing strong support for efficient punching operations.

[0060] The nozzle 10 can effectively flush and clean the inner wall of the borehole, remove debris and impurities generated during the drilling process, and ensure the quality and efficiency of the drilling.

[0061] The pressure-resistant large-diameter slag-discharging sealed drill pipe is used for slag-discharging operations after punching. The water pipe is quickly plugged and pulled out of the pressure-resistant large-diameter slag-discharging sealed drill pipe through the pressure-resistant quick-plug water braid, which facilitates the pressurized water in the water pipe to enter the pressure-resistant large-diameter slag-discharging sealed drill pipe through the pressure-resistant quick-plug water braid. The pressure-resistant quick-plug water braid not only has the function of channel connection and water supply, but also can discharge the coal slag and debris generated during the drilling process out of the hole through the flushing effect of the water flow, keeping the borehole clean and unobstructed. In addition, during the drilling process, the friction between the drill bit and the coal rock mass will generate a lot of heat. The water flow provided by the quick-plug water braid can effectively cool the drill bit to prevent it from being damaged due to overheating.

[0062] The pressure-resistant large-diameter deslagging seal drill pipe has a channel 12 for deslagging inside, and outer grooves 13 are arranged at intervals on the outer circumference. The outer grooves 13 can significantly enhance the deslagging effect. During the drilling process, drill cuttings and flushing fluid will flow and be discharged more smoothly along the outer grooves 13 of the drill pipe, thereby significantly improving the deslagging efficiency. This helps to reduce the accumulation of drill cuttings around the drill pipe, keep the borehole clean and unobstructed, and thus improve the efficiency and quality of the entire drilling operation.

[0063] A construction process for drilling holes using an integrated combined straightening and permeability-enhancing combined drilling tool comprises the following steps:

[0064] S1, drilling site preparation and equipment installation and commissioning;

[0065] Before drilling, the site must be prepared, including cleaning the drilling area and ensuring the safety of equipment and operators. At the same time, the equipment needs to be installed and debugged according to the design requirements to ensure that the drilling rig, pump, drill pipe and other equipment can operate normally.

[0066] S2, use the top drill bit to open and expand the hole to the designed depth; use different drilling tool combinations to open and expand the hole to ensure the uniformity and stability of the hole diameter.

[0067] S3, insert the sealing casing and inject grout to wait for setting;

[0068] After the borehole reaches the designed depth, the sealing casing is lowered and grouting and sealing are performed. The grouting pressure, solidification time, etc. are monitored and adjusted in real time.

[0069] S4, connecting the components of the combined drilling tool in sequence and drilling to the designed hole depth;

[0070] Connect each component in sequence to the top drill bit. During drilling, monitor the status of the drill bit and drilling parameters (such as torque, rotational speed, etc.) in real time, judge the changes in the formation and make corresponding adjustments;

[0071] S5, backreaming and underreaming;

[0072] Start the pump, apply pressure, open the mechanically expandable square hole drill bit, and perform backreaming and underreaming operations, and timely clean the debris at the bottom of the hole;

[0073] S6, flushing the hole;

[0074] Open the hollow high-low pressure hydraulic flushing device, control the flow rate and pressure of the drilling flushing fluid, and perform flushing operations; to ensure the flushing effect, use a new type of high-efficiency flushing fluid formula and flushing technology, reduce the usage amount of the flushing fluid, reduce costs, and improve efficiency.

[0075] S7, lower the screen pipe into the entire hole section; after flushing the hole, lower the screen pipe into the entire hole section, and control the lowering speed and position of the screen pipe to avoid deviation or inclination.

[0076] S8, connect to the gas drainage system for gas drainage;

[0077] After completing the drilling and flushing operations, use a pump to pump out the residual mud and water in the hole, and connect to the gas drainage system for gas drainage.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An integrated combined straightening and permeability-enhancing combined drilling tool, characterized in that: It includes a top drill bit, a straightening short section, a mechanically expandable square hole drill bit, a hollow high and low pressure hydraulic punching device, a pressure-resistant large-diameter slag-discharging sealing drill pipe, and a pressure-resistant quick-insertion water braid connected in sequence; The straightening short section is used to prevent the drilling trajectory from deviating. The straightening short section is provided with a plurality of upsetting sections (3) in sequence. A blade rib (1) is provided between adjacent upsetting sections (3). One end of the straightening short section is connected to the top drill bit via a sealing male buckle (4). The mechanically expandable square hole drill bit is used for back hole expansion operations; The hollow high and low pressure hydraulic punching device is used for punching operations after drilling; The pressure-resistant large-diameter deslagging sealing drill rod is used for deslagging operations after punching.

2. The integrated combined straightening and permeability-enhancing combined drilling tool according to claim 1 is characterized in that: The hollow high-low pressure hydraulic punching device comprises a reset disc spring (6) and a large diameter inner cavity cylinder (5) which are connected in sequence.

3. The integrated combined straightening and permeability-enhancing combined drilling tool according to claim 2 is characterized in that: A high-pressure water flow channel (7) and a low-pressure water flow channel (8) are provided on the outer periphery of the large-diameter inner cavity cylinder (5); a high-low pressure conversion device (9) is provided between the high-pressure water flow channel (7) and the low-pressure water flow channel (8); and a nozzle (10) is provided on the high-pressure water flow channel (7).

4. The integrated combined straightening and permeability-enhancing combined drilling tool according to claim 2 is characterized in that: It also includes a connecting male buckle (11) which is arranged near one end of the mechanically expandable square hole drill and plays a connecting role.

5. The integrated combined straightening and permeability-enhancing combined drilling tool according to claim 1 is characterized in that: The pressure-resistant large-diameter slag discharge sealing drill rod is provided with a channel (12) for slag discharge, and outer grooves (13) are arranged at intervals on the outer circumference.

6. The integrated combined straightening and permeability-enhancing combined drilling tool according to claim 1 is characterized in that: The water pipe is quickly plugged in and out of the pressure-resistant large-diameter deslagging sealed drill pipe through the pressure-resistant quick-plug water braid, so that the pressurized water in the water pipe can enter the pressure-resistant large-diameter deslagging sealed drill pipe through the pressure-resistant quick-plug water braid.

7. The integrated combined straightening and permeability-enhancing combined drilling tool according to claim 1 is characterized in that: A spiral groove (2) is provided on the outer periphery of the upsetting section (3).

8. A construction process for drilling holes using the integrated combined straightening and permeability-enhancing combined drilling tool according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, drilling site preparation and equipment installation and commissioning; S2, using the top drill bit to drill and expand the hole to the designed depth; S3, insert the sealing casing and inject grout to wait for setting; After the borehole reaches the designed depth, the sealing casing is lowered and grouting and sealing are performed. The grouting pressure and solidification time are monitored and adjusted in real time. S4, connecting the components of the combined drilling tool in sequence, and drilling to a designed hole depth; Connect each component to the top drill bit in sequence, monitor the status and drilling parameters of the drill bit in real time during drilling, judge the changes in the formation and make corresponding adjustments; S5, reverse hole and expansion hole; Open the mechanical expandable square hole drill bit, perform back hole expansion operation, and clean up the debris at the bottom of the hole in time; S6, punching; Open the hollow high and low pressure hydraulic punching device, control the flow and pressure of the drilling flushing fluid, and perform the punching operation; S7, the screen pipe is lowered into the full hole section; S8, connecting to the gas extraction system for gas extraction; After completing the drilling and punching operations, use a pump to pump out the residual mud and water in the hole and connect it to the gas extraction system for gas extraction.

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