Efficient drilling process for coal mine working face bottom plate oil type gas ground horizontal well

Abstract

The invention discloses an efficient drilling process for a coal mine working face bottom plate oil type gas ground horizontal well, which comprises the following steps of: 1, drilling downwards along a working face stratum by using a drill rod, and continuously mixing and extruding cement paste in the drill rod and discharging the cement paste outwards in the process that the drill rod rotates clockwise to drill, so that a cement protection layer is formed on a hole wall; secondly, after drilling is completed, a drill rod is driven to rotate anticlockwise and pulled out upwards, and in the process, the drill rod is heated, cement on the hole wall is dried, and the cement curing process is accelerated; according to the efficient drilling technology for the coal mine working face bottom plate oil type gas ground horizontal well, the hole wall can be coated with cement while drilling is conducted in a stratum, so that the hole wall strength is effectively improved, the hole collapse condition is effectively avoided, and the device can emit heat and effectively improve the cement hardening speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of drilling process, in particular to a high-efficiency drilling process for coal mine working face floor oil-type gas ground horizontal well. BACKGROUND

[0002] The floor oil-type gas refers to the natural gas resources existing in the floor (underlying stratum) of the coal-bearing stratum, mainly of "oil-type origin", and is one of the important types of unconventional natural gas in the coal mine area, and its formation, distribution and development are closely related to coal mining and floor stratum conditions.

[0003] The floor oil-type gas reservoir conditions mainly include "source - reservoir - cap - migration - preservation" five parts.

[0004] The hydrocarbon generation condition: the floor exists stable thickness, high organic matter abundance of sapropelic type hydrocarbon source rock (such as deep marine facies shale, limestone), and has experienced enough burial depth (usually > 1500m) and thermal evolution degree (Ro value 0.6%-2.0%), which meets the temperature-pressure requirement of oil generation and cracking.

[0005] The reservoir condition: the floor stratum exists effective reservoir, mainly of fractured limestone, pore-fractured sandstone, and the reservoir porosity is usually 5%-15%, and the fracture development degree (such as tectonic fracture, dissolution fracture) is the key to determine the productivity (fracture provides natural gas seepage channel).

[0006] The cap rock condition: the dense rock layer (such as mudstone, shale, gypsolayer) above the reservoir as cap rock exists, which prevents natural gas from escaping upward, and the main coal seam of coal mine itself can also be used as the "indirect cap rock" of floor oil-type gas.

[0007] Migration and preservation: after the natural gas migrates from the hydrocarbon source rock to the floor reservoir through the fault and fracture channel, it needs to have stable tectonic environment (no large-scale pressure relief channel) and good sealing condition, so as to be long-term enrichment.

[0008] The floor oil-type gas distribution law mainly includes: Regional distribution: concentrated in the "depression zone" or "tectonic stable area" of the coal-bearing basin, such as the coal-bearing basin of North China Craton (Shanxi, Henan, Shandong, etc.), the eastern margin of Ordos Basin, etc., and the floor hydrocarbon source rock develops in these areas, the burial depth is moderate, and the tectonic activity is relatively gentle.

[0009] The horizon distribution: corresponding to the "target layer" of the floor of the main coal seam of the coal mine, and preferentially existing in the floor limestone or sandstone section (such as the Ordovician limestone and Taiyuan Formation limestone of the Carboniferous-Permian coal seam floor in North China) closest to the coal seam and having the most developed fractures.

[0010] Enrichment control: Controlled by structural fracture zones and dissolution zones, natural gas usually forms enrichment zones near faults, the axis of anticlines, and areas with dense fractures. The production capacity of single wells varies greatly (high-yield areas are mostly located in fracture development zones).

[0011] The development value of bottom-plate oil-type gas is mainly reflected in: Energy properties: High methane content (high combustion efficiency, low pollution), it can be used as industrial fuel, city gas or chemical raw material, and is a high-quality alternative to traditional fossil energy.

[0012] Safety significance: Pre-extraction of oil-type gas from the bottom plate before coal mining can reduce the risk of gas escaping to the working face, avoid safety accidents such as gas outbursts and explosions, and ensure safe production in coal mines ("extraction before mining, disaster prevention and increased income").

[0013] Economic and environmental benefits: As a "common resource" in coal mining areas, developing bottom oil-type gas can extend the industrial chain of coal mining enterprises and improve the comprehensive utilization rate of resources; at the same time, it can reduce methane (a strong greenhouse gas) emissions, which is in line with the "dual carbon" goal.

[0014] Currently, in the drilling process for bottom-plate oil and gas extraction, drill rods are often used for drilling. For example, patent application number 202220478747.8 discloses an oil and gas extraction drill rod that is easy to connect, including a first cylinder, a second cylinder, and a mounting block. The outer wall of the first cylinder is connected to an anti-slip pad, and one side of the outer wall of the first cylinder is also connected to an anti-slip pad. The inner wall of the first cylinder is connected to a connecting rod, one end of which is connected to a fixing frame. The inner wall of the fixing frame is connected to a first oil pipe, and the inner wall of the fixing frame is connected to a second oil pipe. The inner wall of the first cylinder is connected to a hinge, the outer wall of the hinge is connected to a rack, the bottom of the rack is connected to a fixing plate, the bottom of the fixing plate is connected to a second spring, and one end of the second spring is connected to a mounting plate. The inner wall of the mounting block is connected to a first spring, one end of which is connected to a locking block, and one end of the mounting block is connected to a protective pad. This device can improve the speed of direct connection of the drill rod, while also ensuring the internal pressure resistance of the drill rod.

[0015] Patent application number 202220634282.0 discloses a drill pipe for oil and gas development, including a connector. The connector has an outer cylinder at its bottom, a connecting pipe at its bottom, a drill bit, and a rotating rod at its bottom. The rotating rod is installed at both ends of the connecting pipe, and a sealing plate is located at its bottom. Limiting components are provided on both sides of the rotating rod. This invention relates to the field of oil and gas development. The sealing plate, which includes a sealable channel inside the connecting pipe, expands under external force when a viscosity reducer is injected, allowing the viscosity reducer to flow in. A spring clamp resets the sealing plate, preventing backflow of the viscosity reducer. During drilling, the blades rotate due to the obstruction of crude oil, changing the flow direction and agitating the crude oil. This allows the viscosity reducer to mix evenly with the crude oil through a distribution hole, effectively reducing oil tension and increasing the efficiency of oil and gas extraction.

[0016] However, existing drill pipes often experience localized borehole collapses after drilling is completed due to the poor stability of the underlying strata, necessitating improvements. Summary of the Invention

[0017] The purpose of this invention is to provide an efficient drilling process for horizontal wells of oil-gas type on the bottom plate of coal mine working faces, so as to solve the above-mentioned technical problems.

[0018] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A high-efficiency drilling process for horizontal oil-gas surface wells in the bottom plate of a coal mine working face includes: Step 1: Using a drill rod, drill a hole downwards along the working face stratum. During the drilling process, the cement slurry inside the drill rod is continuously mixed and squeezed outwards, forming a cement protective layer on the hole wall. Step 2: After drilling is completed, drive the drill rod to rotate counterclockwise and pull it upward. During this process, the drill rod heats up, drying the cement on the hole wall and accelerating the cement curing process. Step 3: Periodically drive the drill rod to rotate counterclockwise and move it up and down inside the borehole. On the one hand, this clears the borehole and removes areas where partial collapse has occurred. On the other hand, it drives cement from other areas to the collapsed areas, refilling the borehole wall with cement in those areas. The heat generated by the drill rod also accelerates the further solidification of the cement.

[0019] Preferably, in step three, the borehole is cleared every two hours within eight hours.

[0020] Preferably, the drill pipe includes a driven tube, a drive rod is disposed inside the driven tube, a plurality of drive plates are arranged in a ring array outside the drive rod, the drive plates are located inside the driven tube, the drive plates are fixedly connected to the drive rod, a baffle is disposed between two adjacent drive plates, the baffle is fixedly connected to the inner wall of the driven tube, and a plurality of through holes are opened through the driven tube.

[0021] Preferably, a top cover is provided above the driven tube, and multiple fixing screws are threadedly connected to the edge of the top cover. Multiple threaded holes are opened at the top of the driven tube, and the fixing screws are threadedly engaged with the threaded holes. A first bearing is provided through the center of the top cover. The outer ring of the first bearing is fixedly connected to the top cover, and the inner ring of the first bearing is sleeved on the top of the drive rod and fixedly connected to the drive rod.

[0022] Preferably, a rechargeable heating rod is disposed through the interior of the driven tube wall, and the heating rod is slidably engaged with the driven tube.

[0023] Preferably, a base is provided on the right side of the baffle, the base is fixedly connected to the baffle, and a controller is fixedly mounted on the base, the controller being wirelessly connected to the heating rod.

[0024] Preferably, a waterproof protective cover is provided on the outside of the controller, the waterproof protective cover is located on the outside of the controller, and the edge of the waterproof protective cover is fixedly connected to the base.

[0025] Preferably, a base plate is provided below the driven tube, the base plate is fixedly connected to the driven tube, a second bearing is sleeved at the bottom end of the drive rod, the inner ring of the second bearing is fixedly connected to the drive rod, and the outer ring of the second bearing is fixedly connected to the base plate.

[0026] Preferably, a drill bit is provided below the base plate, and the drill bit is fixedly connected to the base plate.

[0027] Preferably, the drill bit is conical.

[0028] The beneficial effects of this invention are: This invention presents a highly efficient drilling process for horizontal oil-gas surface wells in the bottom plate of coal mine working faces. While drilling within the formation, cement can be coated onto the borehole wall, effectively improving borehole wall strength and preventing borehole collapse. Furthermore, the device generates heat, further accelerating cement hardening. This effectively solves the problem of localized borehole collapse that frequently occurs after drilling due to poor formation stability in the bottom plate, as is common with existing drill pipes. Attached Figure Description

[0029] Figure 1 This is a structural schematic diagram of an efficient drilling process for a horizontal surface well for oil-type gas in the bottom plate of a coal mine working face, according to the present invention. Figure 2This invention relates to an efficient drilling process for horizontal wells producing oil and gas on the bottom plate of a coal mine working face. Figure 1 Enlarged schematic diagram of part A; Figure 3 This invention relates to an efficient drilling process for horizontal wells producing oil and gas on the bottom plate of a coal mine working face. Figure 1 Enlarged schematic diagram of part B; Figure 4 This is a schematic diagram of the connection structure of the base, controller, and waterproof protective cover for a high-efficiency drilling process of a horizontal oil-gas surface well in the bottom plate of a coal mine working face according to the present invention. Reference numerals: 1. Drive rod; 2. First bearing; 4. Drive plate; 5. Heating rod; 6. Threaded hole; 7. Driven tube; 9. Baffle; 10. Top cover; 11. Fixing screw; 12. Second bearing; 13. Drill bit; 14. Base plate; 15. Base; 16. Controller; 17. Waterproof protective cover; 18. Through hole. Detailed Implementation

[0030] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0031] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1

[0033] A high-efficiency drilling process for horizontal oil-gas surface wells in the bottom plate of a coal mine working face includes: Step 1: Using a drill rod, drill a hole downwards along the working face stratum. During the drilling process, the cement slurry inside the drill rod is continuously mixed and squeezed outwards, forming a cement protective layer on the hole wall. Step 2: After drilling is completed, drive the drill rod to rotate counterclockwise and pull it upward. During this process, the drill rod heats up, drying the cement on the hole wall and accelerating the cement curing process. Step 3: Periodically drive the drill rod to rotate counterclockwise and move it up and down inside the borehole. On the one hand, this clears the borehole and removes areas where partial collapse has occurred. On the other hand, it drives cement from other areas to the collapsed areas, refilling the borehole wall with cement in those areas. The heat generated by the drill rod also accelerates the further solidification of the cement.

[0034] In step three, the borehole is cleared every two hours within eight hours.

[0035] During the drilling process, cement is applied to the hole wall simultaneously. After the cement hardens, it can effectively increase the hardness of the hole wall and effectively prevent the hole from collapsing. Example 2

[0036] like Figures 1-4 As shown, while other parts are the same as in Embodiment 1, the difference between this embodiment and Embodiment 1 is that: the drill rod includes a driven tube 7, a drive rod 1 is provided inside the driven tube 7, a plurality of drive plates 4 are arranged in a ring array outside the drive rod 1, the drive plates 4 are located inside the driven tube 7, the drive plates 4 are fixedly connected to the drive rod 1, a baffle 9 is provided between two adjacent drive plates 4, the baffle 9 is fixedly connected to the inner wall of the driven tube 7, and a plurality of through holes 18 are opened through the driven tube 7.

[0037] A top cover 10 is provided above the driven tube 7. Multiple fixing screws 11 are threadedly connected to the edge of the top cover 10. Multiple threaded holes 6 are opened at the top of the driven tube 7. The fixing screws 11 are threadedly engaged with the threaded holes 6. A first bearing 2 is provided through the center of the top cover 10. The outer ring of the first bearing 2 is fixedly connected to the top cover 10. The inner ring of the first bearing 2 is sleeved on the top of the drive rod 1 and is fixedly connected to the drive rod 1. A rechargeable heating rod 5 is provided through the inside of the driven tube 7. The heating rod 5 is slidably engaged with the driven tube 7. A base 15 is provided on the right side of the baffle 9. The base 15 is fixedly connected to the baffle 9. A controller 16 is fixedly mounted on the base 15. The controller 16 is wirelessly connected to the heating rod 5. A waterproof protective cover 17 is provided on the outside of the controller 16. The edge of the waterproof protective cover 17 is fixedly connected to the base 15.

[0038] A base plate 14 is provided below the driven tube 7, and the base plate 14 is fixedly connected to the driven tube 7. A second bearing 12 is sleeved at the bottom end of the drive rod 1. The inner ring of the second bearing 12 is fixedly connected to the drive rod 1, and the outer ring of the second bearing 12 is fixedly connected to the base plate 14.

[0039] Cement is filled into the driven pipe 7, and then the fixing screw 11 is connected to the threaded hole 6 to seal the top of the driven pipe 7 with the top cover 10. The drive rod 1 is connected to the power output end of the drill rig. The drill rig drives the drive rod 1 to rotate clockwise. The drive rod 1 drives the drive plate 4 to rotate synchronously. The drive plate 4 pushes the baffle 9 on its right side to rotate through the cement in the driven pipe 7. The baffle 9 drives the driven pipe 7 to rotate, so that the driven pipe 7 drills a hole in the formation.

[0040] As the driving plate 4 pushes the right baffle 9 to rotate through the cement in the driven tube 7, the cement in the driven tube 7 is squeezed out through the through hole 18 and coated on the hole wall, which increases the strength of the hole wall after hardening.

[0041] After cleaning the cement from the drive pipe 7, the drilling machine drives the drive rod 1 to reverse, that is, when the drive rod 1 rotates counterclockwise, the drive rod 1 pushes the left baffle 9 to rotate, so that the controller 16 located on the right side of the baffle 9 is pressed, and the controller 16 controls the heating rod 5 to start heating and drying the cement on the hole wall. Example 3

[0042] like Figure 1 , 3 As shown, while all other parts are the same as in Embodiment 2, the difference between this embodiment and Embodiment 2 is that a drill bit 13 is provided below the base plate 14, and the drill bit 13 is fixedly connected to the base plate 14. The drill bit 13 is conical. By providing a conical drill bit 13, drilling efficiency can be improved.

[0043] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency drilling technology for horizontal wells producing oil and gas at the bottom plate of a coal mine working face, characterized in that: include: Step 1: Using a drill rod, drill a hole downwards along the working face stratum. During the drilling process, the cement slurry inside the drill rod is continuously mixed and squeezed outwards, forming a cement protective layer on the hole wall. Step 2: After drilling is completed, drive the drill rod to rotate counterclockwise and pull it upward. During this process, the drill rod heats up, drying the cement on the hole wall and accelerating the cement curing process. Step 3: Periodically drive the drill rod to rotate counterclockwise and move it up and down inside the borehole. On the one hand, this clears the borehole and removes areas where partial collapse has occurred. On the other hand, it drives cement from other areas to the collapsed areas, refilling the borehole wall with cement in those areas. The heat generated by the drill rod also accelerates the further solidification of the cement.

2. The efficient drilling technology for a horizontal surface well for oil-gas in the bottom plate of a coal mine working face according to claim 1, characterized in that: In step three, the borehole is cleared every two hours within eight hours.

3. The efficient drilling technology for a horizontal surface well for oil-gas in the bottom plate of a coal mine working face according to claim 2, characterized in that: The drill pipe includes a driven tube (7), inside which a drive rod (1) is provided. Multiple drive plates (4) are arranged in a ring array on the outside of the drive rod (1). The drive plates (4) are located inside the driven tube (7) and are fixedly connected to the drive rod (1). A baffle (9) is provided between two adjacent drive plates (4). The baffle (9) is fixedly connected to the inner wall of the driven tube (7). Several through holes (18) are opened through the driven tube (7).

4. The efficient drilling technology for a horizontal surface well for oil-gas in the bottom plate of a coal mine working face according to claim 3, characterized in that: A top cover (10) is provided above the driven tube (7). Multiple fixing screws (11) are threadedly connected to the edge of the top cover (10). Multiple threaded holes (6) are opened at the top of the driven tube (7). The fixing screws (11) are threadedly engaged with the threaded holes (6). A first bearing (2) is provided through the center of the top cover (10). The outer ring of the first bearing (2) is fixedly connected to the top cover (10). The inner ring of the first bearing (2) is sleeved on the top of the drive rod (1). The inner ring of the first bearing (2) is fixedly connected to the drive rod (1).

5. The efficient drilling technology for a horizontal surface well of oil-gas type in the bottom plate of a coal mine working face according to claim 4, characterized in that: A rechargeable heating rod (5) is installed inside the wall of the driven tube (7), and the heating rod (5) slides in conjunction with the driven tube (7).

6. The efficient drilling technology for a horizontal surface well for oil-gas in the bottom plate of a coal mine working face according to claim 5, characterized in that: A base (15) is provided on the right side of the baffle (9). The base (15) is fixedly connected to the baffle (9). A controller (16) is fixedly provided on the base (15). The controller (16) is wirelessly connected to the heating rod (5).

7. The efficient drilling technology for a horizontal surface well of oil-gas type in the bottom plate of a coal mine working face according to claim 6, characterized in that: A waterproof protective cover (17) is provided on the outside of the controller (16). The waterproof protective cover (17) is located on the outside of the controller (16), and the edge of the waterproof protective cover (17) is fixedly connected to the base (15).

8. The efficient drilling technology for a horizontal surface well for oil-gas in the bottom plate of a coal mine working face according to claim 7, characterized in that: A base plate (14) is provided below the driven tube (7), the base plate (14) is fixedly connected to the driven tube (7), and a second bearing (12) is sleeved on the bottom end of the drive rod (1). The inner ring of the second bearing (12) is fixedly connected to the drive rod (1), and the outer ring of the second bearing (12) is fixedly connected to the base plate (14).

9. The efficient drilling technology for a horizontal surface well of oil-gas type in the bottom plate of a coal mine working face according to claim 8, characterized in that: A drill bit (13) is provided below the base plate (14), and the drill bit (13) is fixedly connected to the base plate (14).

10. The efficient drilling technology for a horizontal surface well for oil-gas in the bottom plate of a coal mine working face according to claim 9, characterized in that: The drill bit (13) is conical.

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