Underground while-drilling reamer for oil and gas well

Abstract

The invention relates to the technical field of oil and gas well reaming devices, and provides an oil and gas well underground reaming-while-drilling device which comprises a long-strip-shaped groove formed in the middle of the outer wall of a device barrel, a drilling strip is slidably connected to the interior of the long-strip-shaped groove, and an inner cavity communicating with the long-strip-shaped groove is formed in the device barrel; and funnel-shaped telescopic seats are arranged on the two sides of the interior of the inner cavity correspondingly, a pneumatic assembly is fixedly connected to the middle of the interior of the inner cavity so that the telescopic seats can move in a mirror image mode on the two sides of the inner cavity, and the telescopic seats on the two sides are connected through a cross assembly so that the drill strips can slide in the long-strip-shaped grooves. And a plurality of telescopic grooves are formed in the upper side of the outer wall of the device barrel. During reaming, the radius of a hole drilled by the drill bit is increased to reduce the reaming pressure of a drill bar, so that the reaming efficiency is improved, meanwhile, the mechanical pressure required by expansion of the drill bar is effectively reduced, the reaming efficiency is improved by 62%, and the drill bit is particularly suitable for efficient cutting of hard rock strata.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas well reamer, in particular to an oil and gas downhole reamer while drilling. BACKGROUND

[0002] In oil and gas drilling operations, the reamer while drilling is a key tool for expanding the diameter of the wellbore, and its performance directly affects the drilling efficiency and wellbore quality. Traditional reamers rely on mechanical structures to achieve bit expansion, but in complex formations (such as interbedded shale and sandstone), the single expansion force and adjustment lag often result in low expansion efficiency and poor wellbore stability. In addition, existing equipment has obvious shortcomings in dynamically adapting to well diameter changes and quickly handling stuck drill pipes, making it difficult to meet the high-standard operation requirements of deep, ultra-deep and extended reach wells.

[0003] Traditional reamers have fixed bit expansion force in hard rock formations, making it difficult to effectively cut into the rock formation, with low expansion efficiency (usually ≤4.2m / h) and high energy consumption (≥18.5kW·h / m). In soft rock formations, the large expansion force easily causes wellbore collapse (collapse rate >12%), and the existing equipment lacks a self-adaptive positioning mechanism, which easily causes the reamer to deviate (centering error >1.5%) when the well diameter is irregular or the lithology changes, resulting in wellbore deviation and increased drill tool wear. In addition, the stuck drill pipe handling relies on manual intervention, with a recovery time of 15-20 minutes, which seriously affects the continuity of the operation. SUMMARY

[0004] To overcome the shortcomings of the prior art, the present application provides an oil and gas downhole reamer while drilling, which solves the problem of lack of self-adaptive positioning mechanism in existing equipment, easy deviation of the reamer when the well diameter is irregular or the lithology changes, and the fixed bit expansion force, which makes it difficult to effectively cut into the rock formation and low expansion efficiency.

[0005] To achieve the above purpose, the present application realizes the following technical scheme: an oil and gas downhole reamer while drilling, comprising: The long slot is arranged in the middle of the outer wall of the cylinder, and a drill rod is slidably connected in the long slot, an inner cavity is arranged in the cylinder, and funnel-shaped telescopic seats are arranged on both sides of the inner cavity, a pneumatic assembly is fixedly connected to the inner middle of the inner cavity to realize mirror image movement of the telescopic seats on both sides of the inner cavity, the telescopic seats on both sides are connected through a cross assembly to realize sliding of the drill rod in the long slot, a plurality of telescopic grooves are arranged on the upper side of the outer wall of the cylinder, a transfer block is slidably arranged in the telescopic groove through movement of one side of the telescopic seat, a positioning roller is arranged at the outer end of the transfer block, an adjusting seat is rotatably arranged in a plug-in seat through movement of the other side of the telescopic seat, and the outer wall of the adjusting seat is connected with a plug-in block through a mounting assembly, the adjusting seat is in the shape of a sickle, and the plug-in seat is mounted on the bottom of the cylinder through a connecting assembly.

[0006] Preferably, the outer wall of the drill rod is fixedly connected with a plurality of inclined protrusions, and a drill bit is fixedly connected to the side wall of the plug-in block to drill a well.

[0007] Preferably, the pneumatic assembly comprises a cylinder shell fixedly arranged in the inner middle of the inner cavity, piston rods are slidably connected to both sides of the cylinder shell, a gas flow channel is arranged in the middle of the cylinder shell and connected to both sides, and the piston rods are extended and retracted through gas pressure.

[0008] Preferably, the cross assembly comprises abutting rods that slide in the inner wall of the telescopic seat, the abutting rods on both sides are connected to the inner wall of the inner cavity in a cross manner, and the cross is connected to the drill rod.

[0009] Preferably, the two opposite transfer blocks are connected through a reset spring two.

[0010] Preferably, the two opposite adjusting seats are connected through a reset spring one.

[0011] Preferably, the connecting assembly comprises a connecting sub-seat fixedly connected to the outer wall of the plug-in seat, a plug rod is fixedly connected to the top of the connecting sub-seat, connecting female seats are fixedly connected to the upper and lower sides of the outer wall of the cylinder, the connecting female seats on both sides can be plugged with the plug rod, and the connecting female seats and the plug rod after plugging are connected through fixing bolts.

[0012] Preferably, the mounting assembly comprises a plug-in block and an adjusting seat that are pre-mounted in a plug-in manner, and the pre-mounted plug-in block and adjusting seat are fixed through a bolt and a nut.

[0013] A use method of an oil and gas downhole drilling reamer, comprising the following steps: Step one, connect the reamer to the end of the drill string, complete the fixing of the barrel and the fixed seat through the plug-in cooperation of the connecting female seat and the connecting seat, and make it fit the well wall by using the positioning roller to ensure that the reamer remains radially stable during drilling; Step two, inject high-pressure gas into the airflow channel of the pneumatic assembly to push the two piston rods to extend synchronously, drive the telescopic seat to move along the inner cavity mirror image, realize the expansion of the drilling radius of the drill bit, and through the linkage action of the resistance rod, drive the drill bar to slide outward along the long slot until the convex strip contacts the well wall to form an initial reaming radius; Step three, during drilling, adjust the air pressure value of the pneumatic assembly in real time according to the downhole geological conditions: Soft rock layer: reduce the air pressure, reduce the expansion force of the drill bar, and avoid well wall collapse; Hard rock layer: increase the air pressure, increase the expansion force of the drill bar, and ensure effective reaming; At the same time, the positioning roller is driven by the transfer block to slide along the telescopic slot to dynamically adapt to the change of the well diameter and keep the reamer centered; Step four, after reaming is completed, release the air pressure of the pneumatic assembly, and reset spring one and reset spring two to pull the adjusting seat and the transfer block back, respectively, and the drill bar is retracted into the long slot.

[0014] Preferably, when it is detected that the drill bar is stuck due to accumulation of cuttings in step two, the following operations are performed: S1, temporarily increase the air pressure of the pneumatic assembly to 120% of the rated value to drive the drill bar to vibrate at a high frequency to shake off the attached cuttings; S2, if the vibration is ineffective, perform partial reverse rotation through the drill bit of the plug-in block to break the stuck rock layer; S3, reset and restart the reaming process to ensure the continuity of reaming.

[0015] The present application provides a downhole reamer for oil and gas drilling. It has the following advantages: 1. The present application increases the radius of the hole drilled by the drill bit during reaming to reduce the pressure of the drill bar during reaming, thereby improving the efficiency of reaming, and effectively reducing the mechanical pressure required for the expansion of the drill bar, with an increase in reaming efficiency of 62%, especially suitable for efficient cutting of hard rock layers.

[0016] 2. The present application dynamically adjusts the expansion force of the drill bar according to the characteristics of different rock layers to avoid well wall peeling and reduce the collapse rate by 75%, and cooperates with the self-adaptive well diameter change to ensure the consistency of the reaming depth and diameter, with a centering error of <0.5%, ensuring the stability of the operation; 3. The present application maintains the centering effect before and after reaming, automatically compensates for the displacement difference when the well diameter is irregular, avoids deviation caused by unilateral stress, accurately centers, significantly improves the stability and safety of drilling, and prevents eccentricity caused by excessive unilateral expansion force. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a perspective view of the present application; Figure 2 is a schematic view of the present application in an expanded state; Figure 3 is a schematic view of the internal structure of the barrel in the present application; Figure 4 is a schematic view of the internal expansion loading of the barrel in the present application.

[0018] Wherein, 1, plug-in block; 2, drill bit; 3, adjusting seat; 4, drill bar; 5, barrel; 6, positioning roller; 7, telescopic slot; 8, fixing bolt; 9, connecting female seat; 10, connecting sub seat; 11, long slot; 12, plug-in seat; 13, return spring one; 14, telescopic seat; 15, abutting rod; 16, transfer block; 17, inner cavity; 18, barrel shell; 19, piston rod; 20, air flow channel; 21, return spring two. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0020] As an aspect of the present application, please refer to the drawings Figure 1 - the drawings Figure 4 The embodiments of the present application provide an oil and gas downhole drilling reamer, comprising: The inner part of the barrel 5 is provided with an inner cavity 17 connected with the long slot 11, and the inner part of the inner cavity 17 is provided with a telescopic seat 14 in the shape of a funnel on both sides. The telescopic seat 14 is made of titanium alloy material with a tensile strength ≥1000MPa, which is suitable for deep well high pressure environment. The inner middle part of the inner cavity 17 is fixedly connected with a barrel shell 18, and the both sides of the barrel shell 18 are slidingly connected with a piston rod 19. The middle part of the barrel shell 18 is provided with an air flow channel 20 connected with both sides, which is used to be driven by injecting nitrogen to avoid hydraulic oil leakage and pollution of the wellbore, and to realize the telescopic movement of the piston rod 19 by using air pressure. The outer end of the piston rod 19 is connected with the inner wall middle part of the telescopic seat 14 to realize the mirror image movement of the telescopic seat 14 on both sides of the inner cavity 17. A long groove 11 is opened in the middle of the outer wall of the tube 5, and a drill rod 4 is slidably connected inside the long groove 11. Multiple inclined convex strips are fixedly connected to the outer wall of the drill rod 4. The surface of the drill rod and the convex strips 4 are coated with a tungsten carbide-diamond composite coating, which increases the hardness to HRC 70 and extends the service life by 50% for drilling. The inner walls of the telescopic seats 14 on both sides are slidably connected to the inner wall of the inner cavity 17 in a cross manner, and the intersection is connected to the drill rod 4 so as to realize the sliding of the drill rod 4 inside the long groove 11. Multiple telescopic grooves 7 are opened on the upper side of the outer wall of the cylinder 5. A transfer block 16 is slidable inside the telescopic groove 7 by the movement of one of the telescopic seats 14. The outer end of the transfer block 16 is provided with a positioning roller 6. Two opposite transfer blocks 16 are connected by a return spring 21. The adjustment seat 3 rotates inside the plug-in seat 12 by moving the telescopic seat 14 on the other side. The outer wall of the adjustment seat 3 is pre-installed with a plug-in block 1. The pre-installed plug-in block 1 is fixed to the adjustment seat 3 by bolts and nuts. The side wall of the plug-in block 1 is fixedly connected to the drill bit 2 for drilling. The adjustment seat 3 is sickle-shaped. The two opposing adjustment seats 3 are connected by a return spring 13. The connector 12 is fixedly connected to the outer wall of the connector 10. The top of the connector 10 is fixedly connected to the plug rod. The upper and lower sides of the outer wall of the tube 5 are fixedly connected to the connector 9. Both sides of the connector 9 can be plugged into the plug rod. After plugging, the connector 9 and the plug rod are connected by the fixing bolt 8.

[0021] As another aspect of the present invention, a method for using a downhole drilling reamer in oil and gas wells is provided, comprising the following steps: Step 1: Connect the reamer to the end of the drill string. Fix the barrels 5 and 12 by inserting the female connector 9 and the female connector 10. Use the positioning roller 6 to make it fit against the well wall to ensure that the reamer remains radially stable during drilling. Step 2: Inject high-pressure gas into the airflow channel 20 of the pneumatic assembly, pushing the piston rods 19 on both sides to extend outwards synchronously, driving the telescopic seat 14 to move mirror-image along the inner cavity 17, thereby expanding the drilling radius of the drill bit 2. Through the linkage action of the abutment rod 15, the drill rod 4 is driven to slide outwards along the long groove 11 until the convex strip contacts the well wall, forming the initial reaming radius. When it is detected that the drill rod 4 is stuck due to rock cuttings accumulation, perform the following operations: S1. Briefly increase the air pressure of the pneumatic components to 120% of the rated value, drive the drill bit 4 to vibrate at high frequency, and shake off the attached rock cuttings; S2. If vibration is ineffective, the drill bit 2 of the plug block 1 is rotated locally in the opposite direction to break the stuck rock layer. S3, reset after restarting the reaming process, ensure the continuity of reaming; Step three, during drilling, real-time adjust the air pressure value of the pneumatic assembly according to the downhole geological conditions: Soft rock layer: reduce the air pressure, reduce the expansion force of the drill bar 4, avoid the collapse of the well wall; Hard rock layer: increase the air pressure, increase the expansion force of the drill bar 4, ensure effective reaming; At the same time, the positioning roller 6 is driven by the transfer block 16 to slide along the telescopic groove 7, dynamically adapt to the change of the well diameter, and keep the reamer centered; Step four, after completing the reaming, release the air pressure of the pneumatic assembly, reset the reset spring one 13 and the reset spring two 21 to pull the adjusting seat 3 and the transfer block 16 to reset, and the drill bar 4 is retracted into the long slot 11; Step five, real-time monitor the vibration frequency of the reamer, the drill bar expansion force and the well diameter data through the downhole sensor, transmit the data to the ground control system; based on historical data and machine learning algorithm, dynamically optimize the air pressure adjustment threshold and the drill bar expansion strategy, improve the reaming efficiency by 20%-30%.

[0022] The specific embodiments will be described below Embodiment: Implementation scenario: A shale gas well is located in a complex geological area, with a well depth of 3500 meters, and the target layer is shale and sand interbedding with significant hardness difference. The traditional reamer cannot dynamically adjust the reaming force, resulting in frequent well wall collapse. The reamer while drilling is used for operation.

[0023] Specific implementation steps and optimization scheme I. Equipment installation and parameter configuration Modularized quick assembly: The reamer is inserted through the connection female seat 9 and the connection sub seat 10 at the end of the drill string, and is locked by the fixing bolt 8. The initial position of the positioning roller 6 is set to be close to the well wall (well diameter 215.9mm), to ensure the centering stability.

[0024] Sensor integration: The vibration sensor and pressure sensor are embedded in the barrel 5 to real-time monitor the vibration frequency and expansion force of the drill bar 4, and the data is transmitted to the ground control center through the downhole cable.

[0025] II. Dynamic reaming process Soft rock layer operation (shale section): The air pressure of the pneumatic assembly is set to 8MPa, and the expansion force of the drill bar 4 is controlled within 15kN to avoid well wall peeling. The positioning roller 6 automatically adjusts with the change of the well diameter, and the sliding distance of the transfer block 16 in the telescopic groove 7 is ≤5mm, to ensure that the reamer centering error is <0.5%.

[0026] Hard rock formation operation (sandstone section): The gas pressure is raised to 12 MPa, and the expansion force of the drill rod 4 increases to 25 kN. The inclined convex strip cuts into the rock formation, and the reaming efficiency is improved by 40%. The resistance rod 15 evenly distributes the load through the linkage mechanism, reducing local stress concentration.

[0027] III. Emergency handling and optimization Emergency response to stuck drill: When the drill rod 4 is stuck in the sandstone layer due to accumulation of rock debris, the system automatically triggers a high-frequency vibration mode (frequency 50 Hz, duration 5 seconds), and the amount of rock debris shaken off reaches 80%. If the jam is not removed, the drill bit 2 performs local reverse rotation (rotation speed 30 rpm, torque 200 N·m), breaks the jammed rock layer, and shortens the recovery time to 3 minutes.

[0028] Data feedback and adaptive optimization: The ground control system trains an LSTM model based on historical data (such as lithology identification and reaming rate) to dynamically adjust the gas pressure threshold. For example, in alternating rock layers, the model predicts that the next section is shale, and automatically reduces the gas pressure to 7.5 MPa to reduce invalid energy consumption.

[0029] Technical effect verification

[0030] Through dynamic gas pressure adjustment and positioning roller adaptive mechanism, safe and efficient reaming of complex formations is realized; combined with sensor data and machine learning model, the need for manual intervention is reduced, the operation stability is improved by 60%, the modular design reduces maintenance cost, and the rock debris recovery and low energy consumption design meet the green drilling requirements.

[0031] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A downhole reamer for oil and gas wells, characterized in that, include: A long groove (11) is opened in the middle of the outer wall of the tube (5), and a drill bit (4) is slidably connected inside the long groove (11). The tube (5) has an inner cavity (17) that communicates with the long groove (11). On both sides of the inner cavity (17), there are funnel-shaped telescopic seats (14). A pneumatic component is fixedly connected to the middle of the inner cavity (17) to realize the mirror movement of the telescopic seats (14) on both sides of the inner cavity (17). The two telescopic seats (14) are connected by a cross component to realize the drill bit (4) inside the long groove (11). Multiple telescopic grooves (7) are opened on the upper side of the outer wall of the container (5) for sliding. A transfer block (16) slides inside the telescopic groove (7) by moving one of the telescopic seats (14). The outer end of the transfer block (16) is provided with a positioning roller (6). An adjustment seat (3) rotates inside the plug seat (12) by moving the other telescopic seat (14). The outer wall of the adjustment seat (3) is connected to the plug block (1) by the mounting assembly. The adjustment seat (3) is sickle-shaped. The plug seat (12) is installed at the bottom of the container (5) by the connecting assembly.

2. The downhole reamer for oil and gas wells according to claim 1, characterized in that, The outer wall of the drill bit (4) is fixedly connected with a plurality of inclined protrusions, and the side wall of the plug block (1) is fixedly connected with a drill bit (2) for drilling.

3. The downhole reamer for oil and gas wells according to claim 1, characterized in that, The pneumatic assembly includes a cylindrical shell (18) fixed in the middle of the inner cavity (17). Piston rods (19) are slidably connected to both sides of the cylindrical shell (18). An airflow channel (20) is provided in the middle of the cylindrical shell (18) and connects to both sides to achieve the extension and retraction of the piston rod (19) by air pressure. The outer end of the piston rod (19) is connected to the middle of the inner wall of the telescopic seat (14).

4. The downhole reamer for oil and gas wells according to claim 1, characterized in that, The cross assembly includes abutment rods (15) that slide on the inner wall of the telescopic seat (14). The abutment rods (15) on both sides are connected to the inner wall of the inner cavity (17) in a cross manner, and the cross is connected to the drill bit (4).

5. The downhole reamer for oil and gas wells according to claim 1, characterized in that, The two opposing transfer blocks (16) are connected by a second return spring (21).

6. The downhole reamer for oil and gas wells according to claim 1, characterized in that, The two opposing adjustment seats (3) are connected by a return spring (13).

7. The downhole reamer for oil and gas wells according to claim 1, characterized in that, The connecting assembly includes a connecting sub-base (10) fixedly connected to the outer wall of the plug-in base (12). A plug rod is fixedly connected to the top of the connecting sub-base (10). Connecting female bases (9) are fixedly connected to both the upper and lower sides of the outer wall of the tube (5). Both sides of the connecting female bases (9) can be plugged into the plug rod. After plugging, the connecting female bases (9) and the plug rod are connected by fixing bolts (8).

8. The downhole reamer for oil and gas wells according to claim 7, characterized in that, The installation assembly includes a plug-in block (1) and an adjusting seat (3) for pre-installation, and the pre-installed plug-in block (1) and adjusting seat (3) are fixed by bolts and nuts.

9. A method of using a downhole reamer in oil and gas wells, comprising using a downhole reamer as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Connect the drilling reamer to the end of the drill string. Fix the reamer tube (5) and (12) by inserting the connecting female (9) and connecting female (10) together. Use the positioning roller (6) to make it fit against the well wall to ensure that the reamer remains radially stable during drilling. Step 2: Inject high-pressure gas into the airflow channel (20) of the pneumatic component, push the piston rods (19) on both sides to extend outward synchronously, drive the telescopic seat (14) to move in a mirror image along the inner cavity (17), thereby expanding the drilling radius of the drill bit (2). Through the linkage of the abutment rod 15, drive the drill bar (4) to slide outward along the long groove (11) until the convex bar contacts the well wall, forming the initial enlarged hole radius. Step 3: During drilling, adjust the air pressure of the pneumatic components in real time according to the downhole geological conditions. Soft rock layer: reduce gas pressure, reduce the expansion force of drill bit (4), and avoid well wall collapse; Hard rock formations: Increase air pressure to increase the expansion force of drill bit (4) and ensure effective hole enlargement; At the same time, the positioning roller (6) is driven by the transfer block (16) to slide along the telescopic groove (7) to dynamically adapt to the well diameter change and keep the reamer centered; Step 4: After completing the eye enlargement, release the air pressure of the pneumatic components. The first reset spring (13) and the second reset spring (21) pull the adjusting seat (3) and the transfer block (16) to reset respectively, and the drill bit (4) retracts into the long groove (11).

10. The method of using a downhole reamer in oil and gas wells according to claim 1, characterized in that, In step two, when the drill rod (4) is detected to be stuck due to rock cuttings accumulation, the following operations are performed: S1. Briefly increase the air pressure of the pneumatic components to 120% of the rated value, drive the drill bit (4) to vibrate at high frequency, and shake off the attached rock cuttings; S2. If vibration is ineffective, the drill bit (2) of the plug block (1) is rotated locally in the opposite direction to break the stuck rock layer. S3. Reset and restart the eye-expansion process to ensure continuity of eye-expansion.

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