Drill bit jam monitoring tool and monitoring method

Abstract

The present invention relates to a drill bit jam or stuck monitoring tool and detection method, which are mainly used for dynamic control of drill bit torque during oil and gas field drilling, and monitoring of severe drill bit jam or stuck. The tool includes a friction clutch part and a drill bit jam or stuck monitoring part, which are combined by a threaded connection. During operation of the present invention, the threaded core shaft of the drill bit jam monitoring part can expand and contract with the change of the counter-torque on the drill bit, thereby suppressing the violent fluctuation of the torque and realizing dynamic torque control. When the drill bit jams or gets stuck, the torque clutch part of the tool can interrupt the torque between the drill string and the drill bit, and the ground can monitor the reduction of the drill string torque and identify that the drill bit is jammed or stuck. This technical solution can monitor drill bit jams and stucks, thereby improving the safety and working efficiency of deep well drilling.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and in particular to a drill bit jamming and sticking monitoring tool and a detection method. Background Art

[0002] Oil and gas resources, as important strategic resources, play a vital role in human economic development, industrial production, national defense, and daily life. The drilling phase of oil and gas resource development is one of the most costly, risky, and technically challenging. When drilling through intersecting strata of varying hardness, the drill bit penetrates softer formations more easily, but encounters greater resistance in harder formations. This sudden change in resistance can cause vibration and bit and string jamming, or lead to drill bit sticking due to formation collapse or indentation. In severe cases, the drill bit can become stuck. Because drill bit jamming or sticking cannot be detected on the ground in a timely manner, torque increases continuously, leading to drill string breakage and serious impacts on drilling safety and efficiency.

[0003] Existing drill string vibration monitoring technologies, including surface measurement systems and downhole measurement while drilling (MWD) systems, cannot accurately determine lateral drill string vibration due to the high flexibility of the drill string and its frequent contact with the wellbore. Furthermore, most surface measurement systems have a low sampling frequency, making them ineffective for monitoring complex downhole vibration conditions. Real-time downhole MWD is limited by the transmission speed of mud pulse signals and a low sampling frequency, making it ineffective for subsequent in-depth analysis such as signal spectrum analysis. Storage-based measurement methods also lack real-time feedback on downhole vibration, pipe jams, and stuck pipe during drilling.

[0004] In order to solve the problems of regulating drill string vibration, monitoring drill bit sticking and protecting the drill string to improve drilling safety during drilling, it is urgent to invent a monitoring tool and identification method for drill bit sticking during drilling. Summary of the Invention

[0005] The purpose of the present invention is to provide a drill bit stuck monitoring tool and identification method for effectively reducing drill bit vibration. When the drill bit is stuck or stuck, the torque transmission can be technically cut off, the drill string torque can be reduced, and the drill string can be prevented from twisting off. The drill bit stuck can be detected and handled immediately on the ground according to the drill bit stuck identification method. A drill bit stuck monitoring tool is a purely mechanical structure that can work in a high temperature and high pressure environment.

[0006] The following technical solutions are adopted by the present invention to solve the technical problems:

[0007] A drill bit stuck drill monitoring tool, comprising a torque clutch mechanism and a drill bit stuck drill monitoring mechanism;

[0008] The torque clutch mechanism includes an upper joint, an upper sealing shell, an upper sealing ring, a bearing housing, a thrust string bearing, a bearing inner ring fixing nut, a spline housing, an inner friction plate, an outer friction plate, a pressure plate, a push rod, a piston, a piston sealing ring, a piston spring, a sealing nut sleeve, a connecting housing, and a one-way valve.

[0009] The outer diameter of the upper joint decreases from top to bottom, and is described as shaft section I, shaft section II, shaft section III, shaft section IV and shaft section V in sequence;

[0010] Shaft section I is provided with a threaded box for connecting to the upper drill string;

[0011] The upper sealing ring is installed in the sealing groove of the upper sealing shell, which is then fitted onto the upper joint. The upper sealing ring forms a seal with the surface of shaft end II of the upper joint. The inner ring of the thrust string bearing is fitted onto shaft segment III of the upper joint and is positioned and fixed by the bearing inner ring retaining nut. The outer ring of the thrust string bearing is fitted into the bearing housing. The thrust string bearing is positioned and fixed by the threaded connection between the upper sealing shell and the bearing housing. The upper joint and the bearing housing can rotate freely relative to each other.

[0012] The shaft section IV of the upper joint is covered with a spline shell, and a boss is provided in the middle of the spline shell, which divides the inner space into two parts, an upper part and an lower part. The inner hole of the upper part is provided with an internal spline, and the outer disk of the friction plate engages with the inner spline of the spline shell through the external spline; the inner hole wall of the lower part is smooth and is used for installing the piston; the shaft section IV of the upper joint is provided with an external spline, and the inner disk of the friction plate engages with the outer spline of the shaft section IV of the upper joint through the internal spline; the inner disk of the friction plate and the outer disk of the friction plate are staggered to form a friction plate, and a pressure plate and a push rod are provided below; the push rod passes through the through hole on the boss of the spline shell, and the two ends of the push rod are respectively connected to the pressure plate and the piston; the upper and lower ends of the spline shell are respectively connected to the bearing shell and the connecting shell through threads, and the friction plate transmits the torque of the upper joint to the spline shell through friction.

[0013] The piston is provided with a sealing groove, in which a piston sealing ring is provided. The piston divides the smooth lower part of the inner wall of the spline housing into two chambers. The upper hydraulic chamber is connected to the wellbore annulus through the first opening on the spline housing boss, and the lower hydraulic chamber is connected to the upper joint drilling fluid flow channel through the second opening on the upper joint shaft section V; the piston spring is installed in the upper hydraulic chamber, and provides a downward thrust to move the piston downward when the torque transmission is disconnected.

[0014] The one-way valve is installed on the connecting housing;

[0015] The sealing nut sleeve is installed on the upper joint shaft section V through threads.

[0016] The drill stuck monitoring mechanism includes a disc spring housing, a center tube, a disc spring, an anti-drop tube, a sealing ring, a threaded housing, a threaded shaft, a lower sealing housing, and a lower sealing ring.

[0017] The upper end of the disc spring housing is connected to the connecting housing through a threaded buckle, and the lower end is connected to the threaded housing through a threaded buckle. The lower end of the threaded housing is connected to the lower sealing housing through a threaded buckle; a lower sealing ring is installed in the lower sealing housing;

[0018] A center tube is provided in the disc spring housing, and a threaded shaft is provided in the threaded housing; the center tube and threaded shaft are connected by an anti-drop tube;

[0019] The center tube includes an upper end tube column and a lower end tube column. A disc spring is installed in the annular space formed by the upper end tube column and the disc spring housing; a central opening is provided on the lower end tube column, and two sealing rings are installed in the annular space formed by the lower end tube column and the disc spring housing. The two sealing rings are distributed on the upper and lower sides of the central opening.

[0020] An annular groove is provided on the upper end of the center pipe column, which is used to connect the lower hydraulic chamber and the annulus when the torque transmission is disconnected. A sealing ring is installed on the upper end of the center pipe, which is used to seal the lower hydraulic chamber and the second opening of the internal flow channel of the upper joint when the torque transmission is disconnected.

[0021] In the working state of disconnecting the torque transmission, the hydraulic chamber under the piston will be connected to the one-way valve through the annular groove of the center pipe, and the one-way valve is connected to the annulus. The one-way valve allows the drilling fluid to flow only from the lower hydraulic chamber to the annulus, and the drilling fluid in the annulus cannot flow to the lower hydraulic chamber.

[0022] When the torque clutch mechanism is in the torque-engaged operating state, drilling fluid in the wellbore annulus enters the piston's upper hydraulic chamber through the first opening on the spline housing boss. Drilling fluid in the center pipe enters the piston's lower hydraulic chamber through the opening in upper connector shaft segment V. A stuck drill monitoring tool is installed above the screw drill. The drilling fluid pressure within the tool is higher than the annular pressure, and the fluid pressure in the piston's lower hydraulic chamber is higher than that in the upper hydraulic chamber. The piston generates an upward thrust, which is transmitted to the friction plate through the push rod. The friction plate presses the friction plates together, achieving torque transmission. When the center pipe moves to its uppermost position, the sealing nut sleeve and the sealing ring at the upper end of the center pipe form a seal, blocking the second opening in upper connector shaft segment V.

[0023] When the torque clutch mechanism is in the torque-engaged working state, the center pipe moves to the uppermost position, and the hydraulic chamber under the piston is connected to the one-way valve through the annular groove of the center pipe. The one-way valve is connected to the annulus. The one-way valve allows the drilling fluid to flow only from the lower hydraulic chamber to the annulus, and the drilling fluid in the annulus cannot flow into the lower hydraulic chamber.

[0024] The torque clutch mechanism uses multiple friction plates to transmit torque. The clamping force between the friction plates comes from the hydraulic pressure acting on the piston. The engagement and disengagement of the torque clutch is controlled by the position of the center tube.

[0025] The center tube moves up and down with the threaded shaft. When it reaches the uppermost position, the center tube changes the flow path of the drilling fluid in the hydraulic chamber below the piston. The drilling fluid in the hydraulic chamber below the piston is connected to the drilling fluid in the annulus instead of the drilling fluid inside the upper joint. The torque clutch realizes torque separation. When the center tube is in other positions, the torque clutch mechanism realizes torque connection.

[0026] A drill bit stuck or drill bit jam monitoring method is disclosed, specifically, during normal drilling, by monitoring the drill string torque, the torque fluctuates within a certain range, and the fluctuation amplitude is smaller than that when the drill bit stuck or drill bit jam monitoring tool is not used; when the drill string torque is monitored to increase on the ground, and then suddenly decreases after increasing to the limit torque set by the tool, and the limit torque set by the tool is less than the ultimate strength of the drill string, it indicates that the drill bit is stuck or the drill string is stuck. The drill string is slowly lifted. If the drill string can be lifted, it indicates that the drill bit is stuck. If the drill string cannot be lifted, it indicates that the drill bit is stuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is an overall cross-sectional view of the present invention:

[0029] Figure 2 This is a schematic diagram of the joint structure of the present invention:

[0030] Figure 3 This is a schematic diagram of the spline housing structure of the present invention:

[0031] Figure 4 This is a schematic diagram of the central tube structure of the present invention:

[0032] Figure 5 This is a schematic diagram of the center tube and piston in the initial state of the present invention:

[0033] Figure 6 This is a schematic diagram of the center tube and piston in the torque transmission disconnected state of the present invention.

[0034] In the figure: 1-upper joint, 2-upper sealing ring, 3-upper sealing shell, 4-thrust string bearing, 5-bearing housing, 6-bearing inner ring fixing nut, 7-friction plate inner disk, 8-friction plate outer disk, 9-pressure plate, 10-push rod, 11-spline housing, 12-piston spring, 13-piston, 14-piston sealing ring, 15-sealing nut sleeve, 16-sealing ring, 17-connecting housing, 18-check valve, 19-disc spring, 20-disc spring housing, 21-center tube, 22-sealing ring, 23-anti-drop pipe, 24-threaded housing, 25-threaded shaft, 26-lower sealing housing, 27 lower sealing ring. DETAILED DESCRIPTION

[0035] The invention is further described below with reference to the accompanying drawings. The scope of protection of the present invention is not limited to the following description:

[0036] like Figures 1-6 As shown, a drill bit stuck drill monitoring tool includes a torque clutch mechanism and a drill stuck drill monitoring mechanism; the torque clutch mechanism includes an upper joint 1, an upper sealing shell 3, an upper sealing ring 2, a bearing housing 5, a thrust string bearing 4, a bearing inner ring fixing nut 6, a spline housing 11, a friction plate inner disk 7, a friction plate outer disk 8, a pressure plate 9, a push rod 10, a piston 13, a piston sealing ring 14, a piston spring 12, a sealing nut sleeve 15, a connecting housing 17, and a one-way valve 18.

[0037] The outer diameter of the upper joint 1 decreases stepwise from top to bottom, and is described as shaft section I, shaft section II, shaft section III, shaft section IV and shaft section V in sequence;

[0038] Shaft section I is provided with a threaded box for connecting to the upper drill string;

[0039] The upper sealing ring 2 is installed in the sealing groove of the upper sealing shell 3, which is fitted onto the upper joint 1. The upper sealing ring 2 forms a seal with the surface of shaft end II of the upper joint 1. The inner ring of the thrust string bearing 4 is fitted onto shaft section III of the upper joint 1 and is positioned and fixed by the bearing inner ring retaining nut 6. The outer ring of the thrust string bearing 4 is fitted into the bearing housing 5. The thrust string bearing 4 is positioned and fixed by the threaded connection between the upper sealing shell 3 and the bearing housing 5. The upper joint 1 and the bearing housing 5 can rotate freely relative to each other.

[0040] A spline housing 11 is provided on the outer sleeve of the shaft section IV of the upper joint 1, and a boss is provided in the middle of the spline housing 11, which divides the inner space into two parts, an upper and lower part. The inner hole of the upper part is provided with an internal spline 1102, and the friction plate outer disk 8 engages with the internal spline 1102 of the spline housing 11 through the external spline; the inner hole wall of the lower part is smooth and is used to install the piston 13; an external spline is provided on the shaft section IV of the upper joint 1, and the friction plate inner disk 7 engages with the external spline of the shaft section IV of the upper joint 1 through the internal spline 1102; the friction plate inner disk 7 and the friction plate outer disk 8 are staggered to form a friction plate, and a pressure plate 9 and a push rod 10 are provided below; the push rod 10 passes through the through hole 1103 on the boss of the spline housing 11, and the two ends of the push rod 10 are respectively connected to the pressure plate 9 and the piston 13; the upper and lower ends of the spline housing 11 are connected to the bearing housing 5 and the connecting housing 17 by threads, and the friction plate transmits the torque of the upper joint 1 to the spline housing 11 through friction.

[0041] The piston 13 is provided with a sealing groove, in which a piston sealing ring 14 is provided. The piston 13 divides the smooth lower part of the inner wall of the spline housing 11 into two chambers. The upper hydraulic chamber is connected to the wellbore annulus through the first opening 1101 on the boss of the spline housing 11, and the lower hydraulic chamber is connected to the drilling fluid flow channel of the upper joint 1 through the second opening 102 on the shaft section V of the upper joint 1; the piston spring 12 is installed in the upper hydraulic chamber, and provides a downward thrust to move the piston downward when the torque transmission is disconnected.

[0042] The one-way valve 18 is mounted on the connecting housing 17;

[0043] The sealing nut sleeve 15 is installed on the shaft section V of the upper joint 1 through threads.

[0044] The drill stuck monitoring mechanism includes a disc spring housing 20, a center tube 21, a disc spring 19, an anti-drop tube 23, a sealing ring 22, a threaded housing 24, a threaded shaft 25, a lower sealing housing 26, and a lower sealing ring 27.

[0045] The upper end of the disc spring housing 20 is connected to the connecting housing 17 via a threaded buckle, and the lower end is connected to the threaded housing 24 via a threaded buckle. The lower end of the threaded housing 24 is connected to the lower sealing housing 26 via a threaded buckle; a lower sealing ring 27 is installed in the lower sealing housing 26;

[0046] A central tube 21 is provided in the disc spring housing 20, and a threaded shaft 25 is provided in the threaded housing 24; the central tube 21 and the threaded shaft 25 are connected by an anti-drop tube 23;

[0047] The center tube 21 includes an upper end tube column and a lower end tube column. A disc spring 19 is installed in the annular space formed by the upper end tube column and the disc spring housing 20; a center opening 2102 is provided on the lower end tube column, and two sealing rings 22 are installed in the annular space formed by the lower end tube column and the disc spring housing 20. The two sealing rings 22 are distributed on the upper and lower sides of the center opening 2102.

[0048] An annular groove 2101 is provided on the upper end of the central tube 21, which is used to connect the lower hydraulic chamber and the annulus when the torque transmission is disconnected. A sealing ring 16 is installed on the upper end of the central tube 21, which is used to seal the lower hydraulic chamber and the second opening 102 of the internal flow channel of the upper joint 1 when the torque transmission is disconnected.

[0049] The working process of the present invention is as follows:

[0050] Initial state: the disc spring 19 is in a pre-tightened state. Under the action of the disc spring 19, the threaded core shaft is at the bottom dead center. The drilling fluid in the internal flow channel of the tool flows into the lower hydraulic chamber of the piston 13 through the second opening 102 of the upper joint 1. The annular drilling fluid is connected to the upper hydraulic chamber of the piston 13 through the first opening 1101. The tool is installed above the screw drill bit. The internal liquid pressure of the tool is higher than the annular liquid pressure. The liquid pressure in the lower hydraulic chamber of the piston 13 is higher than that in the upper hydraulic chamber. The piston 13 generates an upward axial force. The axial force presses the friction plate through the push rod 10 and the pressure plate 9 to realize torque transmission.

[0051] Working state one: The torque transmission path is from the upper joint 1 to the friction plate, the friction plate to the spline housing 11, the spline housing 11 to the connecting housing 17, the connecting housing 17 to the disc spring housing 20, the disc spring housing 20 to the threaded housing 24, and the threaded housing 24 to the threaded shaft 25. During the drilling process, the tool rotates with the drill string system. When the drill bit counter-torque will produce violent fluctuations, the torque transmitted by the drill string exceeds the contraction torque of the threaded shaft 25 set by the tool, the axial force generated by the spiral pair is greater than the preload force of the disc spring 19, the threaded shaft 25 contracts, the drill string torque decreases, and the threaded shaft 25 extends, thereby achieving the function of reducing drill bit vibration.

[0052] Working state two: When the drill bit is stuck or jammed, the drill bit stops rotating, the drill string torque continues to increase, the threaded shaft 25 contracts, driving the anti-drop pipe 23 and the center pipe 21 to move upward. When the threaded shaft 25 contracts to the limit position, the sealing ring on the center pipe 21 seals the second opening 102 of the upper joint 1, and the hydraulic chamber under the piston is connected to the annulus. The liquid pressure in the hydraulic chamber under the piston is reduced to the same as that in the annulus. The piston moves downward under the action of the spring 12, the friction plate is relaxed, the tool disconnects the torque transmission, and the ground monitoring torque suddenly decreases, realizing the drill string protection and jamming and jamming functions.

[0053] Working state three: After the torque transmission is disconnected, the drill string is lifted, and the center pipe 21, the anti-drop pipe 23 and the threaded shaft 25 move downward under the action of the disc spring 19. The second opening 102 of the upper joint 1 is reopened, and the passage between the hydraulic chamber under the piston and the annulus is closed. The liquid pressure in the hydraulic chamber under the piston is restored, and the piston 13 generates axial force to press the friction plate to realize the recovery of torque transmission.

[0054] Using the above tool, a drill bit stuck or drill drill monitoring method is provided. Specifically, during normal drilling, by monitoring the drill string torque, the torque fluctuates within a certain range, and the fluctuation amplitude is smaller than the amplitude when the drill bit stuck or drill drill monitoring tool is not used. When the drill string torque is monitored to increase on the ground, the torque suddenly decreases after increasing to the limit torque set by the tool. The limit torque set by the tool is less than the limit strength of the drill string, indicating that the drill bit is stuck or the drill string is stuck. The drill string is slowly lifted. If the drill string can be lifted, it indicates that the drill bit is stuck. If the drill string cannot be lifted, it indicates that the drill bit is stuck.

Claims

1. A drill bit jam monitoring tool, characterized by: Including torque clutch mechanism and drill jam monitoring mechanism; The torque clutch mechanism comprises an upper joint (1), an upper sealing shell (3), an upper sealing ring (2), a bearing housing (5), a thrust string bearing (4), a bearing inner ring fixing nut (6), a spline housing (11), a friction plate inner disk (7), a friction plate outer disk (8), a pressure plate (9), a push rod (10), a piston (13), a piston sealing ring (14), a piston spring (12), a sealing nut sleeve (15), a connecting housing (17), and a one-way valve (18); The outer diameter of the upper joint (1) decreases stepwise from top to bottom, and is described as shaft section I, shaft section II, shaft section III, shaft section IV and shaft section V in sequence; Shaft section I is provided with a threaded box for connecting to the upper drill string; The upper sealing ring (2) is installed in the sealing groove of the upper sealing shell (3), and the upper sealing shell (3) is sleeved on the upper joint (1). The upper sealing ring (2) forms a seal with the surface of the shaft end II of the upper joint (1); the inner ring of the thrust string bearing (4) is sleeved on the shaft section III of the upper joint (1) and is positioned and fixed by the bearing inner ring fixing nut (6); the outer ring of the thrust string bearing (4) is sleeved in the bearing housing (5), and the thrust string bearing (4) is positioned and fixed by the upper sealing shell (3) and the bearing housing (5) being threadedly connected. The upper joint (1) and the bearing housing (5) can rotate freely relative to each other; The shaft section IV of the upper joint (1) is covered with a spline housing (11), and a boss is provided in the middle of the spline housing (11), which divides the inner space into two parts, an upper part and an lower part. The inner hole of the upper part is provided with an inner spline (1102), and the outer disc of the friction plate (8) is engaged with the inner spline (1102) of the spline housing (11) through the outer spline; the inner hole wall of the lower part is smooth and is used to install the piston (13); the shaft section IV of the upper joint (1) is provided with an outer spline, and the inner disc of the friction plate (7) is engaged with the shaft section IV of the upper joint (1) through the inner spline (1102). The inner friction plate (7) and the outer friction plate (8) are staggeredly installed to form a friction plate, and a pressure plate (9) and a push rod (10) are provided below. The push rod (10) passes through the through hole (1103) on the boss of the spline housing (11). The two ends of the push rod (10) are respectively connected to the pressure plate (9) and the piston (13); the upper and lower ends of the spline housing (11) are respectively connected to the bearing housing (5) and the connecting housing (17) through threads. The friction plate transmits the torque of the upper joint (1) to the spline housing (11) through friction force. The piston (13) is provided with a sealing groove, in which a piston sealing ring (14) is provided. The piston (13) divides the smooth lower portion of the inner wall of the spline housing (11) into two chambers. The upper hydraulic chamber is connected to the wellbore annulus through a first opening (1101) on the boss of the spline housing (11), and the lower hydraulic chamber is connected to the drilling fluid flow channel of the upper joint (1) through a second opening (102) on the shaft section V of the upper joint (1). The piston spring (12) is installed in the upper hydraulic chamber and provides a downward thrust to move the piston downward in the torque transmission disconnected working state. A one-way valve (18) is mounted on the connecting housing (17); The sealing nut sleeve (15) is installed on the shaft section V of the upper joint (1) through threads; The drill stuck monitoring mechanism comprises a disc spring housing (20), a center tube (21), a disc spring (19), an anti-drop tube (23), a sealing ring (22), a threaded housing (24), a threaded shaft (25), a lower sealing housing (26), and a lower sealing ring (27); The upper end of the disc spring housing (20) is connected to the connecting housing (17) through a threaded buckle, and the lower end is connected to the threaded housing (24) through a threaded buckle. The lower end of the threaded housing (24) is connected to the lower sealing housing (26) through a threaded buckle; a lower sealing ring (27) is installed in the lower sealing housing (26); A central tube (21) is provided in the disc spring housing (20), and a threaded shaft (25) is provided in the threaded housing (24); the central tube (21) and the threaded shaft (25) are connected via an anti-drop tube (23); The center tube (21) includes an upper tube column and a lower tube column, wherein a disc spring (19) is installed in an annular space formed by the upper tube column and the disc spring housing (20); a center opening (2102) is provided on the lower tube column, and two sealing rings (22) are installed in the annular space formed by the lower tube column and the disc spring housing (20), and the two sealing rings (22) are distributed on the upper and lower sides of the center opening (2102); The upper end of the central tube (21) is provided with an annular groove (2101) for connecting the lower hydraulic chamber and the annulus when the torque transmission is disconnected. A sealing ring (16) is installed on the upper end of the central tube (21) for sealing the lower hydraulic chamber and the second opening (102) of the internal flow channel of the upper joint (1) when the torque transmission is disconnected.

2. A drill bit jam monitoring method, characterized in that: A drill bit jam monitoring tool according to claim 1 is used; During normal drilling, by monitoring the drill string torque, the torque fluctuates within the set range, and the fluctuation amplitude is smaller than that when the drill bit jamming and sticking monitoring tool is not used. When the drill string torque is monitored to increase on the ground, it suddenly decreases after increasing to the limit torque set by the tool. The limit torque set by the tool is less than the ultimate strength of the drill string, indicating that the drill bit is jammed or stuck. Slowly lift the drill string. If the drill string can be lifted, it means that the drill bit is jammed. If the drill string cannot be lifted, it means that the drill bit is stuck.

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