Well wall insert detecting and fishing tool

Abstract

The well wall insert detecting and fishing tool comprises an upper connector, a mandrel and a lower connector which are of a barrel structure, the upper connector is connected with the lower connector through the mandrel, a mounting cavity is formed in the upper connector, the mandrel and the lower connector, a transmission shaft is arranged in the mounting cavity, and the head end and the tail end of the transmission shaft are connected with a flow regulator and a low-speed motor respectively. A plurality of through holes with gradually increased apertures are uniformly distributed in the periphery of the upper joint at the position of the flow regulator, the through holes are communicated with a water eye hole of the fishing tool and the outer annulus, the periphery of the mandrel is sleeved with an annular battery and a metal detector, and the annular battery is electrically connected with the metal detector and the low-speed motor; a protection device is arranged on the periphery of the annular battery and the metal detector, the tail end of the lower connector is connected with a strong magnet, and a magnet is installed on the strong magnet. The tool can detect the embedded falling objects on the well wall, converts a detection signal into a mud pulse signal, transmits the mud pulse signal to a wellbay, and carries out real-time salvage operation under the condition of not pulling out a drill, so that the integrated operation of detection and salvage is realized.

Description

Technical Field

[0001] The invention relates to a tool for detecting and salvaging objects embedded in a well wall, belonging to the technical field of downhole detection and salvaging equipment in oil well drilling and repairing operations. Background Art

[0002] With the continuous development of oil drilling tools, countless new drilling tools have been put into use underground. However, these new tools also bring with them new underground accidents. Some tools, after an accident, do not simply fall to the bottom of the well as usual, but become embedded in the wellbore wall. For example, if the roller of a reamer falls, it may become pressed into the wellbore wall. Embedded objects in the wellbore wall can cause pipe sticking and hinder casing and cementing operations.

[0003] On the one hand, we don’t know when the fallen parts embedded in the well wall fell, so we can’t determine where they are embedded. It is very difficult to find an embedded object in a well several thousand meters deep. On the other hand, there are currently no special salvage tools for this kind of underground accident. The well team cannot salvage it in time and can only find a special salvage team.

[0004] Traditional salvage methods rely primarily on physical detection, detecting changes in physical parameters of the downhole environment to determine the location of embedded objects in the well wall. For example, downhole cameras can be used for direct imaging, or ultrasonic detection technology can be used to determine the approximate location of the object based on reflected waves.

[0005] Due to the depth of the well, downhole signals cannot be transmitted wirelessly to the surface. Therefore, the above-mentioned detection equipment needs to be sent in by cable. After detecting the embedded object, the location is recorded, and then the salvage tool is lowered for salvage. Therefore, the traditional salvage method has the following disadvantages:

[0006] 1. Not every drilling team is equipped with specialized detection equipment. After an accident occurs, they can only seek help from a professional salvage team, which greatly increases the time and cost of handling the accident.

[0007] 2. The detection equipment requires cables to transmit signals, so it can only be sent in by cables. The cables cannot withstand excessive forces and operations such as circulating mud, resulting in the detection and salvage being divided into two steps. The operation is cumbersome and not conducive to completing the salvage task. Summary of the Invention

[0008] The present invention aims to provide a tool for detecting and recovering embedded objects in well walls. The tool can detect embedded objects in well walls, convert the detection signal into a mud pulse signal, transmit it to the well platform, and perform real-time recovery operations without starting drilling, thus achieving integrated detection and recovery operations.

[0009] The technical solution of the present invention is as follows: a well wall inlay detection and salvage tool, comprising an upper joint, a core shaft and a lower joint with a cylindrical structure, the upper joint being connected to the lower joint via the core shaft, and an installation chamber is formed inside the three, a transmission shaft is provided in the installation chamber, the head and tail ends of the transmission shaft are respectively connected to a flow regulator and a low-speed motor, a plurality of through holes with gradually increasing apertures are evenly distributed around the upper joint where the flow regulator is located, the through holes connect the water eye and the outer annulus of the salvage tool, an annular battery and a metal detector are sleeved on the outer periphery of the core shaft, the annular battery is electrically connected to the metal detector and the low-speed motor, a protective device is also provided on the outer periphery of the annular battery and the metal detector, the tail end of the lower joint is connected to a strong magnet, and a magnet is installed on the strong magnet.

[0010] In the aforementioned well wall inlay detection and salvage tool, the flow regulator includes a slider that rotates therewith, and the through holes at different positions can be blocked during the rotation of the slider.

[0011] In the aforementioned well wall inlay detection and salvage tool, one end of the upper joint of the core shaft protrudes from the inner wall of the upper joint, so that the connection between the two forms a step-type structure. A thrust bearing and a sealing ring are sleeved on the transmission shaft from the flow regulator to the step-type structure. The sealing ring is provided with inner and outer sealing grooves, in which a rotating sealing ring is installed.

[0012] In the aforementioned well wall inlay detection and salvage tool, the protective device includes a sealing cover sleeved on the outer periphery of the annular battery and the metal detector, the two ends of the sealing cover are supported on the outer walls of the upper joint and the lower joint, and protective covers are also sleeved on the outer periphery of the two ends of the sealing cover.

[0013] In the aforementioned well wall inlay detection and salvage tool, the sealing cover is made of acrylic material; and the protective cover is a birdcage structure.

[0014] In the aforementioned well wall inlay detection and salvage tool, the core shaft is provided with a semicircular hole communicating with the inside and outside.

[0015] In the aforementioned well wall inlay detection and salvage tool, a motor fixing plate is arranged between the tail end of the transmission shaft and the low-speed motor, the housing of the low-speed motor is fixedly connected to the motor fixing plate, and its output shaft passes through the motor fixing plate and is connected to the transmission shaft. The motor fixing plate is provided with a male spline, which cooperates with the female spline on the inner wall of the lower joint, and a semicircular groove is also provided on the motor fixing plate.

[0016] In the aforementioned well wall inlay detection and salvage tool, the strong magnet is provided with semicircular arcs in four directions, and a ring-shaped magnet is fixed on each semicircular arc.

[0017] In the aforementioned well wall inlay detection and salvage tool, the upper joint, the core shaft and the lower joint, as well as the lower joint and the strong magnet are all connected together by threads.

[0018] The beneficial effects of the present invention are as follows: In oil drilling operations, time is money. Timely salvage operations can reduce drilling downtime caused by accidents such as dropped downhole tools, prevent downhole accidents from escalating, and prevent well wall collapse, loss of control of downhole fluids, and other situations. Therefore, it is particularly important to equip appropriate salvage tools in advance. Compared with existing technologies, the present invention has the following advantages:

[0019] 1. The present invention converts electrical signals into mud pulse signals through ingenious design, solving the problem that downhole signals are difficult to transmit to the well platform.

[0020] 2. The technical solution of the present invention integrates detection and salvage in one, and can complete both detection and salvage operations simultaneously with just one drilling, thus shortening the entire salvage time by half.

[0021] Currently, there are no specialized tools for detecting inlaid objects in well walls. Instead, exploration equipment is used. This is a complete set of equipment that is expensive and requires specialized personnel to operate, making it impossible to equip every well crew. The tool of the present invention is simple to operate, reliable in performance, and low in manufacturing cost. It can be equipped in advance to every well crew, allowing for timely salvage after an accident.

[0022] 4. The tool of the present invention greatly simplifies the salvage process of well wall inlays and reduces the salvage cost. It will become an essential tool in the oil drilling process and has a broad market prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure;

[0025] Figure 3 for Figure 2 AA-direction cross-sectional structural diagram;

[0026] Figure 4 for Figure 2 BB-direction cross-sectional structural diagram;

[0027] Figure 5 for Figure 2 CC-direction cross-sectional structural diagram;

[0028] Figure 6 for Figure 2 DD-direction cross-sectional structural diagram;

[0029] Figure 7 It is the salvage principle diagram of the present invention.

[0030] Figure numerals: 1. upper connector; 2. flow regulator; 3. thrust bearing; 4. sealing ring; 5. protective cover; 6. sealing cover; 7. annular battery; 8. metal detector; 9. transmission shaft; 10. spindle; 11. motor fixing plate; 12. low-speed motor; 13. lower connector; 14. strong magnet; 15. magnet; 16. through hole; 17. slider; 18. semicircular hole; 19. male spline; 20. semicircular groove; 21. semicircular arc. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and examples, but they are not intended to limit the present invention.

[0032] An embodiment of the present invention: A well wall inlay detection and salvage tool includes an upper joint 1, a core shaft 10 and a lower joint 13 with a cylindrical structure. The upper joint 1 is connected to the lower joint 13 via the core shaft 10, and an installation chamber is formed inside the three. A transmission shaft 9 is provided in the installation chamber. The head and tail ends of the transmission shaft 9 are respectively connected to a flow regulator 2 and a low-speed motor 12. A plurality of through holes 16 with gradually increasing apertures are evenly distributed around the upper joint 1 at the position of the flow regulator 2. The through holes 16 connect the water eyelet and the outer annulus of the salvage tool. An annular battery 7 and a metal detector 8 are sleeved on the outer periphery of the core shaft 10. The annular battery 7 is electrically connected to the metal detector 8 and the low-speed motor 12. A protective device is also provided on the periphery of the annular battery 7 and the metal detector 8. The tail end of the lower joint 13 is connected to a strong magnet 14, and a magnet 15 is installed on the strong magnet 14.

[0033] The working principle of the salvage tool of the present invention is as follows: the metal detector 8 and the low-speed motor 12 are powered by the annular battery 7. When the metal detector 8 passes over a well wall inlay, eddy currents are induced inside the inlay. The receiving coil of the metal detector 8 detects the change in this reverse magnetic field and converts it into an electrical signal. This electrical signal opens the path of the low-speed motor 12, and the low-speed motor 12 starts to operate. Its output shaft drives the transmission shaft 9 to rotate, which in turn drives the flow regulator 2 to rotate. This rotation disturbs the mud ejected through the through holes 16 of different aperture sizes. The disturbance is converted into a pulse signal, which is captured by the drilling rig pressure sensor and displayed on the drilling rig console as a change in the positive waveform, allowing the driller to know the location of the well wall inlay. By increasing the mud discharge rate, the high-speed mud jet ejected from the different through holes 16 destroys the rock around the well wall inlay, thereby flushing the well wall inlay out. When the well wall inlay falls out, it is attracted by the magnet 15 below the tool, completing the salvage operation.

[0034] There are multiple through holes 16 with gradually increasing apertures evenly distributed on the upper joint 1. The through holes 16 connect the tool water eye and the outer annulus. The flow regulator 2 is provided with a slider 17 that rotates with the regulator. The slider 17 rotates at a uniform speed on the circumference of the inner hole along with the flow regulator 12, continuously forming a seal with different through holes 16. Due to the different apertures of the through holes 16, the mud discharge volume will change differently when sealing with each hole, resulting in continuous changes in the internal pressure, forming a pulse signal, and the instrument on the drilling rig operating table can display the periodic changes in the internal pressure.

[0035] One end of the mandrel 10 protrudes from the inner wall of the upper joint 1, forming a stepped structure at the connection between the two. A thrust bearing 3 and a sealing ring 4 are sleeved onto the transmission shaft 9 from the flow regulator 2 to the stepped structure. Mud pressure exerts thrust on the flow regulator 2, hindering its rotation. The thrust bearing 3 minimizes the rotational resistance of the flow regulator 2. The sealing ring 4 is provided with inner and outer sealing grooves, each containing a rotating seal ring, which prevents mud from entering the internal mounting chamber and damaging the annular battery 7, metal detector 8, and low-speed motor 12.

[0036] The protective device includes a sealing cover 6 sleeved on the outer periphery of the annular battery 7 and the metal detector 8. The two ends of the sealing cover 6 are supported on the outer walls of the upper connector 1 and the lower connector 13. The outer periphery of the two ends of the sealing cover 6 is also sleeved with a protective cover 5.

[0037] The sealing cover 6 is made of acrylic material. Acrylic material is an insulating material with no free electrons inside, so it will not isolate electromagnetic signals and can also play a sealing and pressure-bearing role.

[0038] The protective cover 5 is used to protect the sealing cover 6 from impact. Its shape is like a birdcage, which can protect the sealing cover 6 without affecting the electromagnetic signal of the metal detector 8.

[0039] The spindle 10 is used to connect the upper and lower joints and install the annular battery 7 and the metal detector 8. A semicircular hole 18 connecting the inside and outside is provided on the spindle 10 for laying and passing the lines between the annular battery 7, the metal detector 8 and the low-speed motor 12.

[0040] A motor fixing plate 11 is provided between the tail end of the transmission shaft 9 and the low-speed motor 12. The housing of the low-speed motor 12 is fixedly connected to the motor fixing plate 11, and its output shaft passes through the motor fixing plate 11 and is connected to the transmission shaft 9. The motor fixing plate 11 is provided with a male spline 19, and the male spline 19 cooperates with the female spline on the inner wall of the lower joint 13 to fix the low-speed motor 12 to prevent the motor housing from rotating during the rotation of the output shaft of the low-speed motor 12. A semicircular groove 20 is also provided on the motor fixing plate 11 for cooperating with the semicircular hole 18 for passing the circuit of the low-speed motor 12.

[0041] The strong magnet 14 is provided with semicircular arcs 21 on all four sides, each of which is secured with a ring-shaped magnet 15. No matter which direction an inlaid object falls from the well wall, it will be caught by the magnet 15. The arc-shaped structure of the strong magnet 14 protects the caught object from colliding with the well wall during the ascent, preventing it from falling during the drilling process.

[0042] The upper joint 1, the spindle 10 and the lower joint 13, as well as the lower joint 13 and the strong magnet 14 are all connected together by threads, which facilitates the installation and disassembly of parts.

Claims

1. A tool for detecting and salvaging inlaid objects in a well wall, characterized by: The invention comprises an upper joint (1), a core shaft (10) and a lower joint (13) of a cylindrical structure. The upper joint (1) is connected to the lower joint (13) via the core shaft (10). The three of them form an installation chamber. A transmission shaft (9) is provided in the installation chamber. The head and tail ends of the transmission shaft (9) are respectively connected to a flow regulator (2) and a low-speed motor (12). A plurality of through holes (16) with gradually increasing apertures are evenly distributed around the upper joint (1) at the position where the flow regulator (2) is located. The through holes (16) are connected to the water eye of the salvage tool and the outer annulus. An annular battery (7) and a metal detector (8) are sleeved on the outer periphery of the core shaft (10). The annular battery (7) is electrically connected to the metal detector (8) and the low-speed motor (12). Protective devices are also provided on the outer peripheries of the annular battery (7) and the metal detector (8). The tail end of the lower joint (13) is connected to a strong magnet (14). A magnet (15) is installed on the strong magnet (14).

2. A well wall inlay detection and salvage tool according to claim 1, characterized in that: The flow regulator (2) includes a slider (17) that rotates therewith, and the slider (17) can block the through holes (16) at different positions during the rotation process.

3. The well wall inlay detection and salvage tool according to claim 1, characterized in that: One end of the spindle (10) protrudes from the inner wall of the upper joint (1), so that the connection between the two forms a step-type structure. A thrust bearing (3) and a sealing ring (4) are sleeved on the transmission shaft (9) from the flow regulator (2) to the step-type structure. The sealing ring (4) is provided with inner and outer sealing grooves, in which a rotating sealing ring is installed.

4. The well wall inlay detection and salvage tool according to claim 1, characterized in that: The protective device comprises a sealing cover (6) sleeved on the outer periphery of the annular battery (7) and the metal detector (8), the two ends of the sealing cover (6) being supported on the outer walls of the upper joint (1) and the lower joint (13), and protective covers (5) being sleeved on the outer periphery of the two ends of the sealing cover (6).

5. A well wall inlay detection and salvage tool according to claim 4, characterized in that: The sealing cover (6) is made of acrylic material; the protective cover (5) is a birdcage structure.

6. The well wall inlay detection and salvage tool according to claim 1, characterized in that: The core shaft (10) is provided with a semicircular hole (18) communicating with the inside and outside.

7. The well wall inlay detection and salvage tool according to claim 1, characterized in that: A motor fixing plate (11) is provided between the tail end of the transmission shaft (9) and the low-speed motor (12). The housing of the low-speed motor (12) is fixedly connected to the motor fixing plate (11). The output shaft thereof passes through the motor fixing plate (11) and is connected to the transmission shaft (9). The motor fixing plate (11) is provided with a male spline (19), which cooperates with a female spline on the inner wall of the lower joint (13). A semicircular groove (20) is also provided on the motor fixing plate (11).

8. The well wall inlay detection and salvage tool according to claim 1, characterized in that: The strong magnet (14) is provided with semicircular arcs (21) in four directions, and a magnet (15) with an annular structure is fixed on each semicircular arc (21).

9. The well wall inlay detection and salvage tool according to claim 1, characterized in that: The upper joint (1), the spindle (10) and the lower joint (13), as well as the lower joint (13) and the strong magnet (14) are all connected together via threads.

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