Coring tool capable of monitoring length of core entering cylinder

Abstract

The invention belongs to the technical field of oil and gas drilling, and particularly relates to a coring tool capable of monitoring the length of a core entering a cylinder. The coring tool comprises an outer cylinder, an inner cylinder arranged in the outer cylinder, a drill bit arranged at the lower end of the outer cylinder and a core locking mechanism arranged at the lower end of the inner cylinder, and further comprises a beacon arranged in the inner cylinder in an axial sliding mode; and the monitoring module is fixedly arranged at the top of the inner cylinder and can measure the distance between the monitoring module and the beacon. The length of the rock core entering the shaft can be monitored.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas drilling, and in particular relates to a coring tool capable of monitoring the length of a core entering a barrel. Background Art

[0002] Drilling coring is the only way to provide original specimens of stratigraphic sections deep in the earth's crust and the most ideal means to obtain the lithology and reservoir characteristics of underground rock formations. The fundamental purpose of drilling coring is to discover and evaluate oil and gas reservoirs.

[0003] Coring is done using coring tools that drill holes in the earth, cut the formation into columns (called cores) and carry them to the surface.

[0004] During the coring operation, the core is blocked somewhere in the inner barrel (commonly known as "core blockage") due to formation fragmentation, tool performance, human operation and other reasons. In this case, when coring drilling continues, the formation at the drill bit mouth cannot enter the inner barrel due to resistance, causing the formation to be eroded without becoming a core column, that is, the core cannot enter the inner barrel. In most cases, coring engineers cannot determine whether the bottom hole core has entered the inner barrel through on-site drilling parameters, drilling tool torque swing amplitude, riser pressure and other data, and they cannot confirm the length of the core that has entered the inner barrel. Summary of the invention

[0005] In view of the technical problem mentioned above, the present invention aims to provide a coring tool, which can monitor the length of the core entering the wellbore.

[0006] According to the present invention, a coring tool is provided, comprising an outer cylinder, an inner cylinder arranged inside the outer cylinder, a drill bit arranged at the lower end of the outer cylinder, and a core locking mechanism arranged at the lower end of the inner cylinder, the coring tool also comprising:

[0007] A beacon, wherein the beacon is slidably arranged in the inner cylinder along the axial direction;

[0008] A monitoring module is fixedly arranged on the top of the inner cylinder and can measure the distance between the monitoring module and the beacon.

[0009] In addition to meeting the requirements of conventional coring operations, the present invention can also monitor the length of the core entering the barrel online.

[0010] In a specific embodiment, the monitoring module includes a signal transmitter and a signal receiver, and both the signal transmitter and the signal receiver point to the beacon.

[0011] The signal transmitter can transmit a signal in the direction of the beacon. The signal transmitted by the signal transmitter reaches the signal reflection part of the beacon and then reflects back. The signal receiver can receive the reflected signal. A calculation module is provided in the monitoring module, which can calculate the transmission and reception feedback of the signal, obtain the distance from the beacon to the monitoring module, and then obtain the position information of the core, that is, the length of the core entering the inner tube.

[0012] In a preferred embodiment, the monitoring module is connected to the pulse transmitter, and the core position information obtained by the monitoring module is transmitted to the ground receiving device through the pulse transmitter. In this process, the pulse transmitter converts the calculation result of the calculation module of the monitoring module into an analog signal, and feeds the analog signal back to the ground receiving device through the drilling fluid circulating in the well.

[0013] The staff can judge the core entry status based on whether the actual footage is consistent with the length of the core entering the inner tube, so as to deal with abnormal core entry situations in time and ensure the length of the core entering the tube.

[0014] During the drilling process of the coring tool, if the actual footage is inconsistent with the length of the core entering the inner barrel, it is very likely that a core blockage accident has occurred, and the staff can take corresponding measures in time. When the coring tool is pulled up after coring, if the core locking mechanism fails to fix the core, it may cause the core to fall into the well. In this case, the beacon will move downward, and the monitoring module can monitor the displacement of the beacon, providing a basis for subsequent remedial operations such as salvaging the core.

[0015] In a specific embodiment, a suspension assembly is disposed in the outer cylinder, and the inner cylinder is connected to the outer cylinder via the suspension assembly.

[0016] In a specific embodiment, the monitoring module is disposed between the suspension assembly and the inner tube, the upper portion of the monitoring module is fixedly connected to the suspension assembly, and the lower portion of the monitoring module is fixedly connected to the inner tube.

[0017] In a specific embodiment, the lower end of the monitoring module extends to the interior of the inner cylinder.

[0018] In a specific embodiment, the monitoring module and the inner tube are connected to each other by threaded connection.

[0019] An external thread is arranged at the lower end of the monitoring module, and an internal thread is arranged at the upper end of the inner tube. The monitoring module and the inner tube are connected to each other by thread connection.

[0020] In a specific embodiment, the maximum outer diameter of the monitoring module is equal to the outer diameter of the inner tube. The outer diameter of the middle part of the monitoring module is the largest, and the maximum outer diameter is equal to the outer diameter of the inner tube.

[0021] In a specific embodiment, an upper joint is fixedly provided on the upper end of the outer cylinder.

[0022] The upper end of the upper joint is used to connect the upper drilling tool, and the lower part is fixedly connected to the suspension assembly, and then connected to the inner tube. The upper joint is connected to the outer tube through a special buckle.

[0023] In a specific embodiment, an internal thread is provided at the upper end of the outer cylinder, an external thread is provided at the lower end of the upper joint, and the lower end of the upper joint extends into the interior of the outer cylinder and is connected by threads.

[0024] After the upper joint is connected to the upper drilling tool, it can be driven by the drilling tool to rotate the outer cylinder and transmit the torque to the drill bit for coring at the lower end of the outer cylinder, so that the drill bit can rotate and cut the formation to form a columnar core.

[0025] In a specific embodiment, the beacon includes a contact portion, a main body and a signal reflecting portion, and the signal reflecting portion and the contact portion are respectively arranged at upper and lower ends of the main body.

[0026] The main body is cylindrical, and its diameter is smaller than the inner diameter of the inner tube. The signal reflecting part and the contact part are both set in a disc shape, and the diameters of the signal reflecting part and the contact part are both larger than the diameter of the main body. The beacon is connected to the inner tube in a sliding manner through the contact part and the signal reflecting part, so that the beacon can move axially within the entire length range of the inner tube.

[0027] The lower end of the contact portion of the beacon is a flat surface for contacting with the drilled core. In this embodiment, initially, the coring tool drills downward in a vertical downward posture, so the beacon is located at the lowest end of the inner cylinder under the action of gravity. After the core drilled by the coring tool enters the inner cylinder, the upper end surface of the core contacts the contact portion, thereby pushing the beacon to move upward, changing the depth position of the beacon in the inner cylinder.

[0028] Compared with the prior art, the advantages of the present application are as follows.

[0029] The present invention sets a monitoring module on the top of the inner tube, and sets a beacon in a sliding manner inside the inner tube. The monitoring module can monitor the distance to the beacon. During operation, after the core enters the inner tube, it will push the beacon upward, thereby shortening the distance between the beacon and the monitoring module. Through the change in the position of the beacon, the length of the core entering the inner tube can be known. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be described below with reference to the accompanying drawings.

[0031] Figure 1 A schematic diagram of an embodiment of a coring tool according to the present invention is shown.

[0032] In the figure:

[0033] 1. Outer cylinder;

[0034] 2. Inner tube;

[0035] 3. Drill bit;

[0036] 4. Locking core mechanism;

[0037] 5. beacon; 51. contact part; 52. main body; 53. signal reflection part;

[0038] 6. Monitoring module;

[0039] 7. Suspension assembly;

[0040] 8. Upper joint;

[0041] 9. Core;

[0042] 100. Coring tool.

[0043] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0044] The present invention will be described below with reference to the accompanying drawings.

[0045] It should be noted that, in the present application, the direction close to the wellhead after the present invention enters the well is described as "up" or similar terms, and the direction away from the wellhead is described as "down" or similar terms.

[0046] In the present application, "axial direction" refers to the direction of the central axis of the inner cylinder 2 of the present invention.

[0047] The above directional description is not intended to limit the absolute positions of the components involved, but may vary according to specific circumstances.

[0048] Figure 1 The structure of a coring tool 100 according to the present invention is shown.

[0049] like Figure 1 As shown, the coring tool includes an outer tube 1, an inner tube 2, a drill bit 3 and a core locking mechanism 4.

[0050] The outer tube 1 and the inner tube 2 are both cylindrical, the inner tube 2 is sleeved inside the outer tube 1 , and the length of the inner tube 2 is smaller than that of the outer tube 1 .

[0051] The drill bit 3 is annular as a whole and is arranged at the lower end of the outer cylinder 1 for drilling the core 9. When the outer cylinder 1 rotates under the drive of external force, it can drive the drill bit 3 to rotate, thereby drilling in the formation, and the rock in the formation is cut by the drill bit 3 to form a cylindrical core 9. At the same time, the outer cylinder 1 and the drill bit 3 continuously move downward, so that the core 9 enters the inner cylinder 2.

[0052] The core locking mechanism 4 is arranged at the lower end of the inner cylinder 2 and is located inside the outer cylinder 1. During operation, the outer cylinder 1 drives the drill bit 3 to rotate, and the drill bit 3 drills the formation to drill a cylindrical core 9. At the same time, the coring tool 100 moves downward along the axial direction as a whole, so that the drilled core 9 passes through the core locking mechanism 4 and enters the inner cylinder 2. Finally, the core locking mechanism 4 cuts off the core 9 and locks it in the inner cylinder 2, completing the coring.

[0053] It is easy to understand that the outer tube 1, the inner tube 2, the drill bit 3 and the core locking mechanism 4 are prior arts, and are not the technical points of the present invention. The specific structure and working principle of obtaining the core 9 and cutting the core 9 can refer to the prior art and will not be repeated here.

[0054] In one embodiment of the present invention, the coring tool 100 further includes a beacon 5 and a monitoring module 6. The beacon 5 is axially slidably arranged in the inner tube 2. The monitoring module 6 is fixedly arranged on the top of the inner tube 2 and can measure the distance between it and the beacon 5. In addition to meeting the requirements of conventional coring operations, the present invention can also monitor the length of the core 9 entering the tube online.

[0055] Under this setting, in the initial state, when the coring tool 100 has not yet drilled the core 9, the beacon 5 is located at the lowermost end of the inner tube 2. Specifically, the maximum outer diameter of the beacon 5 is smaller than the inner diameter of the inner tube 2 and larger than the inner diameter of the core locking mechanism 4, and the core locking mechanism 4 can prevent the beacon 5 from escaping from the lower end of the inner tube 2. In the working state, when the coring tool 100 starts to drill into the formation to obtain the core 9, the core 9 enters the inner tube 2 and abuts against the lower end surface of the beacon 5. The core 9 continuously extends into the inner tube 2, so that the beacon 5 moves upward relative to the inner tube 2. Therefore, by measuring the distance of the beacon 5 by the monitoring module 6, the length of the core 9 entering the inner tube 2 can be obtained. The staff can judge the entry state of the core 9 based on whether the actual footage (the actual depth of the coring tool 100 entering the formation) is consistent with the length of the core 9 entering the inner tube 2, so as to deal with abnormal core entry in time and ensure the length of the core 9 entering the tube.

[0056] Specifically, the beacon 5 includes a contact portion 51, a main body 52 and a signal reflecting portion 53. Figure 1As shown, the signal reflecting portion 53 and the contact portion 51 are respectively arranged at the upper and lower ends of the main body 52. ​​The main body 52 is cylindrical, and its diameter is smaller than the inner diameter of the inner tube 2. The signal reflecting portion 53 and the contact portion 51 are both arranged in a disc shape, and the diameters of the signal reflecting portion 53 and the contact portion 51 are both larger than the diameter of the main body 52. ​​The beacon 5 is slidably connected with the inner tube 2 through the contact portion 51 and the signal reflecting portion 53, so that the beacon 5 can move axially within the entire length range of the inner tube 2.

[0057] The lower end of the contact portion 51 of the beacon 5 is a plane, which is used to abut against the drilled core 9. In this embodiment, initially, the coring tool 100 drills downward in a vertical downward posture, so the beacon 5 is located at the lowermost end of the inner tube 2 under the action of gravity. After the core 9 drilled by the coring tool 100 enters the inner tube 2, the upper end surface of the core 9 abuts against the contact portion 51, thereby pushing the beacon 5 to move upward, changing the depth position of the beacon 5 in the inner tube 2.

[0058] In a preferred embodiment, the outer diameter of the signal reflecting part 53 is larger than the outer diameter of the contact part 51, and the outer diameter of the contact part 51 is smaller than the inner diameter of the lock core mechanism 4, the outer diameter of the signal reflecting part 53 is larger than the inner diameter of the lock core mechanism 4, and the length of the main body 52 is adapted to the length of the lock core mechanism 4.

[0059] Under this setting, in the initial state, when the core 9 has not entered the inner tube 2, the beacon 5 is located at the lower end of the inner tube 2, that is, the signal reflecting part 53 is axially abutted against the locking core mechanism 4, thereby preventing the beacon 5 from escaping from the lower end of the inner tube 2, and the length of the main body 52 is adapted to the length of the locking core mechanism 4, so that the lower end face of the contact part 51 is flush with the lower end face of the drill bit 3, thereby ensuring that the core 9 can be drilled by the drill bit 3 and abut against the end face of the contact part 51.

[0060] The monitoring module 6 includes a signal transmitter (not shown in the figure) and a signal receiver (not shown in the figure), and both the signal transmitter and the signal receiver point to the beacon 5. The signal transmitter can transmit a signal in the direction of the beacon 5, and the signal transmitted by the signal transmitter reaches the signal reflection part 53 of the beacon 5 and then reflects back, and the signal receiver can receive the reflected signal. A calculation module is provided in the monitoring module 6, which can calculate the transmission and reception feedback of the signal, obtain the distance from the beacon 5 to the monitoring module 6, and then know the position information of the core 9, that is, the length of the core 9 entering the inner tube 2.

[0061] In a preferred embodiment, the monitoring module 6 is connected to the pulse transmitter, and the position information of the core 9 obtained by the monitoring module 6 is transmitted to the ground receiving device through the pulse transmitter. In this process, the pulse transmitter converts the calculation result of the calculation module of the monitoring module 6 into an analog signal, and feeds the analog signal back to the ground receiving device through the drilling fluid circulating in the well.

[0062] The staff can judge the entry status of the core 9 according to whether the actual footage is consistent with the length of the core 9 entering the inner tube 2, so as to deal with abnormal core entry in time and ensure the length of the core 9 entering the tube.

[0063] During the drilling process of the coring tool 100, if the actual penetration is inconsistent with the length of the core 9 entering the inner tube 2, it is very likely that a core blockage accident has occurred, and the staff can make corresponding treatment in time. When the coring tool 100 is pulled up after coring, if the core locking mechanism 4 fails to fix the core 9, the core 9 may fall into the well. In this case, the beacon 5 will move downward, and the monitoring module 6 can monitor the displacement of the beacon 5, providing a basis for subsequent remedial operations such as salvaging the core 9.

[0064] The present invention measures the position of the beacon 5 through a simple signal transmitter and a signal collector, thereby obtaining the length of the core 9 entering the inner tube 2, and sends the information to the ground through a pulse transmitter. No ground command operation is required, and the use is convenient.

[0065] It should be noted that the monitoring module 6, the pulse transmitting device, the ground receiving device, the signal transmitter, the signal receiver and the computing module are all prior art. At present, the Sperry-Sun series tools of Halliburton, the TeleScope tools of Schlumberger, the OnTrack tools of Baker Hughes, the YST-48R positive pulse wireless drilling measurement instrument of Beijing Hailan, the MWD650 mud pulse generator of Aerospace Depth Technology (Beijing) Co., Ltd., etc. can all achieve the above-mentioned required functions, so their specific structures are not the technical points of the present invention and will not be repeated here.

[0066] In the present invention, a suspension assembly 7 is provided in the outer tube 1, and the inner tube 2 is connected to the outer tube 1 through the suspension assembly 7. Specifically, the monitoring module 6 is provided between the suspension assembly 7 and the inner tube 2, the upper part of the monitoring module 6 is fixedly connected to the suspension assembly 7, the lower part of the monitoring module 6 is fixedly connected to the inner tube 2, and the lower end of the monitoring module 6 extends to the inside of the inner tube 2. The outer diameter of the middle part of the monitoring module 6 is the largest, and the maximum outer diameter is equal to the outer diameter of the inner tube 2. An external thread is provided at the lower end of the monitoring module 6, and an internal thread is provided at the upper end of the inner tube 2, and the monitoring module 6 and the inner tube 2 are connected to each other by threaded connection.

[0067] The monitoring module 6 of the present invention is installed between the inner tube 2 and the suspension assembly 7, which is easy to install and simple to debug on site. The specific structure of the suspension assembly 7 is not the technical point of the present invention, and the structure of the coring tool in the prior art can be referred to.

[0068] In a specific embodiment, an upper joint 8 is fixedly provided at the upper end of the outer tube 1. The upper end of the upper joint 8 is used to connect the upper drilling tool, and the lower part is fixedly connected to the suspension assembly 7, and then connected to the inner tube 2. The upper joint 8 is connected to the outer tube 1 through a special buckle. The specific structure of the special buckle is not the technical point of the present invention, and can refer to the structure of the coring tool in the prior art.

[0069] After the upper joint 8 is connected to the upper drilling tool, it can be driven by the drilling tool, so that the outer cylinder 1 can rotate and transmit the torque to the drill bit 3 for coring at the lower end of the outer cylinder 1, so that the drill bit 3 can rotate and cut the formation to form a columnar core.

[0070] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0072] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coring tool, comprising an outer cylinder (1), an inner cylinder (2) arranged inside the outer cylinder (1), a drill bit (3) arranged at the lower end of the outer cylinder (1), and a core locking mechanism (4) arranged at the lower end of the inner cylinder (2), characterized in that: The coring tool also includes: A beacon (5), wherein the beacon (5) is slidably arranged in the inner tube (2) along the axial direction; A monitoring module (6), wherein the monitoring module (6) is fixedly arranged on the top of the inner tube (2) and is capable of measuring the distance between the monitoring module and the beacon (5).

2. The coring tool according to claim 1, characterized in that: The monitoring module (6) comprises a signal transmitter and a signal receiver, and both the signal transmitter and the signal receiver are directed toward the beacon (5).

3. The coring tool according to claim 1, characterized in that: A suspension assembly (7) is arranged inside the outer cylinder (1), and the inner cylinder (2) is connected to the outer cylinder (1) via the suspension assembly (7).

4. The coring tool according to claim 3, characterized in that: The monitoring module (6) is arranged between the suspension assembly (7) and the inner tube (2); the upper part of the monitoring module (6) is fixedly connected to the suspension assembly (7), and the lower part of the monitoring module (6) is fixedly connected to the inner tube (2).

5. The coring tool according to claim 4, characterized in that: The lower end of the monitoring module (6) extends to the interior of the inner cylinder (2).

6. The coring tool according to claim 4, characterized in that: The monitoring module (6) and the inner cylinder (2) are connected to each other by means of a threaded connection.

7. The coring tool according to claim 4, characterized in that: The maximum outer diameter of the monitoring module (6) is equal to the outer diameter of the inner cylinder (2).

8. The coring tool according to claim 1, characterized in that: An upper joint (8) is fixedly arranged on the upper end of the outer cylinder (1).

9. The coring tool according to claim 8, characterized in that An internal thread is provided at the upper end of the outer cylinder (1), and an external thread is provided at the lower end of the upper joint (8). The lower end of the upper joint (8) extends into the interior of the outer cylinder (1) and is connected via threads.

10. The coring tool according to claim 1, characterized in that: The beacon (5) comprises a contact portion (51), a main body (52) and a signal reflecting portion (53), wherein the signal reflecting portion (53) and the contact portion (51) are respectively arranged at the upper and lower ends of the main body (52).

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