A through-the-bit logging sitting mechanism

Abstract

The application relates to a through-drill bit well logging sitting mechanism which comprises a non-magnetic conversion nipple, a sitting nipple, a drill bit, a suspension structure, a sitting sleeve and a fishing head structure, wherein the non-magnetic conversion nipple, the sitting nipple and the drill bit are sequentially connected to form a whole drill string, a communicating sitting channel is formed, the sitting channel is used for pressurized pumping of downhole instruments and circulation of mud; the suspension structure is sleeved on the outside of downhole logging instruments, the sitting sleeve is arranged in the inside of the sitting nipple, the suspension structure and the sitting sleeve form an axial limiting structure, the suspension structure, the sitting nipple and the sitting sleeve form a downhole sitting mechanism; a magnetic marker device is arranged on the outer circumferential wall of the non-magnetic conversion nipple; the fishing head structure is connected to the top end of the downhole logging instrument, meanwhile, the fishing head structure is used for being connected with external grabbing tools, and the fishing head structure and the downhole logging instrument are arranged in the sitting channel. The through-drill bit well logging sitting mechanism can assist through-drill bit storage logging operation and improve logging timeliness.

Description

Technical Field

[0001] This invention belongs to the field of exploration and well logging instruments, specifically relating to a logging placement mechanism that allows logging through the drill bit. Background Technology

[0002] With the development of logging technology, while meeting the requirements of direct-reading cable logging operations, various storage logging methods can further enable logging operations in horizontal wells, highly deviated wells, and deep wells, thereby addressing the increasingly complex downhole environments encountered during exploration and logging.

[0003] When using existing technical solutions, especially in horizontal and highly deviated wells, the downhole instrument string is difficult to lower to the measurement layer due to its own weight, and it is also impossible to directly determine whether it is in place. This results in cumbersome measurement operations and low logging efficiency.

[0004] As a type of storage logging operation, the over-bit storage logging operation mode requires a positioning mechanism on the bottom hull assembly (BHA) to assist in completing the over-bit storage logging operation during the lowering and raising of the downhole instrument string, so as to realize various operations such as suspension and raising of the downhole instrument string. Summary of the Invention

[0005] In order to solve all or some of the above problems, the present invention aims to provide a logging over-the-bit placement mechanism that can assist in logging over-the-bit storage operations and improve logging efficiency.

[0006] This application provides a logging-through-bit placement mechanism, including a non-magnetic conversion sub, a placement sub, a drill bit, a suspension structure, a placement sleeve, and a retrieval head structure. The non-magnetic conversion sub, placement sub, and drill bit are sequentially connected to form a drill string, creating a connected placement channel. This channel serves as a pressurized pumping channel for downhole instruments and a mud circulation channel. The suspension structure is fitted onto the outside of the downhole logging instrument, and the placement sleeve is fitted inside the placement sub. The suspension structure and the placement sleeve form an axial limiting structure. The suspension structure, placement sub, and placement sleeve constitute the downhole placement mechanism. A magnetic marker is disposed on the outer peripheral wall of the non-magnetic conversion sub. The retrieval head structure is connected to the top of the downhole logging instrument and is used to connect to an external retrieval tool. The retrieval head structure and the downhole logging instrument are integrally housed within the placement channel.

[0007] In some embodiments, a first fluid channel is formed within the suspension structure, and a second fluid channel is formed within the mounting sleeve, the first fluid channel and the second fluid channel constituting an internal mud channel.

[0008] In some embodiments, a first fluid channel is formed axially within the sidewall of the suspension structure. The first fluid channel includes a plurality of sub-channels, which are symmetrically arranged or evenly distributed along the circumference of the suspension structure.

[0009] In some embodiments, the second fluid channel is configured as an annulus between the inner wall of the settling sleeve and the outer wall of the suspension structure.

[0010] In some embodiments, the suspension structure and the mounting sleeve are limited by contact with an inclined plane.

[0011] In some embodiments, the end of the suspension structure is constructed as an inclined slope structure, and the end of the mounting sleeve is formed with a plurality of limiting blocks, which contact and limit the inclined surface of the slope structure.

[0012] In some embodiments, a plurality of limiting blocks are spaced apart and evenly distributed along the circumference of the mounting sleeve.

[0013] In some embodiments, a magnetic marking device is also included, which is disposed on the outer peripheral wall of the non-magnetic conversion section.

[0014] In some embodiments, the mounting sleeve is threadedly connected to the mounting short section.

[0015] In some embodiments, the outer wall of the short section is formed with a straightening structure.

[0016] As can be seen from the above technical solution, the over-bit logging placement mechanism provided by the present invention can transport downhole logging instruments from the water hole inside the drill string to the bottom of the drill string through mud. At the same time, the position of the downhole logging instruments is confirmed by a magnetic marker device, which assists in the lowering and retrieval of downhole logging instruments, improves the safety and timeliness of logging operations, and is particularly suitable for logging operations in horizontal wells and highly deviated wells. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the over-the-bit logging placement mechanism according to an embodiment of the present invention;

[0018] Figure 2 This is a partial structural schematic diagram of the over-the-bit logging placement mechanism according to an embodiment of the present invention;

[0019] Figure 3 This is a view along the AA direction of the over-bit logging placement mechanism according to an embodiment of the present invention;

[0020] Figure 4 This is a view along the BB direction of the over-the-bit logging placement mechanism according to an embodiment of the present invention. Detailed Implementation

[0021] To better understand the purpose, structure, and function of this invention, the following detailed description of a drilling bit logging placement mechanism of this invention is provided in conjunction with the accompanying drawings.

[0022] Figure 1The structure of the over-bit logging placement mechanism 100 according to an embodiment of the present invention is shown. Figure 1 As shown, this application provides a logging placement mechanism 100, including a non-magnetic conversion sub 1, a placement sub 2, a drill bit 3, a suspension structure 4, a placement sleeve 5, and a retrieval head structure 6. The non-magnetic conversion sub 1, the placement sub 2, and the drill bit 3 are sequentially connected to form an integral drill string. The sequentially connected non-magnetic conversion sub 1, the placement sub 2, and the drill bit 3 form interconnected placement channels, which serve as channels for pressurized pumping of downhole instruments and circulation of drilling mud. The suspension structure 4 is fitted with... Outside the downhole logging instrument 7, the landing sleeve 5 is fitted inside the landing sub 2. The suspension structure 4 and the landing sleeve 5 form an axial limiting structure. The suspension structure 4, the landing sub 2, and the landing sleeve 5 constitute the downhole landing mechanism. The logging instrument 7 is connected to the top of the downhole logging instrument 7 by a magnetic marking device 8 set in the non-magnetic conversion sub. The retrieval head structure 6 is connected to the top of the downhole logging instrument 7. At the same time, the retrieval head structure 6 is used to connect with the external grabbing tool. The retrieval head structure 6 and the downhole logging instrument 7 are set up as a whole in the landing channel.

[0023] In exploration wells, particularly in horizontal and highly deviated wells, the downhole logging instrument string 7 is difficult to lower to the downhole measurement layer due to its own weight. In such cases, the over-bit logging placement mechanism 100 of this embodiment of the invention, through the drill bit to the bottom of the downhole measurement layer, transports the downhole logging instrument string 7 and cable together through the placement channel, with mud pumping, to the bottom of the drill string to ultimately reach the downhole measurement layer; the logging instrument 7 is connected to a magnetic marker device 8 located on a non-magnetic conversion sub. After completing the above operations, the over-bit logging placement mechanism 100 is lifted to move the downhole logging instrument 7 upwards, simultaneously completing the logging operation.

[0024] With the above-mentioned settings, the over-bit logging placement mechanism 100 of this embodiment of the invention assists in the lowering and grabbing of the downhole logging instrument 7, effectively judging the placement of the instrument and improving the safety and timeliness of logging operations. It is particularly suitable for logging operations in horizontal wells and highly deviated wells.

[0025] Please refer to Figure 2 In some embodiments, a first fluid channel 41 is formed in the suspension structure 4, and a second fluid channel 51 is formed in the settling sleeve 5. The first fluid channel 41 and the second fluid channel 51 constitute an internal mud channel.

[0026] In this embodiment, through this configuration, during the mud pumping and placement process, the first fluid channel 41 on the suspension structure 4 and the second fluid channel 51 on the placement sleeve 5 together constitute the internal mud channel. Specifically, in this embodiment, the structural design of the mud channel needs to match the mud flow capacity of the water holes within the drill string to avoid reducing the overall mud flow capacity of the drill string, ensuring effective mud circulation during logging and enabling functions such as well washing and pumping.

[0027] Please continue to refer to Figure 2 and Figure 3 In some embodiments, a first fluid channel 41 is formed axially within the sidewall of the suspension structure 4. The first fluid channel 41 includes several sub-channels, which are symmetrically arranged or evenly distributed along the circumference of the suspension structure 4.

[0028] Please continue to refer to Figure 2 and Figure 4 In some embodiments, the second fluid channel 51 is configured as an annulus between the inner wall of the settling sleeve 5 and the outer wall of the suspension structure 4.

[0029] The above settings allow for a more uniform flow of mud.

[0030] Please refer to Figure 2 In some embodiments, the suspension structure 4 and the mounting sleeve 5 are limited by contact with an inclined plane.

[0031] Please continue to refer to Figure 2 In some embodiments, the end of the suspension structure 4 is constructed as an inclined slope structure, and the end of the mounting sleeve 5 is formed with a plurality of limiting blocks 52, which are in contact with the inclined surface of the inclined structure for limiting.

[0032] Please continue to refer to Figure 2 and Figure 4 In some embodiments, a plurality of limiting blocks 52 are spaced apart and evenly distributed along the circumference of the mounting sleeve 5.

[0033] Please return Figure 1 In some embodiments, a magnetic marking device 8 is also included, which is disposed on the outer peripheral wall of the non-magnetic conversion section 1 and is used to determine the pumping position of the instrument.

[0034] In this application, during mud pumping, a magnetic marker device 8 is used to acquire magnetic marker signals on the surface to confirm that the downhole logging instrument 7, through the magnetic conversion sub 1 and the landing sub 2, passes through the drill bit's inner bore to reach the downhole measurement layer, until the suspension structure 4 on the downhole logging instrument 7 contacts and limits contact with the inclined surface of the landing sleeve 5 inside the drill string. During this process, depending on the actual situation, the grab tool can be lowered to the bottom through the water hole inside the drill string; after logging is completed, in conjunction with the retrieval head, the downhole logging instrument 7 is retrieved from the drill string water hole to the surface. The signal from the magnetic marker device 8 is used to determine the lowered position of the grab tool, assisting the retrieval operation and improving timeliness and safety.

[0035] In some embodiments, the mounting sleeve 5 and the mounting sub 2 may be threaded together.

[0036] Please continue to refer to Figure 1 In some embodiments, the outer wall of the short section 2 may be formed with a straightening structure 21.

[0037] In this embodiment, the landing section 2 has a centering structure 21, which can be effectively used to stabilize the drill string as a whole and during downhole operations.

[0038] In summary, the over-the-bit logging placement mechanism 100 according to this embodiment of the invention allows the downhole logging instrument 7 to be transported from the water inlet within the drill string to the bottom of the drill string via mud. The upper end of the downhole logging instrument 7 is confined within the drill string. The position of the downhole logging instrument 7 is confirmed by the magnetic marker device 8. The main body of the downhole logging instrument 7 reaches the measurement layer through the water inlet within the drill bit. Raising the over-the-bit logging placement mechanism 100 causes the downhole logging instrument 7 to rise accordingly for logging and formation parameter measurement. After the measurement is completed, the downhole logging instrument 7 is retrieved with the assistance of the magnetic marker device 8, improving the safety and timeliness of logging operations. This method is particularly suitable for logging operations in horizontal wells and highly deviated wells.

[0039] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by those skilled in the art to which this invention pertains.

[0040] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0041] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0042] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A logging-through-the-bit positioning mechanism, characterized in that, The system includes a non-magnetic conversion sub, a landing sub, a drill bit, a suspension structure, a landing sleeve, and a retrieval head structure. The non-magnetic conversion sub, the landing sub, and the drill bit are sequentially connected to form a drill string. These components form a connecting landing channel, which serves as a channel for pressurized pumping of downhole instruments and for mud circulation. The suspension structure is fitted onto the outside of the downhole logging instrument, and the landing sleeve is fitted onto the inside of the landing sub. The suspension structure and the landing sleeve form an axial limiting structure. The suspension structure, the landing sub, and the landing sleeve constitute a downhole landing mechanism. The retrieval head structure is connected to the top of the downhole logging instrument and is used to connect to an external retrieval tool. The retrieval head structure and the downhole logging instrument are integrally housed within the landing channel. The suspension structure and the mounting sleeve are limited by a beveled contact surface; The end of the suspension structure is constructed as an inclined slope structure, and the end of the settling sleeve is formed with a plurality of limiting blocks, which contact and limit the movement with the inclined surface of the inclined structure. The over-the-bit logging landing mechanism also includes a magnetic marking device, which is disposed on the outer peripheral wall of the non-magnetic conversion sub.

2. The over-the-bit logging positioning mechanism according to claim 1, characterized in that, A first fluid channel is formed within the suspension structure, and a second fluid channel is formed within the mounting sleeve. The first fluid channel and the second fluid channel together constitute an internal mud channel.

3. The over-the-bit logging positioning mechanism according to claim 2, characterized in that, The first fluid channel is formed axially within the sidewall of the suspension structure. The first fluid channel includes several sub-channels, which are symmetrically arranged or evenly distributed along the circumference of the suspension structure.

4. The over-the-bit logging positioning mechanism according to claim 2, characterized in that, The second fluid channel is constructed as an annular space between the inner wall of the settling sleeve and the outer wall of the suspension structure.

5. The over-the-bit logging positioning mechanism according to claim 1, characterized in that, Several of the limiting blocks are spaced apart and evenly distributed along the circumference of the settling sleeve.

6. The over-the-bit logging positioning mechanism according to claim 1, characterized in that, The mounting sleeve is threadedly connected to the mounting short section.

7. The over-the-bit logging positioning mechanism according to claim 1, characterized in that, The outer wall of the seated short section has a straightening structure.

Images