A coring device for oil well logging

Abstract

The application belongs to the field of petroleum exploration equipment, and particularly relates to a coring device for petroleum logging, which comprises a drilling part (2) penetrating through a main body (1), a driving part (3) capable of making the drilling part (2) rotate and drill, and a bearing part (4) sleeved outside the driving part (3). The drilling part (2) comprises a drill rod (21) and a drill bit (22), and the drill rod (21) is of a vacuum and straight-through structure. Thanks to the structural design of the drill rod (21), the coring device can be miniaturized to adapt to a small-diameter wellhead operation environment, and has the advantages of facilitating mud discharge and sampling.

Description

Technical Field

[0001] This invention belongs to the field of petroleum exploration equipment, specifically relating to a coring device for petroleum logging. Background Technology

[0002] In oil well logging, coring equipment is frequently used to obtain high-quality core samples for rock property and reservoir analysis. Traditional direct-drive coring equipment, with its drill bit structure, cannot fully utilize the radial dimensions of the device. To obtain larger particles, the outer diameter of the instrument must be increased, resulting in bulky and cumbersome equipment unsuitable for small wellhead environments. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention aims to provide a coring device for oil well logging, comprising: a main body having a first through hole and a second through hole arranged in parallel; a drilling section extending through the first through hole, including a drill rod and a drill bit connected to one end of the drill rod; a drive unit for driving the drilling section to rotate and drill, including a connector extending through the second through hole, a main drive gear and a secondary drive gear spaced apart axially on the connector, and a torque gear and a drill pressure gear sleeved on the outside of the drill rod; and a bearing portion sleeved on the axially outer side of the torque gear and the drill pressure gear; wherein the drill rod is a hollow, straight-through structure, the main drive gear and the drill pressure gear are in a meshing state, and the secondary drive gear and the torque gear are in a meshing state.

[0004] As an extension and supplement to the above technical solution, the present invention also provides the following embodiments:

[0005] The torque gear includes a first gear body and a first gear sleeve connected to the first gear body.

[0006] The drilling gear includes a second gear body, and a second gear sleeve and a third gear sleeve respectively connected to both ends of the second gear body.

[0007] The torque gear is sleeved on the outside of the second gear sleeve.

[0008] The torque gear includes a vertical tooth that extends radially inward from the end of the first gear sleeve to contact the drill rod, and the drill rod includes a connecting groove on the outer wall that meshes with the vertical tooth.

[0009] The drill bit includes threaded teeth on the inner wall that contact the drill rod, and the drill rod includes external threads on the outer wall that mesh with the threaded teeth.

[0010] The connecting grooves are arranged along the axial direction of the drill rod and penetrate the external thread.

[0011] The bearing section includes deep groove ball bearings respectively disposed on the outer sides of the first gear sleeve, the second gear sleeve and the third gear sleeve, and an end face bearing disposed at the end of the third gear sleeve.

[0012] The drill bit includes drill teeth for drilling rock cores, the drill teeth being evenly distributed circumferentially on the end face of the drill bit.

[0013] The drilling section includes a retaining spring disposed inside the drill bit for holding the rock core.

[0014] The advantages of this invention compared to existing technologies are: the hollow and straight-through structure of the drill pipe allows for maximum utilization of the radial space of the drill pipe during drilling and sampling, contributing to the miniaturization of the drill pipe and instruments, thus enabling the device to be used for sampling operations at small wellheads. Furthermore, the hollow and straight-through drill pipe structure facilitates the discharge of mud that enters the device during drilling, overcoming the problems of insufficient drilling depth and drill pipe breakage caused by excessive mud accumulation inside the drill pipe. Additionally, core samples can be retrieved from both ends of the drill pipe, making sample extraction more convenient. Attached Figure Description

[0015] Figure 1 A cross-sectional view of the coring apparatus for oil well logging according to the present invention;

[0016] Figure 1a This is a front view of the coring apparatus for oil well logging according to the present invention;

[0017] Figure 2 This is a schematic diagram of the drilling section of a coring device for oil well logging according to the present invention;

[0018] Figure 2a This is a side view of the drilling section of a coring apparatus for oil logging according to the present invention;

[0019] Figure 2b for Figure 2a Cross-sectional view of section BB in the middle;

[0020] Figure 3 This is a schematic diagram of the snap ring structure of the coring device for oil well logging according to the present invention;

[0021] Figure 3a This is a front view of the retaining ring of the coring device for oil well logging according to the present invention.

[0022] All accompanying drawings of this invention are schematic diagrams used to illustrate the structure and principle, and are not drawn to actual dimensions and scale.

[0023] The specific meanings of the various labels in the figure are as follows:

[0024] 1. Main body; 11. First through hole; 12. Second through hole; 2. Drilling section; 21. Drill rod; 211. Connecting groove; 212. External thread; 22. Drill bit; 221. Drill teeth; 222. Snap ring groove; 3. Drive section; 31. Connecting piece; 32. Main drive gear; 33. Secondary drive gear; 34. Torque gear; 341. First gear body; 342. First gear sleeve; 343. Vertical tooth; 35. Drill press gear; 351. Second gear body; 352. Second gear sleeve; 353. Third gear sleeve; 354. Threaded tooth; 4. Bearing section; 41. Deep groove ball bearing; 42. End face bearing. Detailed Implementation

[0025] The embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

[0026] Figure 1 and Figure 1a The overall structure of a coring device 100 for oil well logging according to the present invention (hereinafter referred to as "coring device 100") is shown. The coring device 100 includes a main body 1, a drilling part 2, a drive part 3, and a bearing part 4.

[0027] According to the present invention, the main body 1 includes a first through hole 11 and a second through hole 12 arranged in parallel. The drilling part 2 extends through the first through hole 11 and includes a hollow, straight drill rod 21 and a drill bit 22 connected to one end of the drill rod 21. The drive part 3 includes a connector 31 extending through the second through hole 12, a main drive gear 32 and a secondary drive gear 33 sleeved on the connector 31 and spaced apart along the axial direction of the connector 31. The drive part 3 also includes a torque gear 34 and a drill pressure gear 35 sleeved on the outside of the drill rod 21. The main drive gear 32 and the drill pressure gear 35 are meshed, and the secondary drive gear 33 and the torque gear 34 are meshed. The function of the drive part 3 is to drive the drilling part 2 to rotate and drill to complete the core sampling operation. The core sampling device 100 also includes a bearing part 4 sleeved on the axial outside of the torque gear 34 and the drill pressure gear 35 to support the rotating drive part 3.

[0028] During coring operations, external power drives the main drive gear 32 to rotate. On one hand, the main drive gear 32, being engaged with the drill pressure gear 35, drives the drill pressure gear 35 to rotate. Since the drill pressure gear 35 is fitted onto the outside of the drill rod 21, it drives the drill rod 21 to rotate and drill. On the other hand, the main drive gear 32 and the auxiliary drive gear 33 are simultaneously mounted on the connecting member 31. When the main drive gear 32 rotates, it drives the connecting member 31, which in turn drives the auxiliary drive gear 33 to rotate. The auxiliary drive gear 33 is engaged with the torque gear 34, thus driving the torque gear 34 to rotate. The torque gear 34 is also fitted onto the outside of the drill rod 21, driving the drill rod 21 to rotate and increasing the drilling torque of the drill rod 21.

[0029] According to the present invention, under the action of the drive unit 3, the drill pipe 21 drives the drill bit 22 to rotate and drill, completing the task of core drilling. Furthermore, by adjusting the magnitude of the external power acting on the main drive gear 32, which is transmitted through the gears, the torque gear 34 and the drilling pressure gear 35 ultimately affect the torque and drilling force acting on the drill pipe 21, thus meeting the requirements of different geological conditions for the drilling force of the drilling unit 2. Since the drill pipe 21 has a hollow and straight-through structure, except for the wall thickness, the central empty space can be used as a working part, maximizing the use of the radial space of the drill pipe 21. This allows for miniaturization of the equipment, making it suitable for wellheads with smaller diameters and expanding the applicability of the core drilling device 100.

[0030] In addition, the hollow and straight-through structure of the drill pipe 21, which is open at both ends, has two beneficial effects. First, it facilitates the discharge of mud generated during drilling operations, reducing the occurrence of various malfunctions caused by the blockage of the drill bit 22 due to the difficulty in discharging mud. Second, it facilitates the removal of samples, allowing core samples to be taken from both the head and tail of the drill pipe 2.

[0031] The above are the basic embodiments of the present invention. The present invention also includes the following extended technical solutions:

[0032] like Figure 1 and Figure 2As shown, in one embodiment of the present invention, the torque gear 34 includes a first gear body 341 and a first gear sleeve 342 connected to one end of the first gear body 341. The drill pressing gear 35 includes a second gear body 351 and a second gear sleeve 352 and a third gear sleeve 353 respectively connected to both ends of the second gear body 351. Furthermore, the torque gear 34 is sleeved on the outside of the second gear sleeve 352 of the drill pressing gear 35. This design makes the arrangement between the torque gear 34 and the drill pressing gear 35 more compact, which helps to save design space in the core-taking device 100. Further, on the one hand, at the end of the first gear sleeve 342 in the torque gear 34, a vertical tooth 343 extending radially inward and contacting the drill rod 21 is provided. Correspondingly, a connecting groove 211 that meshes with the vertical tooth 343 is provided on the outer wall of the drill rod 21. On the other hand, threaded teeth 354 are provided on the inner wall of the drill pressing gear 35 to engage with the drill rod 21. Correspondingly, an external thread 212 that meshes with the thread teeth 354 is provided on the outer wall of the drill pipe 21.

[0033] like Figure 2 , Figure 2a as well as Figure 2b As shown, the connecting groove 211 and the external thread 212 on the drill rod 21 are spaced apart, and the connecting groove 211 is arranged along the axial direction of the drill rod 21 and passes through the external thread 212. In this embodiment, the connecting groove 211 and the external thread 212 spaced apart on the outer wall of the drill rod 21 respectively mesh with the vertical teeth 343 of the torque gear 34 and the thread teeth 354 of the drilling pressure gear 35. When the core-taking device 100 is started, the drilling pressure gear 35 drives the drill rod 21 to rotate and drill by helical push. The torque gear 34 rotates, and the vertical teeth 343 drive the drill rod 21 to rotate, which strengthens the torque of the drill rod 21 and makes the drilling part 2 easier to operate. Since the connecting groove 211 is arranged along the axial direction of the drill rod 21 and passes through the external thread 212, during the drilling process of the drill rod 21, the vertical teeth 343 rotate on one hand and move backward relative to the drill rod 21 along the connecting groove 211, so that the drilling of the drill rod 21 will not affect the function of the torque gear 34.

[0034] like Figure 1 As shown, in one embodiment of the present invention, the bearing section 4 includes deep groove ball bearings 41 disposed on the outer sides of the first gear sleeve 342, the second gear sleeve 352, and the third gear sleeve 353. Further, the number of deep groove ball bearings 41 is set to four. The bearing section 4 also includes an end face bearing 42 disposed at the end of the third gear sleeve 353 for sealing and reducing wear; further, the number of end face bearings 42 is set to one.

[0035] like Figure 1 and Figure 2As shown, in another embodiment of the invention, drill teeth 221 are uniformly arranged circumferentially on the end face of the drill bit 22. The drill teeth 221 have a sharp shape, which makes it easier for the core sampling device 100 to break the rock and obtain a core sample. Furthermore, the line connecting the center of the circumferential section of the drill bit 22 containing the innermost end point of the drill teeth 221 to the innermost end point of the drill teeth 221 is no greater than half the inner diameter of the drill rod 21. This design prevents the core sample obtained by the drill bit 22 from becoming clogged at the connection between the drill bit 22 and the drill rod 21 due to its maximum diameter being larger than the inner diameter of the drill rod 21, thus preventing core sampling failure. Furthermore, as... Figure 3 and Figure 3a As shown, a retaining ring 23 is installed inside the drill bit 22. The retaining ring 23 has a "C"-shaped structure, and its main function is to hold the core sample tightly, preventing the core sampling device 100 from losing the core sample during retraction. The retaining ring 23 is made of a highly elastic metal material and is placed in the retaining ring groove 222 inside the drill bit 22. When the retaining ring 23 is in its free state, its inner diameter is smaller than the maximum diameter of the core sample. After the core sample enters the retaining ring 23, the inner diameter of the retaining ring 23 increases, holding the core sample tightly. After the outer diameter of the retaining ring 23 increases accordingly, a 1mm gap is still maintained between the retaining ring 23 and the retaining ring groove 222 in the drill bit 22, ensuring that the drill bit 22 can rotate freely.

[0036] According to the coring device 100 of the present invention, the drill pipe 21 adopts a hollow and straight-through structure. Except for the wall thickness, the radial space of the drill pipe 21 can be used for operation, resulting in high space utilization and enabling the equipment to be miniaturized and adaptable to the working environment of small-diameter wellheads. Furthermore, the hollow and straight-through structure of the drill pipe 21, i.e., the structure with openings at both ends, facilitates the discharge of drilling mud entering the drill pipe 21 during drilling, reducing the failure rate of the coring device 100. It also allows for sampling from both the head and tail of the drill pipe 21, facilitating the extraction of core samples.

[0037] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, substitutions, combinations, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coring device for oil well logging, comprising: The main body (1) has a first through hole (11) and a second through hole (12) arranged in parallel. The drilling section (2) extending through the first through hole (11) includes a drill rod (21) and a drill bit (22) connected to one end of the drill rod (21). The drive unit (3) for rotating and drilling the drill bit (2) includes a connector (31) extending through the second through hole (12), a main drive gear (32) and a secondary drive gear (33) spaced axially on the connector (31), and a torque gear (34) and a drill pressure gear (35) spaced on the outside of the drill rod (21); and The bearing portion (4) is sleeved on the axial outer side of the torque gear (34) and the drilling gear (35). The torque gear (34) includes a first gear body (341) and a first gear sleeve (342) connected to the first gear body (341). The drill press gear (35) includes a second gear body (351), and a second gear sleeve (352) and a third gear sleeve (353) respectively connected to both ends of the second gear body (351). The torque gear (34) is sleeved on the outside of the second gear sleeve (352). The torque gear (34) includes a vertical tooth (343) that extends radially inward at the end of the first gear sleeve (342) to contact the drill rod (21), and the drill rod (21) includes a connecting groove (211) on the outer wall that meshes with the vertical tooth (343). The drill bit (35) includes threaded teeth (354) on the inner wall that contact the drill rod (21), and the drill rod (21) includes external threads (212) on the outer wall that mesh with the threaded teeth (354). The drill rod (21) is a hollow straight-through structure. The main drive gear (32) is meshed with the drill pressure gear (35), and the auxiliary drive gear (33) is meshed with the torque gear (34).

2. The coring device for oil well logging according to claim 1, characterized in that: The connecting groove (211) is arranged along the axial direction of the drill rod (21) and passes through the external thread (212).

3. The coring device for oil well logging according to claim 1 or 2, characterized in that: The bearing section (4) includes a deep groove ball bearing (41) disposed on the outer side of the first gear sleeve (342), the second gear sleeve (352) and the third gear sleeve (353), respectively, and an end face bearing (42) disposed at the end of the third gear sleeve (353).

4. The coring device for oil well logging according to claim 1 or 2, characterized in that: The drill bit (22) includes drill teeth (221) for drilling cores, which are evenly distributed circumferentially on the end face of the drill bit (22).

5. The coring device for oil well logging according to claim 1 or 2, characterized in that: The drilling section (2) includes a retaining spring (23) for holding the rock core inside the drill bit (22).

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