Coring drilling tool

Abstract

The coring drilling tool comprises an outer barrel, a jet inner barrel, a coring inner barrel and a flow adjusting connector, the jet inner barrel, the coring inner barrel and the flow adjusting connector are arranged in the outer barrel, and the flow adjusting connector is provided with a first hole and a second hole; the spraying inner cylinder comprises a spraying inner cylinder body and a spraying nozzle installed in the spraying inner cylinder body, the first end of the flow adjusting connector is inserted into the spraying inner cylinder body, the first end of the flow adjusting connector and the spraying nozzle are arranged in a spaced mode, the first end of the flow adjusting connector and the spraying inner cylinder body form a negative pressure space, and the first hole communicates with the negative pressure space and is opposite to the spraying nozzle; the second hole is staggered with the jet nozzle and is communicated with the negative pressure space; the coring inner cylinder is connected with the flow adjusting connector and is communicated with the second hole, an annular gap is formed between a whole formed by the flow adjusting connector and the coring inner cylinder and the outer cylinder, and the first hole is communicated with the annular gap; the drilling fluid sprayed from the spraying inner barrel to the first hole can enter the annular gap, so that the negative pressure space is in a negative pressure state, and the negative pressure space in the negative pressure state is used for adsorbing the drilling fluid in the coring inner barrel through the second hole.

Description

Technical Field

[0001] The present invention relates to the technical field of drill tools, and particularly to a core drill tool. Background Art

[0002] In the field of oil and gas drilling coring, coring in fractured formations has long been a difficult point and an area to be broken through in drilling coring. In the related art, the coring drill tool for fractured formations belongs to a conventional self-locking coring drill tool. During the coring operation, the flow direction of the drilling fluid follows the traditional reverse circulation mode. After the ball is thrown, the drilling fluid will pass through the annular gap between the inner and outer cylinders of the coring drill tool, then pass through the nozzle or water groove of the drill bit of the coring drill tool to reach the bottom of the well, and finally carry the cuttings at the bottom of the well back to the wellhead through the annulus between the coring drill tool and the wellbore.

[0003] This kind of coring drill tool has achieved good on-site application effects in conventional formation coring operations, but it has repeatedly encountered problems when coring in fractured formations. Compared with conventional formations where the formation in the coring section is well-cemented and the core columnarity is relatively high. This kind of coring drill tool faces the following problems: First, there is a problem of insufficient cleaning at the bottom of the well during coring drilling. Most of the drilling fluid can only wash and carry the bottom of the drill bit of the coring drill tool or a small area of the drill bit, and the cuttings near the core catcher on the inner side of the drill bit cannot be washed in time. If these cuttings cannot be washed away in time, it will have a greater impact on the core recovery rate of the fractured formation, and it is more likely to cause repeated cutting during coring drilling, resulting in a longer time spent on coring drilling. Second, when coring in hard fractured formations, the drilling time is relatively long, and the cuttings that are not cleaned in time at the bottom of the well will accumulate. These cuttings will move upward in the inner cylinder along with the core, and if there are too many accumulations, it is easier to cause core blockage. Third, although the core in the deep well fractured formation is hard, its column-forming performance is poor. After entering the inner cylinder in an extruded shape, the cores rub against each other and vibrate to generate secondary cuttings. These cuttings cannot be removed in time and are likely to cause core blockage after accumulating in the inner cylinder for a long time.

[0004] As coring, as a branch of drilling, is gradually becoming more competitive, how to design a coring drill tool to solve the above technical problems is an urgent problem for technical personnel in the related technical fields. Summary of the Invention

[0005] Embodiments of the present invention disclose a core drill tool to solve the technical problems presented in the background art.

[0006] To solve the above technical problems, the embodiments of the present invention disclose the following technical solutions:

[0007] A core drill tool includes an outer cylinder, a jet inner cylinder, a core inner cylinder, and a flow regulating joint disposed within the outer cylinder. The flow regulating joint is provided with a first hole and a second hole; wherein:

[0008] The injection inner cylinder includes an injection inner cylinder body and an injection nozzle installed inside the injection inner cylinder body. The first end of the flow regulating joint is inserted into the injection inner cylinder body and is spaced apart from the injection nozzle. The first end of the flow regulating joint and the injection inner cylinder body form a negative pressure space. The first hole communicates with the negative pressure space and faces the injection nozzle. The second hole is misaligned with the injection nozzle and communicates with the negative pressure space;

[0009] The core barrel is connected to the flow regulating joint. The core barrel communicates with the second hole. An annular gap is formed between the integral formed by the flow regulating joint and the core barrel and the outer cylinder. The first hole communicates with the annular gap; The drilling fluid sprayed from the injection inner cylinder to the first hole can enter the annular gap, so that the negative pressure space is in a negative pressure state. The negative pressure space in the negative pressure state is used to adsorb the drilling fluid in the core barrel through the second hole.

[0010] Optionally, the injection inner cylinder body is provided with a conical mounting hole. The injection nozzle includes a conical section and an equal-diameter section. The conical section is fixed in the conical mounting hole. The equal-diameter section is connected to the conical section and extends into the negative pressure space. The equal-diameter section faces the water inlet of the first hole.

[0011] Optionally, the injection inner cylinder further includes a threaded compression sleeve. The threaded compression sleeve is fixed inside the injection inner cylinder body by thread fitting and presses on the large end of the conical section facing away from the negative pressure space. The inner cavity of the injection inner cylinder body communicates with the conical section through the inner cavity of the threaded compression sleeve.

[0012] Optionally, the first hole includes a first hole section and a plurality of second hole sections. The first hole section extends along the central axis direction of the outer cylinder. The first hole openings of the plurality of second hole sections communicate with the first hole section. The plurality of second hole sections extend obliquely relative to the first hole section, and the second hole openings of the plurality of second hole sections communicate with the annular gap.

[0013] Optionally, the hole opening of the first hole section facing away from the second hole section is a conical opening. The projection of the injection opening of the injection nozzle in the central axis direction is located in the conical opening.

[0014] Optionally, the flow regulating joint includes a base and a protrusion provided on the base. The first hole section extends from the protrusion into the base. The base extends into the injection inner cylinder body and is threadedly connected to the injection inner cylinder body. The base includes an annular surface surrounding the protrusion. The annular surface, the protrusion and the injection inner cylinder body form an annular groove. The second hole is opened on the base and penetrates to the annular surface. The negative pressure space includes the space inside the annular groove.

[0015] Optionally, the flow regulating joint further includes an annular protrusion distributed around the base portion and fixed to the base portion, and an end of the injection inner cylinder body connected to the base portion abuts against the annular protrusion.

[0016] Optionally, there are a plurality of the second holes, and the plurality of second holes are spaced apart in the direction around the central axis of the outer cylinder on the flow regulating joint, and the cross-sectional shape of the second holes in a plane perpendicular to the central axis is arc-shaped or elliptical.

[0017] Optionally, the core barrel further includes a core inner cylinder joint, a central shaft, a bearing and a cylindrical gland, the flow regulating joint further includes a cylindrical section, the central shaft is inserted into the core inner cylinder joint and fixed by thread fit, the cylindrical gland is sleeved outside the core inner cylinder joint, the cylindrical gland is inserted into the cylindrical section and fixedly connected to the cylindrical section by thread fit, the bottom end of the bearing is supported on the cylindrical gland, the central shaft passes through the bearing and overlaps on the top end of the bearing, an interface space is formed between the central shaft and the cylindrical section, the second holes communicate with the interface space, and the cavity of the core inner cylinder is communicated with the second holes in sequence through the central hole of the core inner cylinder joint, the central hole of the central shaft and the interface space.

[0018] Optionally, the core barrel further includes a filter joint, the filter joint is located inside the core inner cylinder and is connected at the central hole of the core inner cylinder joint near the orifice of the core inner cylinder, and the filter joint is detachably connected to the core inner cylinder joint.

[0019] The damper disclosed in the embodiment of the present invention has the following technical effects:

[0020] Before core drilling, high-pressure drilling fluid can be conveyed to the injection inner cylinder. After the pressure energy of the drilling fluid is converted into kinetic energy through the convergence and energy concentration of the injection nozzle, it has a relatively high injection speed and finally sprays out from the injection nozzle. After the high-speed sprayed drilling fluid sprays out, a negative pressure effect will be formed, and then the drilling fluid located around the injection nozzle in the negative pressure space will be taken away. The drilling fluid around the injection nozzle being taken away can form a negative pressure area around the injection nozzle, and this negative pressure area makes the negative pressure space in a negative pressure state. The negative pressure space in the negative pressure state will force the second holes communicated with it to suck the relatively low-pressure drilling fluid in the core inner cylinder into the negative pressure space. The drilling fluid sucked into the negative pressure space through the second holes will be mixed with the drilling fluid sprayed out by the injection nozzle and then enter the first hole again and be discharged. During this process, since the injection nozzle continuously sprays drilling fluid, and at the same time the negative pressure space continuously sucks the drilling fluid in the core inner cylinder through the second holes, a flowing effect of continuously sucking and discharging drilling fluid is formed.

[0021] During the coring process, the drill bit contacts the bottom of the wellbore. The drilling fluid is ejected through the ejection nozzle into the first hole and enters the bottom of the well through the annular gap communicating with the first hole. Then, a small part of the drilling fluid reaching the bottom of the well invades the coring inner barrel and is sucked into the negative pressure space through the second hole, thus performing a kind of circulation. Most of the drilling fluid reaching the bottom of the well will return to the wellhead through the annular space, thus performing another kind of circulation.

[0022] From the above process, it can be seen that a part of the drilling fluid transported to the bottom of the well will enter the coring inner barrel. The flow direction of this part of the drilling fluid invading the coring inner barrel is the same as the direction of the core entering the coring inner barrel. Furthermore, it can carry the cuttings inside the drill bit and the secondary cuttings generated by the mutual collision of the broken core in the coring inner barrel, causing these cuttings to move to a higher position away from the drill bit inside the coring inner barrel. Finally, the cuttings can leave the bottom of the well and the lower bottom of the coring inner barrel in a timely manner, reducing the chance of the drill bit repeatedly cutting the cuttings. Since the process of the drilling fluid invading the coring inner barrel can provide a lubricating effect, it can reduce the friction resistance of the core entering the coring inner barrel, prevent the core that has entered the coring inner barrel from generating secondary cuttings and causing the probability of core blockage, and at the same time can increase the mechanical drilling speed. Description of the Drawings

[0023] Figure 1 is a cross-sectional view of the coring tool disclosed in the embodiment of the present invention;

[0024] Figure 2 is a cross-sectional view of the drainage diverter disclosed in the embodiment of the present invention;

[0025] Figure 3 is Figure 1 a partial structural schematic diagram in

[0026] 10 - outer barrel,

[0027] 20 - ejection inner barrel, 21 - ejection inner barrel body, 211 - tapered mounting hole, 22 - ejection nozzle, 221 - tapered section, 222 - equal-diameter section, 23 - threaded compression sleeve,

[0028] 30 - coring inner barrel,

[0029] 40 - flow control joint, 41 - first hole, 411 - first hole section, 412 - second hole section, 42 - second hole, 401 - base, 402 - protrusion, 403 - annular protrusion, 404 - cylindrical section,

[0030] 51 - coring inner barrel joint, 511 - central hole, 52 - central shaft, 521 - central hole, 53 - bearing, 54 - cylindrical gland, 55 - filter joint,

[0031] 61 - upper joint of ejection inner barrel, 62 - safety joint,

[0032] 01 - Negative pressure space, 02 - Annular gap, 03 - Annular groove, 04 - Connecting space. Detailed implementation manners

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0034] The following will, with reference to the drawings, detail the technical solutions disclosed in each embodiment of the present invention.

[0035] Please refer to Figures 1 to 3 , an embodiment of the present invention discloses a core barrel. The disclosed core barrel includes an outer barrel 10, a jet inner barrel 20, a core inner barrel 30 and a flow regulating joint 40.

[0036] The outer barrel 10 is the peripheral barrel member of the core barrel. The jet inner barrel 20, the core inner barrel 30 and the flow regulating joint 40 are all arranged inside the outer barrel 10. The flow regulating joint 40 is used to regulate the flow direction of the drilling fluid flowing through the core barrel. The specific flow regulating process will be discussed later. Specifically, the flow regulating joint 40 may be provided with a first hole 41 and a second hole 42.

[0037] The jet inner barrel 20 can jet out the drilling fluid flowing into it. Specifically, the jet inner barrel 20 includes a jet inner barrel body 21 and a jet nozzle 22. Among them, the jet inner barrel body 21 is fixed inside the outer barrel 10 and at the same time provides an installation position for the jet nozzle 22. The jet nozzle 22 is installed inside the jet inner barrel body 21. The jet inner barrel body 21 is communicated with the jet nozzle 22. After the drilling fluid enters the jet inner barrel body 21, it will then be jetted out through the jet nozzle 22 so that the drilling fluid is jetted towards the flow regulating joint 40. The upper end of the jet inner barrel body 21 is threadedly connected with a jet inner barrel upper joint 61, and the upper end of the outer barrel 10 is connected with a safety joint 62, and the safety joint 62 is sleeved outside the jet inner barrel upper joint 61.

[0038] One end of the flow regulating joint 30 is inserted into the injection inner cylinder body 21 and is spaced from the injection nozzle 22. One end of the flow regulating joint 40 and the injection inner cylinder body 21 form a negative pressure space 01. The first hole 41 communicates with the negative pressure space 01 and faces the injection nozzle 22. The drilling fluid ejected from the injection nozzle 22 can enter the first hole 41 and then enter the flow regulating joint 30. During the specific working process, the drilling fluid ejected from the injection nozzle 22 enters the first hole 41 through the negative pressure space 01. Since the drilling fluid enters the flow regulating joint 30 after passing through the negative pressure space 01 at a high speed, a negative pressure will be formed in the negative pressure space 01.

[0039] The second hole 42 is misaligned with the injection nozzle 22 and communicates with the negative pressure space 01. This structure can prevent the drilling fluid ejected from the injection nozzle 22 from entering the second hole 42. Since the second hole 42 communicates with the negative pressure space 01, the second hole 42 can be regarded as a negative pressure suction hole.

[0040] The coring inner cylinder 30 is connected to the flow regulating joint 40 and is used for coring during drilling. The coring inner cylinder 30 communicates with the second hole 41.

[0041] An annular gap 02 is formed between the whole formed by the flow regulating joint 40 and the coring inner cylinder 30 and the outer cylinder 10. The first hole 41 communicates with the annular gap 02. The drilling fluid sprayed from the injection inner cylinder 20 to the first hole 41 can enter the annular gap 02 and be discharged. During this process, the drilling fluid passes through the negative pressure space 01 and then enters the first hole 41 and then enters the annular gap 02, which can make the negative pressure space 01 in a negative pressure state. The drilling fluid entering the annular gap 02 will flow into the bottom of the well, and a part (a small part of the drilling fluid) will enter the coring inner cylinder 30 along the gap between the core and the coring inner cylinder 30, and another part (the majority of the drilling fluid) will flow back to the wellhead along the annular space between the coring tool and the wellbore of the well.

[0042] The drilling fluid entering the coring inner cylinder 30 will be sucked into the negative pressure space 01 under the suction of the second hole 41 and will finally enter the first hole 41 through the negative pressure space 01 and be discharged.

[0043] The working process of the coring tool disclosed in the embodiment of the present invention is as follows:

[0044] Before coring drilling, high-pressure drilling fluid can be delivered to the jet inner cylinder 20. After the drilling fluid passes through the converging and energy-gathering of the jet nozzle 22, the pressure energy is converted into kinetic energy and has a relatively high jet velocity, and finally sprays out from the jet nozzle 22. After the high-speed jetting drilling fluid sprays out, a negative pressure effect will be formed, and then the drilling fluid located around the jet nozzle 22 in the negative pressure space 01 will be carried away. The removal of the drilling fluid around the jet nozzle 22 can form a negative pressure area around the jet nozzle 22, and this negative pressure area makes the negative pressure space 01 in a negative pressure state. The negative pressure space 01 in the negative pressure state will force the second hole 42 connected to it to suck the relatively low-pressure drilling fluid in the coring inner cylinder 30 into the negative pressure space. This part of the drilling fluid sucked into the negative pressure space 01 through the second hole 42 will be mixed with the drilling fluid sprayed out by the jet nozzle 22 and then enter the first hole 41 again and be discharged. In this process, due to the continuous spraying of the drilling fluid by the jet nozzle 22 and the continuous suction of the drilling fluid in the coring inner cylinder 30 by the negative pressure space through the second hole 42, a flowing effect of continuously sucking and discharging the drilling fluid is formed.

[0045] During the coring drilling process, the drill bit contacts the bottom of the wellbore, and the drilling fluid is sprayed to the first hole 41 through the jet nozzle 22 and enters the bottom of the well through the annular gap 02 connected to the first hole 41. Then, a small part of the drilling fluid reaching the bottom of the well invades the coring inner cylinder 30 and is sucked into the negative pressure space 01 through the second hole 42, thus carrying out a kind of cycle. Most of the drilling fluid reaching the bottom of the well will return to the wellhead through the annular space, thus carrying out another cycle.

[0046] It can be seen from the above process that a part of the drilling fluid delivered to the bottom of the well will enter the coring inner cylinder 30. The flow direction of this part of the drilling fluid invading the coring inner cylinder 30 is the same as the direction in which the core enters the coring inner cylinder 30. Then, it can carry the cuttings inside the drill bit and the secondary cuttings generated by the collision between the broken core in the coring inner cylinder 30, making these cuttings move to a higher position away from the drill bit inside the coring inner cylinder 30. Finally, the cuttings can leave the bottom of the well and the lower bottom of the coring inner cylinder 30 in time, reducing the chance of the drill bit repeatedly cutting the cuttings. Since the process of the drilling fluid invading the coring inner cylinder 30 can provide a lubricating effect, it can reduce the frictional resistance of the core entering the coring inner cylinder 30, prevent the core that has entered the coring inner cylinder 30 from generating secondary cuttings and causing the probability of core blockage, and at the same time can improve the mechanical drilling speed.

[0047] The coring tool disclosed in the embodiments of the present invention may further include a filtering structure, which is used to filter the drilling fluid entering the second hole 42, so that small particle cuttings can pass through and participate in the normal circulating flow, and large particle cuttings will stay at the higher top of the coring inner barrel 30 and can be taken out together with the core when the core is taken out. In this solution, the setting of the filtering structure can prevent larger particle cuttings from entering the second hole 42, thereby preventing the second hole 42 from being blocked.

[0048] For the convenience of assembly, a tapered mounting hole 211 may be provided in the injection inner barrel body 21, and the injection nozzle 22 may include a tapered section 221, and the tapered section 221 may be fixed in the tapered mounting hole 211. The drilling fluid entering the injection inner barrel body 21 will enter the tapered section 221, and the drilling fluid converges and accumulates energy in the tapered section 221, thereby converting the pressure energy of the drilling fluid into kinetic energy. The setting of the tapered mounting hole 211 in the injection inner barrel body 21 can facilitate the adaptive installation of the tapered section 221.

[0049] Further, the injection nozzle 22 may further include an equal-diameter section 222, which is communicated with the tapered section 221 and extends into the negative pressure space 01. The equal-diameter section 222 is opposite to the water inlet of the first hole 41. After the drilling fluid is ejected at a high speed in the tapered section 221, it will enter the equal-diameter section 222 and finally be ejected into the first hole 41 through the equal-diameter section 222. Since the inner diameter of the equal-diameter section 222 is equal everywhere, it will not have a great impact on the ejected drilling fluid. At the same time, the equal-diameter section 222 extending into the negative pressure space 01 can make the ejection port of the injection nozzle 22 closer to the first hole 41, so that the drilling fluid ejected from the injection nozzle 22 is easier to enter the first hole 41 and is easier to form a negative pressure around the equal-diameter section 222.

[0050] To improve the installation stability of the injection nozzle 22, in a more specific solution, the injection inner barrel 20 disclosed in the embodiments of the present invention may further include a threaded compression sleeve 23, which is fixed within the injection inner barrel body 21 by threaded cooperation and presses on the large end of the tapered section 221 facing away from the negative pressure space 01. The inner cavity of the injection inner barrel body 21 is communicated with the tapered section 221 through the inner cavity of the threaded compression sleeve 23. In this structure, by adding a threaded compression sleeve 23 to further compress the injection nozzle 22, the injection nozzle 22 can be more stably installed in the tapered mounting hole 211.

[0051] In the embodiments of the present invention, the shape of the first hole 41 can be various. For example, the first hole 41 is an inclined hole as a whole, so that the drilling fluid ejected from the injection nozzle 22 can be gradually guided into the annular gap 02 after entering the first hole 41. Of course, the first hole 41 can also have other structures. In one embodiment, the first hole 41 can include a first hole section 411 and a plurality of second hole sections 412. The first hole section 411 extends along the central axis direction of the outer cylinder 10. Optionally, the first hole section 411 can be located on the central axis of the outer cylinder 10. The first orifices of the plurality of second hole sections 412 communicate with the first hole section 411, and the plurality of second hole sections 412 extend obliquely relative to the first hole section 411. The second orifices of the plurality of second hole sections 412 communicate with the annular gap 02. This structure enables the first hole section 411 to receive the drilling fluid ejected from the injection nozzle 22 and then flow to the annular gap 02 through the plurality of second hole sections 412, which is beneficial to improving the drainage efficiency.

[0052] The plurality of second hole sections 412 can be evenly distributed around the central axis direction of the outer cylinder 10 to achieve the effect of balanced drainage into the annular gap 02.

[0053] In order to better receive the drilling fluid ejected from the injection nozzle 22, the orifice of the first hole section 411 can be a conical orifice, and the projection of the ejection orifice of the injection nozzle 22 in the central axis direction of the outer cylinder 10 is located in the conical orifice. Of course, the first hole section 411 can also be a non-conical orifice, and the embodiments of the present invention do not limit the specific shape of the first hole section 411.

[0054] The flow regulating joint 40 disclosed in the embodiments of the present invention can include a base 401 and a protrusion 402. The protrusion 402 is provided on the base 401. Specifically, the protrusion 402 is fixed to the base 401. For example, the protrusion 402 and the base 401 can be an integral structure. The first hole section 411 can extend from the protrusion 402 into the base 401. The base 401 extends into the injection inner cylinder body 21 and is threadedly connected to the injection inner cylinder body 21, so as to facilitate the connection between the flow regulating joint 40 and the injection inner cylinder 20.

[0055] The base 401 can include an annular surface surrounding the protrusion 402. The annular surface, the protrusion 402 and the injection inner cylinder body 21 can form an annular groove 03. The second hole 42 can be opened in the base 401 and penetrate through to the annular surface. The negative pressure space 01 includes the space inside the annular groove 03. This structure enables the first hole section 411 to penetrate through to the protrusion 402, so as to be closer to the injection nozzle 22, and further makes it easier to form the negative pressure space 01 between the injection nozzle 22 and the flow regulating joint 40. At the same time, the space inside the annular groove 03 is relatively narrow, which is more conducive to the second hole 42 to suck the drilling fluid under negative pressure.

[0056] Further, the flow regulating joint 40 may further include an annular protrusion 403, which is distributed around the base 401 and fixed to the base 401. The end of the injection inner cylinder body 21 connected to the base 401 may abut against the annular protrusion 403, so as to avoid the problem that the base 401 extends excessively into the injection inner cylinder body 21 during the connection process between the injection inner cylinder body 21 and the base 401, resulting in too small a distance or even contact between the injection nozzle 22 and the base 401. Optionally, the flow regulating joint 40 may be of an integral structure. Correspondingly, the annular protrusion 403 and the base 401 are of an integral structure.

[0057] In the embodiment of the present invention, the second hole 42 may be one or multiple. When there are multiple second holes 42, the multiple second holes 42 are spaced apart in the direction around the central axis of the outer cylinder 10 on the flow regulating joint 40. The cross-sectional shape of the second hole 42 in the plane perpendicular to the central axis of the outer cylinder 10 may be arc-shaped or elliptical. Of course, the cross-sectional shape of the second hole 42 in the plane perpendicular to the central axis of the outer cylinder 10 may be circular, square, etc. The embodiment of the present invention does not limit the specific shape of the second hole 42.

[0058] In some specific embodiments, the core drill bit disclosed in the embodiment of the present invention may further include a core inner cylinder joint 51, a central shaft 52, a bearing 53, and a cylindrical gland 54. The flow regulating joint 40 further includes a cylindrical section 403. The central shaft 52 is inserted into the core inner cylinder joint 51 and fixed by threaded cooperation. The central hole 521 of the central shaft 52 communicates with the central hole 511 of the core inner cylinder joint 51. The cylindrical gland 54 is sleeved outside the core inner cylinder joint 51. The cylindrical gland 54 is inserted into the cylindrical section 403 and fixedly connected to the cylindrical section 403 by threaded cooperation. The bottom end of the bearing 53 is supported on the cylindrical gland 54. The central shaft 52 passes through the bearing 53 and overlaps on the top end of the bearing 53. An interface space 04 is formed between the central shaft 52 and the cylindrical section 403. The second hole 42 communicates with the interface space 03. The cavity of the core inner cylinder 30 is sequentially communicated with the second hole 42 through the central hole 511 of the core inner cylinder joint 51, the central hole 521 of the central shaft 52, and the interface space 04. This structure can realize the rotation of the core inner cylinder 30 relative to the flow regulating joint 40, the outer cylinder 10, and the injection inner cylinder 20, so that the core inner cylinder 30 rotates with the drill bit during drilling, and the taken core gradually enters the core inner cylinder 30.

[0059] As described above, the core barrel disclosed in the embodiments of the present invention may further include a filtering structure. Specifically, the filtering structure may be a filter joint 55. The filter joint 55 is located within the core inner barrel 30 and is connected to the central hole 511 of the core inner barrel joint 51 near the orifice of the core inner barrel 30. The filter joint 55 may be detachably connected to the core inner barrel joint 51, so as to facilitate subsequent replacement or maintenance of the filter joint 55. Optionally, the filter joint 55 may be detachably connected to the central hole 511 of the core inner barrel joint 51 by means of threaded engagement. Of course, the embodiments of the present invention do not limit the specific detachable connection manner between the filter joint 55 and the core inner barrel joint 51.

[0060] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims, and all of them fall within the protection scope of the present invention.

Claims

1. A core barrel, characterized in that, It includes an outer cylinder (10), a jet inner cylinder (20), a core barrel (30) and a flow regulating joint (40) arranged inside the outer cylinder (10). Among them, the flow regulating joint (40) is provided with a first hole (41) and a second hole (42); where: The jet inner cylinder (20) includes a jet inner cylinder body (21) and a jet nozzle (22) installed inside the jet inner cylinder body (21). The first end of the flow regulating joint (40) is inserted into the jet inner cylinder body (21) and is spaced from the jet nozzle (22). A negative pressure space (01) is formed between the first end of the flow regulating joint (40) and the jet inner cylinder body (21). The first hole (41) communicates with the negative pressure space (01) and faces the jet nozzle (22). The second hole (42) is offset from the jet nozzle (22) and communicates with the negative pressure space (01); The core barrel (30) is connected to the flow regulating joint (40). The core barrel (30) communicates with the second hole (41). An annular gap (02) is formed between the integral formed by the flow regulating joint (40) and the core barrel (30) and the outer cylinder (10). The first hole (41) communicates with the annular gap (02); The drilling fluid sprayed from the jet inner cylinder (20) to the first hole (41) can enter the annular gap (02) so that the negative pressure space (01) is in a negative pressure state. The negative pressure space (01) in the negative pressure state is used to adsorb the drilling fluid in the core barrel (30) through the second hole (42).

2. The coring drill tool according to claim 1, characterized in that, The jet inner cylinder body (21) is provided with a conical mounting hole (211). The jet nozzle (22) includes a conical section (221) and an equal-diameter section (222). The conical section (221) is fixed in the conical mounting hole (211). The equal-diameter section (222) is connected to the conical section (221) and extends into the negative pressure space (01). The equal-diameter section (222) faces the water inlet of the first hole (41).

3. The coring drill tool according to claim 2, wherein, The jet inner cylinder (20) further includes a threaded compression sleeve (23). The threaded compression sleeve (23) is fixed inside the jet inner cylinder body (21) by thread fitting and presses on the large end of the conical section (221) facing away from the negative pressure space (01). The inner cavity of the jet inner cylinder body (21) communicates with the conical section (221) through the inner cavity of the threaded compression sleeve (23).

4. The coring drill tool according to claim 1, characterized in that, The first hole (41) includes a first hole section (411) and a plurality of second hole sections (412). The first hole section (411) extends along the central axis direction of the outer cylinder (10). The first hole openings of the plurality of second hole sections (412) communicate with the first hole section (411). The plurality of second hole sections (412) extend obliquely with respect to the first hole section (411), and the second hole openings of the plurality of second hole sections (412) communicate with the annular gap (02).

5. The coring tool according to claim 4, characterized in that, The orifice of the first hole section (411) facing away from the second hole section (412) is a conical orifice, and the projection of the injection orifice of the injection nozzle (22) in the axial direction of the central axis is located in the conical orifice.

6. The coring tool according to claim 4, wherein The flow regulating joint (40) includes a base (401) and a protrusion (402) provided on the base (401). The first hole section (411) extends from the protrusion (402) into the base (401). The base (401) extends into the injection inner cylinder body (21) and is threadedly connected to the injection inner cylinder body (21). The base (401) includes an annular surface surrounding the protrusion (402). The annular surface, the protrusion (402) and the injection inner cylinder body (21) form an annular groove (03). The second hole (42) is opened in the base (401) and penetrates through to the annular surface. The negative pressure space (01) includes the space inside the annular groove (03).

7. The coring drill tool according to claim 6, wherein The flow regulating joint (40) further includes an annular protrusion (403) distributed around the base (401) and fixed to the base (401). The end of the injection inner cylinder body (21) connected to the base (401) abuts against the annular protrusion (403).

8. The coring tool according to claim 1, wherein There are multiple second holes (42). The multiple second holes (42) are spaced apart in the direction around the central axis of the outer cylinder (10) on the flow regulating joint (40). The cross-sectional shape of the second hole (42) in a plane perpendicular to the central axis is arc-shaped or elliptical.

9. The coring drill tool according to claim 1, characterized in that, The core barrel drill also includes a core barrel inner joint (51), a central shaft (52), a bearing (53) and a cylindrical gland (54). The flow regulating joint (40) further includes a cylindrical section (403). The central shaft (52) is inserted into the core barrel inner joint (51) and fixed by thread fitting. The cylindrical gland (54) is sleeved outside the core barrel inner joint (51). The cylindrical gland (54) is inserted into the cylindrical section (403) and fixedly connected to the cylindrical section (403) by thread fitting. The bottom end of the bearing (53) is supported on the cylindrical gland (54). The central shaft (52) passes through the bearing (53) and is lapped on the top end of the bearing (53). An interface space (04) is formed between the central shaft (52) and the cylindrical section (403). The second hole (42) communicates with the interface space (03). The cavity of the core barrel (30) is sequentially communicated with the second hole (42) through the central hole (511) of the core barrel inner joint (51), the central hole (521) of the central shaft (52) and the interface space (04).

10. The coring tool according to claim 9, characterized in that, The core barrel drill further includes a filter joint (55). The filter joint (55) is located inside the core barrel (30) and is connected to the core barrel inner joint (51) at the orifice of the central hole (511) adjacent to the core barrel (30). The filter joint (55) is detachably connected to the core barrel inner joint (51).

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