CN219262326U - Core barrel connecting structure of long barrel core drilling tool - Google Patents

Abstract

The utility model discloses a core barrel connecting structure of a long barrel core drilling tool, which is technically characterized by comprising a core barrel, a joint pipe and a shrinkage clamp; a first conical surface is arranged in the joint pipe; the outer wall surface of the shrinkage clamp is tightly attached to the first conical surface; when the diameter of the shrinkage clamp is reduced, the shrinkage clamp slides in a direction approaching the small diameter side of the first conical surface. The utility model solves the problems of complicated disassembly of the core barrel of the long barrel core drilling tool, easy release of the core, multiple auxiliary tools and the like. The core pulling-out device has the main advantages that two points are achieved, firstly, the core tube is preinstalled before being connected, the wellhead operation time is not required to be increased after the core tube is pulled out of a well, the core pulling-out risk is avoided after the shrinkage clamp is matched and locked with the joint seat, and auxiliary tools are not required to be added; secondly, when the connecting method is adopted for core drilling of the long barrel, the core is clamped and supported by taking a single section of core barrel as a unit, so that all weight of the long core column is prevented from being concentrated at the clamp position of the drill bit, the stress state of the clamp at the drill bit is improved, and the reliability of core drilling is improved.

Description

Core barrel connecting structure of long barrel core drilling tool

Technical Field

The utility model relates to the technical field of long-barrel core drilling tools, in particular to a core barrel connecting structure of a long-barrel core drilling tool.

Background

In the continuous coring process of a long well section, if the stratum is complete and the cementing degree is good, a long cylinder coring technology can be generally adopted to improve the coring efficiency. The long barrel core drilling tool is of a multi-barrel connecting structure, the total length of the drilling tool is larger than 18m, an upper drilling platform and a lower drilling platform cannot be directly connected, and the long barrel core drilling tool is generally detached into the upper drilling platform and the lower drilling platform of a single barrel drilling tool at a wellhead.

In order to improve the coring efficiency of the drill bit and the strength of the core column, the core diameter is generally the maximum allowable value when the coring drilling tool is designed, so that in order to increase the space for accommodating the core in the core barrel, the core barrel is mostly in a thin-wall structure. The direct threaded connection between the thin-wall core tubes in the long-barrel drilling tool cannot meet the strength requirement, and the long-barrel drilling tool is usually connected by adopting a joint. For example, chinese patent CN211524741U discloses a middle-long barrel coring expansion joint, which comprises a spline joint, wherein the upper end of the spline joint is a female thread, the middle outer part is a spline, the lower end of the spline is provided with a guiding tip, and the spline joint is externally provided with a spline housing; the lower end of the spline joint is connected with the inner pipe; the spline sleeve is internally provided with a spline, and the upper end of the spline is provided with a guide tip; the lower part of the spline housing is connected with the outer tube through threads; a cylindrical baffle ring is arranged in the spline housing, and the upper end and the lower end of the baffle ring are respectively limited by a spline on the spline housing and the threaded end face of the outer tube; the lower part of the inner pipe is connected with a sealing piston through threads; the lower part of the outer tube is connected with the lower joint through screw threads.

The long core drilling tool can not be directly thrown down from the drilling platform due to length limitation after the long barrel core drilling tool is out of the well, the long core barrel is required to be disassembled and assembled into a single pipe to be thrown down from the drilling platform successively at the well mouth, and when the long core barrel filled with the core with the structure is detached, the core in the pipe is easy to break off under the action of dead weight. At present, in order to disassemble a long core barrel and prevent a core from falling off, two methods are adopted: the first is to apply a special clamping tool to perform installation clamping when the screwing and unscrewing of the connecting threads between the core tubes are completed, as shown in fig. 1. The clamping tool can be installed after the connecting threads between the core tubes are screwed and disassembled, the core falling risk exists in the installation process, on the other hand, the clamping tool is fixed with the core tubes and the core by means of friction force, when mud is adhered or mud skin is adhered to the outer surface of the drilling tool, the clamping tool is easy to slide relatively with the core tubes after being installed, and certain core falling risk exists. The second is to design bolt holes in the circumference of the core barrel connecting joint, and assemble bolts through the bolt holes when the screwing and the unscrewing of connecting threads between the core barrels are completed, and the core is fixed from the circumference by applying the jackscrew principle, so as to avoid falling out, as shown in fig. 2. The bolt installation procedure is loaded down with trivial details, occupy well head time long, and the bolt core barrel is easily scraped and rubbed when throwing down the drilling platform, and the operation is inconvenient enough.

Therefore, the utility model hopes to provide a core barrel connecting structure of a long barrel core drilling tool, which can be directly disassembled into a single barrel without installing additional structures such as clamping tools and bolts after well logging, so that the possibility of core falling during core barrel disassembly is reduced, and meanwhile, the convenience of core barrel disassembly procedures is improved.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model aims to provide a core tube connecting structure of a long-barrel core drilling tool, which adopts a connecting joint structure capable of self-locking by utilizing core gravity, when the core tube is disassembled, the core descends under the action of dead weight, and the friction force between the outer surface of the core and the inner surface of a shrinkage clamp drives the shrinkage clamp to descend along the inner conical surface of a joint seat so as to hold the core tightly, thereby improving the core taking reliability.

In order to achieve the above purpose, the present utility model provides the following technical solutions: a core barrel connecting structure of a long barrel core drilling tool comprises a plurality of core barrels, joint pipes and shrinkage hoops, wherein two adjacent core barrels are connected through the joint pipes, and each joint pipe is internally provided with one shrinkage hoop; two ends of the joint pipe are respectively connected with the two core tubes in a threaded manner, and a first conical surface is arranged in the joint pipe; the shrinkage clamp is C-shaped, the inner diameter of the shrinkage clamp is equal to the inner diameter of the core barrel, and the outer wall surface of the shrinkage clamp is tightly attached to the first conical surface; when the diameter of the shrinkage clamp is smaller, the shrinkage clamp slides in a direction close to the small diameter side of the first conical surface, and when the diameter of the shrinkage clamp is larger, the shrinkage clamp slides in a direction close to the large diameter side of the first conical surface.

The utility model is further provided with: the inner side surface of the shrinkage clamp is provided with a plurality of bulges.

The utility model is further provided with: the protrusions are annular, and all the protrusions are distributed along the axis of the shrinkage clamp.

The utility model is further provided with: and a plurality of notches are formed in the inner side face of the shrinkage clamp, and penetrate through the shrinkage clamp along the axis of the shrinkage clamp.

The utility model is further provided with: all cuts are evenly distributed about the shrink band axis.

The utility model is further provided with: and two ends of the joint pipe are respectively positioned at the outer sides of the two core tubes.

The utility model is further provided with: the connector tube is internally provided with a second conical surface, and the small diameter side of the second conical surface is close to the small diameter side of the first conical surface; the end of the core barrel close to the large diameter side of the second conical surface is attached to the second conical surface.

The utility model is further provided with: the joint pipe is internally provided with a spacing belt, the spacing belt is positioned between the first conical surface and the second conical surface, and the diameter of the spacing belt is smaller than or equal to the small diameter of the first conical surface and the small diameter of the second conical surface.

The utility model is further provided with: and when the diameter of the shrinkage clamp is maximum, the shrinkage clamp abuts against the end face of the core barrel close to the first conical surface.

The utility model is further provided with: and each core barrel is provided with a limiting surface, and the limiting surfaces are attached to the end surfaces of the joint pipes.

In summary, compared with the prior art, the utility model has the following beneficial effects: the utility model solves the problems of complicated disassembly of the core barrel of the long barrel core drilling tool, easy release of the core, multiple auxiliary tools and the like. The core pulling-out device has the main advantages that two points are achieved, firstly, the core tube is preinstalled before being connected, the wellhead operation time is not required to be increased after the core tube is pulled out of a well, the core pulling-out risk is avoided after the shrinkage clamp is matched and locked with the joint seat, and auxiliary tools are not required to be added; secondly, when the connecting method is adopted for core drilling of the long barrel, the core is clamped and supported by taking a single section of core barrel as a unit, so that all weight of the long core column is prevented from being concentrated at the clamp position of the drill bit, the stress state of the clamp at the drill bit is improved, and the reliability of core drilling is improved.

Drawings

FIG. 1 is a schematic diagram of a prior art clamp disassembly using an auxiliary tool;

FIG. 2 is a schematic view of a prior art bolt-on assembly;

fig. 3 is a full cross-sectional view of an embodiment.

In the figure: 1. a core barrel; 2. a joint pipe; 21. a first conical surface; 22. a second conical surface; 23. a spacer tape; 3. shrink the clamp; 31. a notch; 32. a protrusion.

Detailed Description

The technical solutions of the present utility model will be clearly described below with reference to the accompanying drawings, and it is obvious that the described embodiments are not all embodiments of the present utility model, and all other embodiments obtained by a person skilled in the art without making any inventive effort are within the scope of protection of the present utility model.

It should be noted that, the positional or positional relationship indicated by the terms such as "center", "upper", "lower", "horizontal", "left", "right", "front", "rear", "lateral", "longitudinal", etc. are based on the positional or positional relationship shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Examples

As shown in fig. 3, which is a basic structure of a preferred embodiment of the present utility model, a core barrel connecting structure of a long barrel core drilling tool comprises a plurality of core barrels 1, joint pipes 2 and shrinkage clips 3, wherein two adjacent core barrels 1 are connected through the joint pipes 2, and each joint pipe 2 is internally provided with a shrinkage clip 3; two ends of the joint pipe 2 are respectively in threaded connection with the two core pipes 1, and a first conical surface 21 is arranged in the joint pipe 2; the shrinkage clamp 3 is C-shaped, the inner diameter of the shrinkage clamp is equal to the inner diameter of the core barrel 1, and the outer wall surface of the shrinkage clamp is tightly attached to the first conical surface 21; when the diameter of the shrinkage fit 3 is reduced, the shrinkage fit slides in a direction toward the small diameter side of the first tapered surface 21, and when the diameter of the shrinkage fit 3 is increased, the shrinkage fit slides in a direction toward the large diameter side of the first tapered surface 21.

In this embodiment, the first conical surface 21 is used with a large diameter upward, and during normal drilling, the core moves upward from the core barrel 1, and the outer wall of the core contacts with the inner wall of the shrinkage clamp 3. Under the action of friction force, the core drives the shrinkage clamp 3 to move upwards for a distance; when the drill lifts the core, the core descends relative to the core tube 1 under the action of gravity, and simultaneously drives the shrinkage clamp 3 to descend together. At this time, the shrinkage clamp 3 is limited by the first conical surface 21 to shrink in diameter, and gradually holds the core tightly. When the shrinkage clamp 3 reaches the lowest position, no relative sliding exists among the core, the shrinkage clamp 3 and the joint pipe 2, and the normal disassembly procedure of the long core barrel 1 after the lifting of the drill and the well taking of the drilling tool can be performed at the moment.

Specifically, the two ends of the joint pipe 2 are respectively positioned at the outer sides of the two core barrel 1, the joint pipe 2 tightly holds the core barrel 1 from the outer sides, and the connection stability between the joint pipe 2 and the core barrel 1 is improved.

Specifically, each core barrel 1 is provided with a limiting surface, and the limiting surfaces are attached to the end surfaces of the joint pipes 2. The limiting surface can avoid the tight threaded connection between the joint pipe 2 and the core barrel 1, and reduce the occurrence of the phenomenon of sliding wires.

Specifically, the inner side surface of the shrinkage clamp 3 is provided with a plurality of protrusions 32. The protrusions 32 can increase the friction force between the outer wall of the core and the inner wall of the shrinkage clamp 3, and further reduce the possibility of dropping the core when the core barrel 1 is disassembled.

Specifically, the protrusions 32 are annular, and all the protrusions 32 are arranged along the axis of the shrinkage clamp 3.

Specifically, a plurality of notches 31 are formed in the inner side surface of the shrinkage clamp 3, and the notches 31 penetrate through the shrinkage clamp 3 along the axis of the shrinkage clamp 3. The cut-out 31 enables the shrink band 3 to be more easily changed in size of the diameter.

In particular, all the cuts 31 are uniformly distributed about the axis of the shrink band 3.

Specifically, a second conical surface 22 is disposed in the joint pipe 2, and the small diameter side of the second conical surface 22 is close to the small diameter side of the first conical surface 21; the end of the core barrel 1, which is close to the large diameter side of the second conical surface 22, is attached to the second conical surface 22. During drilling, the core barrel 1 is held tightly by the second conical surface 22, and the stability of the connection between the joint pipe 2 and the core barrel 1 is improved. When the drill lifts the cutting core, the core barrel 1 is more easily detached under the guidance of the second conical surface 22.

Specifically, a spacer 23 is disposed in the joint pipe 2, the spacer 23 is located between the first conical surface 21 and the second conical surface 22, and the diameter of the spacer 23 is smaller than or equal to the minor diameters of the first conical surface 21 and the minor diameters of the second conical surface 22. If the shrinkage clamp 3 slides into the second conical surface 22, the clamping effect on the core can not be achieved when the core is lifted on the drilling tool, and the arrangement of the spacing belt 23 reduces the possibility that the shrinkage clamp 3 enters the second conical surface 22.

Specifically, when the diameter of the shrinkage clamp 3 is maximum, the shrinkage clamp 3 abuts against the end face of the core barrel 1 close to the first conical surface 21, and the highest position of the shrinkage clamp 3 is limited, so that the shrinkage clamp 3 is prevented from entering the core barrel 1 at the upper end of the joint pipe 2.

In summary, the present embodiment solves the problems of complicated disassembly of the core barrel 1 of the long barrel core drilling tool, easy core removal, multiple auxiliary tools, and the like. The core pulling-out device has the main advantages that two points are adopted, firstly, the core tube 1 is pre-installed before being connected, the wellhead operation time is not required to be increased after the well is pulled out, the core pulling-out risk is avoided after the shrinkage clamp 3 is matched and locked with the joint seat, and auxiliary tools are not required to be added; secondly, when the connecting method is adopted for core drilling of the long barrel, the core is clamped and supported by taking the single-section core barrel 1 as a unit, so that all weight of the long core column is prevented from being concentrated at the clamping hoop position of the drill bit, the stress state of the clamping hoop at the drill bit is improved, and the core drilling reliability is improved.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. A long barrel core drilling tool core barrel connection structure which characterized in that: the device comprises a plurality of core tubes (1), joint pipes (2) and shrinkage hoops (3), wherein two adjacent core tubes (1) are connected through the joint pipes (2), and each joint pipe (2) is internally provided with one shrinkage hoop (3);

two ends of the joint pipe (2) are respectively in threaded connection with the two core pipes (1), and a first conical surface (21) is arranged in the joint pipe (2); the shrinkage clamp (3) is C-shaped, the inner diameter of the shrinkage clamp is equal to the inner diameter of the core barrel (1), and the outer wall surface of the shrinkage clamp is tightly attached to the first conical surface (21); when the diameter of the shrinkage clamp (3) is reduced, the shrinkage clamp slides towards the small diameter side of the first conical surface (21), and when the diameter of the shrinkage clamp (3) is increased, the shrinkage clamp slides towards the large diameter side of the first conical surface (21).

2. The long barrel coring drilling tool core barrel connection structure according to claim 1, wherein: the inner side surface of the shrinkage clamp (3) is provided with a plurality of bulges (32).

3. The long barrel coring drilling tool core barrel connecting structure according to claim 2, wherein: the protrusions (32) are annular, and all the protrusions (32) are distributed along the axis of the shrinkage clamp (3).

4. The long barrel core drilling tool core barrel connecting structure according to any one of claims 1-2, wherein: the inner side surface of the shrinkage clamp (3) is provided with a plurality of notches (31), and the notches (31) penetrate through the shrinkage clamp (3) along the axis of the shrinkage clamp (3).

5. The long barrel coring drilling tool core barrel connection structure according to claim 4, wherein: all the notches (31) are uniformly distributed around the axis of the shrink band (3).

6. The long barrel core drilling tool core barrel connecting structure according to any one of claims 1-2, wherein: two ends of the joint pipe (2) are respectively positioned at the outer sides of the two core pipes (1).

7. The long barrel coring drilling tool core barrel connection structure according to claim 6, wherein: a second conical surface (22) is arranged in the joint pipe (2), and the small diameter side of the second conical surface (22) is close to the small diameter side of the first conical surface (21); the end of the core barrel (1) which is close to the large diameter side of the second conical surface (22) is attached to the second conical surface (22).

8. The long barrel coring drilling tool core barrel connection structure according to claim 7, wherein: the connector pipe (2) is internally provided with a spacing belt (23), the spacing belt (23) is positioned between the first conical surface (21) and the second conical surface (22), and the diameter of the spacing belt (23) is smaller than or equal to the small diameter of the first conical surface (21) and the small diameter of the second conical surface (22).

9. The long barrel coring drilling tool core barrel connection structure according to claim 1, wherein: when the diameter of the shrinkage clamp (3) is maximum, the shrinkage clamp (3) is abutted against the end face of the core barrel (1) close to the first conical surface (21).

10. The long barrel coring drilling tool core barrel connection structure according to claim 1, wherein: and each core barrel (1) is provided with a limiting surface, and the limiting surfaces are attached to the end surfaces of the joint pipes (2).

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