Gas box sealing structure for reverse circulation double-wall drilling tool

Abstract

The utility model discloses a gas box sealing structure for a reverse circulation double-wall drilling tool, which relates to the technical field of geological drilling equipment or drilling construction and mainly structurally comprises a sealing shell, a sealing ring, a spacer bush, an oil nipple wear-resistant sleeve and a gland. The structure is simple and reliable, lubricating oil can be filled at any time, and abrasion to the abrasion-resistant sleeve is reduced; the upper sealing ring and the lower sealing ring are separated by the spacer bush, the opening size of the sealing lip is adjusted by adjusting the tightness of the gland at the bottom, and the sealing effect is enhanced; the two layers of sealing rings are separated by the spacer ring, so that a sealing cavity can be formed, a certain amount of lubricating oil can be stored, the sealing rings can be cooled, lips can be lubricated, the sealing rings are prevented from being damaged due to dry grinding, and the service life of the sealing rings and the service life of the wear-resistant sleeve are prolonged; the sealing effect is enhanced, and gas leakage is prevented from affecting formation of a reverse circulation drilling process and the deslagging effect; and the lubricating oil is stored in the sealed cavity, so that the lubricating oil can be effectively prevented from being introduced into the hole by high-pressure gas, and the lubricating reliability is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of geological drilling equipment or drilling construction, in particular to an air box sealing structure for a reverse circulation double-wall drilling tool. Background Art

[0002] When reverse circulation drilling technology is used, the air box is the main component of the reverse circulation double-wall drill bit. Its main function is to allow high-pressure air to enter the annular gap of the double-wall drill pipe from the outside, reach the bottom of the hole, cool the drill bit, and carry rock powder.

[0003] For example, the patent with publication number CN104453716A discloses a compound double-circulation underbalanced casing drilling process, which is characterized by: using drilling and single-connection drilling process steps, starting the air compressor and water pump, the vaporized water in the pipeline drives the air hammer to work through the air inlet pipe, drives the compound double-circulation drilling tool to work, and finally discharged by the chip removal device, and starts the mud pump at the same time, the mud enters the casing and drill pipe annulus through the lower air box, flows to the well wall and the casing annulus through the fairing, and returns to the wellhead mud tank, and circulates repeatedly to ensure the pressure balance of the well wall; when connecting a single root, the three-way valve is opened, and the vaporized water formed by the air compressor and the water pump is reversed through the three-way valve, enters the continuous air supply system, and enters the air inlet pipe through the continuous air supply system to drive the air hammer to work, and drives the compound double-circulation drilling tool to work. The present invention solves the problems of collapse, air leakage, diameter reduction, block drop, anti-deflection, straightening, water cone, drill jam, blowout, etc. in the process of underbalanced drilling, and greatly improves the drilling speed.

[0004] The reliability of the sealing structure of the air box directly affects the drilling effect and drilling efficiency. During the construction process, the sealing ring needs to be replaced frequently due to problems such as unreliable sealing structure or poor sealing effect, severe wear of the sealing ring, etc., which greatly reduces the drilling efficiency and increases the drilling cost.

[0005] At present, during the reverse circulation drilling construction, the sealing effect of the air box of the reverse circulation double-wall drill bit is often not good. Most of them use V-rings, Y-rings or other seals. The sealing layer often uses a single layer of sealing. The sealing ring is only coated with a certain amount of lubricating oil during assembly. Lubricating oil cannot be added after assembly. Moreover, when high-pressure air enters the air box, a large part of the lubricating oil will be directly blown away. As the high-pressure air is replaced into the drill bit, the air box sealing ring can only be in a dry grinding state. At the same time, the sealing ring has a large diameter and a high external linear speed, which often causes the sealing ring to burn out or the sealing effect to be poor, and damages the wear-resistant sleeve. The sealing ring or the wear-resistant sleeve needs to be replaced with frequency conversion. This will result in the reverse circulation drilling process not being formed or the drilling efficiency being low due to air leakage in the air box during drilling, which increases the labor intensity of workers and increases the drilling cost. Therefore, it is necessary to improve the sealing structure of the air box and design an air box for reverse circulation double-wall drill bits with reliable sealing structure. Summary of the invention

[0006] In order to solve the above technical problems, the utility model provides an air box sealing structure for reverse circulation double-wall drilling tools, which can add lubricating oil to the sealing ring at any time to increase the lubrication effect and the reliability of the seal, thereby effectively extending the service life of the air box, reducing the labor intensity of workers and improving drilling efficiency. The structure is simple and practical, easy to install and use, and has low investment cost.

[0007] To achieve the above purpose, the utility model provides the following solutions:

[0008] The utility model provides a gas box sealing structure for reverse circulation double-wall drilling tools, comprising a sealing shell, a sealing ring, a spacer, a fuel nozzle, a wear-resistant sleeve and a pressure cover; the sealing shell and the wear-resistant sleeve are both annular parts, the wear-resistant sleeve is arranged on the outer wall of the drilling tool, the sealing shell is arranged on the outside of the wear-resistant sleeve and is connected to the main shell of the gas box; the spacer is arranged between the sealing shell and the wear-resistant sleeve, and the sealing ring is arranged at the upper end and the lower end of the spacer; the fuel nozzle is arranged on the sealing shell and is connected to the gap between the sealing shell and the wear-resistant sleeve, and the position of the fuel nozzle corresponds to the position of the sealing ring; the pressure cover is arranged at the bottom of the sealing shell, and the pressure cover extends into the gap between the sealing shell and the wear-resistant sleeve.

[0009] Optionally, the sealing ring is a Y-shaped sealing ring; the Y-shaped sealing ring is a Y-shaped structure.

[0010] Optionally, an air inlet is provided in the middle of the sealing shell, and the air inlet passes through the sealing shell, the spacer sleeve and the wear-resistant sleeve in sequence.

[0011] Optionally, the gland is connected to the bottom of the sealing housing via an adjusting bolt.

[0012] Optionally, two sealing rings are respectively provided at the upper end and the lower end of the spacer sleeve, and the spacer ring is provided between two adjacent sealing rings.

[0013] Optionally, the spacer ring is an annular member, and a plurality of oil storage grooves are circumferentially arranged on the spacer ring.

[0014] Compared with the prior art, the utility model has achieved the following technical effects:

[0015] The utility model discloses a gas box sealing structure for reverse circulation double-wall drilling tools, which has a simple and reliable structure and is convenient for workers to install. By arranging a refueling nozzle, lubricating oil can be added to the sealing chamber at any time, which can well increase the lubrication and sealing performance of the sealing ring lip, prolong the service life of the sealing ring, reduce the wear on the wear-resistant sleeve, and prolong the service life of the wear-resistant sleeve. The upper and lower sealing rings are separated by a spacer sleeve, and the opening size of the sealing lip is adjusted by adjusting the tightness of the pressure cover at the bottom to enhance the sealing effect. The two layers of sealing rings are separated by a spacer ring to form a sealing chamber, which can store a certain amount of lubricating oil, cool the sealing ring, lubricate the lip, prevent the sealing ring from being damaged due to dry grinding, and prolong the service life of the sealing ring and the wear-resistant sleeve. The double-layer sealing ring structure can well enhance the sealing effect, prevent gas leakage, and affect the formation and slag removal effect of the reverse circulation drilling process. The lubricating oil is stored in the sealing chamber, which can effectively prevent the lubricating oil from being replaced into the hole by high-pressure gas, thereby ensuring reliable lubrication. The frequency of replacing the sealing ring can be reduced, the labor intensity of workers can be reduced, the drilling efficiency can be improved, and the construction cost can be saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of the air box sealing structure for reverse circulation double-wall drilling tools in the utility model;

[0018] Figure 2 It is a partial enlarged structural schematic diagram of the A position in the air box sealing structure for the reverse circulation double-wall drilling tool in the utility model;

[0019] Figure 3 It is a partial enlarged structural schematic diagram of the B portion of the air box sealing structure for the reverse circulation double-wall drilling tool in the utility model;

[0020] Figure 4 It is a structural schematic diagram of a spacer ring in a gas box sealing structure for a reverse circulation double-wall drilling tool in the utility model;

[0021] Figure 5 The utility model is a schematic cross-sectional view of the spacer ring in the air box sealing structure for reverse circulation double-wall drilling tools.

[0022] Explanation of the accompanying drawings: 1. Y-type sealing ring; 2. Sealing housing; 3. Oil nozzle; 4. Spacer; 5. Wear-resistant sleeve; 6. Spacer ring; 7. Pressure cap; 8. Adjusting bolt; 9. Oil storage tank. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] like Figures 1 to 5 As shown, this embodiment provides an air box sealing structure for reverse circulation double-wall drilling tools, including a sealing shell 2, a sealing ring, a spacer sleeve 4, a refueling nozzle 3, a wear-resistant sleeve 5 and a pressure cover 7; the sealing shell 2 and the wear-resistant sleeve 5 are both annular parts, the wear-resistant sleeve 5 is arranged on the outer wall of the drilling tool, and the sealing shell 2 is arranged on the outside of the wear-resistant sleeve 5 and connected to the main shell of the air box; a spacer sleeve 4 is arranged between the sealing shell 2 and the wear-resistant sleeve 5, and two sealing rings are respectively arranged at the upper and lower ends of the spacer sleeve 4, and a spacer ring 6 is arranged between two adjacent sealing rings; the spacer ring 6 is an annular part, and a plurality of oil storage grooves 9 are circumferentially arranged on the spacer ring 6; the refueling nozzle 3 is arranged on the sealing shell 2 and is connected to the gap between the sealing shell 2 and the wear-resistant sleeve 5, and the position of the refueling nozzle 3 corresponds to the position of the sealing ring; the pressure cover 7 is connected to the bottom of the sealing shell 2 through the adjusting bolt 8, and the pressure cover 7 extends into the gap between the sealing shell 2 and the wear-resistant sleeve 5.

[0025] The sealing ring is a Y-shaped sealing ring 1; the Y-shaped sealing ring 1 is a Y-shaped structure.

[0026] An air inlet is arranged in the middle of the sealing shell 2 , and the air inlet passes through the sealing shell 2 , the spacer sleeve 4 and the wear-resistant sleeve 5 in sequence.

[0027] During assembly, first install the upper Y-type sealing ring 1 and spacer ring 6 in the sealing shell 2. The sealing shell 2 is connected to the main shell of the gas box by bolts. Install the spacer sleeve 4, and then install the Y-type sealing ring 1, spacer ring 6 and Y-type sealing ring 1 in sequence, and then install the pressure cover 7. The pressure cover 7 is connected to the sealing shell 2 by adjusting bolts 8. Do not press the pressure cover 7 too tightly with the newly installed Y-type sealing ring 1.

[0028] During operation, high-pressure gas reaches the bottom of the hole through the annular gap along the air inlet, and then returns to the hole mouth with rock powder. When in use, oil storage chambers are formed on the left and right layers between the two upper sealing rings, and lubricating oil can be added through the oil filling nozzle 3 at any time. The lubricating oil can enter the oil storage chamber through the oil storage groove 9 on the spacer ring 6, and the presence of lubricating oil in the oil storage chamber is always guaranteed. The lubricating oil is stored in the oil storage chamber, which can effectively prevent the lubricating oil from being brought into the hole by high-pressure air and the dry grinding of the sealing ring. As the use time increases, the sealing ring is slightly worn, and the tightness of the sealing ring can be adjusted by adjusting the pressing depth of the pressure cover 7 to ensure the reliability of the seal.

[0029] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0030] This specification uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the method and core idea of ​​the utility model. At the same time, for those skilled in the art, according to the idea of ​​the utility model, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the utility model.

Claims

1. A gas box sealing structure for reverse circulation double-wall drilling tools, characterized in that: It includes a sealing shell, a sealing ring, a spacer, a refueling nozzle, a wear-resistant sleeve, a spacer ring and a pressure cover; the sealing shell and the wear-resistant sleeve are both annular parts, the wear-resistant sleeve is arranged on the outer wall of the drilling tool, the sealing shell is arranged on the outside of the wear-resistant sleeve and is connected to the main shell of the air box; the spacer is arranged between the sealing shell and the wear-resistant sleeve, and the sealing ring is arranged on the upper and lower ends of the spacer; the refueling nozzle is arranged on the sealing shell and is connected to the gap between the sealing shell and the wear-resistant sleeve, and the position of the refueling nozzle corresponds to the position of the sealing ring; the pressure cover is arranged at the bottom of the sealing shell, and the pressure cover extends into the gap between the sealing shell and the wear-resistant sleeve.

2. The air box sealing structure for reverse circulation double-wall drilling tools according to claim 1 is characterized in that: The sealing ring is a Y-shaped sealing ring; the Y-shaped sealing ring is a Y-shaped structure.

3. The air box sealing structure for reverse circulation double-wall drilling tools according to claim 1 is characterized in that: An air inlet is arranged in the middle of the sealing shell, and the air inlet passes through the sealing shell, the spacer sleeve and the wear-resistant sleeve in sequence.

4. The air box sealing structure for reverse circulation double-wall drilling tools according to claim 1 is characterized in that: The gland is connected to the bottom of the sealing shell through an adjusting bolt.

5. The air box sealing structure for reverse circulation double-wall drilling tools according to claim 1 is characterized in that: Two sealing rings are respectively arranged at the upper end and the lower end of the spacer sleeve, and the spacer ring is arranged between two adjacent sealing rings.

6. The air box sealing structure for reverse circulation double-wall drilling tools according to claim 5 is characterized in that: The spacer ring is an annular member, and a plurality of oil storage grooves are arranged on the spacer ring along the circumferential direction.

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