A packing seal device for a reverse circulation drilling faucet used in air drilling.

Abstract

This utility model provides a packing sealing device for a reverse circulation drilling hydrant used in air drilling, relating to the field of oil drilling technology. It includes a flushing pipe, a central pipe at the lower end of the flushing pipe, and a gooseneck pipe at the upper end of the flushing pipe. A three-phase mixture of drilling fluid flows sequentially from the central pipe towards the flushing pipe and then the gooseneck pipe. A packing box is fitted onto the flushing pipe. An upper nut is fitted onto the outer surface of the upper end of the packing box, pressing the packing box against the end face of the gooseneck pipe. A clamping nut is fitted onto the outer surface of the lower end of the packing box, pressing it against the flushing pipe via the packing box. The lower end of the flushing pipe is pressed against the end face of the central pipe by a lower nut. This utility model features a novel structure, with the packing sealing device designed according to the flow direction of the three-phase mixture, perfectly adapting to the characteristics of the drilling medium. This structure ensures reasonable stress distribution on the sealing packing, facilitates easy assembly and disassembly, and has low overall assembly requirements. Simultaneously, the sealing packing in this structure has a high clamping force, improving the sealing effect and extending the service life of the packing.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling technology, and more specifically, to a packing seal device for a reverse circulation drilling faucet used in air drilling. Background Technology

[0002] Existing oil drilling swivels typically employ a forward circulation drilling method, using drilling fluid (also known as mud) as the drilling medium. Clean, high-pressure drilling fluid flows from the swivel into the gooseneck, then through the packing system into the center tube, and finally into the drill pipe to cool the drill bit. The rock broken by the drill bit flows out to the surface with the mud through the annular space between the drill pipe and the wellbore. This is the forward circulation drilling method. Air drilling, on the other hand, uses a reverse circulation method. High-pressure compressed air enters through the annular space of a special drill pipe, cools the drill bit, and carries the broken rock, mud, and water from the formation back out through the drill pipe's inner bore. This air then flows through the inner bore of the swivel's center tube into the packing system, the gooseneck, and finally out through the swivel. This is the reverse circulation drilling method. The working medium inside the packing unit is not clean drilling fluid, but a three-phase mixture of gas, liquid, and solid, consisting of compressed air, water, soil, and drill cuttings. Traditional packing seal structures use clean drilling fluid flowing in the forward direction as the working medium, which cannot meet the sealing requirements of the reverse flow of the three-phase mixture of gas, liquid, and solid.

[0003] Therefore, a new technical solution is needed to address the above problems. Utility Model Content

[0004] The purpose of this utility model is to provide a packing sealing device for a reverse circulation drilling faucet for air drilling, so as to solve one or more problems mentioned in the background art.

[0005] To achieve the above objectives, this application provides a packing sealing device for a reverse circulation drilling faucet used in air drilling, comprising a flushing pipe, a central pipe located at the lower end of the flushing pipe, and a gooseneck pipe located at the upper end of the flushing pipe. The drilling fluid solid-phase three-phase mixed medium flows sequentially from the central pipe toward the flushing pipe and the gooseneck pipe. A packing box is fitted on the flushing pipe, and an upper nut is fitted on the outer surface of the upper end of the packing box. The upper nut presses the packing box tightly against the end face of the gooseneck pipe. A clamping nut is fitted on the outer surface of the lower end of the packing box. The clamping nut is pressed onto the flushing pipe through the packing box. The lower end of the flushing pipe is pressed against the end face of the central pipe by a lower nut.

[0006] As a preferred implementation method, an upper pressure ring is provided between the upper end of the packing box and the gooseneck tube, and the upper nut presses the upper pressure ring tightly against the end face of the gooseneck tube through the packing box. A lower washer ring is provided between the lower end of the packing box and the punch pipe. The clamping nut presses the lower washer ring onto the punch pipe through the packing box.

[0007] As a preferred and feasible method, a clamping nut is provided above the clamping nut and fitted onto the outer circle of the packing box.

[0008] As a preferred method, multiple felt sealing ring mounting grooves are provided on the contact ring surface of the upper pressure ring that fits the punch pipe, and a punch pipe felt sealing ring is installed in each felt sealing ring mounting groove.

[0009] As a preferred embodiment, the inner contact surfaces of the upper pressure ring and the gooseneck tube, as well as the inner contact surfaces of the upper pressure ring and the packing box, are provided with first sealing ring mounting grooves, and first O-rings are installed in the first sealing ring mounting grooves.

[0010] As a preferred feasible method, the punched tube stepped tubular structure has an inner hole of the same size as the inner hole of the central tube. The lower end of the inner hole of the punched tube is provided with a concave stepped hole, which matches the outer step of the central tube. When the central tube rotates, the punched tube rotates synchronously with the central tube.

[0011] As a preferred embodiment, an annular sealing ring groove and an end face felt sealing ring groove are provided on the inner contact surface between the concave stepped hole at the lower end of the punch and the central tube. The end face felt sealing ring groove is located inside the annular sealing ring groove, and an end face felt sealing ring is installed in the end face felt sealing ring groove, while an annular sealing ring is installed in the annular sealing ring groove.

[0012] As a preferred embodiment, the packing box contains, from bottom to top, a lower packing washer, a sealing packing, a packing pressure ring, a sealing packing, a packing spacer, a sealing packing, a packing spacer, a sealing packing, and a packing washer. The clamping nut, through its thread engagement with the packing box, sequentially clamps the lower packing washer, the sealing packing, the packing pressure ring, the sealing packing, the packing spacer, the sealing packing, the packing spacer, the sealing packing, and the packing washer until the clamping force is applied to the inner step of the packing box.

[0013] As a preferred embodiment, the contact surfaces of the outer circle of the packing ring and the packing box, as well as the contact surfaces of the outer circle of the packing spacer ring and the packing box, are provided with second O-ring mounting grooves, and second O-rings are installed in the second O-ring mounting grooves.

[0014] Compared with the prior art, the beneficial effects of this utility model are: This utility model features a novel structure. The packing sealing device is designed according to the flow direction of the three-phase mixture, perfectly adapting to the characteristics of drilling media. This structure ensures reasonable stress distribution on the sealing packing, facilitates easy assembly and disassembly, and has low overall assembly requirements. Furthermore, the high clamping force of the sealing packing in this structure improves the sealing effect and extends the service life of the packing. Attached Figure Description

[0015] Figure 1A schematic diagram of a packing seal device for a reverse circulation drilling faucet for air drilling provided by this utility model. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] It should be noted that all uses of "first", "second", "third" and "fourth" in the embodiments of this utility model are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first", "second", "third" and "fourth" are only for the convenience of expression and should not be construed as limiting the embodiments of this utility model. Subsequent embodiments will not explain this in detail.

[0018] In the description of this utility model, it should be understood that the terms "center", "lateral", "longitudinal", "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0019] like Figure 1 As shown, this utility model provides a packing seal device for a reverse circulation drilling faucet used in air drilling, including a flushing pipe 1, a central pipe 2 located at the lower end of the flushing pipe, and a gooseneck pipe 3 located at the upper end of the flushing pipe. A three-phase mixture of drilling fluid (water, cuttings, and air) flows sequentially from the central pipe 2 towards the flushing pipe 1 and then towards the gooseneck pipe 3. A packing box 4 is fitted onto the flushing pipe 1, and an upper nut 5 is fitted onto the outer surface of the upper end of the packing box 4, pressing the packing box 4 against the end face of the gooseneck pipe 3. A clamping nut 7 is fitted onto the outer surface of the lower end of the packing box 4, pressing it against the flushing pipe 1 through the packing box 4. The lower end of the flushing pipe 1 is pressed against the end face of the central pipe 2 by a lower nut 8. The arrows in the figure represent the flow direction of the three-phase mixture of drilling fluid (water, cuttings, and air).

[0020] An upper pressure ring 9 is provided between the upper end of the packing box 4 and the gooseneck tube 3. The upper nut 5 presses the upper pressure ring 9 tightly against the end face of the gooseneck tube 3 through the packing box 4. A lower washer ring 6 is provided between the lower end of the packing box 4 and the punch tube 1. The clamping nut 7 presses the lower washer ring 6 tightly onto the punch tube 1 through the packing box 4.

[0021] Specifically, the upper nut 5 is connected to the gooseneck tube 3 via a trapezoidal thread. The upper end face and outer circumference of the upper pressure ring 9 are respectively provided with first sealing ring mounting grooves, and the inner hole of the upper pressure ring 9 is also provided with a felt sealing ring mounting groove. A first O-ring 92 is installed in the first sealing ring mounting groove on the upper end face of the upper pressure ring 9, and the same first O-ring 92 is also installed in the first sealing ring mounting groove on the outer circumference of the upper pressure ring 9. Multiple felt sealing ring mounting grooves are provided on the contact ring surface of the upper pressure ring 9 that contacts the punch tube, and a punch tube felt sealing ring 91 is installed in each felt sealing ring mounting groove.

[0022] In addition, a clamping nut 10 is provided above the clamping nut 7 and is sleeved on the outer circle of the packing box 4.

[0023] As shown in the figure, the punch 1 has a stepped tubular structure. The inner hole of the punch 1 is the same size as the inner hole of the central tube. The lower end of the inner hole of the punch 1 is provided with a concave stepped hole, and two annular grooves are provided on the lower end face. The two annular grooves are an annular sealing ring groove and an end face felt sealing ring groove, with the end face felt sealing ring groove located inside the annular sealing ring groove. Specifically, an annular sealing ring groove and an end face felt sealing ring groove are provided on the inner contact surface between the concave stepped hole at the lower end of the punch 1 and the central tube 2. An end face felt sealing ring 11 is installed in the end face felt sealing ring groove, and an annular sealing ring 12 is installed in the annular sealing ring groove.

[0024] It should be noted that the concave stepped hole at the lower end of the punch tube 1 matches the outer step of the central tube 2. When the central tube rotates, the punch tube 1 rotates synchronously with the central tube 2.

[0025] As shown in the figure, the upper end of the outer circle of the packing box 4 is provided with a stepped surface, and the upper end of the inner hole of the packing box 4 is also provided with a stepped surface. The upper nut 1 applies axial clamping force through the stepped surface of the outer circle of the packing box 4, and transmits it to the upper pressure ring 9 through the stepped surface of the inner hole, so that the upper end face of the upper pressure ring is pressed against the end face of the gooseneck tube. The lower end of the outer circle of the packing box 4 is provided with an external thread, and the clamping nut 7 is provided with an internal thread and screwed onto the packing box 4.

[0026] Specifically, the packing box 4 contains, from bottom to top, a packing under gasket 6, a sealing packing 41, a packing pressure ring 42, a sealing packing 41, a packing spacer 43, a sealing packing 41, a packing spacer 43, a sealing packing 41, and a packing washer 44. The clamping nut 7, through the threaded engagement with the packing box 4, sequentially clamps the packing under gasket 6, the sealing packing 41, the packing pressure ring 42, the sealing packing 41, the packing spacer 43, the sealing packing 41, the packing spacer 43, the sealing packing 41, and the packing washer 44 until the clamping force is applied to the inner step of the packing box 4.

[0027] The outer circle of the packing ring 44 and the inner contact surface of the packing box 4, as well as the outer circle of the packing spacer 43 and the inner contact surface of the packing box, are provided with second O-ring mounting grooves, and a second O-ring 46 is provided in the second O-ring mounting groove.

[0028] It should be noted that the punch tube 1 penetrates the inner bore of the packing gasket 44, the second O-ring seal 46, the packing spacer 43, the packing compression ring 42, and the sealing packing 41. There is a radial clearance between the outer circle of the punch tube 1 and the inner bore of the packing gasket, packing spacer, packing compression ring, and upper compression ring; there is an axial clearance between the packing gasket, packing spacer, packing compression ring, and upper compression ring. The outer circle of the punch tube 1 is pressed and sealed by the inner bore of the sealing packing 41 through the elastic deformation of the packing material.

[0029] Explanation of the principle: 1) In use, the upper nut 5 is screwed onto the gooseneck tube, pressing the upper pressure ring 9. The end face of the upper pressure ring 9 and the end face of the gooseneck tube are sealed by the first O-ring seal 92. The inner hole of the upper pressure ring 9 and the outer circle of the punch tube 1 are simply sealed by the punch tube felt seal 91. The felt filters rock debris, allowing moisture and compressed air to enter the axial gap between the upper pressure ring 9 and the packing ring 4. When the upper nut 5 presses the upper pressure ring 9 onto the end face of the gooseneck tube through the packing box 4, the upper pressure ring 9 is fixed and cannot rotate. The sealing packing 41, packing spacer ring 43, packing ring 44, second O-ring seal 46, oil cup 45, etc. assembled inside the packing box 4 are all fixed and do not rotate.

[0030] The lower nut 8 is screwed onto the central tube 2, simultaneously pressing the punch 1 against the central tube. The concave stepped hole at the lower end of the punch 1 mates with the stepped surface of the central tube for positioning. Solid matter is first filtered between the punch 1 and the end face of the central tube by the end face felt sealing ring 11, and then moisture and compressed air are sealed by the annular sealing ring 12 to prevent leakage. When the central tube rotates, the punch 1 rotates along with it because it is pressed against the central tube. The inner lip of the sealing packing 41 rotates relative to the outer surface of the punch 1, which constitutes a dynamic seal.

[0031] The upper nut 5 drives the packing box 4 to press the upper pressure ring 9. The end face of the upper pressure ring 9 is sealed with the end face of the gooseneck tube by the first O-ring 9, and the outer circle of the upper pressure ring 9 is sealed with the inner hole of the packing box 4 by the first O-ring 9. When the upper nut 5 presses the upper pressure ring 9 onto the end face of the gooseneck tube through the packing box 4, the lower nut 8, the packing box 4, the upper pressure ring 9, the clamping nut 7, and the packing gasket 44, sealing packing 41, packing spacer 43, and packing pressure ring 42 installed inside the packing box are all fixed together.

[0032] When the three-phase mixture of solid and liquid phases in reverse circulation drilling flows from the lower end through the central pipe and into the flushing pipe, the packing device operates as follows: 1) The inner diameter of the central pipe 2 and the flushing pipe 1 are the same, so the drilling medium smoothly enters the inner hole of the flushing pipe and flows into the gooseneck pipe; 2) Due to machining errors, there is a certain gap between the flushing pipe 1 and the central pipe plane, so a small amount of drilling medium enters this gap. First, the solid phase in the drilling medium is filtered by the end face felt sealing ring 11, and the solid phase is isolated to the O-ring seal, i.e., the annular sealing ring 12. The remaining liquid-gas mixture is sealed by the O-ring seal 12; 3) Another part of the drilling fluid passes through the outer circle of the flushing pipe 1 and the upper pressure The gap between the inner holes of ring 9 is first filtered by the felt sealing ring 91 to remove solids from the drilling medium, preventing them from entering the sealing surface between the sealing packing 41 and the outer circle of the punch pipe 1. The remaining liquid-gas mixture enters the axial gap between the upper pressure ring 9 and the packing gasket 44. The pressure of the liquid-gas mixture in this gap acts simultaneously on the end faces of the upper pressure ring 9 and the packing gasket 44, and the resulting axial force further presses the upper pressure ring 9 against the end face of the gooseneck tube; at the same time, it compresses the packing gasket 44 towards the sealing packing 41, further squeezing the sealing packing 41. The greater the pressure of the liquid-gas mixture, the greater the clamping force and the better the sealing effect. If the working pressure of the liquid-gas mixture is not high, a large clamping force is not required. In this way, the sealing packing 41 does not have to be under constant working pressure compression, and its service life will be extended. 4) After the liquid-gas mixture enters the cavity between the packing ring 44 and the sealing packing through the annular gap between the outer circle of the punch pipe 1 and the upper pressure ring 9 and the inner hole of the packing ring 44, the pressure of the liquid-gas mixture deforms the inner lip of the packing 41, causing the inner lip to fit against the outer circle of the punch pipe 1. Similarly, the greater the pressure of the liquid-gas mixture, the greater the clamping force and the better the sealing effect. If the working pressure of the liquid-gas mixture is not high, a large clamping force is not required. In this way, the sealing packing 41 does not have to be under constant working pressure compression, and its service life will be extended.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A packing seal device for a reverse circulation drilling faucet for air drilling, characterized in that, The system includes a flush pipe (1), a central pipe (2) located at the lower end of the flush pipe, and a gooseneck pipe (3) located at the upper end of the flush pipe. The drilling fluid solid-phase three-phase mixed medium flows sequentially from the central pipe (2) to the flush pipe (1) and the gooseneck pipe (3). A packing box (4) is fitted on the flush pipe (1). An upper nut (5) is fitted on the outer surface of the upper end of the packing box (4). The upper nut (5) presses the packing box (4) against the end face of the gooseneck pipe (3). A clamping nut (7) is fitted on the outer surface of the lower end of the packing box (4). The clamping nut (7) is pressed against the flush pipe (1) through the packing box (4). The lower end of the flush pipe (1) is pressed against the end face of the central pipe (2) by a lower nut (8).

2. The packing seal device for a reverse circulation drilling faucet for air drilling according to claim 1, characterized in that: An upper pressure ring (9) is provided between the upper end of the packing box (4) and the gooseneck tube (3). The upper nut (5) presses the upper pressure ring (9) against the end face of the gooseneck tube (3) through the packing box (4). A lower washer ring (6) is provided between the lower end of the packing box (4) and the punch tube (1). The clamping nut (7) presses the lower washer ring (6) against the punch tube (1) through the packing box (4).

3. The packing seal device for a reverse circulation drilling faucet for air drilling according to claim 1, characterized in that: Above the clamping nut (7) is a tightening nut (10) sleeved on the outer circle of the packing box (4).

4. The packing seal device for a reverse circulation drilling faucet for air drilling according to claim 2, characterized in that: The upper pressure ring (9) is provided with multiple felt sealing ring mounting grooves on the contact ring surface of the punch pipe, and a punch pipe felt sealing ring (91) is installed in each of the felt sealing ring mounting grooves.

5. The packing seal device for a reverse circulation drilling faucet for air drilling according to claim 2, characterized in that: The inner contact surface between the upper pressure ring (9) and the gooseneck tube, as well as the inner contact surface between the upper pressure ring (9) and the packing box, are provided with a first sealing ring mounting groove, and a first O-ring (92) is installed in the first sealing ring mounting groove.

6. The packing seal device for a reverse circulation drilling faucet for air drilling according to claim 1, characterized in that: The punch (1) has a stepped tubular structure. The inner hole of the punch (1) is the same size as the inner hole of the central tube. The lower end of the inner hole of the punch (1) is provided with a concave stepped hole. The concave stepped hole at the lower end of the punch (1) cooperates with the outer step of the central tube (2). When the central tube rotates, the punch (1) rotates synchronously with the central tube (2).

7. The packing seal device for a reverse circulation drilling faucet for air drilling according to claim 6, characterized in that: An annular sealing ring groove and an end face felt sealing ring groove are provided on the inner contact surface between the concave stepped hole at the lower end of the punch and the center tube (2). The end face felt sealing ring groove is located inside the annular sealing ring groove. An end face felt sealing ring (11) is installed in the end face felt sealing ring groove, and an annular sealing ring (12) is installed in the annular sealing ring groove.

8. An air drilling reverse circulation drilling swivel packoff as defined in claim 2 wherein: The packing box (4) is equipped with a packing under gasket (6), sealing packing (41), packing pressure ring (42), sealing packing (41), packing spacer (43), sealing packing (41), packing spacer (43), sealing packing (41), and packing gasket (44) in the order from bottom to top. The clamping nut (7) clamps the packing under gasket (6), sealing packing (41), packing pressure ring (42), sealing packing (41), packing spacer (43), sealing packing (41), packing spacer (43), sealing packing (41), and packing gasket (44) in sequence by the thread engagement force with the packing box (4) until the clamping force is applied to the inner step of the packing box (4).

9. The packing seal device for a reverse circulation drilling faucet for air drilling according to claim 8, characterized in that: The outer circle of the packing ring (44) and the inner contact surface of the packing box (4), as well as the outer circle of the packing spacer (43) and the inner contact surface of the packing box, are provided with a second O-ring mounting groove, and a second O-ring (46) is provided in the second O-ring mounting groove.

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