Tubing head

Abstract

A tubing head relates to the technical field of oil production wellheads. Horizontal connectors on the two sides of the four-way joint are located on the middle channel, a pipe column at the lower end of the oil pipe hanger extends to the position below the horizontal connectors on the two sides of the four-way joint, an annulus exists between the pipe column at the lower end of the oil pipe hanger and the middle channel, the pipe column at the lower end of the oil pipe hanger is in external threaded connection with a protection pipe, and spiral blades are welded to the outer side of the protection pipe. The oil pipe hanger has the advantages that the lower portion of the oil pipe hanger is connected with the protection pipe through the threads, the protection pipe plays a role in protecting the oil pipe hanger, and the spiral blade of the protection pipe enables fracturing flow-back fluid flowing out of the well bottom to be converted into a spiral flowing state. The spiral flow enables sand grains in the fracturing flow-back fluid to be thrown by centrifugal force to be close to the middle channel to flow, the fracturing flow-back fluid close to the protection pipe contains extremely few sand grains, abrasion of the oil pipe hanger, the sealing seat and the protection pipe is reduced, the service life is prolonged, and the protection pipe is of a detachable structure and can be replaced regularly.

Description

Technical Field

[0001] The utility model relates to the technical field of oil production wellheads, in particular to an oil pipe head. Background Art

[0002] In existing fracturing wellhead devices, the tubing spools are generally vertically intersected, and the fracturing fluid return fluid (containing sand particles) enters the horizontal interfaces on both sides of the tubing spool from the annulus between the tubing and casing and is discharged. The lower end of the tubing hanger is usually located at the interfaces on both sides. After the fracturing return fluid flows into and out of the central main diameter, the liquid will produce high-speed scouring of the tubing hanger, causing scouring, wear and perforation damage to the tubing hanger and failure. At the same time, it also damages the sealing seat at the bottom of the tubing hanger, resulting in seal failure and even tubing rupture accidents, affecting fracturing operations and oil and gas well production. Utility Model Content

[0003] In order to solve the problem of short service life of the current fracturing wellhead tubing hanger, the utility model provides a tubing head.

[0004] The technical solution provided by the utility model is: a tubing head including a four-way pipe, the vertical channel of the four-way pipe including a lower channel, a middle channel and an upper channel connected in sequence from bottom to top, the horizontal interfaces on both sides of the four-way pipe are located on the middle channel, the tubing hanger is sealed and connected to the upper channel through a sealing seat, top screws are provided on both sides of the upper channel to fix the tubing hanger, the lower end pipe string of the tubing hanger extends to a position below the horizontal interfaces on both sides of the four-way pipe, the lower end pipe string of the tubing hanger has a female thread for connecting the tubing, an annulus is formed between the lower end pipe string of the tubing hanger and the middle channel, the outer thread of the tubing hanger is connected to a protective tube, and spiral blades are welded to the outer side of the protective tube.

[0005] A layer of tungsten carbide is sprayed on the outer surface of the protective tube and the spiral blades.

[0006] The wall thickness of the protective tube is 2.5 mm.

[0007] A guide sleeve is extended downward from the protection tube. The outer circle of the guide sleeve is a conical ring surface with a reduced diameter downward. The inner hole of the guide sleeve is larger than the outer diameter of the oil pipe.

[0008] The beneficial effects of the utility model are as follows: a protective tube is connected to the lower part of the tubing hanger by a threaded connection, and the protective tube plays the role of protecting the tubing hanger. The spiral blades of the protective tube convert the fracturing return fluid flowing out from the bottom of the well into a spiral flow state. The spiral flow causes the sand particles in the fracturing return fluid to be thrown to flow near the middle channel by centrifugal force, and the fracturing return fluid near the protective tube contains very little sand particles, which reduces the wear of the tubing hanger, the sealing seat and the protective tube itself, and increases the service life. The protective tube has a detachable structure and can be replaced regularly. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] AttachmentFigure 1 It is a structural diagram of the present utility model.

[0010] In the figure, 1-cross-connection, 2-horizontal interface, 3-tubing hanger, 4-lower channel, 5-middle channel, 6-protection tube, 7-flow guide sleeve, 8-top screw, 9-sealing seat, 10-spiral blade, 11-upper channel. DETAILED DESCRIPTION

[0011] like Figure 1 As shown, a tubing head includes a spool 1. The vertical channels of the spool 1 include a lower channel 4, a middle channel 5, and an upper channel 11 that are sequentially connected from bottom to top. The horizontal interfaces 2 on both sides of the spool 1 are located on the middle channel 5. The tubing hanger 3 is sealed with the upper channel 11 by a sealing seat 9. Top screws 8 are provided on both sides of the upper channel 11 to fix the tubing hanger 3. The lower end tubing string of the tubing hanger 3 extends to a position below the horizontal interfaces 2 on both sides of the spool 1. The lower end tubing string of the tubing hanger 3 has a female thread for connecting the tubing. There is an annulus between the lower end tubing string of the tubing hanger 3 and the middle channel 5. The lower end tubing string of the tubing hanger 3 is externally threadedly connected to a protective tube 6, and a spiral blade 10 is welded to the outside of the protective tube 6.

[0012] A protective tube 6 is connected to the lower part of the tubing hanger 3 through a threaded connection. The protective tube 6 serves to protect the tubing hanger 3. The spiral blades 10 of the protective tube 6 convert the fracturing return fluid flowing out from the bottom of the well into a spiral flow state. The spiral flow causes the sand particles in the fracturing return fluid to be thrown by centrifugal force to flow near the middle channel 5. The fracturing return fluid near the protective tube 6 contains very little sand particles, which reduces the wear of the tubing hanger 3, the sealing seat 9 and the protective tube 6 itself, and increases the service life. The protective tube 6 is a detachable structure and can be replaced regularly.

[0013] A layer of tungsten carbide is sprayed on the outer surface of the protective tube 6 and the spiral blade 10 to increase the service life.

[0014] The wall thickness of the protection tube 6 is 2.5 mm, which has sufficient structural strength and minimizes the reduction of the annular cross-sectional area between the lower end string of the tubing hanger 3 and the middle channel 5, thereby reducing the resistance of the fracturing return fluid.

[0015] A guide sleeve 7 extends downward from the protection tube 6 . The outer circle of the guide sleeve 7 is a conical ring surface with a decreasing diameter downward. The inner hole of the guide sleeve 7 is larger than the outer diameter of the oil pipe, protecting the lower end surface of the oil pipe hanger 3 .

Claims

1. A tubing head, comprising a cross-piece (1), characterized in that: The vertical channel of the four-way (1) comprises a lower channel (4), a middle channel (5) and an upper channel (11) which are connected in sequence from bottom to top. The horizontal interfaces (2) on both sides of the four-way (1) are located on the middle channel (5). The tubing hanger (3) is sealed and connected to the upper channel (11) through a sealing seat (9). Top screws (8) are provided on both sides of the upper channel (11) to fix the tubing hanger (3). The lower end pipe string of the tubing hanger (3) extends to a position below the horizontal interfaces (2) on both sides of the four-way (1). The lower end pipe string of the tubing hanger (3) has a female thread for connecting the tubing. An annulus exists between the lower end pipe string of the tubing hanger (3) and the middle channel (5). The outer thread of the lower end pipe string of the tubing hanger (3) is connected to the protection pipe (6). The outer side of the protection pipe (6) is welded with a spiral blade (10).

2. The tubing head according to claim 1, characterized in that: A layer of tungsten carbide is spray-plated on the outer circumferential surfaces of the protection tube (6) and the spiral blade (10).

3. The tubing head according to claim 1, characterized in that: The wall thickness of the protection tube (6) is 2.5 mm.

4. The tubing head according to claim 1, characterized in that: A guide sleeve (7) extends downward from the protection tube (6). The outer circle of the guide sleeve (7) is a conical ring surface with a reduced diameter downward. The inner hole of the guide sleeve (7) is larger than the outer diameter of the oil pipe.

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