Sand washing pipe for T-shaped multilateral well

Abstract

The utility model discloses a T-shaped multilateral well sand washing pipe which comprises a sand washing pipe body, the sand washing pipe body comprises a plurality of pipe joint assemblies, every two adjacent pipe joint assemblies are hinged through a ball head, and the angle between every two adjacent pipe joint assemblies is adjusted within the range of 1-3 degrees. The ball head comprises an inner hemisphere assembly and an outer hemisphere assembly which are connected end to end through a pipe joint assembly, the inner hemisphere assembly and the outer hemisphere assembly are arranged at the two ends of the pipe joint assembly respectively, the outer diameter of the inner hemisphere assembly is matched with the inner diameter of the outer hemisphere assembly, and communicated through holes are formed in the inner hemisphere assembly and the outer hemisphere assembly. The sand washing pipe for the T-shaped multilateral well can be suitable for the T-shaped multilateral well and a well with a high build-up rate, and sand washing, acid washing, descaling and the like can be carried out on the well; the overall structure is stable, using is convenient and fast, and application and popularization are facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of oil field production, in particular to a sand flushing pipe for a T-shaped branch well. Background Art

[0002] T-shaped drilling technology is a new technology developed based on sidetracking horizontal wellbore technology. Currently, nearly 500 new T-shaped lateral wellbores are added annually both domestically and internationally. After T-shaped lateral wells are put into production, sand production will occur in oil formations with loose cementation and good physical properties. Formation sand enters the wellbore with the produced fluid. Larger sand particles first settle at the lower level of the horizontal section, forming a sand bed. Smaller sand particles then enter the vertical section with the produced fluid. The increased flow area reduces the flow rate, causing some sand particles to settle further, forming sand bridges in the build-up section. Sand carried by the produced fluid causes wear on the pump, sand sticking in the tubing, and even sand burying the oil formation, rendering the well inoperable.

[0003] Since the inclination rate of T-branch wells is relatively large, generally greater than 16° / m, it is difficult for conventional coiled tubing or ordinary tubing to enter T-branch wells for sand flushing operations, affecting normal production and making it inconvenient to use. Utility Model Content

[0004] The purpose of the utility model is to solve the above problems and provide a T-type branch well sand flushing pipe that is suitable for T-type branch wells and high-inclination wells, can perform sand flushing, acid washing, descaling, etc. on such wells; and has a stable overall structure and is easy and quick to use.

[0005] To achieve the above-mentioned purpose, the technical solution of the utility model is: a sand flushing pipe for a T-shaped branch well, comprising a sand flushing pipe body, wherein the sand flushing pipe body comprises a plurality of pipe joint assemblies, each adjacent two pipe joint assemblies are hingedly connected by a ball head, and the angle between each adjacent two pipe joint assemblies is adjustable within the range of 1-3°.

[0006] Preferably, the ball head includes an inner hemisphere assembly and an outer hemisphere assembly connected end to end of the pipe joint assembly, the inner hemisphere assembly and the outer hemisphere assembly are respectively arranged at both ends of the pipe joint assembly, the outer diameter of the inner hemisphere assembly is adapted to the inner diameter of the outer hemisphere assembly, and the inner hemisphere assembly and the outer hemisphere assembly are both provided with connecting through holes.

[0007] Preferably, two pins are symmetrically provided on the outside of the circumference of the outer hemispherical component, and two limiting holes corresponding to the pins are provided on the circumference of the inner hemispherical component, and the inner diameter of the limiting holes is larger than the outer diameter of the pins.

[0008] Preferably, a first sealing ring is provided on the outer wall of the inner hemisphere assembly, and a second sealing ring is provided on the inner wall of the outer hemisphere assembly, and the first sealing ring and the second sealing ring are always in a compressed state.

[0009] Preferably, the pipe segment assembly includes an anti-corrosion coating, an intermediate layer and a metal shell. The anti-corrosion coating is provided at the innermost layer of the pipe segment assembly, and the intermediate layer is provided between the anti-corrosion coating and the metal shell.

[0010] The utility model discloses a sand flushing pipe for a T-shaped branch well, comprising a sand flushing pipe body, wherein the sand flushing pipe body comprises a plurality of pipe segment assemblies, each adjacent two pipe segment assemblies are hingedly connected by a ball head, and the angle between each adjacent two pipe segment assemblies is adjustable within the range of 1-3 degrees, the ball head comprises an inner hemisphere assembly and an outer hemisphere assembly connected end to end with the pipe segment assemblies, the inner hemisphere assembly and the outer hemisphere assembly are respectively arranged at two ends of the pipe segment assembly, the outer diameter of the inner hemisphere assembly is adapted to the inner diameter of the outer hemisphere assembly, and the inner hemisphere assembly and the outer hemisphere assembly are both provided with communicating through holes; compared with the prior art, the sand flushing pipe for a T-shaped branch well has the advantages of being applicable to T-shaped branch wells and wells with high build-up rates, and being capable of performing sand flushing, pickling, descaling, etc. on such wells; and the overall structure is stable, and the use is convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The utility model is a schematic diagram of the overall structure of a sand flushing pipe for a T-shaped branch well.

[0012] Figure 2 The utility model is a structural schematic diagram of a pipe segment assembly in a sand flushing pipe for a T-shaped branch well.

[0013] Figure 3 This is a schematic diagram of the connection of two adjacent pipe segment assemblies of the present invention.

[0014] Figure 4 It is a cross-sectional schematic diagram of the middle pipe section assembly of the present invention.

[0015] In the figure: 1. Sand blasting pipe body; 2. Pipe joint assembly; 21. Inner hemisphere assembly; 22. Outer hemisphere assembly; 23. Limiting hole; 24. Pin; 25. First sealing ring; 26. Countersunk hole; 27. Second sealing ring; 201. Anti-corrosion coating; 202. Middle partition layer; 203. Metal shell. DETAILED DESCRIPTION

[0016] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner, and thus only show components related to the present invention.

[0017] Please refer to Figure 1-4 A sand flushing pipe for a T-shaped branch well includes a sand flushing pipe body 1, wherein the sand flushing pipe body 1 includes multiple pipe section assemblies 2, each adjacent two pipe section assemblies 2 are hingedly connected by a ball head, and the angle between each adjacent two pipe section assemblies is adjusted within the range of 1-3°.

[0018] In actual use, the length of each pipe segment assembly 2 is about 15 cm, and the adjustment range of each adjacent pipe segment assembly 2 is 1-3°; therefore, after multiple pipe segment assemblies 2 are connected, as the overall length increases, the overall bending degree also gradually increases, thereby facilitating the overall entry into the T-shaped branch well for sand flushing operations.

[0019] For T-shaped branch wellbores with a curvature radius of less than 3.6 meters, after sand is produced in the formation, the sand flushing pipe body 1 can be used to smoothly enter and exit the T-shaped branch; and can directly reach the bottom of the branch wellbore, effectively improving the single well production of T-shaped branch wells and high-inclination wellbores, and extending the production increase period of such wells.

[0020] Specifically, the ball head includes an inner hemisphere component 21 and an outer hemisphere component 22 connected at the end of the pipe joint component 2. The inner hemisphere component 21 and the outer hemisphere component 22 are respectively arranged at both ends of the pipe joint component 2. The outer diameter of the inner hemisphere component 21 is adapted to the inner diameter of the outer hemisphere component 22. The inner hemisphere component 21 and the outer hemisphere component 22 are both provided with a connecting through hole 23, so that the sand flushing pipe body is connected as a whole, which is used to circulate the sand flushing working fluid to achieve hydraulic flushing.

[0021] Among them, two pins 24 are symmetrically provided on the outside of the circumference of the outer hemispherical assembly 22, and two limiting holes 26 corresponding to the pins 24 are provided on the circumference of the inner hemispherical assembly 21. The inner diameter of the limiting hole 26 is larger than the outer diameter of the pin 24, and the end of the pin 24 does not contact the bottom of the limiting hole 26; the purpose of setting the pin 24 is to prevent the inner hemispherical assembly 21 and the outer hemispherical assembly 22 from rotating, affecting the flow of the internal sand washing working fluid.

[0022] Please refer again Figure 3 After the hemispherical component 21 and the outer hemispherical component 22 are connected by a pin 24 (which can be understood as a hinge), the two can swing back and forth between the two pins 24, and the swing angle is between 1-3°. When swinging to the maximum angle, the outer walls of the two adjacent pipe segment components are connected.

[0023] In this embodiment, notches are provided at both ends of the pipe joint assembly 2. The notches are set to reserve margin for angle adjustment to avoid interference and jamming when adjusting the angle; since the swing angle between the two pipe joint assemblies is only 1-3° and the amplitude is small, a slight margin is sufficient for adjustment.

[0024] As a preferred solution, the outer wall of the inner hemisphere assembly 21 is provided with a first sealing ring 25, and the inner wall of the outer hemisphere assembly 22 is provided with a second sealing ring 27. The first sealing ring 25 and the second sealing ring 27 are always in a compressed state. The first sealing ring 25 and the second sealing ring 27 can be rubber rings to prevent the internal sandblasting working fluid from leaking out and improve the sealing performance.

[0025] In addition, the pipe joint assembly 2 includes an anti-corrosion coating 201, an intermediate layer 202 and a metal shell 203. The anti-corrosion coating 201 is arranged at the innermost layer of the pipe joint assembly, the intermediate layer 202 is arranged between the anti-corrosion coating 201 and the metal shell 203, and the metal shell 203 is arranged at the outermost layer; the anti-corrosion coating can be an epoxy coating, a perchlorethylene anti-corrosion coating or an acrylic anti-corrosion coating, etc. The intermediate layer 202 and the metal shell 203 are hard metals, the purpose of which is to improve the mechanical strength of the pipe joint assembly 2.

[0026] How to use the T-type branch well sand flushing pipe:

[0027] Mechanical flushing: ① Circulate and rotate the pipe while connecting and tripping the string. Combined mechanical and hydraulic flushing destroys the cuttings bed. This is a very effective wellbore flushing method. ② Rotate and move the string up and down, using the drill coupling to destroy the cuttings bed. ③ Strengthen solids control to promptly and effectively remove solids from the flushing fluid.

[0028] Hydraulic flushing: ① Use appropriate hydraulic parameters and well-flushing fluid properties to improve flushing effect; ② Increase the flow rate to achieve turbulent flow and reduce rheological properties to achieve the best effect.

[0029] Notes:

[0030] The sand flushing operation should shorten the time of connecting single roots and operate continuously as much as possible to prevent the annulus from settling during the pump stop period, which may cause sand blockage or sand jam.

[0031] Every 10 meters of sand flushing operation, the pipe string should be lifted to flush the sediment bed;

[0032] Pay close attention to the hydrocarbon content and performance changes of the sand flushing fluid, judge the changes in the downhole fluid, and prevent well control accidents;

[0033] If a jam occurs, slowly release the counter torque to keep the circulation unobstructed, lift the drill string, and ensure underground safety.

[0034] This new downhole tool is a specialized downhole tool for T-branch wellbores and wellbores with high build-up rates (build-up rates greater than 10° / m). It can be used to address production issues such as sand flushing, pickling, descaling, and plugging in T-branch wellbores and wellbores with high build-up rates.

[0035] This type of downhole tool can enter and exit horizontal wellbores quickly and easily without obstruction; it can directly reach the bottom of the branch wellbore; it can solve most production problems in T-shaped branch wellbores and wellbores with high inclination rates, effectively increasing the single-well production of T-shaped branch wells and wellbores with high inclination rates, and extending the production increase cycle of such wells.

[0036] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A sand flushing pipe for a T-shaped branch well, characterized in that: The sand flushing pipe body comprises a plurality of pipe section assemblies. Every two adjacent pipe section assemblies are hingedly connected via a ball head, and the angle between every two adjacent pipe section assemblies is adjustable within the range of 1-3 degrees.

2. The sand flushing pipe for T-shaped branch well according to claim 1, characterized in that: The ball head includes an inner hemisphere assembly and an outer hemisphere assembly connected end to end with a pipe joint assembly. The inner hemisphere assembly and the outer hemisphere assembly are respectively arranged at both ends of the pipe joint assembly. The outer diameter of the inner hemisphere assembly is adapted to the inner diameter of the outer hemisphere assembly. The inner hemisphere assembly and the outer hemisphere assembly are both provided with connecting through holes.

3. The sand flushing pipe for T-shaped branch well according to claim 2, characterized in that: Two pins are symmetrically arranged on the outside of the circumference of the outer hemispherical component, and two limiting holes corresponding to the pins are arranged on the circumference of the inner hemispherical component. The inner diameter of the limiting hole is larger than the outer diameter of the pin.

4. The sand flushing pipe for T-shaped branch well according to claim 3, characterized in that: A first sealing ring is provided on the outer wall of the inner hemisphere assembly, and a second sealing ring is provided on the inner wall of the outer hemisphere assembly. The first sealing ring and the second sealing ring are always in a compressed state.

5. The sand flushing pipe for a T-shaped branch well according to any one of claims 1 to 4, characterized in that: The pipe segment assembly comprises an anti-corrosion coating, an intermediate layer and a metal shell. The anti-corrosion coating is arranged on the innermost layer of the pipe segment assembly, and the intermediate layer is arranged between the anti-corrosion coating and the metal shell.

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