Anti-corrosion, anti-scale and anti-wax underground device for oil well

Abstract

The device comprises a bearing frame, an anode plate made of an aluminum alloy anode material is arranged on the outer side of the upper portion of the bearing frame, the lower portion of the bearing frame is filled with a solid scale inhibitor, and a blind hole used for containing a permanent magnet rod is formed in the lower end of a supporting frame. According to the anti-corrosion, anti-scale and anti-wax underground device for the oil well, the anti-corrosion function, the anti-scale function and the anti-wax function are integrated, and the anti-corrosion, anti-scale and anti-wax functions of magnetic anti-wax, solid agent anti-scale and electrochemical anti-corrosion functions are achieved from bottom to top.

Description

Technical Field

[0001] The invention belongs to the technical field of oil well equipment, and in particular relates to an anti-corrosion, anti-scaling and anti-wax downhole device for oil wells. Background Art

[0002] During the production process, crude oil needs to be lifted to the ground through the channel formed by the oil pipe, casing, and casing annulus. Most oil wells use the oil pipe string channel formed by the oil pipe connection to ensure the continuous production of crude oil. Due to the complex content of the lifted crude oil medium and the impact of the production increase operation, the oil pipe string is affected by various corrosive media during service, and corrosion often occurs. In severe cases, corrosion perforation will affect the function of the pipe string. Different oil well output media are usually accompanied by water with a certain mineralization degree. The formation water will contain scaling ions, which will cause scaling in the pipe string with the changes in temperature, pressure, and flow state. When scaling is serious, the flow area of ​​the oil pipe will gradually decrease, affecting the normal operation of the oil well lifting system. During the lifting process of crude oil, as the temperature and pressure change, the macromolecular carbon chain will aggregate, which we call waxing. As the waxing phenomenon becomes more and more serious, it is easy to cause the flow area of ​​a certain section of the oil pipe string to become smaller and smaller, resulting in an increase in the ground back pressure and the load of the lifting system. In severe cases, it will cause system failure and the pump operation has to be re-checked. Different treatment methods have been developed to address the adverse effects of the above three types of crude oil lifting on the oil pipe column. Existing devices with certain permanent magnetic anti-wax functions, such as the permanent magnetic anti-wax device described in CN 210343308 U, only place an annular permanent magnet in the short section, so that the magnetic lines of force pass through the flow surface to prevent the wax formation of the flowing crude oil. The function is relatively simple, with only the anti-wax function. CN 219587553U discloses an anti-corrosion and anti-scaling tool in the casing, which is integrated in a short section tool in the form of electrochemical anti-corrosion and solid scale inhibitors, but it also only has the two functions of anti-corrosion and anti-scaling. Summary of the invention

[0003] The purpose of the present invention is to provide an anti-corrosion, anti-scale and anti-wax downhole device for oil wells, which integrates the three functions of anti-corrosion, anti-scale and anti-wax into one, and plays the roles of magnetic anti-wax, solid agent anti-scale and electrochemical anti-corrosion from bottom to top respectively.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an anti-corrosion, anti-scale and anti-wax downhole device for oil wells, comprising a support frame, an anode plate made of aluminum alloy anode material is arranged on the outer side of the upper part of the support frame, and the bottom of the support frame is filled with a solid scale inhibitor for the oil well output fluid type, and a blind hole for placing a permanent magnet rod is arranged at the lower end of the support frame.

[0005] As a preferred technical solution of the present invention, it includes a support frame, an anode plate made of aluminum alloy anode material is arranged on the upper outer side of the support frame, the bottom of the support frame is filled with solid scale inhibitor, and a blind hole for placing a permanent magnet rod is arranged at the lower end of the support frame, and a permanent magnet rod is arranged in the blind hole.

[0006] As a preferred technical solution of the present invention, the support frame is cylindrical.

[0007] As a preferred technical solution of the present invention, the number of the anode plates is two, and the structure is tile-shaped.

[0008] As a preferred technical solution of the present invention, a stopper is provided in the middle of the support frame, the anode plate is located on the upper side of the stopper, and the solid scale inhibitor is located on the lower side of the stopper.

[0009] As a preferred technical solution of the present invention, the number of the blind holes is eight.

[0010] As a preferred technical solution of the present invention, threaded joints are provided at both ends of the support frame.

[0011] The beneficial effects of the present invention are as follows: when using the anti-corrosion, anti-scaling and anti-wax downhole device for oil wells of the present invention, after the anode plate made of magnetic rods, solid anti-scaling particles and anode materials is installed in a fixed position, the device is installed at the bottom of the oil pipe column and connected to the well. The magnetic field formed by the magnetic rods can inhibit the formation of macromolecular chains in the crude oil, thereby controlling the wax deposition process. At the same time, according to the scaling trend of the single well water type, the anti-scaling particles can gradually diffuse and dissolve to achieve a scaling effect. Anti-corrosion follows the electrochemical anti-corrosion mechanism, and the installed anode material is further dissolved to form a protective current, thereby protecting the oil pipe from large-scale corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of an anti-corrosion, anti-scaling and anti-wax downhole device for oil wells of the present invention;

[0013] Figure 2 The present invention is a schematic structural diagram of an anode plate in an anti-corrosion, anti-scaling and anti-wax downhole device for oil wells.

[0014] In the figure, 1. supporting frame, 2. anode plate, 3. stopper, 4. solid antiscalant, 5. blind hole, 6. threaded joint. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0016] Example 1

[0017] like Figure 1As shown, a downhole anti-corrosion, anti-scale and anti-wax device for a wellhead oil well of the present invention comprises a support frame 1, an anode plate 2 made of an aluminum alloy anode material is arranged on the outer side of the upper part of the support frame 1, a solid scale inhibitor 4 is filled below the support frame 1, a blind hole 5 for placing a permanent magnet rod is arranged at the lower end of the support frame 1, and a permanent magnet rod is arranged in the blind hole 5.

[0018] like Figure 2 As shown, the support frame 1 in the anti-corrosion, anti-scale and anti-wax downhole device for oil wells of the present invention is the main structure and is the main bearing component supporting other parts.

[0019] The bottom of the support frame 1 is a cylinder formed by an outer circle of φ114mm and an inner diameter of φ62mm, and the length of the cylinder is 250mm. There are 8 φ11mm blind holes evenly distributed according to the pitch circle diameter of φ88mm. The upper and lower ends of the blind holes are perpendicular to the axis, and a magnetic line release hole is processed 25mm away from the end of the cylinder. The outer hole layer of the release hole is M10×1.5mm threaded for installing magnetic line blocking nails.

[0020] like Figure 2 As shown, the anode plate 2 in the anti-corrosion, anti-scaling and anti-wax downhole device for wellhead oil wells of the present invention is a double-slip structure, and the material is Al alloy anode. The total design length is 769.86mm, the maximum design working temperature is 160℃, and the current efficiency is ≥65%. The radius of the large circle is R53.38mm, and the radius of the small circle is R37.50mm. 20mm is cut off along the center line in the middle.

[0021] A solid antiscalant particle filling space is formed inside the lower end of the support frame 1 , and an outer wall steel sleeve is used to wrap the storage space, and the space is filled with a solid antiscalant 4 .

[0022] Working principle of the tool: The support frame 1 in the anti-corrosion, anti-scale and anti-wax downhole device for wellhead oil wells of the present invention is connected to the oil pipe string, and the oil pipe string is lowered to the set depth. When the oil pump starts to work, the lifting medium flows through the oil pipe string to the position of the magnetic rod of the device, and the carbon chains with a waxing tendency in the crude oil will be suppressed under the action of the magnetic field. When it flows to the solid scale inhibitor filling section (i.e., the position where the solid scale inhibitor 4 is placed), the scale inhibitor further diffuses and dissolves, and is continuously released into the lifting medium through the flow channel of the inner screen tube, which plays a role in inhibiting scaling. At the same time, when the lifting medium flows through the anode installation pipe section (i.e., the anode plate 2 made of aluminum alloy anode material), a protective current is generated under the action of the flowing medium, thereby realizing electrochemical protection of the oil pipe string.

[0023] Example 2

[0024] like Figure 1As shown, different from Example 1, in Example 2, a downhole anti-corrosion, anti-scale and anti-wax device for oil wells of the present invention is provided with a block 3 in the middle of the support frame 1, the anode plate 2 is located on the upper side of the block 3, and the solid scale inhibitor 4 is located on the lower side of the block 3.

[0025] The stopper 3 and the support frame 1 are integral structures, and a filling hole is processed in the middle of the stopper 3. The filling hole is a waist-shaped hole structure with a diameter of φ8mm. The circumferential distribution dividing circle is φ90.5mm, accounting for 1 / 2 of the circumference.

[0026] Solid antiscaling particles are added from the filling holes in the block 3, and the particles depend on the water type of the oil well being used.

[0027] The blind hole is also an integral structure with the support frame 1, with a φ114mm outer diameter circular column and a φ62mm inner diameter through hole, of which 8 φ11mm blind holes are evenly distributed according to the pitch circle diameter φ88mm, and magnetic line release holes are processed vertically at the upper and lower ends of the blind hole, with a hole diameter of φ11mm, and a through hole structure. The total length of this part is 250mm.

[0028] Example 3

[0029] like Figure 1 As shown, different from Example 2, in Example 3, in an anti-corrosion, anti-scale and anti-wax downhole device for oil wells of the present invention, threaded joints 6 are provided at both ends of the support frame 1.

[0030] The support frame 1 can be quickly assembled on the oil pipe string through two threaded joints 6 .

Claims

1. Anti-corrosion, anti-scale and anti-wax downhole equipment for oil wells, It is characterized in that The invention comprises a support frame (1), wherein an anode plate (2) made of an aluminum alloy anode material is arranged on the outer side of the upper part of the support frame (1), a solid scale inhibitor (4) is filled below the support frame (1), and a blind hole (5) for placing a permanent magnet rod is arranged at the lower end of the support frame (1), and a permanent magnet rod is arranged in the blind hole (5).

2. The anti-corrosion, anti-scaling and anti-wax downhole device for oil wells according to claim 1, It is characterized in that The supporting frame (1) is cylindrical.

3. The anti-corrosion, anti-scaling and anti-wax downhole device for oil wells according to claim 2, It is characterized in that The number of the anode plates (2) is two, and the structure is tile-shaped.

4. The anti-corrosion, anti-scaling and anti-wax downhole device for wellhead oil wells according to claim 3, It is characterized in that A stopper (3) is provided in the middle of the support frame (1), the anode plate (2) is located on the upper side of the stopper (3), and the solid scale inhibitor (4) is located on the lower side of the stopper (3).

5. The anti-corrosion, anti-scaling and anti-wax downhole device for wellhead oil wells according to claim 4, It is characterized in that The number of the blind holes (5) is eight.

6. The anti-corrosion, anti-scaling and anti-wax downhole device for wellhead oil wells according to claim 5, It is characterized in that Threaded joints (6) are provided at both ends of the support frame (1).

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