Cathode protection assembly for oil well Christmas tree in carbon dioxide injection block

Abstract

The utility model discloses a carbon dioxide injection block oil well Christmas tree cathode protection assembly which comprises a test pile, a sacrificial anode and a reference electrode, the test pile is provided with an insulation wiring panel, the insulation wiring panel is provided with a first binding post, a second binding post, a third binding post and a fourth binding post, and the first binding post, the second binding post, the third binding post and the fourth binding post are arranged on the test pile. The first binding post is connected with the sacrificial anode through a third cable, the second binding post is connected with an oil nozzle plug of the Christmas tree through a first cable, and the third binding post is connected with a large flange plate of the Christmas tree through a second cable. And the fourth binding post is connected with the reference electrode through a fourth cable. According to the cathode protection assembly for the oil well Christmas tree in the carbon dioxide injection block, a metal device on the Christmas tree is protected, anti-corrosion protection on the device is achieved under the condition that the Christmas tree is sealed, interference to surrounding equipment is small, the service life of the protection device is long, and the detection effect of the device is good.

Description

Technical Field

[0001] The utility model relates to a Christmas tree protection component, more specifically, to a cathode protection component for a Christmas tree in an oil well in a carbon dioxide injection area. Background Art

[0002] Corrosion is a common problem in the production process of existing oil wells in CO2-injected areas, affecting every stage of production. Due to a variety of factors, corrosion often occurs in metal equipment and pipelines, impacting the normal operation and safety of oilfield production. In the gathering and transportation system, the most prominent issues are corrosion of the wellhead equipment and internal corrosion of the gathering and transportation pipelines in CO2-injected wells. As the water content in CO2-injected wells increases, the CO2 dissolves in water and forms weakly acidic carbonic acid. The electrolysis of this carbonic acid causes metal corrosion, with ferrous carbonate flakes flaking off the metal pipe walls. Furthermore, trace amounts of hydrogen sulfide in the oil well's produced fluid react with water to form corrosive sulfuric acid, which can cause severe corrosion within the wellhead equipment and gathering and transportation pipelines. Equipment corrosion can lead to a gradual thinning of the metal material, and in severe cases, can cause perforations or punctures, damaging the equipment and causing leaks. Utility Model Content

[0003] Based on this, it is necessary to provide a cathodic protection assembly for the Christmas tree of oil wells in the carbon dioxide injection block to address the above technical problems.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A cathodic protection assembly for a Christmas tree in an oil well in a carbon dioxide injection block, characterized in that the cathodic protection assembly comprises a test pile, a sacrificial anode, and a reference electrode; the test pile is provided with an insulating wiring panel; the insulating wiring panel is provided with a first terminal, a second terminal, a third terminal, and a fourth terminal; the first terminal is connected to the sacrificial anode via a third cable; the second terminal is connected to the oil nozzle plug of the Christmas tree via a first cable; the third terminal is connected to the large flange of the Christmas tree via a second cable; and the fourth terminal is connected to the reference electrode via a fourth cable.

[0006] As a preferred embodiment of the present invention, the sacrificial anode is made of aluminum alloy.

[0007] As a preferred embodiment of the present invention, the sacrificial anode contains 8% zinc and 5% magnesium in terms of mass.

[0008] As a preferred embodiment of the present invention, the test pile is a hollow structure.

[0009] As a preferred embodiment of the present invention, the first cable, the second cable, the third cable and the fourth cable are all routed from the bottom of the test pile.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] The utility model provides a cathodic protection assembly for a Christmas tree in an oil well in a carbon dioxide injection block. The cathodic protection assembly protects metal devices on the Christmas tree, thereby achieving corrosion protection for the devices while the Christmas tree is sealed. The assembly has minimal interference with surrounding equipment, a long service life for the protection device, and good device detection effects. Furthermore, the assembly effectively resolves the problem of Christmas tree corrosion damaging the gathering and transportation process, thereby maintaining the normal operation and safety of oilfield production. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the solutions in the present invention, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 This is a schematic diagram of the three-dimensional structure of the cathodic protection assembly of the Christmas tree of the oil well in the carbon dioxide injection block of the present invention;

[0014] The markings in the figure are as follows: 1. Oil nozzle plug; 2. Large flange; 3. Test pile; 30. Insulated terminal panel; 31. First terminal; 32. Second terminal; 33. Third terminal; 34. Fourth terminal; 4. Sacrificial anode; 5. First cable; 6. Second cable; 7. Third cable; 8. Fourth cable; 9. Reference electrode. DETAILED DESCRIPTION

[0015] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0016] like Figure 1As shown, the cathodic protection assembly of the Christmas tree of the oil well in the carbon dioxide injection block includes a test pile 3, a sacrificial anode 4 and a reference electrode 9. The test pile 3 is provided with an insulating wiring panel 30, and the insulating wiring panel 30 is provided with a first terminal 31, a second terminal 32, a third terminal 33 and a fourth terminal 34. The first terminal 31 is connected to the sacrificial anode 4 through a third cable 7, the second terminal 32 is connected to the oil nozzle plug 1 of the Christmas tree through a first cable 5, the third terminal 33 is connected to the large flange 2 of the Christmas tree through a second cable 6, and the fourth terminal 34 is connected to the reference electrode 9 through a fourth cable 8.

[0017] It should be noted that the sacrificial anode 4 is made of aluminum alloy.

[0018] In addition, the sacrificial anode 4 contains 8% zinc and 5% magnesium by mass.

[0019] In addition, the test pile 3 is a hollow structure.

[0020] The first cable 5 , the second cable 6 , the third cable 7 and the fourth cable 8 are all routed from the bottom of the test pile 3 .

[0021] The working mode of the cathodic protection assembly of the Christmas tree of the oil well in the carbon dioxide injection block is described below.

[0022] First, modifications were made based on the nozzle plug and the large flange of the casing of the wellhead Christmas tree device.

[0023] Determine the welding position on the nozzle plug 1 of the Christmas tree and grind out the space required for the welding mold. Split the first cable 5 to a length that roughly matches the length of the groove below the welding mold. Place the welding mold in the welding position, split the cable and insert it under the mold. Place the patch, thermite flux, and ignition powder in the mold in that order. Use the igniter to ignite the ignition port of the welding mold. Hammer the surface of the weld clean and apply the patch to repair the pipeline's corrosion protection layer.

[0024] Perform the same operation on the large flange 2 of the Christmas tree to lead out the second cable 6. Connect the other ends of the first cable 5 and the second cable 6 to the test pile 3, and lead out the third cable 7 to the sacrificial anode 4.

[0025] Finally, a fourth cable 8 is led out from the test pile 3 and connected to a reference electrode 9. The reference electrode 9 is used to accurately monitor the state of the cathodic protection and perform potential measurement of the sacrificial anode protection.

[0026] By attaching a more active metal to the wellhead Christmas tree, making it the anode, the oxidation reaction is concentrated at the external anode. Sufficient sacrificial anode electron flow compensates for the potential electrochemical corrosion of the wellhead Christmas tree (carbon steel / low-alloy steel) components, which are originally at a relatively low potential. This places the low-potential components at a higher potential relative to the anode, achieving cathodic protection and inhibiting corrosion of the protected Christmas tree, which acts as the cathode. Furthermore, the reference electrode can be used to detect the pipeline's protective potential and monitor the current.

[0027] The cathodic protection assembly of the Christmas tree in the oil wells of the CO2 injection block protects the metal devices on the Christmas tree, realizing anti-corrosion protection of the devices while the Christmas tree is sealed. It has little interference with surrounding equipment, long service life of the protection device, and good device detection effect. It also effectively solves the problem of Christmas tree corrosion damaging the gathering and transportation process, maintaining the normal operation and safety of oilfield production.

[0028] Obviously, the embodiments described above are only part of the embodiments of the present application, rather than all the embodiments. The drawings provide preferred embodiments of the present application, but do not limit the patent scope of the present application.

Claims

1. A cathodic protection assembly for an oil well Christmas tree in a carbon dioxide injection area, characterized in that: The cathodic protection assembly of the oil well Christmas tree in the carbon dioxide injection block comprises a test pile (3), a sacrificial anode (4) and a reference electrode (9); the test pile (3) is provided with an insulating wiring panel (30); the insulating wiring panel (30) is provided with a first terminal (31), a second terminal (32), a third terminal (33) and a fourth terminal (34); the first terminal (31) is connected to the sacrificial anode (4) through a third cable (7); the second terminal (32) is connected to the oil nozzle plug (1) of the Christmas tree through a first cable (5); the third terminal (33) is connected to the large flange (2) of the Christmas tree through a second cable (6); and the fourth terminal (34) is connected to the reference electrode (9) through a fourth cable (8).

2. The cathodic protection assembly for the Christmas tree of an oil well in a carbon dioxide injection block according to claim 1, characterized in that: The sacrificial anode (4) is made of aluminum alloy.

3. The cathodic protection assembly for the Christmas tree of an oil well in a carbon dioxide injection block according to claim 1, characterized in that: The test pile (3) is a hollow structure.

4. The cathodic protection assembly for the Christmas tree of an oil well in a carbon dioxide injection block according to claim 3, characterized in that: The first cable (5), the second cable (6), the third cable (7) and the fourth cable (8) are all routed from the bottom of the test pile (3).

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