RU2394942C1 - Procedure for anode earthing - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: procedure consists in positioning electrodes in borehole and filling borehole with current conducting non-metallic material from bottom to head. Also a platform and assembling wellhead conductor of electro-technical "mat" type are mounted on the borehole. Electrodes are made out of ferrosilid. Current lead electrodes and a dielectric padding between the string of electrodes and the platform are added to the string of ferrosilid electrodes. The electrode string is hung in the borehole on a cable out of dielectric material. A gas withdrawing polymer perforated tube is installed the borehole.

EFFECT: simplification of earth lead assembly and its increased service life.

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Description

The invention relates to electrochemical protection against soil corrosion and can find application in the oil, gas, energy industries, as well as in the public utilities sector when performing anode grounding.

There is a method of installing deep anode grounding, including drilling a well, placing a metal conductor in the well and filling the well from the bottom to the well with conductive non-metallic material - graphite, crushed coke (R. Yukhnevich and other Corrosion Control Techniques. Leningrad, Chemistry, 1980 , p. 172-174).

The disadvantages of this method are the high cost of the metal conductor due to the large consumption of metal, descent, tamping or filling operations with conductive non-metallic material and the short life of the anode due to its destruction due to poor cementation and increased solubility of conductive materials.

Closest to the proposed invention in technical essence is a method of performing deep anode grounding, including drilling a well, placing a metal conductor in the well and filling the well from the bottom to the mouth with conductive non-metallic material. An electrically conductive cement mortar is used as a conductive non-metallic material. The solution is placed into the well by a vertically moving pipe method, and the metal conductor is placed in an uncoated electrically conductive cement mortar in the upper part of the well. As a metal conductor, an injection pipe can be used, as well as a bar made of reinforcing steel (RF patent No. 2153537, published. 07.27.2000 - prototype).

The known method has a low cost, however, the service life remains low due to subsidence of grounding during subsidence. In addition, the known method does not provide for dismantling and repair.

The proposed invention solves the problem of simplifying installation and increasing the duration of the anode ground.

The problem is solved in that in a method for performing anode grounding, including drilling a well, placing electrodes in the well and filling the well from the bottom to the well with conductive non-metallic material, according to the invention, a platform is mounted on the well and an mounting wellhead conductor such as an electrotechnical “carpet”, the electrodes are made of ferrosilide, the column of electrodes is supplemented with current-conducting electrodes and a dielectric spacer between the column of electrodes and the platform, the column of electrodes is suspended in a well on a cable from dielectric material and operate in a suspended state, and during operation, gases are removed from the well through a gas exhaust polymer perforated tube.

SUMMARY OF THE INVENTION

During operation, anode grounding conductors sag, especially in cases of ingress into underground rivers and springs. Soil from under the lower electrodes is washed out, and the anode earthing switch sinks down. As a result, breaks in the connecting cables appear. A load of up to 400 kg acts on the lowermost connecting unit, which can lead to kinks of the connecting busbars and depressurization of the electrode connection points. The result is a complete failure of the anode ground electrode. In addition, existing anode grounding structures cannot be dismantled for repair or inspection. The proposed invention solves the problem of simplifying installation and increasing the duration of the anode ground. The problem is solved as follows.

When performing anode grounding, a well is drilled, electrodes are placed in the well, and the well is filled from the bottom to the mouth with conductive non-metallic material. A scaffold, a dielectric lining and an assembly wellhead conductor of the type of an electrotechnical “carpet” are mounted at the well. The platform serves to accommodate the electrotechnical carpet and mount the anode earthing switch on the ground. The dielectric lining acts as an insulator between the platform and the electrotechnical carpet. An electrotechnical carpet allows you to access the anode grounding attachment assembly and is used during installation to mount it in a suspended state and to take the gas outlet pipe to the surface, during operation it is used to dismantle the anode grounding electrode when it prematurely breaks down, as well as to fill water or mud into the well.

The electrodes are made of ferrosilide according to TU 4834-001-48814120-2005. Main technical characteristics: length - 1500 mm, diameter 65 mm, weight 33 kg, wire cross section 6 mm ² .

From above, from below and in the middle, the column of electrodes is supplemented with current-lead electrodes connected via cables to current sources. A column of electrodes is suspended in a well on a cable of dielectric material and is operated in suspension. A cable made of polymeric materials, for example, polypropylene, fiberglass, etc., can be used as a dielectric cable. During operation, gases (hydrogen) are removed from the anode ground electrode through a gas perforated polymer tube.

The drawing shows an embodiment of the anode ground electrode according to the invention.

In the well 1, a column of electrodes is suspended on a cable 2 of dielectric material, consisting of working electrodes 3 and electrodes-current leads 4 connected by cables 5 to a current source (not shown). A gas perforated polymer tube 6 is placed along the entire length of the well with the outlet to the atmosphere. A platform 7 is mounted on the surface of the earth above the well 1 with elements 8 buried in the ground to prevent displacement of the platform 7. An electrotechnical carpet 9 is mounted on platform 7. The rod 7 is also fixed 10, on which the cable 2 is suspended. The cable 2 from the other end is fixed to the clamp 11, covering the upper electrode of the column of electrodes 3, 4. A dielectric lining 12 is placed above the clamp 11, separating the platform 7 and the column of electrodes 3, four.

Anode grounding is performed as follows.

Well 1 is drilled in the ground. A platform 7 is mounted above the well. A column of electrodes 3, 4 is assembled, cables 5 are connected, a clamp 11 is installed, a cable 2, a dielectric pad 12, a cable 2 is hung on the rod 10 and lowered into the well 1. The gas outlet is lowered there. polymer perforated tube 6. The rod 10 is fixed on the platform 7. From above install an electrotechnical carpet 9. The well is filled with conductive material such as clay mud.

A cathodic protection circuit is assembled, for example, pipelines, oil wells, and the like. and start the anode earthing switch to work.

Due to the suspension and support on the earth's surface, the pressure of the electrodes on the ground and the possibility of subsidence of the anode ground electrode when washing the soil out from under the electrodes with groundwater are completely eliminated. A cable made of a dielectric material ensures the absence of corrosion and an extended service life of the entire device. Installation is facilitated. It is possible to repair the anode ground electrode after lifting it from the well.

Concrete example

Perform anode grounding for cathodic protection of an oilfield pipeline. To do this, drill a well with a depth of 21 m and a diameter of 0.015 m. A scaffold and an assembly wellhead conductor of the type of an electrical "carpet" are mounted on the well. A column is assembled of working electrodes and current lead electrodes made of ferrosilide 18 m long. A clamp and a dielectric gasket are fixed to the upper electrode. A column of electrodes is suspended in a well on a cable made of a dielectric material - polypropylene. A gas outlet polyethylene perforated tube with a diameter of 25.0 mm and holes per linear meter in the amount of 5 pieces is lowered into the well.

The cathodic protection circuit is assembled and the anode ground electrode is put into operation.

Tests have shown that the proposed anode ground electrode serves 2-5 times longer than known.

Application of the proposed method will solve the problem of simplifying installation and increasing the duration of the anode grounding.

Claims (1)

A method of installing an anode ground electrode in a well, including placing electrodes in the well and filling the well from the bottom to the well with conductive non-metallic material, characterized in that the platform and the wellhead conductor are mounted on the well, such as an electrotechnical “carpet”, the electrodes are made of ferrosilide and assembled in the form of a column which is supplemented by electrodes with current leads and a dielectric gasket between it and the platform, cables are connected, the column of electrodes is suspended in the well on a cable made of dielectric material and install a gas discharge polymer perforated tube.

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