The high corrosion activity of groundwater and the extracted products of wells containing aggressive components (hydrogen sulfide, salts, etc.) is the cause of the corrosion destruction of the casing.
An effective means of protection against corrosion damage of casing strings and discharge lines of wells is joint cathodic protection, which is provided by shifting the electrode potential of the string and pipelines to the negative side by electric current from an external constant voltage source (DC unit).
The cathodic protection of the borehole housings is carried out by connecting the negative pole of the DC unit to the borehole casing, and the positive pole to the anode earthing device.
A pit is drilled for the anode earthing device. Electrodes are lowered into the pit.
A control and measuring point (KIP) is installed in the enclosure at the anode grounding.
The number of anode earthing devices is determined by calculation.
The installation of insulating connections and control and measuring points is provided on the discharge lines.
The scheme of cathodic protection of the borehole casing
1 –Borehole casing. 2 – Anode grounding. З – Drainage cable.
4 – Control and measuring point (KIP). 5 – Cathodic Protection Station (CPS).
