Oil casing pipe cathode protecting system based on pulse current power supply and building method thereof

Abstract

The invention discloses an oil casing pipe cathode protecting system based on pulse current power supply and a building method thereof. The oil casing pipe cathode protecting system comprises an oil well casing pipe. The oil well casing pipe is connected with an anode well system through a pulse power source. The oil well casing pipe is connected with a potential detector. The potential detector is connected with a reference electrode. When the oil well casing pipe carries out pulse current cathode protection, an anode is continuously dissolved, a large number of electrons are produced to continuously flow into the surface of the casing pipe through the stratum, and the electrons flowing into the surface of the casing pipe are gathered on the surface of the casing pipe, so that the potential on the surface of the casing pipe moves in the negative direction, and cathode polarization is produced. The capability of electrons released by a micro anode area on the surface of the oil well casing pipe is restrained; in addition, the larger the pulse current is, the more electrons are gathered, the more negative the potential on the surface of the casing pipe is, the weaker the electrons released by the micro anode area are; when potential polarization reaches a certain value, surface anode and cathode areas are equipotential, and corrosion is stopped. The potential detector monitors the protecting potential on the surface of the oil well casing pipe in real time through a protecting potential sensor, the protecting effect and the energy-saving effect are achieved, and the protecting depth of the oil well casing pipe is increased.

Description

technical field [0001] The invention belongs to the technical field of corrosion and protection of oil wells in oil fields, and specifically relates to a cathodic protection system for oil well casing based on pulse current power supply and a construction method thereof, which is used to protect a cathodic protection system with long transmission distance and uniform protection current distribution, which can be used Further expand the application to the field of gas well casing. Background technique [0002] Oil well casing damage caused by corrosion is common in many oil fields at home and abroad. During the development of oil fields, especially oil fields with a long development time and oil wells or oil wells with complex geographical environment, due to the continuous deterioration of downhole technical conditions and other reasons, the oil well casings are deformed, leaked or severely corroded to varying degrees. It not only makes the oil well produce with disease or ...

AI Technical Summary

Problems solved by technology

This protection method has the following disadvantages: First, due to the uneven distribution of the protection current, the local oil well casing does not achieve effective protection.

Second, due to the limited distance of DC current propagation, the result is that it is difficult to extend the protection depth

Third, in order to obtain a better protection effect, it must be compensated by a large amount of electricity and a large anode bed, so the power consumption is large and the anode bed is large

Images