Casing Potential Profile
Definition - What does Casing Potential Profile mean?
Casing Potential Profile is an in situ log of electrical potential which is created on the internal wall of the well casing. It is helpful in letting operators know about the possibilities of corrosion or if any corrosion has taken place in the inner walls of the well casing. The log is helpful in providing the intervals which can be further analyzed to suspect any corrosion.
Petropedia explains Casing Potential Profile
Casing Potential Profile can be measured with the help of a Casing Potential Profile tool. This tool consists of two spring loaded probes which are roughly 25 feet apart from each other. The tool is fed into the casing and the probes are allowed to contact the casing in every 15-meter to 30-meter distance and the voltage readings are recorded. After logging up the voltage readings, a voltage potential versus depth plot is drawn. If the slope of the plot is upward to the left side, it indicates an anodic area, whereas if it is upward but to the right side, it indicates a cathodic area. Now the current is passed through the casing for protection and another potential profile is drawn. All the anodic locations are considered to be corrosion prone zones. To convert anodic locations to cathodic locations, a high amount of current is passed through them until the slope of the plot is upward and right sided.